CATALOGUE OF RIVERS FOR SOUTHEAST ASIA AND

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2 CATALOGUE OF RIVERS FOR SOUTHEAST ASIA AND THE PACIFIC-Volume V mu The UNESCO-IHP Regional Steering Committee for Southeast Asia and the Pacific Edited by: YASUTO TACHIKAWA Disaster Prevention Research Institute (DPRI) Kyoto University, Japan ROSS JAMES Hydrology Unit, Bureau of Meteorology Australia KEIZRUL ABDULLAH Department of Irrigation and Drainage Malaysia MOHD. NOR BIN MOHD. DESA Regional Humid Tropics Hydrology and Water Resources Centre for Southeast Asia and the Pacific (HTC Kuala Lumpur), Malaysia May 2004

3 Rivers Catalogued in Vols. I to V The following 1 14 rivers are compiled in the five volumes of the Catalogue of Rivers in Southeast Asia and the Pacific, which are products of UNESCO's International Hydrological Programme (IHP) regional activities in the framework of the Asian Pacific FRIEND. Country Vol. I (1995) Vol. II (1997) Vol. Ill (2000) Vol. IV (2002) Vol. V (2004) Australia Cambodia Burdekin River Pioneer River Prek Thnot Todd River East Finniss River Stung Chinit Torrens River Scott Creek Snowy River below Lake Jindabyne China Bei-jiang Jin-jiang Jiyun-he Gan-jiang Taizi-he Ou-jiang Bailong-jiang You-jiang Huang-he Fen-he Hongshui-he Jialing-jiang Luan-he Rong Jiang Indonesia Citarum Bengawan Solo Kali Brantas Sungai Asahan Citanduy Kali Progo Cimanuk Kali Serayu Kali Tuntang Jeneberang River Kali Ciliwung Kali Cisadane Japan Yoshino-gawa Ara-kawa Mogami-gawa Chikugo-gawa Fuji-kawa Ishikari-gawa Shimanto-gawa Shonai-gawa Watarase-gawa Shinano-gawa Tone-gawa Yodo-gawa Nagara-gawa Natori-gawa Yasu-gawa Korea (Rep. of) Pyungchang-gang Geumho-gang Miho-chun Soyang-gang Nam-gang Gap-chun Nam Han-gang Hwang-gang Geum-gang Seomjin-gang Milyang-gang Sapkyo-chun Banbyeon-chun Lao PDR Nam Khane Nam Ngum Sedone Nam Theun/Cading Nam Ou Nam Sebangfay Nam Suang Nam Sebanghieng Nam Sekong Nam Ngiep Nam Sane Nam Song Malaysia Rajang Batang Sungai Johor Kelantan River Chalok River Pahang River New Zealand Buller River Motu River Hurt River Taieri River Mahurangi River Motueka River Papua New Guinea Ramu Wara Purari Wara Sepik Wara Philippines Hog Magat Hog Pampanga Hog Itaas ng Agno Pasig-Marikina- Laguna de Bay Basins Thailand Mae Nam Ping Mae Nam Mae Klong Mae Nam Nan Mae Nam Yom Mae Nam Wang Prachinburi River Bang Pakong River Tonle Sap River East Coast Gulf River Chao Phraya River Sakae Krang River Pasak River Tha Chin River Viet Nam Song Ky Cung Song Thu Bon Song Ba Song Srepok Cau River Tra Khuc River Chay River Huong River Number of Rivers

4 Members of IHP Regional Steering Committee for Southeast Asia and the Pacific ( ) Chairman* Secretary Keizrul Abdullah Kaoru Takara Malaysia Japan Member Countries Observer Secretariat Australia Cambodia People's Republic of China Indonesia Japan Democratic People's Republic of Korea Republic of Korea Malaysia New Zealand Papua New Guinea The Philippines Thailand Viet Nam Lao People's Democratic Republic SOPAC countries** UNESCO Jakarta Office * Since 31 October 2003 Chairman Tran Thuc Viet Nam ** SOPAC ' the South Pacific Applied Geoscience Commission ISBN PRINTED IN JAPAN

5 Preface It is our great pleasure that we present the fifth volume of the Catalogue of Rivers for Southeast Asia and the Pacific. This volume contains 20 rivers from 1 1 countries and brings the total number of rivers catalogued in the region, including those in volumes I to IV, to Besides the printed book, a CD- ROM version is also included with the volume. The electronic versions of the catalogues including some previous volumes are available through the web page of Asian Pacific Water Archive (APWA) at maintained by the Humid Tropics Centre (HTC), Kuala Lumpur, Malaysia. The objectives of the publication of the Catalogue are: To promote mutual understanding of hydrology and water resources of the region and of the neighboring countries. This is essential for better regional co-operation in hydrological sciences as well as for water resources development and management. To promote information exchange among different organizations in each country. This is essential for the development of hydrological sciences and for better development and management of the water resources within each country. To promote the establishment of an international data exchange and collaborative research network in the region. This is expected to assist the Asian FRIEND (Flow Regime from International Experimental and Network Data) Projects in IHP VI ( ) to meet their goals. It is heartening to note that all these objectives are being realized. With the dissemination of more information it is hoped that there will be better understanding and co-operation on matters related to water resources within each country as well as regionally. Of particular importance are the establishment of the Asian Pacific FRIEND, a UNESCO-IHP regional collaborative project, and the Asian Pacific Water Archive (APWA) that archives and makes available hydrometeorological and related data for Asian Pacific FRIEND projects and other IHP related activities in the region. In connection with the APWA that is held at the HTC Kuala Lumpur, the contents of the Catalogue of Rivers acts as a source of "meta-data" for some of the data in the APWA. Owing to differences in national data-release policies not all basins covered in the Catalogue of Rivers have matching data in the APWA. It is hoped that over time these differences can be resolved and that a complete set of matching data will become available. We would like to express our sincere appreciation and due respect to all the individual contributors of all the countries who have consolidated the data and information from various and often diverse sources, prepared the text, maps and tables, and co-operated with us by responding to revision requests. We also express our sincere gratitude to the many institutes, agencies and other organizations that provided the data, facilities, and above all, the funds and the personnel to carry out the work. In particular, we would like to thank the following organizations for providing the necessary financial supportr ) ' UNESCO Jakarta Office The Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, which provides the following funds to support the UNESCO IHP activities: D "Leadership for International Scientific Cooperation" Project (PI: Prof. Kaoru Takara, Disaster Prevention Research Institute, Kyoto University) under the Special Coordination Funds for Promoting Science and Technology Grant-in-Aid for Scientific Research (A)(1) (PI: Prof. Shuichi Ikebuchi, Disaster Prevention Research Institute, Kyoto University)

6 The editors hope that this volume can serve in various ways to further fulfill the national and regional objectives that were originally aimed for. Finally, we ask the readers to provide critical comments and ideas to improve future volumes of the Catalogue. Editors: Yasuto Tachikawa Disaster Prevention Research Institute, Kyoto University, Japan Ross James Hydrology Unit, Bureau ofmeteorology, Australia Keizrul Abdullah Department ofirrigation and Drainage, Malaysia Mohd. Nor bin Mohd. Desa Regional Humid Tropics Hydrology and Water Resources Centrefor Southeast Asia and the Pacific, Malaysia May 2004

7 CONTENTS Regional Steering Committee Preface 1 ii 1. Australia 7. Snowy River below Lake Jindabyne China 14. Rong Jiang Indonesia KaliCiliwung Kali Cisadane Japan Nagara-gawa Natori-gawa Yasu-gawa Korea (Republic of) Banbyeon-chun LaoPDR NamNgiep Nam Sane Nam Song Malaysia Pahang River IV

8 8. New Zealand Motueka River Philippines Pasig-Marikina-Laguna de Bay Basins Thailand Chao Phraya River Sakae Krang River Pasak River Tha Chin River Viet Nam Chay River Huong River

9 Australia Australia-7: Snowy River below Lake Jindabyne INDIAN PACIFIC OCEAN OCEAN Snowy River TASMANIA

10 Introduction The continent of Australia is the lowest, the flattest and, with the exception of Antarctica, the driest of the continents with a total land area of 7,682,000 km2. The land lies between latitudes 10 41'S (Cape York) and 43 39'S (South East Cape, Tasmania) and between longitudes 'E (Steep Point) and 'E (Cape Byron). The latitudinal distance between Cape York and South East Cape, Tasmania is 3,680 kilometres. The longitudinal distance between Steep Point and Cape Byron is about 4,000 km. There are two major classes of rivers in Australia, those of the coastal margins with moderate gradients and those of the central plains with very slight gradients. The continent has a wide range of climatic zones, from the tropical regions of the north, through the arid expanses of the interior, to the temperate regions of the south. Seasonal fluctuations can be great, with the temperatures ranging from above 50 C to well below zero. The continent often experiences natural disasters, particularly droughts, floods, tropical cyclones, severe storms and bushfires. While the mean annual precipitation is 472 mm in Australia, it varies from 100 mm in the arid central plains to over 4,000 mm in the region with the highest mean annual rainfall on the north east coast of Queensland near the township of Tully. The overall population of Australia in 2001 was 19.5 million with most of the population concentrated in coastal regions. The river catalogued in this volume is the Snowy River below Lake Jindabyne. The headwaters of the river are in the State of New South Wales and the middle and lower reaches are located in the State of Victoria. The Snowy Mountains Hydro-electric Scheme (Snowy Scheme) is a major infrastructure development that was constructed between 1949 and It is a dual purpose hydro-electric and irrigation scheme to divert the south flowing waters of the upper Snowy River inland to the Murray and Murrunbidgee rivers where it is used for irrigation. The diverted water, together with water from regulated flows from other nearby rivers generates mainly peak-load hydro electricity. The power generating capacity of the Scheme is 3,740 MW and it provides 2,360 GL annually of water for irrigation in the Murray and Murrumbidgee rivers. The Snowy River is the major river catchment of the Snowy Scheme with 99 percent of flows above Jindabyne being diverted for use by the Scheme. As a result of increasing concerns about the environmental impacts of the Snowy Scheme, the Snowy Water Inquiry was commissioned in 1998 with a brief to recommend environmental water release options. Following consideration of the options developed by the inquiry, agreement has been reached that Snowy River flows below Lake Jindabyne will be restored to 21 percent of their original levels within 10 years and to 28 percent in the longer term. Acknowledgements The following organizations are thanked for their assistance and the provision of data for the preparation of this work. Victorian Department of Sustainability and Environment NSW Department of Infrastructure Planning and Natural Resources Commonwealth Bureau of Meteorology Much of the material presented in this work has been extracted from: Snowy Water Inquiry, Final Report October 1998 General Reference Maps of Australia are Copyright Commonwealth of Australia, Geoscience Australia ( All rights reserved.

11 Australia-7 Snowy River below Lake Jindabyne 36"S -37'S -33'S 148"E 149"E

12 Australia-7 Table of Basic Data Name(s): Snowy River below Lake Jindabyne Serial No. : Australia-7 Location: Southeastern Australia N 36 27' ' E 148 ~ ' Area: 1 1,720 km2 below Lake Jindabyne Length of main stream: 350 km Origin: Lake Jindabyne Highest point: Mt Cobberas, 1,833 m Outlet: Tasman Sea Lowest point: River mouth at sea level Main geological features: Low grade metamorphic and granitic rocks Main tributaries: Maclaughlin, Delegate, Deddick and Buchan rivers Main lakes: None Main reservoirs: Jindabyne Dam (most upstream point of the catchment) Mean annual precipitation: 500 mm in the coastal region to 3,800 mm in the upper central region Mean annual runoff: 43.1 m3/s post Jindabyne Dam construction Population: approx 12,000 (2001) Main cities: Orbost Land use: Grazing, National Park, forestry, intensive cropping in lower reaches 1. General Description The Snowy River catchment extends from Kiandra in the Snowy Mountains to the river mouth at Mario where it flows into the Tasman Sea. The total catchment area is 13,570 km2 with the area below Lake Jindabyne being 11,720 km2. The annual precipitation ranges from 500 mm to 3,800 mm with the highest precipitation occurring on the mountain peaks in the form of winter snow. Precipitation in the upper Snowy catchment is highest during late autumn and lowest during summer and is increased by orographic effects. The central portion of the catchment (below Lake Jindabyne) is in a rainshadow and experiences mean annual rainfall of about 500 mm. The mean annual precipitation then increases moving south to the coast where it is about 800 mm. Construction of the Snowy Mountains Hydro-electric Scheme has reduced annual average natural flows in the Snowy River immediately below Jindabyne Dam by 99 percent. Two tributaries below the dam, Mowamba River and Cobbin Creek are substantially diverted into the dam. The Delegate River is the first substantial river to contribute to the Snowy below Lake Jindabyne. Flow releases from Jindabyne Dam range from a 'visible' flow to 50 ML/d to satisfy riparian users. Under natural conditions the Snowy River exhibited a strong seasonal pattern characterized by low summer flows and high persistent spring flows due to snowmelt. The elimination of the high spring flows is evident even at the river mouth. Moving downstream from Jindabyne Dam, tributary inflows substantially increase the flow of the Snowy River. The Delegate River contributes approximately 30% of the post-scheme mean annual flow of the Snowy River. At Jarrahmond the Snowy flows are approximately 53 percent of pre-scheme flows. The catchment from the Buchan River and below generates low summer flows with the highest flows occurring in autumn. The lower reaches of the Snowy (below the Buchan River) change from riverine to estuarine. Under natural conditions the Snowy River experienced a number of floods each year that could occur at any time but particularly in spring when rainfall coincided with snowmelt. Under existing conditions there are no floods immediately downstream of Jindabyne. Even at the coast, the frequency and magnitude of floods have been reduced.

13 Australia-7 2. Geographical Information 2.1 Landform and Geological Map Lands of Low Relief ( ft) [_ j 2P Dissected plateaux [ j 2R Escarpments and ridges [ïï^rri 2H Hills Lands of Moderate Relief (]00-<00 ft) ""^ I liwji^l 3H Hills 3P Dissected plateaux 3K Escarpments and ridges Lands of High Relief ( ft) ^^^H 4P Dissected plateaux ^^^H ^^^H AK MountalYi ridges 4H Mountains Lands of Very High Relief (over 1200 ft) ^I^H 5P Dissected plateaux ^^^B SR Mountain ridges ^^^H 5H Mountains Unconsolidated superficial sediments Carbonates o Well-sorted sand I Porous limestone, mainly Cainozoic b Alluvium, dark cracking clay c Limestone and dolomite, mainly Palaeozoic & a Alluvium, undifferentiated older e Evaporites, mainly saline lake Metamorphic deposits p Low-grade (metasediments, metavolcanics, w Swampy alluvial-flat deposits, including peat schists of greenschist fades) Consolidated rocks q High-grade (schist, greenstone, amphibolite Sedimentary etc) s Sandstone and conglomerate laneous

14 Australia Land Use Map H«p^Ai jpprw 201 kim Und use CJasaficabon - 1km rutun conhfvifttan Oà)v protkttd «n«induding md^gmoui Uf«fl Mnrntl u» Uvts^df 7*Elng Fo r«3vy Irriqittd «gricukurt Wjttrboditf not «lf*i^hvt dtfsii«d Nd due«2.3 Characteristics of River and Main Tributaries No. Name of river Length [km] Catchment area Highest peak [m] Lowest point [m Cities Population (2001) Land use'' 1 Snowy (below L Jindabyne) (Main river) ,720 1,833 0 Orbost Approx. 3, Maclaughlin (Tributary) Delegate (Tributary) ,687 1, , A G N 4 Buchan (Tributary) 81 1,214 1, )A: Agricultural G: Stuck grazing N: National Park

15 Australia Longitudinal Profiles ? e ' / Delegate River / y V / Maclaughlin River v / ^ y - Buchan River -^ ' ~~~" Snowy River 0 - () Distance (km) Climatological Information 3.1 Annual Isohyetal Map and Observation Stations 149 E 36 S S- 37 S S 38'S «KitomMtrs I. IlllliilllH. lililí 148 E 149'E r- ~- liytr» i Í f^^bitkn b«undirv Riinfilltatil IriMn R«90 eoo «o.mo ^ ; MM 1jOOO _ W BOO i.eoo i.«oa - z.ooo j.ooo-jjoo Based on thin plate spline analysis of all available rainfall stations. -38'S

16 Australia List of Meteorological Observation Stations ' No. Station Elevation [m] Location Observation period Mean annual Mean annual precipitation2' evaporation [mm] [mm] Observation items3' Bómbala PO 705 S 36 54' 41" E ' 16" P,T Nimmitabel PO 1,075 S 36 30' 44" E ' 06" P,T Tombong (Hilcrest) 800 S 36 55' 57" E ' 21" P Cathcart 803 S 36 50" 42" E ' 18" P Cooma (Visitor Centre) 778 S 36 13' 54" E ' 27" P,T Dalgety (Jimenbuen) 790 S 36 43' 30" E ' 17" P Dalgety (Hamilton St) 765 S 36 30' 15" E ' 02" P Jindabyne (Lynwood) 1,030 S 36 29' 14" E ' 56" P Guthega Power Station 1,340 S 36 21' 06" E ' 45" ,780 P Ingebyra (Grosses Plains) 1,240 S 36 36' 08" E ' 04" P,TB Berridale (Eucumbene Trout Farm) 1,050 S 36 16' 27 E ' 06" P Khancoban SMHEA 337 S 36 13' 31" E ' 35" ,193 P, T, W, E Bendoc Park 790 S 37 07' 07" E ' 48" P Bonang 675 S 37 10' 23" E ' 16" P Buchan 90 S 37 29' 55" E ' 23" P,TB Butchers Ridge 670 S 37 16' 52" E ' 14" P Cabbage Tree Creek 51 S 37 42' 36" E ' 29" ,084 P Orbost 41 S 37 41' 30" E ' 32" ,073 P, TB, T, E Black Mountain 915 S 37 00' 31" E ' 52" P Combienbar 213 S 37 24' 59" E ' 44" P,TB Orbost (Bete Bolong) 20 S 37 42' 54" E ' 38" P

17 Australia-7 No. Station Elevation m] Location Observation period Mean annual precipitation2' [mm] Mean annual evaporation mm] Observation items3' Wulgulmerang 914 S 37 05' 03" E ' 40" P,E Goongerah 235 S 37 20' 28" E ' 38" P 1 ) Only a representative sub-set of stations available in the basin are presented. 2) For period of observation. 3) P: Precipitation. TB: Tipping bucket with recording chart or logger. T: Temperature E: Evaporation W: Wind 3.3 Monthly Climate Data Observing station: Khancoban Observation item Temperature [ C] Precipitation [mm] Number of rain days Evaporation [mm] Duration of sunshine [hr] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual , Period for the mean Observing station: Orbost Observation item Temperature [ C] Precipitation [mm] Number of rain days Evaporation [mm] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annua] ,073.0 Period for the mean Observing station: Wulgulmerang Observation item Precipitation [mm] Number of rain days Evaporation [mm] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean

18 Australia Long-term Variation of Monthly Precipitation Bómbala Post OfTicc (Record commt-nct's 1885, plot commences Jan 1930) ^ }I (.LiiMiiilJÍll.állJ.i Procipiuiioii 37 monlh moving average JliilllLiliillill Iir,.,. I I'll I.' i.-ii-'-i i- m,11 I,", :*ill'fir 'i' I», 'iai'!l o»í^ o "^ o >f> r^ t^ ^ & w^ Vi (^ íji ^n o^ o*i ^^ ^ ^ O^ ÖV ^ ^ ^ 0\ Year 4. Hydrological Information 4.1 Map of Hydrological Observation Stations 38* & Me*E ; /W" ""sj ^V'"^""'') / M9'E -^ Vlrf 36'S V.^;/^*^'^^/ W! i \y- r ÎT» l^^níííi^ J ^ -37*3 ^'^ srs- a 510 IQ MKmwttrt n A -3e's WH*' u.'- 10

19 Australia List of Hydrological Observation Stations No. Station Location Catchment area (A) [km2] Observation period Observation items1' The Falls (Bómbala River) Buchan (Buchan River) Deddick (Caseys) (Deddick River) Quidong (Delegate River) The Hut (Maclaughlin River) Suggan Buggan (Suggan Buggan River) Jindabyne (Snowy River) Dalgety (Snowy River) Burnt Hut Crossing (Snowy River) D/S of Basin Creek (Snowy River) Jarrahmond (Snowy River) Orbost (Snowy River) Mario Jetty (Snowy River) S 36 55' 00" E ' 36" S 37 30' 00" E ' 30" S 37 05' 30" E ' 30" S 36 54' 24" E ' 00" S 36 39' 18" E ' 06" S 36 57' 12" E ' 30" S 36 25' 24" E ' 00" S 36 30' 00" E ' 00" S 36 50' 30" E ' 54" S 37 30' 00" E ' 12" S 37 39' 42" E ' 30" S 37 43' 00" E ' 30" S 37 47' 54" E ' 42" , ,850 3,040 7,081 11,964 13,421 13,570 NA H,Q H, Q, W Q H, Q, WQ H,Q H,Q H, Q, WQ H,Q H,Q H,Q H, Q, WQ H, Q, WQ H,WQ H No. Q2) [m3/s Qmax3' [m3/sl Qmax4' [m3/s Qmin5' [m3/s] Q/A ]m3/s/100km2] Qmas/A [m3/s/100km2] Period of statistics , , , ' ' , , , ) H: Water Level 2) Mean annual discharge Q; Discharge 3) Maximum instantaneous discharge WQ: Water Quality 4) Mean monthly instantaneous maximum discharge 5) Mean monthly instantaneous minimum discharge ) Pre Snowy Scheme construction 7) Post Snowy Scheme construction

20 i 1 'i Australia-7 a 4.3 Long-term Variation of Monthly Discharge ^. 200 ~T~ jl loo - Vi 9 Q i! i 1 i iífl 4VJ /ill m Snowy River at Dalgety (222006) Streamflow 37 mth moving average 4~ Reservoir ~^ Construction period! M I 2v 1 vo \0 vu vo l M ffi Al ui.,. Il, Yl'^l 1 i 'i" i i 1 i "1 V ' i ' * Date 4.4 Annual Pattern of Discharge Snowy River at Dalgety (222006) (mean monthly flows) , 1 It 100 -i Pre Snowy Scheme "s 10 M os t 1 - c ( ) Percentage of time equalled or exceeded 1()0 12

21 Australia Unique Hydrological Features Four hundred million years ago the Snowy region was a deep marine basin near the edge of a continent and prone to submarine volcanoes. Later, about three hundred and fifty million years ago, the area had risen above the ocean. Although the terrain was volcanic the mountains are believed to have been pushed up as fold mountains when Australia and New Zealand geologically separated. During the next two hundred and fifty to three hundred million years the region was gradually eroded, with the more resilient rock types forming the mountain ranges which have remained much the same for the past sixty million years to the present. The Snowy River catchment (including the area above Jindabyne) can be broadly divided into four parts: the mountain rivers above Jindabyne Dam; the Monaro reach between Jindabyne Dam and the Delegate River; the Escarpment, a large tract of steeply dissected land stretching between the Delegate River and to upstream of the junction of the Buchan and Snowy rivers; and the lower Snowy floodplain, centred on the town of Orbost close to the river mouth. The Monaro reach of the river is in a rain shadow and experiences a mean annual rainfall of 500 mm while the mean annual rainfall increases to 800 mm at the coast. The Escarpment reach is thinly populated, mainly covered in forest reserves and National Parks and is difficult to access. Major floods in the lower Snowy are generated in the escarpment zone. Under natural conditions the Snowy River experienced a number of floods each year that could occur at any time, although they were more frequent in the spring when rainfall coincided with snowmelt. Under existing conditions, after the construction of the Snowy Scheme, there are no floods immediately downstream of Jindabyne. Even at the coast, where there is a significant residual catchment unaffected by the Scheme the frequency and magnitude of floods have been reduced. 4.6 Annual Maximum and Minimum Discharges At Dalgety [3,040 km 2, Year 1949 Maximum1' Month ]m3/s] Minimum2' Month [m3/sl Year 1973 Maximum" Month [m3/s] Minimum2' Month [m3/sl ,

22 1 I Australia-7 102/71 02 '002 Year Maximum1' Month [m3/sl ), 2) Instantaneous observation Minimum ' Maximum'* Minimum2' Year Month [m3/s Month [m3/sl Month [m3/s Hyetographs and Hydrographs of Major Floods S» ' 5000 u D « J c :> o :> o r r C o ~- c 2 o o Snowy River at Jarrahmond (222200) lij 1 tí A o o o o o o o ÍM O ÍN O <N O O ~ o o ' o \o \o r-^ r> oo oo o, o o o o o o o Date and time (1 hour data) o o (N N o o Tfp-B r í o o O o lg S - 10 i. sr n - 12 w - 14 lo o o fn o 5. Water Resources 5.1 General Description Australian rivers have some of the most variable flow regimes in the world, with long periods of drought induced low flows followed by flooding in wetter periods. A key feature of the Snowy Scheme is to provide greater security, by large long-term storage capability, to allow for electricity production and water releases for irrigation to continue at close to average output during long droughts. The design dry sequence taken from the historical record commenced in December 1936 and extended 5 years and 4 months on the Snowy-Murray, and 9 years and 7 months on the Snowy-Tumut On average 1,140 Gl/year (1.14X109 m3/year) of the southern flowing Snowy River flows above 14

23 Australia-7 Jindabyne are diverted to the other side of the Snowy Mountains to the northern flowing Murrumbidgee and Tumut rivers and the western flowing Murray River. These diverted flows are primarily released for electricity production in times of greatest demand. This has been primarily for winter heating but is increasingly being used for summer cooling through increased use of air conditioners. Releases are also provided for irrigation purposes. As a result of the diversions, flow in the Snowy River immediately below Jindabyne dam has been reduced to 1 percent and end of river flows have been reduced to 55 percent of pre-snowy Scheme annual average natural flows. Below Jindabyne there are no significant water impounding structures. There are some minor diversions of flow for stock and domestic and horticultural purposes. 5.2 List of Major Water Resources Facilities Major Reservoirs Name of river Name of dam (reservoir) Catchment area [km2 Gross capacity [106m3[ Effective capacity [106m3l Purposes1' Year of completion Snowy River Jindabyne2' 18502) N/A P 1967 I ) P: Hydro-power 2) The reservoir is trie upstream extremity of trie basin being described. 5.3 Major Floods and Droughts Date Floods Station (River) Peak Discharge (m3/s) Droughts Date Jul 1922 Jarrahmond (Snowy) 3, Jan 1934 Jarrahmond (Snowy) 7, /15 Feb 1971 Jarrahmond (Snowy) 7, Jun 1978 Jarrahmond (Snowy) 5, Jul 1991 Jarrahmond (Snowy) 2, Jun 1998 Jarrahmond (Snowy) 2, /73 Apr 1950 Buchan (Buchan) /80 Feb 1971 Buchan (Buchan) /83 Jun 1978 Buchan (Buchan) /88 Jul 1984 Buchan (Buchan) 220 Nov 1988 Buchan (Buchan) 280 Jun 1998 Buchan (Buchan)

24 Australia Groundwater and Water Quality A shallow aquifer system exists in the Snowy River basin that comprises four rock types. A strip approximately 20 km in width runs along the southern portion of the basin and consists of a gravelly aquifer overlain by Quaternary alluvial aquifers. An aquifer of dune sand occurs along the coast. The remainder of the basin is composed of a Palaeozoic basement of folded sediment, metamorphic and granite that act as minor erratic aquifers. Outcrops of Tertiary basalt and Devonian granite are scattered throughout the region. These rocks form local minor fractured rock aquifers. There is no deep aquifer system in the Snowy River basin. The groundwater resource is generally fresh declining to marginal in the south-western corner of the basin. River Water Quality1' at Jarrahmond in 2003 Date 8/1 12/2 5/3 2/4 7/5 4/6 2/7 6/8 3/9 8/10 12/11 3/12 ph DO [mg/l] SS [mg/l] Elect conductivity us/cm Discharge2' [m3/s] I } Observed once a month on a dry day normally several days after rainfall. 2) Discharge on the water quality observation date. Socio-cultural Characteristics Humans first moved into the mountains about twenty thousand years ago. Evidence in one cave near the Buchan River traces seventeen thousand years of almost constant occupancy, right up to the 1830s and 1860s when the Aborigines were annihilated by conflict and disease brought by white settlers. Cave art along the Snowy River dates back twenty thousand years, older than the famous paintings of the Lascaux bison hunters in Southern France and Spain. The Snowy Mountains played a profound spiritual and material role in the lives of Aborigines in the region. Cooma and the Monaro district were the scene of brisk settlement in the 1820s and early 1830s as the pioneer stockman settled the grassy downs of the Snowy and upper Munumbidgee catchments. By the 1840s all of the great grazing properties of the area were occupied and were supporting a population of 600. Consolidation of the grazing industry was punctuated by timber logging and the gold rush. The 25 year construction period of the Snowy Scheme commencing in 1949 had a major impact on the social structure of the region. A country founded almost entirely by settlers from Britain almost overnight became one of the world's great pancultures. Tens of thousands of workers from more than 30 lands poured into what was an undisturbed pastoral realm. Following the completion of the Snowy Scheme the construction workers have dispersed throughout the country and their settlements have disappeared. Orbost, the largest town in the catchment is a service centre for the local timber logging and saw milling industry and for the surrounding agricultural industry that raises beef and dairy cattle and grows beans and maize. The Snowy area below Jindabyne is an increasingly popular tourist destination featuring a range of outdoors and nature activities. A number of ski resorts are located in mountains above Jindabyne. 16

25 Australia-7 7. References, Databooks and Bibliography Australian Natural Resources Atlas - website: Climate data provided by The Commonwealth Bureau of Meteorology, Melbourne - website: Collis, Brad, Snowy: the making ofmodern Australia, Hodder & Stoughton, Sydney, 1990, 304 pp. Finlayson, Brian, The Snowy River Debate: which river would you like to 'save'? Communication to The Royal Society of Victoria, 1 1 December 2003 ( New South Wales streamflow data provided by Department of Infrastructure Planning and Natural Resources, Sydney - website: Snowy Water Inquiry, Final Report October Victorian streamflow data provided by Department of Sustainability and Environment, Melbourne (Thiess Environmental Services) - website: Victorian water quality data obtained from Victorian Water Resources Data Warehouse - website: Water Victoria: A Resource Handbook, Department of Water Resources Victoria,

26 China China-14: Rong Jiang km Rongjiang River 18

27 Introduction One river catalogued in this volume is the Rong Jiang, which is a really very small if we compare it with other rivers. It is a representative of many such small river basins along southeast costal zone in the country. The Rong Jiang is a river directly flowing to the sea, which located in Guangdong Province in the Southeast China. The catchment area is 4,408 km2 with main length of 175 km. The river flows from Phoenix Mountain in the Southwest of the basin with sharp valley in upper stream to the Northeast direction. There are many small tributaries, e.g., Shashui, Hengjiangshui, Longtanshui etc. Water resources control projects including the Daxi, Qiantang, Wushi and Sanzhou Dam water gates were constructed in the main stream. The river has been influenced by tide of the South Sea. Due to it is a relative smaller river basin, constructed reservoirs are middle and small scale ones based on China State Reservoir Identification Standard. Total reservoir storage capacity is 569 million m. Two county level cities, Jieyang and Jiexi, are very important from an economic point of view. Water quality in the river can be identified as II, III and IV grades from upper to down stream. The average annual precipitation for the basin was 2,033 mm and annual discharge was 112 m /s for period in the basin. Acknowledgements The following people and organizations are highly appreciated and acknowledged for their contributions. Zhou Bingqing (Chair), Xie Ziyin, Jin Guansheng, Nanjing Hydraulic Research Institute of China, Zhu Xiaoyuan, Liang Jiazhi, Bureau of Hydrology, Ministry of Water Resources, Information Center, Ministry of Water Resources (MWR), Pearl River Water Resources Commission, MWR, Water Resources Department of Guangdong Province, and Hydrology and Water Resources Bureau of Guangdong Province. 19

28 China-14 Rong Jiang Map of River Table of Basic Data Name(s): Rongjiang Serial No. : China-14 Location: Guangdong Province, Coastways China N 23 11' ' E115''37'~116='38' Area: 4,408 km Length of the main stream: 175 km Origin: Mt. Luhe County Fenghuangshan (Phoenix) Highest point: Mt. Lufeng County (741.3 m) Outlet: Nanhai (South Sea) Bay Lowest point: Shantou Habour 0 m Main geological features: Various hard, Massive intrusive rocks; Cohesive soil Main tributaries: Wujingfushui (719 km^), Beixi (1,629 km^), Longtanshui (101 km^), Henjiang (219 km^), Shangshashui (134 km ) Main lakes: None Main reservoirs: Henjiang (64.5 x 10* m3, 1971), Longjin (165 x lo' m3, 1960),Longtan (121 x 10* m3, 1960) Mean annual precipitation: 2,033 mm (1954~1979) (basin average) Mean annual runoff: Population: 5,084,600 in m /s (1954~1979) (basin average) Main cities: Jieyang, Jiexi Land use: Forest (52%), Urban land (12%), Agriculture (30%), Others (8%) 20

29 China General Description The Rong Jiang is a small river flowing directly to the South Sea. It is located in the southeast part of Guangdong Province. The catchment area is 4,408 km2 with a main river length of 175 km. The river flows in a northeast direction from its origin near Phoenix Mountain in the southwest of the catchment. There are several tributaries, Shashui, Hengjiangshui, Longtanshui. Water resources control projects including the Daxi, Qiantang, Wushi and Sanzhou Dam water gates were constructed in the main stream. The river is influenced by the tide of the South Sea. Due to it being a relatively small river basin, constructed reservoirs are of medium and small scale based on the China State Reservoir Identification Standard. Total reservoir storage capacity is 569 million m. Two county level cities, Jieyang and Jiexi, are very important from an economic point of view. Water quality in the river can be identified as grade II, III and IV from the upper river reaches to down stream. The average annual precipitation for the basin was 2,033 mm and annual discharge was 112 m /s for the period The coverage of forests in the basin takes up 50% of the total area. The geographical features include mountain, hill, basin and plain. There are several kinds of rocks and soils, which can be identified from the geological map. Geographical Information 2.1 Geological Map w 21

30 China Land Use Map Brieibufh CTUsher * Paddy rice, ' comiiifrriál cn^f Masfont pine Broad leafed BsrdcTsfBuin IS 30kM 2.3 Characteristics of the River and the Main Tributaries No. Name of river Length [km] Catchment area [km'l Higest peak [m\ Lowest point [m Cities Population (1990) Land use [% (1985) 1 Rongjiang (Main River) 178 4, Jieyang 305, Shangshashui (Tributary) Hengjiang (Tributary) Forest (52%) Urban land (12%) Agriculture (30%) Others (8%) 4 Longtanshui (Tributary) Wujingfushui (Tributary) Beixi (Tributary) 92 1,

31 China Longitudinal Profiles 900 T ^ E ^ s " X Wujingfiishui Beixi / / / Longtanshui / /. Shangshashui / / yhengjiangy A -_Z^ Distance (km) 3. Climatological Information 3.1 Annual Isohyetal Map and Observation Stations C 3 Boiider ofbiim km 23

32 China List of Meteorological Observation Stations No. Station Elevation [m] Location Observation period Mean annual precipitation1' [mm) Mean annual evaporation1' [mm] Observation items2' 1 Jilong 80 N 23 19" El 15 44' 1956 ~ present 2,255 P(TB) 2 Shangsha 150 N 23 28" El 15 42' 1957 ~ present 1,996 P(TB) 3 Fengshulang 73 N 23 25' El 15 43' 1956 ~present 2,173 P(TB) 4 Fukou 50 N 23 24' El 15 46' 1956 ~ present 2,146 P(TB) 5 Liangtian 170 N 23 34' El 15 50' ~ present 1,951 P(TB) 6 Hengjiang 45 N 23" 30' E ' 1958 ~ present 1,970 P(TB) 7 Hepo 50 N 23 26' E ' 1954 ~ present 2,095 3,758 P (TB), E 8 Gaojiping 720 N23 28' E ' present 2,187 P(TB) 9 Longtan 35 N 23 29' E ' present 2,445 P(TB) 10 Likeng 370 N23 17' E115 51' present 2,663 P(TB) 11 Qiankeng 10 N 23 24' E ' present 2,064 P(TB) 12 Nanshan 20 N23 31' E ' present 1,957 P(TB) 13 Longjing 30 N23 35' E ' present 2,104 P(TB) 14 Dongqiaoyuan 5 N 23 29' E ' present 1,808 P(TB) 15 Jieyang 3 N 23 32' E ' present 1,718 P(TB) 16 Shijiaoba 50 N 23 50' E ' present 1,837 P(TB) 17 Cikan 13 N23 41' E ' present 1,738 P(TB) 18 Nanlong 3 N 23 28' E ' present 1,487 P(TB) Evaporation used with C 80 Evaporation vessel 1) Period for the mean is from 1956 to ) P: Precipitation, E: Evaporation, TB: Tipping bucket with recording chart. 24

33 China Monthly Climate Data At Shantou station (the nearest state-owned station) Observation item Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ q Precipitation [mm] , Evaporation [mm] , Solar radiation [MJ/m2/day] Duration of sunshine [hr] , Long-term Variation of Monthly Precipitation j 600 Rongjiang River at Dongqiaoyuan (2,016 km ) (37-month moving average added) Annual Mean: 1813 mm/y i 500 f Year

34 China Hydrological Information 4.1 Map of Streamflow Observation Stations Station of Dischaigs Borde of B«sm 10 20km 4.2 List of Hydrological Observation Stations No. Station Location Catchment area (A) (km'] Observation period Observation items (frequency)1* 39 Fongshulang N 23 25' El 15 43' present H2,Q 30 Fukou N 23 24' El 15 46' present H2,Q 32 Dongqiaoyuan N 23 29' El 16 08' 2, present H2,Q 33 Chikan N23 41' E116 15' present H2,Q 1) H2; water level by manual, Q: discharge No. Q1' [m'/s] Qmax^' [m'/s] Qmax [m'/s] Qmin" m'/s Q/A [m'/s/lookm^] Qmax/A [mvs/lookm'j Period of statistics ,710 4,830 2, , ) Mean annual discharge 2) Maximum discharge 3) Mean maximum discharge 4) Mean minimum discharge

35 China Long-term Variation of Monthly Discharge Series Rongjiang River at Dongqiaoyuan (2,016 km ) (37-month moving averages added) Mean: m3/s Year 4.4 Annual Pattern of Discharge Series Rongjiang River at Dongqiaoyuan (2,016 km ) Daily flows in 1986 «^ 2500 m 2000 " Flow duration curve I I Q= rrr /s 0 ^tetf^mb^f^rt Month 27

36 China Annual Maximum and Minimum Discharges At Dongqiaoyuan (2,016 km ) Year Maximum1' Date [m3/s Minimum2' Month nï7s] Year Maximum1' Date m3/s] Minimum2' Month [m3/s] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ] ), 2) Instantaneous observation by recording chart 4.6 Hyetographs and Hydrographs of Major Floods ^ 4000 J, f 3000 e J Dongqiaoyuan station at Ruijiang river basin : : : /10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 Time

37 China Water Resources 5.1 General Description The Rong Jiang is a river that flows direct to the South Sea in the southeast costal zone of China. The river is totally located in Guangdong Province. The precipitation is concentrated in April-September when 80%-85% of the annual precipitation is recorded. The annual variation of precipitation is large., For example, the maximum precipitation at Dongqiaojoian was 2,465 mm in 1961 but the minimum was only 1,160 mm, the ratio being 2.12 times. The annual runoff has similar characteristics. Generally high precipitation occurs in the mountain areas with annual precipitation of 2,400-2,600 mm. Water availability in Rong Jiang is abundant compared with other areas in the country. However, due to the high density of population, average water availability per capita is extremely limited. Based on water resom^ces assessment, the average water availability is only 1,218 m^ This is only 48% of the provincial average or 57% of the national average. The city of Jieyang is located in the downstream area of the Rong Jiang. Even though some water flowing from upper stream besides local water availability, the water cannot be used due to pollution. There are four medium and small size reservoirs in the river basin, Hengjiang, Wujingfushui, Longtanshui and Beixi, that were mainly completed in the 1950s-1970s'. The main purpose of these reservoirs is hydropower generation and flood control. 5.2 Map of Water Resource Systems f^ Rjeseivoii BoideofBasin 10 20kin 29

38 China List of Major Water Resources Facilities Major Reservoirs Name of river Name of dam Catchment area [km2] Gross capacity [10V] Effective capacity [106m3] Purposes1' Year of completion Hengjiang Hengjiang F,P 1960 Wujingfushui Longjin F, P 1960 Longtanshui Longtan F,P 1971 Beixi Xinxihe F,P ) F: Flood control, P: Hydro-power, N: Navigation 5.4 Major Flood and Drought Experiences Major Floods at Dongqiaoyuan (Catchment area 2,016 km2) Date Peak discharge m3/s] Rainfall mm Duration Meteorological cause Death and Missing Major damages (Districts affected) ,900 Typhoon ,010 Typhoon ,830 Typhoon 779 Major Droughts Period 1962, ,5 Affected area Jieyang, Jiexi major damages and counteractions River dry, No products in irrigation land 6. Socio-cultural Characteristics The Rong Jiang area is in the special economic zone, Shantou, which is one of three large economic zones. The GDP has increased dramatically in the past two decades. Currently it is a base for light industries. It is also a base for fruits, such as longyan, olive, tea etc. Shantou is a harbour and coastal city in the downstream area of Rong Jiang. There are many scenic points to visit such as Laoma Palace and Mayu Island. 7. References, Databooks and Bibliography Geology Press (1973): The atlas of geology in China. China Atlas Press (1978): China Meteorology Atlas. Qingdao Press (1993): Dictionary of China's River Distribution. Guangdong Water Resources Department, Water resources development for Guangdong, 1985 Pearl River Water Commission (1989), Integrated Water Resources Planning for Pearl River Basin. Pearl River Water Commission (1984): The Collection of Flood Control Data in Pearl River Basin. Pearl River Water Commission ( ), The Hydrological Year-book of Pearl River Basin. China Bookstore Press, China Historical Floods, China Population Investigation, China Statistical Press, D

39 Indonesia Indonesia-ll: Kali Ciliwung Indonesia-12: Kali Cisadane 31

40 Introduction The Indonesia archipelago situated in Southeast Asia consists of five main islands (Sumatra, Kalimantan, Sulawesi, Java and Irian Jaya) and some 13,667 other smaller islands with a total area of 1.9x10 km. Geographically, Indonesia is located between the latitudes 6 08' N ' S, and longitudes 94 45' E ' E. The total population according to the 2002 census was 212 million with the forecast increase at about 1.15 % per year. Population distribution is uneven throughout the country. Java Island has the highest population density whereas the other islands have very much lower densities. Politically, Indonesia is divided into 30 provinces, 279 districts, 55 urban municipalities, 3,625 sub districts and 67,033 villages. Most of the rivers are short, steep and productive in sedimentation. Indonesia is a tropical country affected by tropical monsoon rainfall having two distinct dry and wet seasons. In the wet season, it experiences heavy rainfall, ranging from 2,500 to 6,000 mm/year. In the dry season it is very dry during a 2 month period normally between July and September. The two rivers catalogued in this volume are the Ciliwung and Cisadane. They are the representative rivers of the salient characteristics indicated above, that is flood, urban, megalopolis, industrial development and agricultural area respectively. Acknowledgemetns A working group was established for the preparation of the catalogue, and a number of institutes and individuals collaborated. The working group chaired by Mrs. Dyah Rahayu Pangesti as Director of Research Institute for Water Resources consisted of: Dr. Agung Bagiawan Ibrahim (Head), Sufjipto, Srimulat Yuningsih, Rosadi Affandi, Tito Masbarlan and Yeyet Heryati (Experimental Station for Hydrology), Ir. Yoesron Loebis, M.Eng (Senior Research for Hydrology). The organizations that have contributed include: Badan Penelitian dan Pengembangan Kimpraswil (Agencyfor Research and Development of Settlement and Regional Infrastructure), Badan Pertanahan Nasional (Natonal Boardfor Land Administration), Badan Meteorologi dan Geofisika (Agencyfor Meteorology and Geophysics), Badan Perencanaan dan Pembangunan Daerah (Provincial Development Planning Board), Direktorat Geologi (Directorate of Geology), Kantor Statistik Propinsi Jawa Barat (West Java Provincial Office of Statistics), and Proyek Induk Pengembangan Wilayah Sungai Ciliwung Cisadane (Ciliwung- Cisadane River Basin Development Project). 32

41 Indonesia-ll Kali Ciliwung Map of River o tapcang Cibeber ^ Table of Basic Data Name: Ciliwung Serial No. : Indonesia- 1 1 Location: West Java-Indonesia, OKI Jakarta S 06 07' 00" ' 00" E ' 00" ' 00" Area: km Length of main stream: 97 km Origin; Mt. Mandalawangi Highest pt: 3,002 m Outlet: Java Sea Lowest: 0 m Main base rocks: Tuffaceous breccia, alluvial fans from quartemary and volcanics rocs, and alluvial and beach ridge deposit.main tributaries: Ciesek River (27.15 km2), Ciluar River (35.25 km2) Main Reservoirs: None Mean annual precipitation: 3,125 mm Mean annual runoff: 95.1 m/s Population: 4,088,000 (2000) Main cities: OKI Jakarta, Bogor Land use: Forest (9.80%), Paddy Field (9.40%), Agriculwre (48.0%), Urban (32.8%) 33

42 Indonesia-ll 1. General Description Ciliwung river is 97 km long, has a catchment area of 476 km, and is located in the western region of Java where it flows through two provinces. West Java and the special region of Jakarta. The Ciliwung river has its source at Mt. Mándala Wangi in Kabupaten Bogor with the highest peak at 3,002 m The river flows in a northern direction passing several active volcanoes, Mt. Salak (2,21 1 m), Mt. Kendeng (1,364 m), and Mt. Halimun (1,929 m), crosses two main cities Bogor and Jakarta before finally flowing into the Java Sea. The main tributaries are located in the upper catchment and are the Ciesek and Ciluar with respective lengths 9.7 km and 21.0 km and catchment areas of km^ and kxn. The Cilivmng basin is a narrow and elongated shape of which 17.2 km upstream has a very steep slope (0.08), 25.4 km in the middle reach has a slope of and the downstream, 55 km has a flat slope of In general the geology of the Ciliwung river basin is dominated by Tuffaceous Breccia and older deposits lahar and lava in the upstream area. The middle reach consists mainly of alluvial fans from quartenary and volcanics rocks, and the downstream area is dominated by alluvial and beach ridge deposits. Mean rainfall reaches 3,125 mm, with mean annual discharge of 16 mvsec. as measured at Ciliwung Ratujaya observation station (231 km'^). With such topographical, geological and hydrological features the Ciliwung river is often overflowing and inundating parts of Jakarta city. The population along the Ciliwung river basin reaches million (Census 2000) and can be regarded as the most densely populated area. 2. Geographical Information 2.1 Geological Map LEGEIVD ALLUVIAL BEACH RJDOE DEPOSfTS BAUTEN TUFT ALLUVIAL FAN GENTENO FORMATION OUNUNO ENDUT-PRABAKTl LAVA BOIONOMANIK FORMATION UNDIFFERENTIATED VOLCANIC ROCKS YOUNO VOLCANIC BRECaAN AND LAVA OF ON KENCANA AND ON LIMO OLDER DEPOSITS TUFF SANDY PUMICEOUS TLTF BASALT LAVA FLOW OF OUNUNO OEOERBENTANO 34

43 Indonesia-ll 2.2 Land Use Map ^ilx. Land L'se Ciliwung- Cisadane Ca th mrat Area Legend : Scnlonent Ptddy KkU nui /j.i V \ ^^H ^ IB ^^ i m ^ i Ara nd loduwial Zoic Mcfldow/Coancr Ctrjiss ßü^i^ Mi^Cropí FjlMt Cnp% Crops [.and l-jnpty Rivcr/l.Akc^eKrvmi Mineral /une Sca>ndjT>' ViiccM ± 2.3 Characteristics of River and Main Tributaries No. Name of river Length (km) Catchment area (km') Highest peak (m) lowest point (m) Cities Population (Million)* Land use (%) Ciliwung (Main River) Ciesek (Tributary) Ciapus (Tributary) Bogor (1.419) DKI (2.433) F (9.80) P (9.40) A (48.0) U (32.8) F: Forest; P: Paddy field; A: Agriculture (vegetable field, grass field); U: Urban (Census 2000) 35

44 ' Indonesia-ll 2.4. Longitudinal Profiles ( Ele Ç Ciliwung Ciesek f ) >/ Ciluar 0 J C) Distance (km) Climatological Information 3.1 Annual Isohyetal Map and Observation Stations P O AMAR BESAR u JCffffWV MEAN ANNUAL RAINFALL SCALE OF RAINFALL : 300 mm 1000 mm 1500 mm 2000 mm 2500 mm 3000 mm 3300 ram 4000 mm 4300 mm 3000 mm 6000 mm 7000 mm 8000 mm 36

45 Indonesia-ll 3.2 List of Meteorological Observation Stations No. Station Elevation (m) Location Observation period Mean annual precipitation (mm) Obsevation item" 1. Cipanas 1,100 S 06 44' 00" E ' 00" , RH, T, R, DS 2. Cibinong 125 S 06 28' 00" E ' 00" , RH, T, R, DS 3. Jakarta Obs. 07 S 06" 10' 00" E ' 00" ,105.9 RH, T, R, DS RH: Relative Humadity, T: Temperature, R: Rainfall, DS: Duration of Sunshine 3.3 Monthly Climate Data Station: Cipanas Observation Station Temperature ( C) Precipitation (mm) Relative Humidity (%) Duration of Sunshine (%) Jan 19.6 Feb Mar Apr May Jun Jul Aug 20.5 Sep Oct Nov 21.2 Dec Annual , Period for the mean Station: Cibinong Observation Station Temperature ( C) Precipitation (mm) Relative Humidity (%) Duration of Sunshine (%) Jan 25.4 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Station: Jakarta Obs Observation Station Temperature ( C) Precipitation (mm) Relative Humidity (%) Duration of Sunshine (%) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 27.5 Dec Annual , Period for the mean

46 Indonesia-ll 3.4 Long-term Variation of Monthly Rainfall Series Depok Station (12month movins avsragss sädsd) 38

47 Indonesia-ll 4. Hydrological Information 4.1 Map of Streamflow Observation Stations J*v«Se«LtgraJ : Awmsmui A ClmalDàify Sui«4.2 List of Hydrological Observation Stations No. Station Location Catchment area (km') Obsevation period Obsevation item'' (frequency) 1. Katulampa S 06 36' 07" E ' 38" QW 2. Ratu Jaya S 06 19' 50" E ' 13" Q(d) 3. Kp. Kelapa S 06 27' 22" El 06 48' 12" Q(d) 4. Sugutamu S 06 26' 20" E ' 00" Q(d) 39

48 I Indonesia-ll No. Q2) (m3/s) Qmax3) (m3/s) Qmax4' (m'/s) Qmin" (m3/s) Qmax/A (m3/s/100km2) Qmax/A (m3/s/100km2) Period of statistics Q: discharge; d: daily measurement; Mean annual discharge; Maximum discharge; ' Mean maximum discharge; Mean minimum discharge. 4.3 Long-term Variation of Monthly Discharge Series Ciliwung at Ratujaya ( km2) ST 351 E 30 (12-month moving averages added). Mean : m3/s i Time (year) 4.4 Annual Pattern of Discharge Ciliwung - Sugutamu ( km2) Daily in 2000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 40

49 Indonesia-ll 4.5 Unique Hydrological Features As explained in the general description, the Ciliwung river basin has a long and narrow shape with steep slopes in the upstream and middle reaches. Rainfall is very high and the recharge area is very small because of the densly populated and settled areas downstream. The relatively short duration of rainfall in the upper areas of the river basin and local inflows downstream cause floods and inundation of the Jakarta area. This condition is aggravated when floods occur during a full moon when the ocean tides are highest. To avoid inundation of the city area, a flood channel to direct flows to the west is being built and called "Banjir Kanal Barat". 4.6 Annual Maximum and Minimum Discharge at Sugutamu (266.6 km ) Year Maximum Discharge1' Date (m3/s) Minimum Discharge ' Month (m3/s) Instantaneous observation by recording chart 4.7 Hyetographs and Hydrographs of Major Floods Ciliwung at Sugutamu a :00 Time(hr) 12:

50 Indonesia-ll 5. Water Resources 5.1 General Description The Ciliwung river basin with an area of 476 km2 covers only a very small percentage (0.363 %) of the entire Java region which is about 130,777 km2. Yet, because this river flows through the capital city of the Republic of Indonesia and often causes floods, special attention is given to flood control measures. Water resources of this river are used for agriculture activities upstream (water taken from Katulampa dam), drinking water (a small amount), sanitation and water flushing. The barrage at Manggarai, located in the center of Jakarta, controls the water flow by directing it into the Banjir Kanal Barat and thus preventing floods during the rainy season. In the dry season water supply is only sufficient for sanitation and flushing purposes. Use of river water for agricultural purposes occurs mainly upstream from a fixed weir at Katulampa. 5.2 Map of Water Resources System Legend o T A \ \ \ A a. Weir Water Level Recorder Rainfall Station CHmatologi Station Mountain Catchment area Power house Barrage j. Cianteu Power home Ai Ll V \ ^ 42

51 Indonesia-ll 5.3 List of Major Water Resources Facilities Major Major Diversions and Canals Name of rivers Location Maximum capacity (m3/s) Purpose1' Ciliwung Banjir Kanal Barat 350 F 1) F: Flood control Others Name of River Facility Purpose" Capacity (m3/s) Year of complection Katulampa Weir A Manggarai Barrage F Bantarjati Weir A 0.03 PDAM Bogor Free Intake W 0.06 PDAM Cibinong Free Intake W 0.05 PDAM Citayam Free Intake PDAM Depok Free Intake 1) A: Agriculture use F: Flood control W: Municipal water supply W W Water Quality River Water Quality at Ciliwung-Katulampa in 2003 Date Jul Aug Sep Oct Nov ph DO (mg/l) COD (mg/l) SS (mg/l) Discharge (m3/sec) Socio-cultural Characteristics The Ciliwung River flows through two provinces, West Java and the Special Region of Jakarta. Two main races dominate the region namely, the Sundanese (West Java) and Orang Betawi (Jakarta), therefore socio cultural characteristics differ from one area to the other. In the Bogor area (Upper Ciliwung River) in the past were found two famous ancient kingdoms; Tarumanegara (4th-5th Century) with its great King Pumawarman and Padj ajaran (15* -16* Century) with its King Sri Baduga. The existence of these Kingdoms is found from ancient inscriptions at Ciaruteun (Tarumanagara) and Batutulis (Padjajaran). Culture in the Bogor area is mainly Sundanese, such as can be observed from traditional dances, the Ketuk Tilu or the Jaipongan which is modern, sensual and full of spirit. Specific Sundanese music can be observed from the Degung, Calung, Angklung and Kecapi Suling. 43

52 Indonesia-ll The upper part of the Ciliwung in the Jakarta region was once famous for a kingdom (Banten) with Pangeran Jayakarta as King. The Yapong is a favourite dance in the area and Gambang Kromong as well as Kroncong music can still be found at Tugu, north of Jakarta. Also famous is a humorous play, the Lenong, using a special Betawi dialect. 7. References, Data-books and Bibliography Badan Pusat Statistik Statistik Lingkungan Hidup Indonesia. Jakarta INDEC & Associates Limited in Associated LAVALIN International Inc and NIPPON Koei Co., Ltd. May Vol. 1 Main Report. Cisadane River Basin Development Feasibility Study. Nikken Consultants, Inc in Association with Nippon Koei Co., Ltd The Study on Comprehensive River Water Management Plan in Jabotabek. PT. Mettana Studi Potensi SDA dan Pemanfaatannya. Laporan Akhir. Proyek PKSA-CC. 44

53 Indonesia-12 Kali Cisadane Map of River LeüWilliang f /A \ ßfimmit Ç'^'^jmn» ' /C.t^.)<t^\i^ s«'arun ç) kp nd^n g Table of Basic Data Name: Cisadane Serial No. : Indonesia-12 Location: West Java - Indonesia, DKl Jakarta, Banten Propvince Area: 1,366.6 km s 06 03' 00" ' 00" E ' 00" ' 00" Length of the main stream: km Origin: Mt. Mandalawangi Outlet: Java Sea Highest Pt.: 3,002 m Lowest: Om Main base rocks: Breccia, andésite, basaltic, alluvial Main tributaries: Cianten River (426.5 km ), Ciapus River (58.15 km ) Main Reservoirs: None Mean annual precipitation: 3,137 mm Mean annual runoff: 95.1 m/s Population: 5,520,000 (2000) Main cities: Bogor, Tanggerang Land use: Agricutaire (48.52%), Forest (16.34%), Lake, river, marsh (1.15%), Paddy field (22.77%), Urban (11.22%) 45

54 Indonesia General Description The Cisadane River which is next to Ciliwung River has a 1,367 km2 river basin and a length of km. It originates from the same source as the Ciliwung, Mt. Mandalawangi in Kabupaten Bogor with a highest peak of 3,002 m and Mt. Salak at 2,211 m, and flows northward through valleys to empty at Tanjungburung river mouth in to the Java Sea. Similar to the Ciliwung, the Cisadane crosses two Kabupaten in two Provinces, Kabupaten Bogor in West Java Province and Kabupaten Tangerang in Banten Province. The river flows through the cities of Bogor and Tangerang. Tributaries are mostly found in the upstream region with the largest tributaries being the Cianten and Ciapus with respective lengths of 49.2 km and 27 km and covering areas of km2 and km. The upper part of the Cisadane River basin has a round shape and from the middle reach to downstream is long and narrow. The upper 10.1 km has steep slopes of 0.228, the 25 km middle reach has slopes of 0.032, and the downstream km has flat slopes of In general, the geological condition of the Cisadane river basin comprises breccia, lava flow of mainly andésite, lava flow basaltic with piroxine and older deposit lahar. The middle reach consists mainly of Genteng Formation, Bojongmanik Formation, alluvial fan beaded fine tuff, sandy tuff interspersed with conglomeratic tuff. The downstream geological condition is dominated by banten tuff with alluvial deposits (clay, silt, sand gravel pebble and boulder) at the river mouth. Mean rainfall for the Cisadane is 3,137 mm, with an annual mean discharge of 92 m /sec as observed at observation station Cisadane Batubelah (819.6 km). The population density in this area is around million (census 2000) and is considered as relatively densely populated. 2. Geographical Information 2.1 Geological Map LEGEND : OA OB OT OA TPG OV TM OV ALLUVIAL BEACH WDGE DEPOSITS BAIirEN TUFF ALLUVIAL FAN NTENO FORMATION OUNUNO ENDUT-PRABAKTI LAVA BOJONOMANIK FORMATION UNDIFFERENTIATED VOLCANIC ROCKS YOUNO VOLCANIC BRECQAN AND LAVA OF ON KENCANA ANDON LIMO OLDER DEPOSITS OV oys OV TUFF SANDVPUMICEOUS TUFT BASALT LAVA FLOW OF OUNUNO GEOERBENTANO 46

55 ' Indonesia Land Use Map ^^i:^ Land Uic Ciiiwunc- CiMdane Catbment Area jt^xm^"^ ^. m 1 1 / Wk^w CT«ir Leg«End : IVima I'onm IB SctlLciDoit PsUy Kield Aica md [ndiuuuj Zone Mcadow/C(H% Gnst liushcs MixCropf l'iüullc Cldpl 'W^ ^ ^ ^ \.axa î:mpt>' RiïCf/I JiLe/Reicn'oir Muicnl/.(»e SfcondAn' l^orcsl -f 2.3 Characteristics of River and Main Tributaries No. I 2 3 Name of river Cisadane (Main River) Cianten (Tributary) Ciapus (Tributary) Length (km) Catchment area (km2) , Highest peak (m) Lowest point (m) 3, , , Cities Population (Million)* Bogor (4.018) Tangerang (1.502) F: Forest; P: Paddy field; A: Agriculture (vegetable field, grass field); U: Urban; L: Lake, River, Marsh *i census 2000 Land use (%) A (48.52) F (16.34) L(1.I5) P (22.77) U (11.22) 47

56 Indonesia Longitudinal Profiles Cisadanei "e ~rr o LU Ciapus _i / / /.Cianten 0 - -i 1 ) C Distance (km)

57 Indone$ia Climatological Information 3.1 Annual Isohyetal Map and Observation Stations F OAMAR eesar» U. Kttwtng ^ f ONRUST torniisv. 1 1^r3>'. K. I. J A K A R ùti ^ MEAN ANNUAL RAINFALL SCALE OF RAINFALL: 500 mm 1000 mm 1500 mm 2000 mm 2500 mm 3000 mm 3500 mm 4000 mm 4500 mm 5000 mm 6000 mm 7000 mm 8000 mm 3.2 List of Meteorological Observation Stations No. Station Elevation (m) Location Observation period Mean annual precipitation (mm) Obsevation item" 1 Curug 46 S 07 23' 18" ' 00" ,917.3 RH, T, R, DS 2 Dermaga 250 S 06 30' 00" ' 00" ,192.4 RH, T, R, DS 1) RH: Relative Humadity, T: Temperature, R: Rainfall, DS: Duration of sunshine 49

58 Indonesia Monthly Climate Data Station: Curug Observation Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature ("C) Precipitation (mm) Relative Humidity (%) Duration of Sunshine (%) Station: Darmaga Observation Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec.annual Period for the mean Temperature ( C) Precipitation (mm) Relative Humidity (%) Duration of Sunshine (%) Long-term Variation of Monthly Rainfall Series 600 Serpong L2-mouiith movlrtt «v4ni* *dd*d AAflultmain Z.lJO.l 500 I I I ^T Time year 50

59 Indonesia Hydrological Information 4.1 Map of Streamflow Observation Stations Jan Sea Lcflcnd : AWIR SUIKm A Clunilolngy SUUMl ^ Rivw Cilimnf -luni Bma Iwk^Pilunibon 4.2 List of Hydrological Observation Station No. Station Location Catchment area (A] (km') Obsevation period Obsevation item'' (frequency) 1 Batubeulah S 06 29' 00" E ' 00" Q(d) 2 Genteng S 08 38' 20" E ' 20" Q(d) 3 Babakan S 06 29' 45" El 06 48' 00" 1, Q(d) 4 Legokmuncang S 06 29' 00" E ' 00" Q(d) 51

60 Indonesia-12 No. Q2) (m3/s) Qmax3) (m3/s) Qmax4) (m3/s) Qmin5) (m3/s) Qmax/A (m3/s/100km2) Qmax/A (m3/s/100km2) Period of statistics ) Q: discharge; d: daily measurement; 2) Mean annual discharge; 3) Maximum discharge; 4) Mean maximum discharge; 5) Mean minimum discharge. 4.3 Long-term Variation of Monthly Discharge Series Cisadane at Batubeulah ( km2) 12 month moving average added Mean : m'/s 5 10 I I I ~i I n r Time (year) Annual Pattern of Discharge Cisadane - Batubeulah ( km2) Daily IN

61 Indonesia Unique Hydrological Features The upper part of the Cisadane Rive has a round shape with steep slopes and has a long and narrow shape with flatter slopes in the middle reach and downstream. Such features are often a cause of flooding because heavy rainfall, upstream is immediately accumulated in the middle reach that is narrower in shape. Obstruction follows the constriction, however because the Cisadane is relatively long from the middle reach to river mouth, about 100 km, floods occurring naturally can be routed and flooding of the area in the vicinity of the Cisadane can be prevented. 4.6 Annual Maximum and Minimum Discharge at Batubeulah ( km ) Year Maximum Discharge1' Date (m3/s) Minimum Discharge21 Month (m3/s) Year Maximum Discharge ' Date (m3/s) Minimum Discharge2' Month (m3/s) , , ), 2) Instantaneous observation by recording chart 53

62 Indonesia Hyetographs and Hydrographs of Major Floods Cisadane at Batubelah Time(hr) 2 4 te J 3 8 g 10 i 12, :00 5. Water Resources 5.1 General Description The Cisadane River basin with an area of 1,367 km2 covers only % of Java island (130,777 km2). Similar to the Ciliwung River, the Cisadane River water in used for agricultural purposes upstream. Downstream in Pasarbaru Tangerang a barrage functions as a water intake and also as a flood control structure. Water taken from the barrage at Tangerang is used to irrigate agricultural land in Kabupaten Tangerang, northern part up to the coast. A power house generating electric power has been built and uses mainly water from the Cianten tributary. The river is also used as a source of raw water for drinking water and for the many industries located in the region. 54

63 Capacity Indonesia Map of Water Resources System Legend Weir Water Level Recorder Rainfall Station Climatologi Station Mountain Catchment area Power house Barrage 5.3 List of Major Water Resources Facilities Major Reservoirs Name of river Name of dam Catchment area (km2) Flood capacity (106 m3) Effective capacity (106 m3) Purpose1' Year of completation Cisadane Pongkor 3.0 1,950 1,830 A ) A: Agricultural use Others Name of River Facility Purpose1' 1 (m3/s) Year of complection Cianten (Tributaries) Dam P 1935 Rumpin Weir A 1940 Empang Weir I 2 Serpong Free Intake I, W 6.17 Pasarbaru Barrage A, W,I ) A: Agricultural use F: Flood control I: Industrial use P: Hydropower Wi Municipal water supply 55

64 Indonesia Water Quality River Water Quality at Batubeulah in 2003 Date Jul Aug Sep Oct Nov PH DO (mg/l) COD (mg/l) SS (mg/l) Discharge (m /sec) Socio-cultural Characteristics The Cisadane flows through two provinces, with the upper part of river flowing through West Java and lower stream through the province of Banten. The upper region in the Kabupaten of Bogor is inhabited predominantly by the Sundanese people and the lower river region in Banten is inhabited by a mixture of Sundanese, and Banten Javanese descended from former solders of the Mataram Kingdom under the reign of Sultan Agung during a war against Dutch colonization. In the past, two kingdoms ruled in the Bogor area (upper Cisadane) respectively the Tarumanegara Kingdom, 4th-5,h Century, with its famous King Purnawarman and the Padjadjaran Kingdom, 15th- 16th Century, with its most powerful King Sri Baduga. Remains of both kingdoms are shown from among others ancient inscriptions at Ciaruteun (Tarumanegara) and Batutulis (Padjadjaran). Culture is represented by dances and music of which the Ketuk Tilu dance is a traditional dance and the Jaipong more modern, sensual and lively. Specific traditional Sundanese music is the Degung, Calling, Angklung, and Kecapi Suling. In the area of Tangerang, in the past ruled by the Banten Kingdom, a mixture of Sundanese and Javanese dances and music is found. Known in the area is the Gamelan music accompanying a singer who is also the dancer. Such events can still be attended, especially during harvest time when farmers are celebrating circumcision or marriage of their children. 7. Reference, Data-books and Bibligraphy Badan Pusat Statistik Statistik Lingkungan Hidup Indonesia. Jakarta INDEC & Associates Limited in Associated LAVALIN International Inc and NIPPON Koei Co., Ltd. May Vol. 1 Main Report. Cisadane River Basin Development Feasibility Study. Nikken Consultants, Inc in Association with Nippon Koei Co., Ltd The Study on Comprehensive River Water Management Plan in Jabotabek. PT. Mettana Studi Potensi SDA dan Pemanfaatannya. Laporan Akhir. Proyek PKSA-CC. 56

65 Japan Japan-13: Nagara-gawa Japan-14: Natori-gawa Japan-15: Yasu-gawa 57

66 Introduction The three rivers compiled into this volume are: the Nagara-gawa, the Natori-gawa and the Yasu-gawa, all of which are in Honshu Island. These rivers have long histories especially in terms of the politics, economy and culture of Japan. The Nagara-gawa is one of the three large rivers which flow through the Nobi Plain, located at the center of the Chubu Economic Region in Japan. In the past, the three rivers named the Three Kiso Rivers (Kiso-sansen) flowed as one turbulent river in the lower reaches. It was divided into the three rivers as we know today by the improvement project from 1887 to 1911 during the Meiji Era. The abundant water resources are used mainly for irrigation and hydroelectric power generation for sustaining the industries in the Chubu area. The Natori-gawa flows through the metropolitan area of Sendai, the capital city in the Tohoku district. The population in the basin is about 429,600, which is 4% of the population nationwide and 42% of that in the city of Sendai. The lower Natori-gawa basin is covered with mainly wide paddy fields. The areas are one of the most famous rice production areas in Japan. Snowfall in the mountainous areas of the basin is an important water resource for rice planting. The Yasu-gawa is the largest river flowing into Lake Biwa which is the largest fresh water lake in Japan. The river flow is highly regulated in the lower reaches with several irrigation schemes and weirs which divert water from the natural river courses. Lake Biwa is water source for 14 million people in the Kansai area which includes Kyoto, Osaka and Kobe; thereby the water quality management of the basin is a quite important issue for the water resources of the Kansai area through Lake Biwa. Acknowledgements The information on the three rivers was compiled by voluntary members of the IHP Working Group of the Japanese National Committee for UNESCO's International Hydrological Programme (IHP), which is chaired by Prof. Kuniyoshi Takeuchi, Yamanshi University. Generous assistance from governmental organizations is acknowledged. Contributors are listed as follows: Nagara-gawa: Seirou Shinoda and Goro Mouri, Information and Multimedia Center, Gifu University; and Mr. Takeshi Yamaguchi, Kiso River Upper Reaches Works Office, Chubu Regional Construction Bureau, Ministry of Land, Infrastructure and Transport (MLIT). Natori-gawa: So Kazama, Graduate School of Environmental Studies, Tohoku University; and Mr. Toshihiko Watanabe, Sendai River and National Highway Office, Tohoku Regional Construction Bureau, MLIT. Yasu-gawa: Kimaro, T. Anderson and Yasuto Tachikawa, Disaster Prevention Research Institute, Kyoto University; and Biwako River Work Office, Kinki Regional Construction Bureau, MLIT. The manuscripts were reviewed by Yasuto Tachikawa, Kyoto University, and Ross James, Bureau of Meteorology, Australia. Financial support was provided by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. 58

67 Japan-13 Nagara-gawa Map of River Table of Basic Data Name: Nagara-gawa Serial No. : Japan-13 Location: Central Honshu, Japan N 34 04' ~ 35 59' E ' ' Area: 1,985 km' Length of main stream: 1 66 km Origin: Mt. Dainichi Highest point: Mt. Dainichi (1,709 m) Outlet: Ise Bay, Pacific Ocean Lowest point: River Mouth (0 m) Main geological features: features: granite, andésite, ryolite, gneiss Main tributaries: Yoshida River (181 km2), Itadori River (298 km2), Mugi River (154 km2), Tsubo River (269 km2) Main lakes: None Main reservoirs: Nagara Estuary Barrage (1995), Atagi Dam (2.55 x 10 m, 1988) Mean annual precipitation: Mean annual runoff: Population: 915,100(1995) 1,915.3 mm ( ) at Gifu 1,16.5 m/s ( ) at Chusetsu Main cities: Gifu, Seki, Mine, Hashima Land use: Mountainous area (75.3%), Urban area ( 6.5%), Cultivated area (18.2%) 59

68 Japan General Description The Nagara River is one of the three rivers, the Kiso, the Nagara and the Ibi, that flow through the Nobi Plain, located at the center of the Chubu Economic Region. In the past, these three rivers named the Three Kiso Rivers (Kiso-sansen) flowed as one turbulent river. However, it was divided into the three rivers as we know today by the improvement project from 1887 to during the Meiji Era. The Nagara River (Nagara-gawa) originates from the Kamasu Valley at the Mt. Dainichi in Takasu Village, Gifu Prefecture. It flows to the southeast and merges with tributaries such as the Yoshida, the Itadori, the Mugi, and the Tsubo flowing in the mountainous area and the cultivated area in the central part of Gifu Prefecture. In the its lower reaches the Nagara River it merges with the Ijira River running across the cultivated area and the urban area of Gifu City and flows southward in the Nobi Plain. The separation levees force the river to run parallel to the Kiso River from Naruto, Kaizu Town located in the southern part of Gifu Prefecmre. And then, it flows through Kuwana in Mie Prefecture, and merges with the Ibi River before flowing into the Ise Bay as one river. Its catchment area is 1,985 km^ and the length of its mainstream watercourse is 166 km. Its abundant waters are used for irrigating an area of 80 km and for hydroelectric power generation at five stations with a maximum output of about 17,000 kw. The water of its lower reaches satisfies the population demand for water in the cities of Tokai and Handa in Aichi Prefecture, and supplies industry in the North Ise district. 2. Geographical Information 2.1 Geological Map GEOLOGY 60

69 Japan Land Use Map Legend ^^^ ^^^0 ^^^B ^5 ^^^B ^^^0 ss 1 i WasleUnd TransportatioD network Forest Field Trees field Orchard Lake River area Olher land mx Paddy field Urban area Residential area 0 20, ' km 2.3 Characteristics of River and Main Tributaries No. Name of river Length [km] Catchment area [km ] Highest peak [m] Lowest point [m] Cities Population Land use [%] 1 Nagara (Main river) 166 1,985 Mt. Dainichi 1,709 River mouth 0 Giñi 402, Yoshida (Tributary) Itadori (Tributary) Mugi (Tributary) Tsubo (Tributary) MtEboshi 1,625 Confluence 215 Mt. Heike 1,442 Confluence 78 Mt. Hinaga 1,216 Confluence 40 Mt. Omae701 Confluence 3 1 Hachiman-cho 17,262 Mino 24,662 Mugi-gun 17,621 Seki 74,438 M (75.3) U(6.5) C(I8.2) 6 Ijira (Tributary) Mt. Kama 696 Confluence 10 Gifu, Ijira-mura 32,871 M: Mountainous area U; Urban area C: Cultivated area 61

70 I I.-' 1 f 1 y Japan Longitudinal Profiles c S 500 _5 400 LU 300! Yoshida River! / /!! y y Ila Joii Rivej \js ^r \ 1.- j./'"nagara! River s^^v! 200 -^^---^--y-,, _ i i ^ ««-1 *^-" ~-~r tswo raver r!! eo Distance(km) Climatological Information 3.1 Annual Isohyetal Map and Observation Stations Ç) \ 2000 m _ \ 1800 N A 30Q0 35 ÛX_ > If/ / 'j w ^-V \ y Ö" o5] 1600 ^r / # Precipitation Obs. Station(mm/y) i 1 i km > I I I 62

71 Japan List of Meteorological Observation Stations^ No. Station Elevation [ml Location Observation period Mean annual precipitation [mm] Observation items4' ' Mumai 1,015 N 36 03' 36" E ' 00" present 2, DS, P, T, W ) Nagataki 430 N 35 55' 30" E ' 54" present 3, DS, P, T, W ) Hachiman 250 N 35 45' 30" E ' 48" present 2, DS, P, T, W ) Mino 68 N 35 33' 24" E ' 36" present 2, DS, P, T, W ) Gifu 13 N 35 24' 00" E ' 42" present 1, DS, P, T, W ) Kuwana 3 N 35 03' 00" E ' 36" present 1, DS, P, T, W ' Kuzuhara 160 N 35 35' 57" E ' 36" present 3, P N 35 25' 42" 1, Chusetsu present E ' 58" ) 1 ) 7 rainfall observation stations managed by Japan Meteorological Agency and 21 stations managed by Ministry of Land, Infrastructure and Transport are operated in the Nagara River basin. Part of the stations are listed here. 2) Serial Number used by Japan Meteorological Agency 3) Serial Number used by Ministry of Land, Infrastructure and Transport 4) DS: Duration of sunshine, P; Precipitation, T; Air temperature, W: Wind velocity and wind direction P 3.3 Monthly Climate Data (Observation station: Gifu) Observation item Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Precipitation [mm] , Solar radiation [MJ/m2/d] Duration of sunshine [hr] ,

72 Japan Long-term Variation of Monthly Precipitation h i 800 ' 700 (37-month moving averages added) : 600 Gifu, Gifu Prefecture Annual Mean: mm/y SQ 314.6mm/y i 500! 400 L : Time 4. Hydrological Information 4.1 Map of Streamflow Observation Stations N Jslagara Rv S\. Yoshida R/ A ( hado rir J\Mugi R. f k Tsubo R5 & Wa R. \ } A i i fâù, J \ A / A t S A D 0 10 i, i Water level station Discharge station km i 1 f 1 r 1 64

73 n List of Hydrological Observation Stations1' No.2' Station Location Catchment area (A) [km2] Observation period Observation items3' Sunomata 39.4 km from the river mouth 1, present H,Q Chusetsu 50.2 km from the river mouth 1, present H,Q Akutami 59.4 km from the river mouth 1, present H,Q Mino 74.5 km from the river mouth 1, present H,Q Furukawabashi 51.0 km from the river mouth present H,Q No.2) Q<> [m3/s] Qmax5) [m3/s] Qmax6' [m3/s] Qmin7' [nrvs] Q/A [m3/s/100km2] Qmax/A [m3/s/100km2] Period of statistics , , , , , , , , )15 water stage stations and 1 7 discharge stations are operated in die Nagara River basin. 2) Serial Number used by Ministry of Land, Infrastructure and Transport 3) H: water level, Q: discharge, Q is obtained from rating curve. 4) Q: Mean annual discharge 5) Q max : Maximum discharge 6) Q max: Mean annual discharge 7) Q min: Mean minimum discharge 65

74 Japan Long-term Variation of Monthly Discharge 700O Nagara R iver at Chusetsu Annual Mean: 113.1m/s SD: 2958m /s 5000 (37-month moving averages added) " 4000 S láui Time 4.4 Annual Pattern of Discharge Nagara River at Chusetsu (1,607km ) Daily in ^ Flow duration curve i ^, k...l^k k- la-jijk.j. 1I Q = "\"r\ " KKL *"" ' Apr May May Jun Jul Aug Sep Nov Time Unique Hydrological Features Since the upstream region of the Nagara River is mostly unsuitable for constructing dams, one of the problems of providing flood protection is that the river course itself needs to be made to cope with larger discharge volumes. The basic plan for the Three Kiso Rivers Project therefore involves to cope with the design flood of 8,000 m3/s using an upstream dam, allowing 7,500 m /s to flow down safely through the river course. The Nagara Estuary Barrage was constructed at the river mouth in 1995 for the purpose of flood protection, prevention of saltwater inflow and water use. Although it is necessary to extend the cross-sectional area of the river course to achieve the above plan, raising the levees or moving the levees backward are not possible in the downstream region of the Nagara River where valuable land and a large number of houses are located along the river. The remaining alternative is dredging the riverbed. The downstream region of the Three Kiso Rrivers facing the Ise Bay has been invaded by saltwater for a long period, and the inhabitants have suffered saline deterioration of both their drinking water and agricultural water. In order to achieve reliable prevention of damage caused by the saltwater inflow resulting from the dredging operations, and to exploit the water resources that are needs for the development of local communities, the estuary barrage was constructed. 66

75 Japan Annual Maximum and Minimum Discharges At Chusetsu [1,607 km2] Year 1954 Maximum1' Date [m3/sl 9.2 1,634 Minimum2' Date [m3/s Year 1978 Maximum ' Date [m3/s] Minimum ' Date [m5/s ,722 2, ,357 1, ,423 2, , , , , _* _* _* _* , , , , _* _* _* _* ,820 _* _* _* _* 2,144 2, _* _* _* _* _* _* _* _* ,025 2, ,528 1,124 1, ,748 2, ,308 1, , _* 1,399 _* _* 13.3 _* , , , , ), 2) Instantaneous observation by recording chart *: missing data 4.7 Hyetographs and Hydrographs of Major Floods n"t Rainfall at Chusetsu 1999 Typhoon No. 16 Discharge at Chusetsu J} 30.0 I f T Time (hour) 67

76 Japan Water Resources 5.1 General Description There are no dams with the purpose of water use in the Nagara River because the topography along the river is flat and the geological features is not suitable for constructing dams. The river is therefore used mainly as a source of irrigation water in the small tributaries and waterways. On the other hand, the water of the Nagara Estuary Barrage is supplied to the Chubu urban district, which is one of three major urban districts in Japan. The maximum amount of water for city and industrial use is 22.5 m3/s. The Nobi Plain, which is a main region of the Chubu urban district, is suffering from extensive ground subsidence caused by exploitation of ground water. It is now the largest zero-meter zone in Japan and a serious problem for the nation's disaster prevention measures. It is therefore impossible to rely on ground water as a new water resource, and positive steps need to be taken to switch from ground water to surface water use in order to prevent ground subsidence. As that mean, the expectations to the Nagara Estuary Barrage have been great in this district. 5.2 Map of Water Resource Systems N A r>çc ^ Power station Dam (J Estuary barrage Nagara Estuary Barrage V, km I I I I I I ' 1 68

77 Japan List of Maj or Water Resources Facilities Major Reservoirs Name of river Name of dam (reservoir) Catchment area [km2l Gross capacity [lov] Effective capacity [106m3] Purpose1' Year of completion Nagara Nagara Estuary Barrage F,N,W 1994 Atagi Atagi F,N ) A: Agricultural use F: Flood control W: Municipal water supply I: Industrial use N: Maintenance of normal flows P: Hydro-power 5.4 Major Major Floods Floods Date Peak discharge at Chusetsu [m3/s] Rainfall [mm] Duration Nagara River Meteorological cause Dead and missing Major damages (Districts affected) , days Typhoon No. 15 (Ise Bay Typhoon) 104 Houses completely destroyed: 3,909 Houses partly destroyed: 12,337 Houses washed away: 2,400 Houses inundated: 8, , N.A. Low pressure front and Typhoon No. 1 1 and Houses completely destroyed: 23 Houses partly destroyed: 333 Houses washed away: 2,053 Houses inundated: 6, * 210 N.A. Low pressure front 15 Houses completely destroyed: 5 Houses partly destroyed: 26 Houses washed away: 4,374 Houses inundated: 19, , days Low pressure front and Typhoon No Houses completely destroyed: 6 Houses partly destroyed: 14 Houses washed away: 11,363 Houses inundated: 30, , days Low pressure front and Typhoon No Houses completely destroyed: 240 Houses partly destroyed: 816 Houses washed away: 8,333 Houses inundated: 58, , days Low pressure front and Typhoon No Houses completely destroyed: 9 Houses partly destroyed: 22 Houses washed away: 308 Houses inundated: 3,006 69

78 Japan Groundwater and River Water Quality River Water Quality1' at Nagara-oohashi2' in 2001 Date 1/16 2/7 3/7 4/11 5/9 6/12 7/4 8/1 9/5 10/3 11/7 12/5 ph BOD [mg/l] CODMn [mg/i] SS [mg/l] Discharge3' [m3/s ) Observed once a month on a dry day normally several days after rainfall. 2) Located near Gifu City 33 km upstream from the river mouth. 3) Discharge on the water quality observation date. Socio-cultural Characteristics In the past, the area downstream from the Three Kiso Rivers was formed by flow nets of the Kiso, the Nagara and the Ibi rivers, the courses of which changed whenever the area was flooded. In 1609, early in the Edo Era, a great embankment was built on the left bank of the Kiso River, surrounding the Owari Province. This embankment, some 50 km in length, was called "the Enclosure Levee." The Enclosure Levee was intended to protect the province from floods. It also had a military role as a defensive wall against invaders from western Japan. However, restrictions with it, such as that "levees on the opposite bank in the Mino Province (Gifu Prefecture) should be 91cm lower than the Enclosure Levee," resulted in frequent flooding in Mino, and prompted the formation of "ringed land communities" in this region. The ringed land community is a communal society bounded by a levee (the ring levee), built to enclose a colony and its cultivated land entirely for the purpose of protecting them from floods. The levee was built by the inhabitants themselves, and the history of the development of ringed land communities is a history of the way in which these communities fought the ever-present threat of flooding. In the mid-edo Era (1603~1866), the Shogunate assigned a flood control work (known as the Horeki period flood control) to the Shimazu Clan, who constructed the Aburajima cofferdam and other works during only two years from During the Meiji Era, the government made an improvement plan, aiming at full diversion of the Three Kiso Rivers. Large-scale river improvement work, involving expenditure of about 12% of the contemporary national budget, was carried out for the period from 1887 to The work brought the downstream region of the Three Kiso Rivers substantially into its present form. The Meiji improvement reduced flood damage at the downstream of the Three Kiso Rivers considerably. However, the Ise Bay Typhoon, which hit the Tokai district in September 1959, damaged Gifu, Aichi and Mie prefectures severely, with fatalities numbering more than 5,000, including the missing. In August 1960, the flood resulting from the typhoons No. 11 and 12 broke the banks of the Nagara and devastated the river. In June 1961, heavy rain produced by a rainy season and by typhoon No. 6 again caused the banks to collapse, and the Nagara River flooded a vast area of Gifu City and Ogaki City. These floods, together with the flood caused by the Ise Bay Typhoon, are known as the three major flood of the Showa Era ( ). More recently the Nagara River also flooded heavily when typhoon No. 17 combined with a rain front in September A week of heavy rain caused severe damage in various regions, including the 70

79 Japan-13 collapse of the right bank in the area lying beyond Moribe in Anpachi Town, Gifu Prefecture. In order to reduce the flood risk, the Nagara Estuary Barrage has been in operation since It prevents the inflow of seawater and enables large-scale dredging of the river course to safety allow the planned high-water discharge of 7,500 m3/s to flow. Through the desalination of water upriver of the barrage, the water of the Nagara River is supplied to the inhabitants and industries of Aichi and Mie Prefectures. This helps to reduce excessive use of groundwater, which is the main cause of the ground subsidence in the Nobi Plain. On the other hand, various river environment maintenance projects have been implemented to harmonize flood control projects such as the construction of the barrage to include waterfront environments. Some of the projects are for hydrophilic bulkheads such as, Sendohira Riverside Park, the Kiso-sansen Park, and promenades at Sembon Matsubara (a riverside planted with 1,000 pine trees), created to improve the landscape. 7. References, Databooks and Bibliography Kiso River Lower Reaches Works Office, (2000): Outline of the Lower Reaches of the Kiso-sansen (brochure in English), Chubu Regional Construction Bureau, Ministry of Land, Infrastructure and Transport. Kiso River Lower Reaches Works Office, Chubu Regional Construction Bureau, Ministry of Construction and Nagara Estuary Barrage Operation and Maintenance Office, Water Resources Development Public Corporation, (1997): Information The Nagara Estuary Barrage (brochure in English). Kiso River Upper Reaches Works Office, (1992): Kiso-sansen River Flow Management with Integrated Operation of Dam Group (brochure in English), Chubu Regional Construction Bureau, Ministry of Construction. River Bureau: Uryo Nenpyo (Rainfall Yearbook), Ministry of Land, Infrastructure and Transport. River Bureau: Ryuryo Nenpyo (Stream Flow Yearbook), Ministry of Land, Infrastructure and Transport. River Bureau: Suishitsu Nenpyo (River Water Quality Yearbook), Ministry of Land, Infrastructure and Transport. 71

80 Japan-14 Natori-gawa Map of River ^ é^ Japan M iyafi Prtfcctnrt Nltort Ri\Tr Bisin Oku» R Hitos«R. Natori R. MilMKin R. Table of Basic Data Name: Natori-gawa Serial No. : Japan-14 Location: Northeast Honshu, Japan Area: 939 km^ Origin: MtKamurodake Outlet: Pacific Ocean N 38 08' ~ 38 37' E ' ~ ' Length of main stream: 55 km Highest point: Mt. Zao (Kumano-dake) (1,841 m) Lowest point: River mouth (0 m) Main geological features: volcanic rock, tuff, alluvial deposit Main tributaries: Hirose River (316 km ), Goishi River (216 km ) Main lakes: Kamafusa (39.3 x lo' m3) Main reservoirs: Kamafiisa (39.3 x low, 1970), Okura (25.0 x 10%3, 1961), Tarumizu (4.2 x low, 1977) Mean annual precipitation: 1,241.8 mm at Sendai ( ). Mean annual runoff: m3/s at Yokata ( ) Population: 429,600 Main cities: Sendai Land use: Forest (71.2%), Paddy field (16%), Cropland (3.6%), Orchard (1%), Urban of Residential area (7%), Water surface ( 1.2%) 72

81 Japan General Description The 354 km long Natori River (Natori-gawa) system, located in the northeast part of Japan, has a catchment area of 939 km. The Natori River basin consists of two main subcatchments, which are the Hirose River basin (316 km^), and the Goishi River basin (216 km ). It reaches to Yamagata prefecture. City areas spread throughout the basin. The metropolitan area of Sendai, capital city in the Tohoku district is located in the river basin. The population in the basin is about 429,600, which is 4% of the population nationwide and 42% of that in the city of Sendai. The lower Natori River basin is covered with mainly wide paddy field where there is one of the most famous rice production areas. Mountainous areas receive snow, which is an important water resource for rice plant in spring. Precipitation in the basin is widely distributed in time and space. The annual precipitation of the Hirose River basin and the Goishi River are about 1,450 mm and 1,390 mm respectively. The mean annual precipitation of the Natori River basin is about 1,680 mm. High flows occur in the Natori River during the snow meh season from March to April, the rainy season from June to July, and the typhoon season from September to October, respectively. Due to the time and space distribution of high water flows and the large storage capacity of the two main reservoirs, Kamafusa and Okura dams, the river flow conditions are more stable than other Japanese basins. 2. Geographical Information 2.1 Geological Map 1 A E ^^^^B ipv H ^ 0 IB tlumtitn ^ 1^. ^^.^ ^S^ tî^êf ^'ï to Ê^^^SW^K Lesend B Muddy sand. Coarse fragment (Alluvial deposit) H Mud, Peat. Sand (Back marsh deposit) ^ Sand, Coarse fragment (Natural levee. River terrace deosit) 1 Sand stone 1 Loam B Agglomerate tuff 1 Tuff 1 Strata! alternation of tuff and mudstone *" Andésite 1 Granitoid rock 73

82 Japan Land Use Map ^^ ^^^B ^^^^^f ^^^^^^^L ^^^^^^^^k h^^^^^^^^^k. '^^^^^^^^^^^Hk I^^^^^I^^H^Bviftn ^^^^^^^^^B^^^Kv ^^^^^^^^^^^^Hfr^V^^flkP JFiJ^v ^^^^^^^^V^^^^HHsLlL^^F ^^^^^H^h^^^^HHwut ^^#i _^^^^^^^^^^^^^^^I^^^^^^^^^^^^^E^^ V'^^^K Legend 0: Paddy field 1 : Cropland 2: Orchard 3: Mulberry field or Tea garden 4: Forest 5: Wasteland 6: Residential area 1 7: Residential area 2 8: Transportation area 9: Other land use 10: Lake 11: Riverbed 12: Riverbed 13: Seashore 14: Ocean Characteristics of River and Main Tributaries No. Name of river Length [km] Catchment area [km'] Highest peak [m] Lowest point [m] Cities Population 1 Natori (Main river) Mt. Zao 1,841 River mouth 0 Sendai (995,725) 2 Hirose (Tributary) Mt.Funakata 1,500 Confluence 0 Sendai (995,725) 3 Masuda (Tributary) Confluence 0 Natori (68,193) 4 Goishi (Tributary) Mt. Kamafiisa 385 Confluence 30 Kawasaki (11,032) 74

83 Japan Climatológica! Information 3.1 Annual Isohyetal Map 3.2 List of Meteorological Observation Stations No. Station Elevation [ml Location Observation period Mean annual precipitation [mm] Mean annual temperature [ C] Observation items" 34421" Kawasaki 200 N ' E 140" 37.9' 22 1, A 34951'* Nikkawa 264 N ' E ' 22 1, A 47590^* Sendai 39 N ' E ' 30 1, ) Serial Number used by JMA (Japan Meteorological Agency) 2) Serial Number used by WMO (World Meteorological Organization) 3) A: The AMeDAS (Automatic Meteorological Data Acquisition System) observation. The observation items are precipitation, air temperature, wind speed, wind direction and sunshine duration. M: Meteorological observation. Fourteen items including precipitation, air temperature, sunshine duration, solar radiation, wind speed, wind direction M 75

84 Japan Monthly Climate Data (Observation station: Sendai) Observation Item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature PC] Sendai Precipitation [mm] Sendai , Solar radiation [MJ/m2/d] Sendai Duration of Sunshine [hi] Sendai , Long-term Variation of Monthly Precipitation years moving average line added Sendai, Miyagi Prefecture Annual Mean : 1220mm SD : 238mm YEAR 76

85 Japan Hydrological Information 4.1 Map of Streamflow Observation Station M M plias h i ntbiira edaîni 4.2 List of Hydrological Observation Stations^' No.^' Station Location Catchment area (A) Observation period Observation items'' Yokata N ' 49" E ' 3" present Q Natoribashi N ' 4" ' 22" present Q Hirosebashi N ' 58" E ' 35" present Q No.» [m'/sl Qmax'' [m'/s] Qmax" [m'/sl Qmin'* [mvs] Q/A [m'/s/lookm^l Qmax/A [m'/s/lookm^l Period of statistics , , ) 13 water stage stations and 4 discharge stations are operated in the Natori River basin. 2} Senal Number used by Ministry of Land, Infrastructure and Transport 3) H: water level, Q: discharge, Q is obtained from rating curve. 4) Q: Mean annual discharge 5) Q max : Maximum discharge 6) Q max: Mean maximum discharge 7) Q min: Mean minimum discharge

86 Japan Long-term Variation of Monthly Discharge 120 Yokata (424.3km2) 37-month moving average added 100 ID bo u n j: ü Jan-60 Jan-65 Jan-70 Jan-75 Jan-80 Jan-85 Jan-90 Jan-95 Jan Annual Pattern of Discharge 400 o ja 300 Yokata (424.3km2) Daily in 1998 a 20 8 loo ImIJUU_ Jan- Feb- Mar- Apr- May- Jun- Jul- Aug- Sep- Oct- Nov- Dec 'S 400» 300 Yokata (424.3km2) Daily in 2000 E Ü,200 1_ I 100 Jan- Feb- Mar- Apr- May- Jun- Jul- Aug- Sep Oct- Nov- Dec

87 Japan Unique Hydrological Features The Natori River basin has two main reservoirs, which are Okura dam reservoir with a lake area of about 1.6 km2 and a storage capacity of 28 million m\ and Kamafusa dam reservoir with an area of about 3.9 km2 and storage capacity of 45.3 million m3. The catchment areas of Okura and Kamafusa are 88.5 km2 and km2 respectively. These two dams play an important role of a regulating reservoir for flood control and water supply. In case of flooding of the main Natori River, these dams are controlled to reduce the high water flow to the lower basins. Also, a headwork in the middle steam irrigates 32 km2 of paddy field. The Natori River also provides a water supply for 1 million people in Sendai city. When severe drought occurs, the users of the water in the downstream areas, the central government and related local governments convene a task force committee and coordinate measures against drought. The minimum necessary water is discharged from the two dams and the headwork for water use in the downstream areas. 4.6 Annual Maximum and Minimum Discharges At Yokata [424.3 km2l Year Maximum [m3/s] Minimum m3/s) Year Maximum [m3/s] Minimum [m3/s] Year Maximum [m3/s] Minimum [m3/sl

88 Japan Hyetographs and Hydrographs of Major Floods E 9 if IE Total rainfall 421mm Flood in September 1994 Rainfall at Sendai " /Sep /Sep. 1 24/Sep. - Time (hr) Water Resources 5.1 General Description The water of the Natori River was mainly used for agricultural water and navigation services in the past. The first water utilization canal of Natori River for irrigation was constructed in 1606 and the canal was planed and designed by domain head Tsunamoto Moniwa. Since 1597, feudal lord Date government had constructed Teizan canal from the Abukuma River to the Kitakami River, 50km, for ship transportation. This canal is the longest in Japan. In modern era, the Okura dam and the Kamafusa dam were constructed in 1961 and 1970, respectively. The first term of Natori River Water Control Work was implemented in 1954 for flood control. The second period of the work in 1962 was in response to increasing demand for water due to the development of the industrial economy. 80

89 Japan Map of Water Resource Systems Teizan Tarumizu-dam 5.3 List of Major Water Resources Facilities Major Reservoirs Name of river Name of dam (reservoir) Catchment area [km'l Gross capacity liow] Effective capacity [lo'm3] Purposes'' Year of completion Goishi Kamafusa F,N,P,W, Okura Okura F,N,A,P,W,I 1961 Masuda Tarumizu F,W,N ) A: Agricultural use F: Flood control I: índustnal use N: Maintenance of normal flows P: Hydro power W: Municipal water supply 81

90 Japan Major Floods and Droughts Major Floods Date Water Level at Natori Bridge [ml Rainfall [mm] Duration Meteorological cause Death and Missing Major damages at Sendai (11th- 15th) Typhoon "Catherine" IBF: at Sendai (15th- 17th) Typhoon "Ion" House destroy, House inundated (3,060 m3/s) 233 at Sendai (2nd - 4th) Tropical storm 6 4 House destroy, House inundated at Sendai (17th- 18th) Tropical storm House inundated at Sendai Tyhoon at Sendai (4th - 5th) Tropical storm House totally destroyed 3 IAF: 2080 IBF at Sendai (22nd - 23rd) Regional downpour House totally destroyed 7 IAF: 2080 IBF: 3139 LAF: Inundation above floor, IBF: Inundation below floor in number of houses. Major Droughts Year Season Minimum Discharge (m3/s) Water Restriction period Restriction ratio 1973 Jul. - Sep st 10/Aug. -26/Sep. 2nd 21/Aug. - 12/Sep. 80% 67% 1978 Jul. - Aug Jul Aug. - Sep May Jul. - Sep

91 Japan Groundwater and River Water Quality River Water Quality1' at Natori bridge2' in 2000 Date 1/5 2/2 3/1 4/19 5/10 6/7 7/5 8/1 9/6 10/4 11/8 12/6 ph BOD [mg/l] CODMn[mg/l] SS [mg/ Discharge3' [m3/s ) Observed once a month on a dry day normally several days afier rainfall. 2) Located near Sendai Ciry 7.4 km upstream from the river mouth. 3) Discharge on the water quality observation date. 6. Socio-cultural Characteristics The Natori River basin is located in the central of Miyage prefecture, and includes Sendai city, the capital city of the Tohoku district. Many industrial activities are concentrated in this basin. The watercourse supplies much water to Sendai Plain with a population of one million people and then flows into the Pacific Ocean. The river mouth is named as the Idoura lagoon, which supports large populations of birds, and is designated as a wildlife refuge area. Although one of the tributaries, the Hirose River is in the urban area of Sendai city, there is much nature that can be seen, including sweet fishes and singing frogs. The ministry of Environment has selected the Hirose River as one of the 100 best waters in Japan. From the era of Feudal Lord, Masamune Date, the Natori River has been indispensable for water supply and ship transportation. Teizan Unga (Canal) is the longest canal in Japan, which connects the Abukuma, Natori, Naruse, and Kitakami rivers. The Kinagashi trench was also linked between the Hirose and Natori rivers for ship transportation for timbers. The Natroi River basin will continue to be developed and support the Tohoku district as expressways and new railway systems will be constructed for upgrading of infrastructure. 7. References, Databooks and Bibliography Sendai Construction Work Office (1995): Essential, Abukuma and Natori River handbook, 203pp. Tohoku District Bureau, Ministry of Construction (1994), Flood Record, 94pp. Tohoku District Bureau, Ministry of Construction (1995), Flood Record, 92pp. Tohoku District Bureau, Ministry of Construction (1986), Flood Record, 82pp. Tohoku District Bureau, Ministry of Construction (1995), Summer drought report in 1994, 400pp. 83

92 Japan-IS Yasu-gawa Map of River Table of Basic Data Name: Yasu-gawa Location: Honshu Island, Japan Area: km^ Origin: Mount Gozaisho Outlet: Lake Biwa Serial No. : Japan- 15 N 34 50' -35" 5' E136 0'~136 30' Length of main stream: 65 km Highest point: Mt. Gozaisho (1,235 m) Lowest point: River Mouth (97 m) Main geological features: Sandstone, Plutonic granite Main tributaries: Yasu River, Soma River Main lakes: None Main reservoirs: Yasu, Ozuchi, Ohara Mean annual basin precipitation: 1,587 mm at Yasu Mean annual runoff: 570 mm at Yasu Population: 260,467 (Nov, 2003) Main cities: Otsu located just outside the basin Land use: Forest (60.7%), Paddy (17.3%), Urban 6.5 % (1997) 84

93 Japan- 15 1, General Description Yasu is the largest river flowing into Lake Biwa which is the largest fresh water lake in Japan. Yasu River has a catchment area of km^ upstream Yasu gauging point and the main channel is 65 km long. The basin is located in Shiga prefecture with a small portion protruding into Mie prefecture on Honshu island central Japan. The river has two main tributaries namely Kashiki and Ukawa draining the north eastern and south western parts of the basin respectively. The Yasu River basin is mainly covered with forest and paddy fields which have remained as the main land use classes over the last 20 years. Recent changes in land use indicate that urbanisation is growing from the lower area near Lake Biwa and more changes are occurring in the Ukawa sub catchment than in the Kashiki sub catchment. Rainfall is unevenly distributed in the basin with a clear trend for mountainous parts to receive more rainfall. The basin receives a high proportion of annual rainfall during summer and typhoon seasons depending on the location. Stations in higher ahitudes have a great proportion of the annual rainfall during typhoon season while those in the lower part of the river basin receive more rainfall during summer season controlled by the Baiyu front. 2. Geographical Information 2.1 Geological Map A Gravel alluvial fan m Sand aluvial fans edge C3ay (Did Biwa) aascjc Hmestone naate chert Sandstone/ Mudstone O quartlqo porphyry Plotoric granite 8 Kilometers J 85

94 Japan Land Use Map Landuse c=3 Paddy ^^ Agrie. Land ^^ Other land usas i Water bodies ^^ Forest ^^ Bare land unmanaged [=3 Urban ise d/builtup ^^ Main Transportation Lines ^^ Golf courses Kilometers ' ' I 2.3 Characteristics of River and Main Tributaries No. Name of river Length [km] Catchment area [km'l Highest peak [m Lowest point [m] Major Towns population Land use [%] 1 Soma River 21.6 km km^ 800 m Outlet: m Kouga & Kounan 31,841 Mixed 2 Yasu River 65.3 km km^ Mt Goizaisho 1,235 m Outlet m Tsuchiyama & Minakuchi 47,501 Mainly forest 86

95 Japan Longitudinal Prollles E ^ 800 CO Soma River Yasu River j r / ~ - - y.^^'^"^._. -""^^ ( Distance from river mouth (km) Climatological Information 3.1 Annual Isohyetal Map and Observation Stations Isohyvtil lin* ^m QRchrn«[>t bourii^ary Riier Rain gauge Kilometers ' I i 87

96 Japan List of Meteorological Observation Stations No. Station Elevation Im] Location Observation period Mean annual precipitation [mm] Observation items1' 1 Gamou 128 N 35 03' 36" E ' 36" ,409 DS, P, T, W 2 Otsu 86 N 34 59' 18" E ' 54" ,562 DS, P, T, W 3 Tsuchiyama 263 N 34 55' 42" E ' 00" ,641 DS, P, T, W 4 Hikone 87 N 35 16' 24' E ' 48' ,587 DS, P, T, W, EB 5 Shigaraki 265 N 34 54' 36" E ' 00" ,528 DS, P, T, W Source : MLIT data processed at DPRI lab Kyoto University l}ds: Duration of sunshine, P: Precipitation, T: Air temperature, W: Wind velocity and wind direction. EB: Energy balance including net radiation, air pressure, dew point, vapour pressure and relative humidity 3.3 Monthly Climate Data (Observation Station: Hikone) Observation item Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annua) Period for the mean Temperature [ C] Precipitation [mm] , Solar radiation [MJ/m2/d] Duration of sunshine [hr] ,

97 Japan Long-term Variation of Monthly Precipitation Hikone Total Monthly Rainfall 37 Month Moving Average S Tinne (month) 4. Hydrological Information 4.1 Map of Streamflow Observation Stations Yasu ^k ^ Chuugumtiashi N A ^U»K&/no/w^*^^_/l» Legend ^^^ ^P^^^^^~\,..^f^} ^" Basin boundary l.^ x^vx S""""^^ at^ River J r^jrf ij^.r-r^^j^ A Streamflow gauge ^ ^ ^ \ \^*l 3Ki;;;3^ Precipitation gauge ^W^^"ï.^\ Viî "^ Kilometers ^^^^il^' 1 t _^Ç" Ogawarßi 89

98 Japan-15 D8 4.2 List of Hydrological Observation Stations No." No Location from Station river mouth [km) Ukawa 25.0 Kashiki 26.3 Yasu River mouth [m'/s] Qmax4' [m3/s Qmax5) [m3/s] Catchment area [km2] Qmin6) [m3/s] Serial Number used by Ministry of Land, Infrastructure and Transport Q/A [m3/s/100km2] Observation Observation items2' period (frequency) 1989-present H, Q(daily) 1978~present H, Q(daily) 1975~present H, Q(hourly) Qmax/A [m3/s/100km2] Period of statistics 1978 ~ Discharge datais available on daily time step for all stations, water level datais available at hourly time step from 1975 to present (Yasu), 1976 to present at Mikumo and at daily time step from 1978 to present at Ukawa. 3> Q: Mean annual discharge. 4) Qmax ; Maximum discharge for those whole observation period. 5> Qmax: Mean maximum discharge. 6> Qmin: Mean minimum discharge. 4.3 Long-term Variation of Monthly Discharge 250 Total Monthly Rainfall m MA rihi. pm 1980 III ~?w I I I jjv M W I li A J w fn W.ÁM Time (month) I i - i w

99 Japan Annual Pattern of Discharge Yasu River at Yasu ( km2) average daily flow and flow duration curve ( ) Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Time (month) 4.5 Unique Hydrological Features The elevation in the Yasu River basin varies from 97 above sea level (masl) at the outlet (Yasu gauging station) to 1,235 on mountains located in the north eastern part of the basin (Kashiki sub catchment). Both tributaries (Kashiki and Ukawa) flow through steep terrain with average slopes of more than 1:40. In the last 50 km to the river mouth the slope fall sharply to only 1:250 and even further as it flows in the flat plains near Lake Biwa. The basin drains fast during heavy storms with maximum runoff occurring within 3 to 4 hours of the peak of the rainfall event. The spatial distribution of the mean annual rainfall shows a clear trend with elevation. Rainfall in the lower part of the basin around Lake Biwa is about 1,300 mm and increases to 1,900 mm in the upper mountainous part. Most of the rainfall occurs in summer (June-July) and in the typhoon season (August-September). Typhoon events account for a higher proportion of mean annual rainfall in the mountainous parts (Ogawara station) compared with summer rains while the lower areas receive most of the annual rainfall during the summer season. Most floods in the basin are caused by typhoon events and they originate from the Kashiki sub catchment which receives high rainfall totals during such events and has steep slopes. Yasu River is highly regulated in the lower reaches with several irrigation schemes and weirs which divert water from the natural river courses. The main use of water is for irrigation of paddy fields and water supply to towns located in the basin. The water used for irrigation of paddy fields is returned to the river through drainage channels. In general both water quality and quantity are highly influenced by artificial controls which need to be well understood for effective water resources management. 91

100 Japan-15 0 è a \ \ \ \ \ V Kumoi Yasu -._ 1600 ~ 1400 " o o> 800 nheon/prt flniu g /30/ /01/ /02/1994 Time (hr) A typical flood event caused by typhoon in the Yasu River basin and distribution of rainfall. 4.6 Annual Maximum and Minimum Discharges Station: Yasu ( km ) Year Maximum1' Date [m3/s] Minimum ' Date [m3/s[ Year Maximum1' Date [m3/s] Minimum2' Date m3/s[ , , , , , , , , , ), 2) Instantaneous observation values. 92

101 Japan Hyetograph and Hydrograph of a Major Flood Event 07/31/ /01/ /02/ X 4 Rainfall at Ogawara ^ 6 I «r 10 a 12 n n ul I LH 1 08/0B/ /04/1982 n o p w $ 1400 "g 1200 ^ 1000 a /31/ /01/ /02/ /03/ /04/1982 Time (hr) 5. Water Resources 5.1 General Description Both ground and surface water sources of the Yasu River basin are heavily utilized. Surface water diverted from the river is the main source for irrigation while the main use for ground water is for industrial and domestic supply. Ground water utilization is concentrated in the lower part of the basin and major users include beverage industries and water supply authorities for towns located in this area. The total ground water extraction load exceeds 10,000 tons per day distributed almost evenly among the different users. The river flow at Yasu is highly seasonal and may vary from almost zero flow in December-January to more that 1,000 m3/s during typhoon events in September. Thirty years of ground water monitoring indicate that some parts of the basin have tendency for declining ground water table. These are areas located away from the influence of Lake Biwa which seems to control the ground water levels in the vicinity of its shore line. Reservoirs in the basin provide only a small capacity for regulating flows. The storage is basically insufficient to augment flows and water shortages can occur during years with below average rainfall. Also, control of floods is minimal making it necessary to protect the lower reaches of the river with dikes and various river improvement schemes. 93

102 n Major ground water users in Yasu River basin User Useof Water use Depth of well Pumping rate (m3/day) Oshima Fiber Industry Co. LTD Moriyama Plant Cooling 150 3,800 Moriyama Town Agricultural uses 100 4,000 Nicchitu Acetate Company-Moriyama Plant Industrial processes 66 4,000 Kyoshin Construction Company Industrial processes 100 4,000 Ueda Fish Farm Fish farming 220 4,000 Moriyama Town Authority Domestic supply 120 4,300 South Lake (Biwa) Sewerage Department Sewerage 95 4,464 Moriyama Town Water Supply department Sewerage 150 4,700 Moriyama Town Water Supply Department Domestic Supply 100 5,000 Gunze K.K Moriyama Plant Industrial uses 90 6,336 Map of Water Resource Systems OzuchI Dkm Mírukuchi W*tar Woriw 5.3 List of Major Water Resources Facilities Major Reservoirs Name of river Name of dam (reservoir) Catchment area ]km ] Gross capacity ]10'm3] Effective capacity [10''m3] Purpose'' Year of completion Yasu Yasugawa A 1951 Yasu Ozuchi A,I,W 1987 Soma Oohara A, W 1965 "A: Agricultural use P: Hydro-power F: Flood control I: Industnal use W: Municipal water supply N: Maintenance of normal flows 94

103 Japan-15 Major Water Transfer ~i- ^ ^... ^, -"-I ::::"::;2^""'""' *!;>' Tsuchiyatn«: Town * i..--'^ ^-^..,...r- ^ ] 1 I ^ v_^ *^ 1 1 f «$uo«wa D««n r, 1 1 j 1 ^^'~-».,^^ Saya V/ Work! : 1 j i i^^^yil j j,^.pj...j...j...^..^..j..^.j. J J J f [ rf, I [ ^#^^>-. '<: x'-"^. 4 ^1 1 1 Ttwn r^'-,.^ L' ' j^ I ^ ^'*^, r IT j r \\\ I 1 ' Dzuc ni Dam. j......:.. ; ;. 1 ^fc^minakuch W /Works 1 j 1, TT!,.lili! I 1 N.- f^ :^. ^ Tsuchiyama - _^ "" Town ^^^^^imgahón ' ^ ^^^^..>^. utí j^ j^^. ] 1 _]_ l_ ^^ ^^^ ^^^^B!l ^ 1 4 4* Yasu Town ^_^ t--i.t-t-4-i- y^ ^^^^^ 1 1 ^^^^^^^..^^^ "-^. ^^m / W/ Ishib«W/ wofkij "FttTT *t r ' { 1,.., Chu7u Town ::::::: T:± 1 1 ^_ Ki^...^.-.,fm_L V. 1 ^s"^^ ^ 3hF~..M^^I^^^B ^H^ < 1! iisr 1 ^ T V««--m. ^ irnnatinn Moiiyama Town ñ Ukawa River Hi! :::íí:::::::::::::: /' _ ^,. / ^ ;:^ z 1 ^ i^k _^^^ 5.4 Major Floods and Droughts Major Floods at Yasu DATE Peak discharge [m'/s] Rainfall [mm], Duration Ogawara Minakuchi Kumoi Yasu Meteorological cause Dead and missing Major damages (Districts affected) , (36h) 203 (24h) 299 (28h) 161 (Id) Typhoon No. 1 0 N.A N.A , (12h) 125 (12h) 100 (12h) 34(12h) Typhoon No.26 N.A. N.A , (4d) 199 (Id) 164 (Id) Low pressure front N.A. N.A 95

104 Japan-15 Major Droughts Year Rainfall - Lake Biwa catchment area (mm/month) (ratio to the average monthly precipitation in %) Jul Aug Sep Oct Nov Dec Lake Biwa Lowest water mark (78) 57 (37) 98 (47) 70 (53) 45 (45) 133 (113) -95 cm Jan (154) 31 (20) 95 (45) 95 (73) 60 (60) 133 (113) -88 cm Dec (75) 86 (55) 450 (214) 168 (128) 234 (234) 128 (108) -69 cm Sept (11) 65 (42) 305 (145) 37 (28) 53 (53) 88 (75) cm Sept River Water Quality Water quality in Yasu River basin is regularly monitored. The quality parameters are generally higher as compared to rivers downstream of Lake Biwa. Water quality data at Hattori station shows that all quality parameters including BOD, COD, ph and SS are higher from May to August corresponding with high flow season. River Water Quality at Hattori in 2002 Date 1/9 2/6 3/8 4/4 5/10 6/7 7/3 8/9 9/4 10/4 11/6 12/2 ph BOD [mg/ CODMn [mg/l] SS [mg/l DO mg/l] T-P [mg/l] T-N [mg/l] Socio-cultural Characteristics The closest city to Yasu River basin is Ootsu, the capital of Shiga Prefecture. During 1960's and 1970's many industries were relocated to Shiga prefecture to utilize ample land space and abundant water resources as compared to Osaka and Kyoto cities which are comparatively crowded. As transportation improved between Shiga and the surrounding areas more people moved to Shiga preferring to live in a natural environment and commute daily to work in Osaka or Kyoto. As a result of this the population of Shiga Prefecture increased from 800,000 in 1970 to 1,500,000 in The percentage of the population employed in agricultural pursuits fell from 50% in 1950 to only 5.1% in These changes indicate a major shift in economic activities through industrialization of the area around Lake Biwa and mechanisation of agriculture. Industries attracted population to the area and provided alternative employment while the mechanisation of agriculture replaced manual labour with machines freeing people to work in other sectors of the economy. 96

105 Japan-15 The impact of these changes on water resources is mainly increased demand and pollution. Both industrial and agricultural pollutants are believed to have increased with the economic changes in the basin. Recent studies also indicate that land use changes have affected rainfall runoff relationships with an increase in flood peaks at the most down stream gauging station. The Yasu River basin is very popular for golf courses. According to 1997 land use data golf courses occupy 2.3% of the total area of the basin. The basin also is a home to the Japanese traditional ceramic sculpture industry. The improved transportation network across the basin seems to be attended with increased urbanisation in the basin following the pattern of the communication network and gradually increasing from the lower part to the upper reaches. River improvement plans in the lower part around Yasu gauging station have provided nice recreational areas suitable for picnicking. Recreational fishing can also be done in specially designated areas near Yasu gauging station. 7. References, Data books and Bibliography Lake Biwa and its watershed a review of LRBI research notes: Lake Biwa Research institute (brochure in English), Lake Biwa Research Institute,146pp. Kinki Regional Bureau: Yodogawa Hyaku-nenn-shi (History of The Yodo River for a hundred years), Ministry of Construction, 1821pp. River Bureau: Uryo nenphyo (Rainfall Yearbook), Ministry of Land, Infrastructure and Transport. River Bureau: Ryuryo nenphyo (Stream flow Yearbook), Ministry of Land, Infrastructure and Transport. River Bureau: Suisitsu nenphyo (River Water Quality Yearbook), Ministry of Land, Infrastructure and Transport. Yodo River Office: The Yodo River (brochure in English), Kinki Regional Development Bureau, Ministry of Land, Infrastructure and Transport, 10pp. Kimaro, T.A., Y. Tachikawa and K. Takara (2002): Development of a hydrological model for predicting the effects of land use changes in Yasu River basin, International symposium on Comparative Regional Hydrology and Mission for IHP Phase VI of Unesco, HP Technical Document in Hydrology No 1. pp , UNESCO Jakarta Office. Kimaro, T.A., Y. Tachikawa and K. Takara (2002): Groundwater Modelling Coupled with SVAT Model and its application to the Yasu River Basin, Annuals of Disas. Prev. Res. Inst., Kyoto Univ., No 45 B,pp Kimaro, T.A., Y. Tachikawa and K. Takara (2003): Evaluating land-use change effects on flood peaks using a distributed rainfall-runoff model in Yasu River, Japan, In Weather Radar Information and Distributed Hydrological Modelling, IAHS Publ., No 282, pp Kimaro, T.A., Y. Tachikawa and K. Takara (2003): The potential for use of ISBA land surface scheme in hydrological modelling, In Proc. of the first International conference on hydrology and water resources in Asia Pacific region, Kyoto, Japan, Vol. 1, pp Kimaro, T.A., Y. Tachikawa and K. Takara (2003):, Urbanization effects on flood flows in Yasu River basin Japan, Proceeding of the 2rd World Wide Workshop of Young Environmental Scientists, Domaine de Chèrioux Vitry Sur Seine France, pp Kimaro, T.A., Y. Tachikawa and K. Takara (2003): Land use changes and sustainable river basin management, in Proc. of International Conference on managing Water Resources under Climatic Extremes and Natural Disasters, Eds. K. Takara and T. Kojima, Sigatoka, Fiji, 27-28, Oct. 2003, IHP-VI Technical Documents in Hydrology, no. 2, Regional Steering Committee for Southeast Asia and the Pacific, UNESCO Jakarta Office, pp

106 Republic of Korea i v M - Korea-13: Banbyeon-chun \ Banbyeon-chun / Cheju-Island C? 98

107 Introduction The Korean peninsula, about 1,300 km long and 300 km wide, is located between the Yellow Sea and the East Sea on the eastern end of the Asian continent. The eastern coast line of the peninsula runs directly along the skirt of the steep mountain slope range, while the western and southern coast lines indicate curved shapes having wide alluvial plains in places. In general, rivers running to the eastern coast are short and steep in their riverbed gradients. Long stretching rivers with gentle slopes such as the Han River, the Geum River, the Nakdong River, and the Seomjin River, discharge to the southern or western coasts. Korea is in the moderately humid zone of medium latitudes. It has a definite, seasonal climate which is greatly defined by dry, cold continental air masses during the winter, and humid warm air masses from the ocean during the summer. The average annual temperature is 14 CC (57 CF) along the southern coast, while it drops to as low as 1 1 C and 8 C (52 F and 46 F), respectively, over the mid and northern climatic zones. The yearly distribution of precipitation is determined by westerly and north westerly dry winds from the Asian continent in the winter and South-easterly winds from the Pacific Ocean in the summer. Thus the rainfall is concentrated in the summer. Of the annual precipitation of 1,274 mm, approximately 66 % occur during the rainy season from June to September, 16 % during the transition period from April to May and the remaining 18 % during the six months from October to March. As of 2000, the population of Korea was 46,136,000 with a population density of 462 person/km2. Of a total land area 99,450 km2, farm lands account for 21,379 km2 while forest cover is about 63,762 km. The river catalogued in this volume is the Banbyeon-chun. The Banbyeon-chun is one of the main tributaries of the Nakdong river which flows through the north-eastern part of the Nakdong river in the Korean peninsula. The Imha Dam located in this river plays very important roles to control floods and to provide various water uses to nearby and downstream areas in the Nakdong river. Acknowledgements A working group was established for the preparation of the catalogues as part of the IHP project of 1998 which was supported by the Ministry of Construction and Transportation of the Republic of Korea. The working group members are as follows: Lee, Soontak (Chair), Yeungnam University, Jee, Hongkee, Yeungnam University, and Song, Sihoon(Assistant), Yeungnam University, The organizations that have contributed include: River Planning Division, Water Resources Bureau, Ministry of Construction and Transportation, Nakdong River Flood Control Office, Ministry of Construction and Transportation, Korea Water Resources Association, and Korea Water Resources Corporation. 99

108 Korea (R. of) -13 Banbyeon Chun Map of River Geographical Survey, MOCT Korea Table of Basic data Name(s): Banbyeon River (in Nakdong River) Serial No. : Korea (R. of) -13 Location: Kyongbuk Province, Korea E ' 09" ~ ' 05" N 36 34' 11" ~ 36 52' 42 Area: 1,932.1 km' Length of the main stream: km Origin: Mt. Ilwol( 1, m) Highest Pt.: Mt. llwol (1,218.5 m) Outlet: Nakdong River Lowest Pt. : River mouth (86.20 m) Main base rocks: Jurassic Period; Debo granite, Cretaceous Period ; Ponghwasan GP. Main tributaries: Dong stream (145.8 km^), Yongjun stream ( km^), Kilan stream (515.2 km^) Main lakes: None Main reservoirs: lmhadam(595 x 10 m, 1992) Mean annual precip. : mm (1966 ~ 1996) (basin average) Mean annual runoff: m'/sec Population: 73,679 Main cities: Chongsong, Yongyang Land use: Forest (78.2%), Rice Paddy (12.3%), Urban (1.3%), Others (8.2%) (1990) 100

109 Korea (R. of) General Description The Banbyeon River is one of the main tributaries of the Nakdong river flowing through the north eastern part of the Republic of Korea. The catchment area is 1,932.1 km2 and the river is km long, originating from Mt. llwol (1,218.5 m). The average annual precipitation is mm and the average annual runoff at Imha (1,361.0 km2) is m /sec. In 1992 the population in the basin was 73,679. Imha multiple dam having a storage volume of 595 x lo' m' was constructed in The basin consists of a relatively motmtainous area upstream and a well developed plain downstream around Imha Dam. The urban areas are Chongsong and Yongyang located in the north-eastem part of Korea. 2. Geographical Information 2.1 Geological Map LEGEND SEDLMENTARY ROCK MESOZOIC *3_ HAYANG GP (BFUCHEON GP PALEOZOIC VOLCANIC ROCK Ki JAEDOKGP PONGHWASAN GP PLUTONIC ROCK lit AMNOKGANG COMP B DAEBO GRANITE FOLIATED GRANITE NAMGANG COMP GREAT LIMESTOM GP 101

110 Korea (R. of) Land Use Map l^"^ Built-up Art«Orchard Padd> Field C^ultJvRtrd Am Kornr 2.3 Characteristics of the River and the Main Tributaries No Names of River Length Catchment Area Highest Peak Cities Population ('92) F L Land use (%) P O A U 1 Banbyeon (Main Stream) km km^ Mt. llwol 1,218.5 m Choungsong 56, Dong stream (Tributary) km km^ Mt. llwol 1,218.5 m Yongyang 16,934 3 Hawon stream (Tributary) 24.0 km km^ Mt. llwol 1,218.5 m 4 Yongjun stream (Tributary) km km^ Mt. Dalureung 743 m S Kilan stream (Tributary) 75.0 km km^ Mt. Meunbong 1,113m F: Forest L: Lake, River, marsh P: Paddy Field U: Urban O: Orchard A: Agricultural field (vegetable field, grass field) 2.4 Longitudinal Profiles 1500 E Banbyeun Stream O ih > to > Q> i-h 5C0 Kilan Stream Yongjun Stream 0 Ü 40 Ö0 30 Distance (Km) 100 \c 0 102

111 Korea (R. of) Climatological Information 3.1 Annual Isohyetal Map and Observation Stations -Ù- 1 I r\" ^ sb. «. A-^v/.-^ -'ÍU / \ S r~^y\j-< r^/ s / y\*r \ 1 i y : \ * s \ «) v jr^ ^^??^~^n >^V /( > /^ V.y >-yc' "^ní M"T, \ ^ y-> ^V V-?/ \ S \^> / "^^cfl / v Svk- v s 1) / \ u. / \ y P\ XHA^ /">-^ ^^n. ^rv'laha Dam \/"*^*' ^"*- '*"*^' Jty Sukdong»^^'^V / ;> '» u«unjv LEGED,.* X W Dam vür Andone ^i - * - Basin of Banbyeon Stream 9 Observation Station of Precipitation Based on the data of Ministry of Construction & Transportation 3.2 List of Meteorological Observation Stations No. Station Elevation (m) Location Observation period Mean annual precipitation1' (mm) Mean annual evaporation2' Observation items 210* Imdong 130 N 36 33' 50" E ' 50" ~ present P(TB) 211* Jinbo 160 N 36 31' 35" E ' 50" 1969 ~ present P(TB) 148* Hyeunseo 555 N36 15' 157" E ' 00" 1961 ~ present P(TB) 147* Kilan 120 N 36 25' 46" E ' 57" 1964 ~ present P(TB) 15** Eusung 73 N36 21' E ' 42" 1971 ~ present ,200.3 P(TB) E,DS 60** Andong N 36 33' 00" E ' 00" 1982 ~ present ,175.1 P(TB) E,DS N 36 32' 00" 63** Yongduk ~ present E ' 00" * : Serial number used by Minibtry of Construction and transportation ** : Weather Office, Korea Meteorological Agency P: Precipitation, E: Evaporation, DS: Duration of sunshine, TB: Tipping bucket with recording chart 1) Period for the mean is from the beginning of the observation period to ) Measured by 20 cm pan. 1,131.0 P(TB) E,DS 103

112 Korea (R.of) Monthly Climate Data Observation Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for The mean Temperature ( C) Eusung ~ 1990 Precipitation (mm) Eusung , ~ 1990 Evaporation (mm)* Eusung , Solar radiation (MJ/m2/day) Eusung Duration of sunshine (hr) Eusung , * measured by 20 cm pan 3.4 Long-term Variation of Monthly Precipitation Series Si Banbyeonchun at lmha(1,361km2) _ 8- ~ (30-month moving average added) Annual Mean : mm/y S D : mm/y 104

113 Korea (R.of) Hydrological Information 4.1 Map of Streamflow Observation Stations '- fr- <-f^-, ^Ç^\{ ^(\y^x % ( J V^ jr\ O Chongsong *! V/». > % ^^_ Imdong ^^«5 ~l V-^^V \ V> r^^-s. r\ // H s-*/ ^ J A/ X YongyangVj/ O Pukkye \^ / f" J i nbo y \i^js ; -,, v r * /T. Bunam X* *) y / Chongsong l ""-O J ^./J S } Vf ^r O Topyong - ^\ M Ian /'"Vu ^ / V Imha Dam /""^. f ^ líy Sukdong,y^" y If -'*^ \ > > U ;' f J Usung /^ LEGEND AnrJung ^ O : City 1 '^^m '" n- C^^ V : Dam ' ^ 0 Observation Station of Precipitation Observation Station of Discharge - * - : Basin of Banbyeon Stream 4.2 List of Hydrological Observation Stations No.* Station Location Catchment area (A) (km2) Observation Period Observation Items" 42* Kilan N 36 25' 46" E ' 57" ~ present HI 40* Yongyang N 36 39' 01" E ' 29" present HI 129* Imha N 36 31' 57" E ' 54" 1, present HI 60* Chongsong N 37 07' 28" E ' 31" present HI No. Q2) (m3/s) Qmax3' (m3/s) Qmax4' (m3/s) Qmin5' (m3/s) Q/A (V/s/lOOkm2) Qmax/A (m3/s/100km2) Period of Statistics 129* , present *: Serial number used by Ministry of Construction 1) HI: water level in recording chart, H2: water level by manual Q: discharge 2) Mean annual discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge 105

114 Korea (R. of)-13 5 D Long-term Variation of Monthly Discharge Series g) o _c u 5 & r* f & 8- o- Banbyeonchun (30 month moving average added), LjJkf, Lv* \Mkjm 1 UUnWulU/ 4flUJU m 1, al UA i 1 r i A Ü 4.4 Annual Pattern of Discharge Series 8-1 S Flow Duration Curve Year lmha(l,361km2) Annual Mean : mvs S D : m1/»..ja Im Ma uruw T 1 1 T 1 1 Banbyeonchun at lmha(1,361 Daily In Unique Hydrological Features o to < r I o- JFMAMJJASOND i 1 r A i i lv i ^ A J Month J fcjwit Km2) Banbyeonchun at lmha(1,361 Km2) 1 1 day moving average 11 Jy Hz O» 1 Uw u_l TJCpcncjt; 36.2 m3/s mVs L Q«21.5mVs.^ rv\. V^_ Month Note that Imha Dam was constructed in

115 Korea (R. of) Annual Maximum and Minimum Discharges At Imha Dam (1,361 km2) D(I Year Maximum '' Minimum2' Date (m3/s) Month (m3/s) , , , , ), 2) Instantaneous observation by recording chart Year Maximum1' Date (m3/s) , Hyetographs and Hydrographs of Major Floods ^ ^ 'OOO' QDQ _ _ pm'i i'"-'i p-... Imha 1990 September. / ^ X / \ 9/9 9/10 Time hr) "IHIIPTT ^/^-^ Imha 1993 August. 8/7 8/6 Time hr) , , , , ,042.5 Minimum ' Month (m3/s) D *O0 g> ao.o T ^ ' g> 60.0 Ü 3 BOO 3^ Based on the data of Ministry of Construction and Transportation 107

116 Korea (R. of) Water Resources 5.1 General Description The Banbyeon River with an area of 1,932.1 km2 consists of a mountainous area upstream and a plain area downstream. The agricultural and forest areas in the basin occupy about 12.3% and 78.2% of the total area respectively. The runoff in the dry season is very small even though floods often occur in the rainy season. To meet the water demand, a reservoir known as Imha was constructed. At present, almost all drinking water needs in the large cities which are located in the upstream area of the basin are supplied from the reservoir. 5.2 Map of Water Resource Systems -Ù- 'f^-, W * / \J \ Yongyang VT O Pukkye \^ / -' Jinboj y \(^-A ; -, S. f /T. Bunan >.* *1 \ f J Chongsong V \^^/l Chongsong. ^ V/ 1 ^' < --O A v- *^, """^^ Imdong y) \ ) \(? O Topyong * i<v-^a \ Kilan SS-3 f \^r \ *J~*^ * Hyensur ^ v V. \ W/'Imha y Dam /""^..' */ Y -" \ // ' M Ye- hon { / ' f" UsunK S LEGEND Andong Vi O :City W : Dam m Sangju 0. Observation station ofprecipitation *ÍÑ. a ib, : Observation station of discharge : Water supply facilities - - : Basin of Banbyeon stream 5.3 List of Major Water Resources Facilities Major Reservoirs Name of stream Name of dam Catchment Area (km2) Gross Capacity (106m3) Effective Capacity (106m3) Purposes1' Year of Completion Banbyeon (main) Imha 1, W,A, I

117 Korea (R. of)-13 Major Interbasin Transfer Name of Transfer line Names of rivers Connected From To Length (km) Maximum Capacity (m3/s) Purposes ' Year of Completion Yongchon spillway Imha Sangju W,I,A 1993 Yongchon spillway Imha Yechon W,I,A 1993 Yongchon spillway Imha Chongsong W,I,A 1993 Yongchon spillway Imha Dosan W,I,A ) W: Municipal water supply I: Industrial use A: Agricultural use. 5.4 Major Flood and Drought Experiences Major Floods (Catchment area 1,932.1 km2) Rainfall Peak (mm) Meteorological Date Discharge Duration Cause (m3/s) Period Dead And Missing Major damages (Districts affected) , Storm 19 Imdong, Imha , Storm 1 llwol, Yongyang , Storm - Hyeonsea , Storm - Jinbo, Sekbo , Storm. Kilan Major Droughts Period 1977, Jan. -Jul ~ , May - Sept _ 1995 Areas Affected Yongyang, Jinbo, Chongsong Jinbo, chongsong, Kilan Imdong, Jinbo, Chongsong Kilan, Imha, Hyensea Andong, Imdong, Imha Major damages and counteractions Damage the crops of 10% Supply cut ratio at the first stage: 10% Supply cut ratio at the first stage: 10% Damage the crops of 10% Supply cut ratio at the first stage: 25% 109

118 Korea (R. of) Groundwater and Water Quality River Water Quality" at Banbyeon stream2', 1996 Date Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ph BOD (mg/i) CODMn (mg/i) SS(mg/I) Coliform Group [Mpn/100ml]m3) 2.4xl xlo2 4.3 xlo2 4.5 xlo2 4.5X xl02 2.7xl02 1.6X xl Discharge (m3/s)4' ) Observed once a month on a dry day normally several days after rainfall. 2) Located near Andong City 14km from Imha Dam. 3) Measurement method: BGLB (brilliant green lactose bile) method. 4) Discharge on the observation date. 6. Socio-cultural Characteristics The Banbyeon River is one of the most upper reaches of Nakdong River, and is located in the north eastern part of the Korean peninsular. It contains the two cities of Chongsong gun and Yongyang gun where there are very beautiful mountainous areas with clean water and fresh air. Chongsong gun contains the Juwangsan National Park and many ancient temples, so it is one of the most famous sightseeing sites. Yongyang gun has also a very beautiful mountainous area where the natural environment is unpolluted and old villages are maintained. These two cities are the most natural regions of Kyongbuk province, famous for mineral water which has a very unique taste and hot-springs. 7. References, Data books and Bibliography Ministry of Construction, Investigation Report on the Nakdong River Basin Overall Development Project (First stage), Ministry of Construction, Investigation Report on the Nakdong River Basin (Second Stage), 1970 (in Korean). Ministry of Construction, Detailed Design Report of Wide Area of Water Supply Work for System of Imha Dam, 1985 (5.3, 5.4) (in Korean). Kim, Kwang Bae, A Study on Vulnerable Area and Disaster Characteristic of Korea, 1994 (5.4) (in Korean). Korean Meteorological Administration, Annual Climatological Report, (3.2, 3.3, 3.4, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7) (in Korean). 110

119 The Lao People's Democratic Republic Lao- 10: Nam Ngiep Lao-11: Nam Sane Lao-12: Nam Song Nam Song Kilometers IN A m

120 Introduction The Lao People's Democratic Republic is a land locked country situated in Southeast Asia, between the latitudes 13 50' 'N and the longitudes '-107o45'E with an area of 236,800 km2. The axis of the country is in the Northwest-Southwest direction with a length of more than 1,700 km. In the East-West direction the distance varies between km. The country is bordered on the North with China along 416 km, on the Northwest with Myanmar along 230 km, on the West with Thailand along 1,730 km, on the East with Vietnam along 1,957 km and on the South with Cambodia along 492 km. The topography is closely related to the geology with watershed highlands of granites and metamorphic rocks, draining down to Jurassic, cretaceous Indonesian sandstone and shale, and finally over piedmont slopes to low flat land with fertile flood plains embracing about 30% of the land along the Mekong River. The forest cover varies from 22% to 70%. The climate is tropical monsoon with two distinct seasons: the wet season from mid-april to mid-october and the dry season from November to March. The average annual precipitation is 1,950 mm with a large variation from 1,300 mm in the northern valleys to 3,500 mm in the southern plateau. The annual runoff is about 600 mm/year or 142 km /year. The population estimated in 2001 is about millions with a even distribution of females and males. Population density is 23 persons/km2 and the growth rate is about 2.6% per year. The three rivers catalogued in this volume are the Nam Ngiep and the Nam Sane which are tributaries of the Mekong River in Bolikhamxay Province, and the Nam Song which is an important tributary of the Nam Lik in the Vangvieng district of Vientiane Province. The Nam Ngiep and the Nam Sane are the medium size of river basins ranging from 2,220 to 4,270 km2 and have high forest coverage from 51%-60%. The Nam Song, the smallest among the three basins with a catchment area of 864 km2 at the Vangvieng gauging station, has a forest coverage about 40%. The total catchment area of the Nam Song at the confluent with the Nam Lik at Hineheup is about 1,770 km2. Between Vangvieng and its outlet near Hineheup there are two important resources development projects: the Nam Mone irrigation project and the Nam Song diversion weir at Ban Vangkhi. Both are completed in Acknowledgements A sub-committee was constituted within the Department of Meteorology and Hydrology for the preparation of these three rivers. Thanks are also for the following organizations: Department of Geography and Geology and Mines of Lao PDR for utilization of their maps as baselines for the preparation the catalogues. - MRC'S for forest cover map and the hydrological yearbooks available until

121 Lao-lO Nam Ngiep Map of River (^^^^^^ Biuln «f Nim Müíp kliw m 10 >o ** _» Table of Basic Data Name: Nam Ngiep Serial No. : Lao-10 Location: Phonsavan, Xiengkhuang N 18 28' ' E ' ' Area: 4,270 km Length of the main stream: 156 km Origin: Xiengkhuang plateau Highest Pt: Phoubia,2,819m Outlet: Mekong River (Paksane) Lowest Pt: 161m (Muang Mai) Main base rocks: upper basin: triassic-permian; lower: cretaceous and carboniferous Main tributaries: Nam Siam ( 1 20 km2). Nam Chian ( 124 km2) Main lakes: None Main reservoirs: None Mean annual precipitation: 2,736.0 mm (basin average rainfall) Mean annual runoff: m/s Population: 58,279 (2002) Main cities: Muang Mai, Thavieng, Phonesavan Land use: Forest (51.0), Paddy (23.0), Urban (5.0), Agriculture (15.0), Lake, river, marsh (1.5), Other (4.5) 113

122 ! intercalated Lao General Description Nam Ngiep is a local name meaning quiet river. It originates from Phonesavan in Xiengkhuang plateau with an altitude of 1,050 m above mean sea level, flows in a southerly direction to meet an important tributary called Nam Siam near Ban XiangKhong and changes to the southeast direction to meet another tributary, Nam Chian. From this point to the outlet near Paksan, the river flows southerly for a distance of about 95 km. The length of Nam Ngiep is 1 56 km and the catchment area at Muang Mai gauging station is 4,270 km2. It is located within 18 28' to I9 25' N and ' to ' E. The annual average basin rainfall is 2,736 mm with nearly 90% occurring in the rainy season from May- September. The source of the Nam Ngiep is the most densely populated areas, severely deforested, with important agricultural developments on gentle slopes and with an important extension of the communication system. As a result, most of the small tributaries in the upper watershed cannot contribute an important grown water discharge of the perennial flow in dry season. 2. Geographical Information 2.1 Geological Map Mofttly red contuwntbl wrvjston««vid days, with lagoan&l mudroocs in tha uppar Mvels Manng evaponte units or halita and oypsum Uostfy continantaj sequonca wrih local water manna faciei persistirg from Upper Palaeozoic. Continvntal red dayey renrtdb with occasional thin coal seams ai>d conglomerates. Mídale Triassic manne hmestone units occur al tn» Oase ot this interval interbedded witn days in NE and NW Manna LiBssic in SE Cartraniferous Shallow shell sea sequenca mterdigitated with a volcanosedimeniaryiequence. Mostly sandstone. siniitone and shale In the N and NW Some silicic, intermediate and matic extrusive rocks (v) assooated with subvolcanic intrusive centres Bedded to massive dark grey (o light grey manne Hmeston» (c) form e:(tenaive karst tracts in N ana. and in the E are wiin siltstona mudstone and some coal seams, Epidastic rocks predominate over limestone m the W ana S. I MoBlV/ snahow sea sequence o( muddy Inriestone \z) Some I continental CartioniferoLis m Vientiane basin I Salaven S Central) and Phongsali Devonian(N) 2.2 Land Use Map LEGEND Cropping Urban Mixed, Continuous cover Evergreen Continuous cover Agricultural land Water bodies 114

123 Lao-10 (E 2.3 Characteristics of the River and Main Tributaries No Name of River Nam Ngiep (Main river) Nam Siam (Tributary) Nam Chian (Tributary) Paksane (Lower branch) Length [km] Catchment area [km2] 156 4, Cities Highest peak [m] Population Lowest point [m] (year) Phoubia 2,819 15,000 Paksane 157 Phouphaxai 2,100 Muang Phaxai 600 4,000 Phouxao 2,590 Ban Nongnguak 500 1, Paksane 157 F: Forest; L: Lake, nver, marsh; P: Paddy field; U: Urban; O: Orchard; A: Agricultural field {vegetable field, grass field) 2.4 Longitudinal Profiles 1200 t n ^^ m0tm^9^^^^^nxao Nam Siam / / Nam Chian / if Nam Phouan^r ^^^ J /Nam Ngiep Land use [%] F (51.0) P (23.0) U (5.0) A (15.0) L(1.5) 0 (4.5) Distance from the confluent point with the Mekong (Km) 115

124 Lao Climatological Information 3.1 Annual Isohyetal Map and Observation Stations LEGEND A -^ Hydrologie Station RAinfal SlJAon Mattorotogical Stcbon Ajintjfli Iftohyiti (minj (g) PAKSANE 3.2 List of Meteorological Observation Stations No. Station Elevation [m] Location Observation period.mean annual precipitation [mm] Mean annual evaporation [mm] Observation items'' 1 Xiengkhuang (Phonesavan) 1,050 N19 28' E ' , ,240.4 (pich) P, T, E, S, Wind 2 Tha thorn 600 N 19 00' E ' , P 3 Muang Mai 161 N18 30' E ' , P 4 Paksane 157 N18 24' E ' , ,759.7 (PAN) P, T, E, S, Wind I) P: Precipitation T: Temperature E: Evaporation S: Solar radiation W: Wind 116

125 Lao Monthly Climate Data Observation station: Paksan Observation item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Paksan Precipitation [mm] Paksan U , Evaporation [mm] Paksan , Solar radiation [MJ/m2/d] Paksan Duration of sunshine [hr] Paksan , Long-term Variation of Monthly Precipitation Monthly Discharge of Nam Ngiep M. May(4,270 km2) Mein. 1866m>,s S.D : 48.7 m3/s Monthly Discharge 37-month moving average added Year 117

126 Lao Hydrological Information 4.1 Map of Stream flow Observation Stations A HydTDtogic SKüon # RiinfsN Ststioo MMHrotegical Stabon 4.2 List of Hydrological Observation Stations No.* Station Location Catchment area (A) [km2] Observation period Observation items (frequency) 1 Muang Mai N 18 30' 03" E ' 07" 4, H, Q = f(h) No.* Q2' [m'/s] Qmax" ImVs] Qmax'' [m'/s] Qmin" [m'/s] Q/A [mvs/lookm2] Qmax/A [m'/s/100km2l Period of statistics , , ) Q: Discharge and water level (daily) 2) Mean annual discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge * Muang Mai, serial number used by MRC is

127 Lao Long-term Variation of Monthly Discharge 1000 Monthly Discharge of Nam Ngiep M. May(4,270 km2) 900 Mean : mvs S.D :4B.7mVs J? 600 " " E> 600 eg c o </> 400 a 300 Monthly Discharge 37-month moving aver age added \ / Ï n eoeioi-cmcj^ioto cococnoigjotcnaia) O)O)O)O)0)O>O)O)O> \j \ Year Annual Pattern of Discharge 2000 Nam Ngiep at Muang Mai ( 4,270 km ), O tfí a Qave = m/s 35* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month 119

128 Lao Unique Hydrological Features Monthly mean discharge of Nam Ngiep at M.Mai (4,270 km1) Mean f\ --Mean / \v J? J o J= U) «=- T II,...,. ^ ^ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Month Dec 4.6 Annual Maximum and Minimum Discharges Station: Muang Mai [4,270km2 Year Maximum Discharge Date [m3/s Minimum Discharge Month Im3/s] Year Maximum Discharge Date [m3/s] Minimum Discharge Month [m3/s] Aug Dec Jul 1, Feb Jul 1, April Jul April Jul 1, April Sep March Jul 1, April Sep 1, March Aug May Aug 1, April Jul May Aug 1, April Jul 1, April Sum = 16, Aug 1, March Mean = 1, Aug 1, April Aug 1, April

129 Lao Hyetographs and Hydrographs of Major Floods " 1000 S 850 en 700 j 550 Q I'l 1 - " CD CD O) CD CD CD 3 3 «Ç «f t- CO 1 1 CD CD o> O) CD CD 3 3 *F "f m h- 1 i H' CD CD CD CD (35 CD CD CD CD CD CD CD *f 5 CO t- «f *F co in "1 1 IBg CD 3 < t- III II CD CD CD Ol CD 3 «f O) II CD CD O) O) CD 3) 3 3 *F «f T- CO CM CM 1 CD CD CD 3 <: CM 1 CD CD CD CD CD CD 3 3 ** *r r- CD CM CM ': 20 ;4o 2" : 60 T : : 100 a '- 120 ~ ^ 140 CD CD CD 3 < CO 5. Water Resources 5.1 General Description People living in the lower reaches of Nam Ngiep are waiting for dam construction in the Nam Ngiep River basin to provide hydropower. However, the problem is not crucial because actually most of the people can use electricity from the Nam Ngum and Nam Leuk projects. There are many pumping stations for irrigation. The main water resources for most families is the exploitation of aquatic animals from a permanent wetland, small size but the lake never dries up. Nong Nia is a wetland type as a permanent lake, marsh with floating vegetation, mats with a size of 800 m times 150 m surrounded by areas of boggy marshland. The maximum depth is about 2 m. On the northern and western sides of the lake there are forests. The northern side is a provincial protected area. The location is only 9 km northwest of Paksane. Natural products derived from the wetland such as fish, reptiles and amphibians, can provide protein sources almost every day for the people. The government has therefore proposed the wetland as a reserve. 5.2 Major Floods and Droughts Major Floods at Muang Mai Date Peak Discharge m3/s] Rainfall [mm] Duration Meteorological Cause Dead and missing Major damages (Districts affected) 7-Aug 95 1, mm (1-10 Aug) Monsoon - 5,300 ha (flooded area) 3,000,000 USD 1-Aug 96 1, mm Monsoon - 3,000 ha (flooded area) 2,000,000 USD 121

130 Lao-10 Major Droughts Period 1998/1999 Affected areas 9,000 ha Major damages and counteractions Major damages are counteraction: rice culture and forest fires in dry season 5.3 Groundwater and River Quality River Water Quality at Paksane Date Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ph 7.2 (91) 7.4 (91) 7.5 (91) 7.7 (91) 7.5 (91) 7.4 (91) 6.0 (90) 6.4 (90) 5.5 (90) 5.1 (90) 6.2 (90) 5.0 (90) CODmo [mg/l] 1.8 (91) 1.5 (91) 1.3 (91) 1.0 (91) 1.5 (91) 0.2 (90) 0.2 (90) 0.2 (90) 0.2 (90) 0.2 (90) 1.5 (90) 2.2 (90) 6. Socio-cultural Characteristics In the upper Nam Ngiep, the ethnic group is called Phouane; Mong highlander shining cultivation is the traditional lifestyle. This form of agriculture affects the natural environment and the habitats of rare species change to land use and traditional agricultural practice is still difficult. People living in the plateau celebrate their lunar New Year. In the lower reach of Nam Ngiep the situation is different. The main ethnic group is Lao Lum who are mostly Buddhist and celebrate annual festivities such as the racing boats. 7. References, Data books and Bibliography - National Geographic Department: all scale maps since Department of Geology and Mines: 1 : 1,000,000 scale map MRC hydrologie year books available until 1998 and additional data from IUCN, The World Conservation Union: Inventory of wetlands in Lao PDR,

131 Lao-ll Nam Sane Map of River ^V-P^ Table of Basic Data Name: Nam Sane Serial No. : Lao-1 1 Location: Bolikharaxay Province, Lao Nig- 16' ' E ' ' Area: 2,230 km Length of the main stream: 120 km Origin: PiemondofPhousamsoum Outlet: Mekong river (Paksane) Highest Pt: Phousamsoum, 2,620 m Lowest Pt: Muang Kao, 160 m Main base rocks: upper basin: Cretaceous-Triassic; Middle: Caboniferous; Lower: Cretaceous, Triassic Main tributaries: Nam Phat (76 km ), Nam Lat (55 km ) Main lakes: None Main reservoirs: None Mean annual precipitation: 2,849 mm (basin average) Mean annual runoff: m7s at Muang Kao, Bolikhan ( ) Population: 21,324(2002) Main cities: Muang Kao, Province capital Land use: Forest (60.0), Paddy (24.0), Urban (3.0), Agriculture (8.0), Lake, river, marsh (2.0), Other (3.0) 123

132 Lao-ll 1. General Description Nam Sane, locally known as steep river, originates fi-om the piemond of Phou SamSoum 2,620 m, flows to the west-northwest through a group of villages around Ban Phouviang. It then flows down in the southwest to Ban Thathom, and continues to the southeast to the confluence with Nam Lat at 300 m altitude and finally to the south-southwest to meet the Mekong at Paksan. The river is 120 km long with a catchment area of 2,230 Km at Muang Kao, Bolikhan and lies within 18 33' N ' N and ' E ' E. Annual average basin rainfall is 2,849 mm and annual runoff at Muang Kao is m'/s. According to the Integrated Resources Center in Watersheds of the Lao P D R the following 5 classes of hydro-geology occur in the upper Nam Sane 2 and the lower Nam Sane 1. Sandy alluvium 56.6% for Nam Sane 1 and 4.2% for Nam Sane 2; Sandstone and conglomerate 4.0% for Nam Sane 1 and 23.5% for Nam Sane 2; Gneiss, Schist, Quartzite, Granite, Gab 3.8% for Nam Sane 1 and 62.5% for Nam Sane 2; Shale and impermeable rocks 0% for Nam Sane 1 and 7.6% for Nam Sane 2; various 35.6% for Nam Sane 1 and 3.3% for Nam Sane 2. PA ME 2. Geographical Information 2.1 Geological Map Cretaceous Jurassic Tnassic Permian Carboniferaus Devonian ^ :3 2 1 S ^ ^ ^ Mostly red continental sandstones and days, with lagoonal mudrocks in the upper levels beanng evaponle units of halite and gypsum Mostly continental sequence with local water manne faciès persisbng from Upper Palaeozoic Continental red dayey arenites with occasional thin coal seams and conglomerates. Middle Tnassic manne limestone units occur at the base of this interval mterbedded witu days In NE and NW Manne Liassic in SE. Shallow shell sea sequence inlerdigitated with a volca nosedimentary sequence. Mostly sandstone, siltstone. and shale in the N and NW. Some silioc, intemiediate and mafic extrusive rocks (v) essoaated with subvolcan ic intrusive centres. Bedded to massive dark grey to light grey manne limestone (c) cti, ' intercalated with siltstone. mudstone and some coal seams Epidastic rocks predominate over limestone in the W and S. ^^^H Mostly shallow sea sequence of muddy limestone (c). Some ^^^H continental Cartoniferous in Vientiane basin. ^^m 2.2 Land Use Map LEGEND Cropping Urban Mixed, Continuous cover Evergreen Continuous cover Agricultural land Water bodies 124

133 Lao-ll i(l 2.3 Characteristics of the River and Main Tributaries No Name of River Nam Sane (Mainstream) Nam Phat (Tributary) Nam Lat (Tributary) Nam Sane (Lower branch) Length [km] Catchment area [km2] 120 2, Highest peak [m] Lowest point [m] Phousamsoum 2,620 Paksane, 157 m Pousamsoum 2, Cities Population Land use1' (year) [%1 Muang Kao F (60.0) 11,636 P (24.0) Ban Thasana 3,000 U(3.0) - Paksane F: Forest; L: Lake, river, marsh; P: Paddy field; U: Urban; O: Orchard; A: Agricultural field (vegetable field, grass field) 2.4 ULI Longitudinal Profiles 900 -, Nam Phat Nam Mang / / NamHeuang / / / / / / iy I v^. Nam Lat / / Name Sane A (8.0) L (2.0) 0 (3.0) Distance from the confluent point with the Mekong (km) 125

134 Lao-ll 3. Climatological Information 3.1 Annual Isohyetal Map and Observation Stations LEGEND Meteorological Station Observation Station of Precipitation Observation Station of Discharge Annual Isohyet (mm) Basin Boundary Extended Basin Boundary River KM 3.2 List of Meteorological Observation Stations No. Station Elevation [m] Location Observation period Mean annual precipitation [mm] Mean annual evaporation [mm] Observation items 1 Thathom 510 N 19 00' E ' , P 2 Muang Kao (Bolikhan) 160 N18 34' E ' , P 3 Paksane 157 N18 24' E ' , ,759.7 (PAN) P, T, E, S, Wind 1) P: Precipitation T: Temperature E: Evaporation S: Solar radiation W: Wind 126

135 Lao-ll 3.3 Monthly Climate Data Observing station: Paksane Observation item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Paksane Precipitation [mm] Paksane , Evaporation [mm] Paksane , Solar radiation [J/m2/d] Paksane , Duration of sunshine [hr] Paksane , Long-term Variation of Monthly Precipitation Monthly Precipitation of M. Kao Station (2,230 km2) Annual mean : mm/y S.D : 492.2mm/y -Monthly Precipitation Year 127

136 Lao-ll 4. Hydrological Information 4.1 Map of Stream flow Observation Stations 0 A k k LEGEND Meteorological Station Observation Station of Precipitation Observation Station of Discharge Basin Boundary Extended Basin Boundary River j^ \p( r ' Â ^\f^z VÍ ^Cv i \ N Miibt iojäorkhal ^ K \ PAMA -S} mmà KM 4.2 List of Hydrological Observation Stations No.* Station Location Catchment area (A) [km2] Observation period. Observation items (frequency) 1 Muang Kao N 18 33' 07" E ' 02" 2, H, Q = f (H) No.* Q2) [m3/s Qmax" [m3/s] Qmax4' [m'/s] QminS) [m'/s] Q/A [m3/s/100km2] Qmax/A ImJ/s/100km2] Period of statistics , , ) Daily water level and discharge 2) Mean annual discharge 3) Maximum discharge * Muang Kao, serial number used by MRCis } Mean maximum discharge 5) Mean minimum discharge 128

137 _ I Lao-ll U 119 D 4.3 Long-term Variation of Monthly Discharge -Í U Ol Monthly Discharge of Nam Sane M, BOO i ' Monthly Discharge f "^~37-month moving average added I k t\ A n JlJUUUuf\ y / +-r1-fr M V VJ VJ VJ \/u u \j vj Year Kao(2,230 km2) Mean : m Jis S.D : 33.8 m'/s n I) \.A 1 TO m rw I U VJ VJ \J u VJ v 4.4 Annual Pattern of Discharge Dally Discharge of Nam Sane at Muang Kao (2, 230 km2), 1996 Qave = 1519 m'/s JÏÏ E Q an Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month 129

138 Lao-ll D 4.5 *ír> c? Uniq ue Hydrological Features i Monthly mean discharge of Nam Sane at M. Kao(2,230 - Mean( *^ \ \ 1994) // \ \ - Mean(1995) // \ \ km2) Jan Feb Mar Apr May Jun Jul Aug Sep Oc Month Nov Dec 4.6 Annual Maximum and Minimum Discharges At Muang Kao [2,230 kin ] Year Maximum Discharge Date [m3/s] Minimum Discharge Month [m3/s] Year Maximum Discharge Date [m3/s] Minimum Discharge Month [m3/s] Aug Dec Aug 1, May Aug March Aug 1, March Sep April Aug 1, March Jun 1, April Jul March Jul 1, May Jun March Jul May Sep 1, April Jul 1, April Sep 1, April Aug 1, March Aug 1, March Sum = 18, Mean = 1,

139 Lao-ll is ar 4.7 Hyetographs and Hydrographie of Major Floods 'tfí' % 0) Q <o to oóz O) ) O) 3 < _ 1 \ : < có H to to CO O) Ó) <. <f m h- li to O) Ó) 3 < d> II to Ol en d < U 1 1 CD CO Ol O) D> Ö) 3 3 "í í co ir> s \ V \ to to O) O) ó) n 3 3 < <p 1 O) V to O) 6) 3 < 1 J A /^ i i i < < < cô IT) hl- CN CM CM CM B 1 ^ 15 1 to to O) O) en D) 3 3 < < CM CO ç 0 f 30 ': 45 ^ 60 \ 75 I 90 I 105 '- 120» to 3" 5? Q. < Water Resources 5.1 General Description In Bolikhamxay Province there are 4-5 wetlands. Nam Kadan wetland site is located about 4-5 km from Nam Sane and approximately 15 km directly east of Paksane, the provincial capital. The total area of the Nam Kadan basin is 82 km2 of which 51 km2 has an elevation below 160 m, the lowest area is 140 m above seal level. Around Nongveng (lake) which is 1.7 m deep in the wet season, there are about ten small Nong with some remaining water. The wetland area is a mosaic of shrubland, grassland and degraded monsoon forest. The most common fish are: pakhoh, padouk, pasium, pakhao, panai, pakeng, and pakot (in wet season). Other aquatic animals are: shrimp (koung) craps (pou), and gastropod snails (hoicheup). Frogs are caught using traps and also setline baited with earthworms. People say that the fish harvest has decreased in the recent years because of population increase and ulcerative fish disease (appeared in mid 1980). 5.2 List of Major Water Resources Facilities Major Reservoir: None Major Interbasin Transfer The study on small scale agricultural and rural development program conducted by J1CA in 1998/1999 has selected two pilot model areas in Bolikhamxay Province; Ban Don in Bolikhan district and Ban Thana in Paksane area, located on the road No 13 about 13 km South of Paksane city. Detailed information of these two villages is as below: Ban Don grouping with 3 villages (Ban Don, Phonekharm, Nahern in Bolikhan district), high demand of the beneficiaries; farmers seeking irrigation development with a size ha and water resource management at the micro basin level with an irrigation system consisting of a pump scheme taking the water from Nam Sane River. In terms of basin water resource management there is no major problem except with flood hazard in wet season. Main activity of the communal organization is the construction of a canal by villagers of all 3 villages. Main problems: poverty low-income lack of irrigated land. 131

140 Lao-ll Ban Thana in Paksane district also has high demand of beneficiaries (farmers) for irrigation development of ha. Flood hazard in the wet season is high. Main activities: improve and extend irrigation canal and structures and improve water management in the service area. As Ban Thana is selected for feasibility area more details are given: village history, year of establishment around 1798, number of households: 80, total population 462, land area: 405 ha. Water supply and sanitation: public well: 7, private dug well: 26. Poverty is considered to be average. 5.3 Major Floods and Droughts Major Floods Date Peak Discharge [m3/s Rainfall [mm] Duration Meteorological cause Dead and missing Major damages (Districts affected) 7-Aug 95 1, mm 31/7-7/8 Monsoon - 5,600 ha (flooded area) 3,200,000 USD 1- Aug 96 1, mm Aug Monsoon - 2,566 ha (flooded area) 1,500,000 USD Major Droughts Period 1998/1999 (Jul/Aug) Affected areas 15,570 ha Major damages and counteractions Rice culture and forest fires in February 5.4 Groundwater and River Quality River Water Quality Date Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ph 7.2 (91) 7.4 (91) 7.5 (91) 7.7 (91) 7.5 (91) 7.4 (91) 6.0 (90) 6.4 (90) 5.5 (90) 5.1 (90) 6.2 (90) 5.0 (90) CODMn [mg/l] 1.8 (91) 1.5 (91) 1.3 (91) 1.0 (91) 1.5 (91) 0.2 (90) 0.2 (90) 0.2 (90) 0.2 (90) 0.2 (90) 1.5 (90) 2.2 (90) 132

141 Lao-ll 6. Socio-cultural Characteristics In the Nam Sane basin the main ethnic group is Lao Lum Yo, particularly in the lower reach (Bolikhan and Paksane districts), where the villagers practise farming with about 51% directly involved in agricultural production and the main religion is Buddism. The annual festivities in water along Nam Sane are the racing boats as practiced by most people in the other plain areas of the major tributaries. A speciality of the people living in the plain areas between Paksane- Pakhinboun is the seasonal prediction of floods from traditional methods. To meet their needs for long-term forecasts for agricultural decisions, villagers have traditional methods of flood forecasting using observations of natural phenomena of which the most popular is to observe stripes on the tails of a young land iguana. If the dark bands are wider than the white bands there will be more rain in that year. Some fruit, such as Mak Khor, if heavy bearing means heavy rain and floods. 7. References, Databooks and Bibliography - National Geographic Department: all scale maps since Department of Geology and Mines: 1 : 1,000,000 scale map MRC hydrologie year books available until 1998 and additional data from IUCN, The World Conservation Union: Inventory of wetlands in Lao PDR, JICA, The study on small scale agricultural and rural development program along the Mekong river in Lao PDR, July

142 Lao-12 Nam Song Map of River ui V ltf N - lu.^^. ^ Bttaittof Nimm Soik^ Ri^vr tfifiaim^. to 10 jg Table of Basic Data Name: Nam Song Serial No. : Lao-12 Location: Vangvieng District N 18 55' 24" ' 00" E ' Area: 864 km Length of the main stream: 36 km Origin: Phoukeo (1,012 m) Highest Pt: PhouNamsang (1,992 m) Outlet: Near Hineheup (Nam Lik) Lowest Pt: 296 m (Vangvieng) Main base rocks: Permian and Carboniferous predominance Main tributaries: Nam Ssnen (35 km ), Nam Pamom (24 km^) Main lakes: None Main reservoirs: Nam Song Diversion weir (divert from Nam Song to Nam Ngum reservoir up to 210 m /s) Mean annual precipitation: 2,481 mm (Basin average) Mean annual runoff: m7s at Vangving ( ) Population: 40,000 persons (2002) Main cities: Vangvieng, Phatang Land use: Forest (40.0), Urban (8.0), Paddy (25.0), Lake, river, marsh ( 1.0), Upland (20.0), Other (6.0) 134

143 1 ^^^^1 Lao General Description The Nam Song originates from Phoukeo at an elevation 1,012 m and flows to the west to Phatang for a distance of about 1 7km and then flows straight to south of Vangvieng. From the south of Vangvieng to the confluence with Nam Lik at Hineheup, the river meanders along a narrow valley. The length of Nam Song to Vangvieng is about 36 km of the total length of 80 km. The catchment area at Vangvieng is 864 km^ of the total area of 1,770 kml The basin is located between 18 55'24"N 'N and I02 15'E 'E. The highest point is Phou Namsang at 1,992 m on the eastern border with the Nam Ngimi basin about 6 km from Phou Miang at an elevation of 2,455 m. Due to the topographic effect, Vangvieng (296 m) receives an average of 3,330 mm of rainfall annually. The basin annual average is about 2,481 mm/year. The annual run-off at Vangvieng is mvs ( ). The Nam Song basin is the most populated basin compared with the surroundings due to rapid development, tirbanization and tourism attraction by Vangvieng Resort extension industrial area from cement factory, the first and big one in Laos. The water law was set up to anticipate population and economic development pressures against limited water supply and to promote conjunctive water management. With rapid growth of population, the problem of water availability becomes crucial during the dry season coupled with high sediment transport during the rainy season. At present there are no serious problems concerning water utilization between upstream and downstream areas. PA MLS 2. Geographical Information 2.1 Geological Map Cretacaous Jurassic Tnassic PerTT>iBn Carboniferous 0..o,. 2 ^^^^H Mostly red continental sandstones and days with legoonal mudmcks m ttia uooet levels beanna evhdonia units of haliia and gypsum. J JUJJ I fcnnh, SIMB Mostly continental sequence with local water manne faoea 3 ^^^^H arenites with occasional thin coal seams stki conglomerates. ^^^^1 MidOle Triasse manne limestone unin occur at the base of J ^^^^1 this intenral intertmdded with clays in NE and NW Manne ^^^^H Uassic SE 1 Mt^ Shallow shell sea sequence inierdigitated with a 2 ^Bklglj Mostly sandstone siltstone and shale in Die N and NW ^^^^1 Some silicic mterniediete and matic axtmsive rocks (v) ~ ^^^^H associated with subvolcanic intnjsive centres 1 ^^^^H Bedded to massive dani grey to iighi grey manne limestone c) \ fm^ intercalated with siltstone. mudsione and some coai seams 1 j Epidastic RKlis predominate over limestone m the W and S. ^^H^H Mostly shallow sea sequence o( muddy limestone (c) Some ^^^^H continental CarboniTemus in Vientiane basin ''^^^ 135

144 Lao Land U$e Map re LEGEND Cropping Urban My, Mixed, Continuous cover Evergreen Continuous cover Agricultural land Water bodies 2,3 Characteristics of the River and Main Tributaries No Name of River Nam Song (Main river) Nam Sanen (Tributary) Nam Pamom (Tributary) Nam Song (Lower branch) F: Forest: U: Urban Length [km] Catchment area [km'l Longitudinal Profiles 'S 900 n J i Highest peak [m] Lowest point [m] 1, , , Nam Sanen Nam Song ^ 1 / Nam Pamom / / / y.^y-" ( Distance from the confluence (km) Cities Population (year) Vangvieng - Phatang Vangkhy, Hineheup Land use [%1 F (40) U(8.0) 136

145 Lao Climatological Information 3.1 Annua] Isohyetal Map and Observation Stations LEGEND Meteorological Station Rainfall Station Hydrologie Station Annual Isohyet (mm) Basin Boundary River 3.2 List of Meteorological Observation Stations Elevation No. Station Location [ml 1 N 19 08' 00" Phatang 340 E ' 00" Observation period Mean annual Mean annual precipitation evaporation [mm] [mm] 2, Observation items1' 1 Vangvieng 296 N 18 56' 00" E " cu 3, ,472.0 P 3 Hineheup 200 N 18 48' 00" E ' 00" , P 1)P: Precipitation 137

146 Lao Monthly Climate Data Observation station: Vangvieng Observation item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Vangvieng , Precipitation [mm] Vangvieng , , Evaporation [mm] Vangvieng , , Solar radiation [MJ/m!/d] Vangvieng , Duration of sunshine [hr] Vangvieng , Long-term Variation of Monthly Precipitation Monthly Precipitation at Vangvieng(864 km2) -Monthly Precipitation 37 month moving average added Annual mean : mm/y S.D : mm/y 138

147 Lao Hydrological Information 4.1 Map of Stream flow Observation Stations L- Nam Songr-^ 1 fi v 1990 m rpv-0^ H km 5 j Nam Nov' E 10 t> \ m J 1 2 y^song 1 -y'v 1736 m I J/angy/eng/ x^ -^-^Xem ") km VfrigWii LEGEND Meteorological Station Rainfall Station a Hydrologie Station 4.2 List of Hydrological Observation Stations No. Station Location Catchment area (A) [km ] Observation period Observation items (frequency)1' 1 Vangvieng N 18 54' 24" E ' 54" H, Q 3 times/day 1 Vangvieng N 18 54' 24" E ' 54" H. two - five Reading/day 2 Vangkhi N 18 46' 00" E ' 00" 1, H, Q (daily) 139

148 Lao-12 No. Q2) [m3/sl Qmax3' [m3/s Qmax [m'/s] Qmin4) [m3/s Q/A m3/s/100km2] Qmax/A lm3/s/100km2] Period of statistics ) Daily water level and discharge 2) Mean annual discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge 4.3 Long-term Variation of Monthly Discharge Monthly Discharge of Nam Song Vangvieng(864 km ) Mean : 47.8 m3/s Monthly Discharge S.D : 9.30 m3/s 37-month moving average added Year 4.4 Annual Pattern of Discharge Nam Song atvangvieng (864 km ), 1995 Qave = 63.9 m3/s _ 400 VI "g Si 300 =^ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month 140

149 Lao Unique Hydrological Features Monthly mean discharge of Nam Song at Vangvieng (864 km ) ÏÏ "e Mean( ) Mean( ) S Q Apr May Jun Jul Aug Sep Month 4.6 Annual Maximum and Minimum Discharges At Vangvieng [864 km2] Year Maximum Discharge Date [m3/s] Minimum Discharge Month [m3/sl Year Maximum Discharge Date [m3/sl Minimum Discharge Month [m3/sl Sep April Sep March Aug March Aug May Jun April Aug Feb Sep April Jun April July March Jul Feb July May Aug Feb Jun March Aug May 3.09 Sum = 5, Aug April 6.89 Mean = No Data 141

150 i i Lao Hyetographs and Hydrographs of Major Floods 620 5" JE u o IB - - III1" p m m m o> CO CT) Ó) ó ) Ó) ^ ^ <f T" -"T N- PE 1 I in CD ) 3 *f O in o> D) 3 <: CO m cp CT) 3 < có is 1 m 1 in en Ô) 3 <í CD 1 in O) Ô) 3 <: CN CN! in CT> Ó) 3 <: m CN T i i i i m m CD CD en n 3 3 "i <? CO T- CM CO n - u '= 25 ^50 g- = 75 = = u = 100 = r 125 M s \ Water Resources 5.1 General Description The Nam Mon river diversion weir was constructed to supply irrigation water to lowland paddy fields. An estimation of volume (1/sec) to be diverted for irrigation, the extent of irrigated area (ha) and peak discharge were made. Also, aspects in terms of predominant soils, their weathering status, soil formation, as well as parent material, rock types and geological formations were described. The Nam Mon is the only main perennial stream which flows through the area and has a watershed of about 80 km2. The average discharge is 5.0 nrvsec with a maximum discharge of 10 m3/sec. The capacity of this flow rate is sufficient for some 200 ha of irrigated area. A private company constructed the weir in It is about 50 m long and 4.5 m high from the bed of the stream giving a flooding storage level of about 5.0 m. The concrete canal was designed directly at the meander of the stream and is approximately 20 m long, 2 m wide and some 1.2 m high. The water distribution system is immediately behind the weir. Parts of the surrounding area (about 1 ha) are designed with gabions to protect this system from erosion and also to avoid damage to the weir during high floods. The weir has a very simple operation: wood pieces are placed in the gate during the dry season to keep the water level at the required height. During the rainy season they are removed to increase discharge capacity. The weir cost was about 30 million Kips of which 30% came from contributions by the 4 neighboring villages while the rest was a government subsidy. The paddy yields have doubled since the irrigation system was implemented. 142

151 ^^^^ Lao Map of Water Resource Systems I : N- S? s à '- Ky z I r^yi y-? / its iy"" wm»i/" v». Civ i. y ^~~^ys V'iJis er \^^ l**-"? JTya. 'S\- ««"«j t* t«\ A. N \ N. l 1" "' 1 \\ ^C & /**)/"' 'o*'«*"»'*0 \ jscí. " «...»* km. f *<!* ««0*0 %..^ waifflmai «nao r *-*r^ si****.z**"^ ELCMItON 1- " List of Major Water Resources Facilities Major Reservoir Name of river Name of dam (reservoir) Catchment area [km2] Gross capacity [10' m3] Effective capacity [10' m3] Purpose ' Year of completion Nam Song downstream of Vangvieng Nam Song (Vangkhi) 1, P ) P: Hydro-power Major Interbasin Transfer Name of transfer line Name of river and places connected From To Lenth [km Maximum capacity [m3/s] Purpose ' Year of completion Vangkhi Nam song Nam Ngum reservoir P ) P: Hydro-power 143

152 Lao Major Floods and Droughts Major Floods at Vangvieng Date Peak Discharge [m3/s[ Rainfall [mm] Duration Meteorological cause Dead and missing Major damages (Districts affected) 5-6 Jul , mm (4-5 Jul) Typhoon (Kelly) - Nam Lik bridge completely destroyed (designed for 100 year flood) Major Droughts None 5.5 Suspended Sediment Loads and Sediment Yields at the Confluence Point Nam Song with Nam Lik Hineheup Water sampling period Number of samples Calculation period Ratio measured to calculated loads Mean annual load [tonnes/year] Sediment yield [tonnes/year/km2] = = 89 = = = xlo3 = xlo3 6. Socio-cultural Characteristics From ancient mythology, around Ban Phatang (Phadaeng) and Vangvieng, there was a duel between two giant "Nhuak" (dragons) to dispute a pretty girl named Nang Ay. The winner from villagers has constructed a magnificent fish catching as known Tham Chang. Vang in Lao means deep water like a retarding pond. So, Vangvieng and Vangkhi have natural landscape as Tham Chang or cave Chang in Vangvieng resort officially recognized in 1996 as a tourism site with beautiful stalactites and stalagmites with Nam Lae flows throughout rock, fresh and cool inviting to bath.vangvieng resort is located about 150 km from Vientiane on the national road N 13 north in a quiet atmosphere and natural attraction with an emerging cement factory on the skyline east of Vangvieng. The origin of the people living in this area is from Hoaphan Province. Their traditional cultivation in the uplands is the slash and burn practice. Nam Song provides natural growing vegetation of cresol where the name of Nam Song comes from. 7. References, Data books and Bibliography - Department of Geography "all scale maps since 1987" 1 : 1,000,000; 1 : 200,000; 1 : 100, Department of Geology and Mines ( ) 1 : 1,000,000 scale, map of geological and mineral occurrence in Lao PDR. - MRC, Hydrologie year books and additional data from GTZ Methods and instrumentations on integrated watershed management in Lao PDR and Vietnam, Vientiane November DMH Hydro-climatic data updated until

153 Malaysia Malaysia-5: Pahang River vy->> N ty A Û ^ k. Pahang River l SOUTH CHINA SEA \ * \ V \ \ \ % \ Peninsular \ -«Malaysia AW \ INDONESIA *&/~\ 145

154 Introduction Malaysia is situated in the heart of Southeast Asia, just north of the equator. It has a total land area of 330,200 km2 and is divided into two distinct regions: Peninsular Malaysia, which extends from the Thai border down to the island nation of Singapore and across the South China Sea, and the two states of Sabah and Sarawak on the northern coast of Borneo, which are bordered by Indonesia to the south and the Philippines to the east. Being in the tropical region, the climate is hot and humid throughout the year. The mean annual rainfall is 2,500mm and the temperature range from 21 C to 32 C. Out of a total population of about 22 million (2000), approximately 18 million live in Peninsular Malaysia whilst 4 million live in Sabah and Sarawak. The population come from a variety of ethnic background. The majority of Malays, Chinese and Indians are in Peninsular Malaysia whereas Iban, Kadazan and Bidayuh are the main indigenous ethnic groups in Sabah and Sarawak. The river catalogued in this volume is the Pahang River, Pahang. It is the longest river in Pahang State with the length of about 440 km and the area of 29,300km. It flows generally in the south and south eastern direction and eventually eastward to discharge into the South China Sea. The river originates from the Central Mountain Range in the west and the East Coast Range in the North East. This area is in the tropical rain forest with a mean annual rainfall of about 2,170 mm. Its mean annual discharge measured at Lubok Paku (27,000 km2) is about 596 m3/s Acknowledgements A working group was established for the preparation of the catalogues, where a number of institutes and individuals collaborated. The working group consisted of: Ir. Hj. Keizrul bin Abdullah, Chairman of Malaysian National Committee for IHP Ir. Hj. Rahim bin Kaparawi, Secretary Malaysian Committee for IHP Ir. Low Koon Sing, Deputy-Secretary, Malaysian National Committee for IHP Mr. Asnor Muizan bin Ishak, Water Resources Engineer, Department of Irrigation and Drainage Malaysia. The organisations that have contributed by providing data include: Department of Malaysian Meteorological Station, Department of Agriculture Malaysian and Geological Survey department of Malaysia. Financial support was provided by Government of Malaysia. 146

155 Malaysia-5 Pahang River Map of River Table of Basic Data Name: Pahang River Location: LubokPaku Catchment Area: 25,600km^ Origin: Mt. Tahan (2,187 m) Outlet: South China Sea Serial No. : Malaysia-5 N 2 48' 45" ' 24" ElOr 16' 31" ' 34" Length of mainstream: 440 km Highest point: Mt. Tahan (2,187 m) Lowest point: River mouth (0 m) Main geological features: Shale, Mudstone, Limestone and rooks Main tributaries: Tembeling river (5,050 km^), Jelai river (7,320 km^) Main reservoirs: Southern Abu Bakar Dam of TNB, Chini Lake and Bera Lake Mean annual precipitation: 2,170 ( ) Mean annual runoff: 596 Lubok Paku ( ) Population: 1,000,000 Main cities: Kuantan Land use: Virgin jungle. Rubber, Paddy, Oil palm. Other agricultural crops. Urban 147

156 Malaysia-5 1. General Description The Pahang River basin is located in the eastern part of Peninsular Malaysia between latitude N 2 48' 45" and N 3 40' 24" and between longitude E ' 31" and E ' 34". The maximum length and breadth of the catchment are 205 km and 236 km respectively. The river is about 440 km long and drains an area of 29,300 km2 of which 27,000 km2 lies within Pahang (which is about 75% of the State) and 2,300 km is located in Negeri Sembilan. It is divided into the Jelai and Tembeling rivers which meet at the confluence near Kuala Tembeling at about 304 km from the river mouth in the central north. Jelai River originates from the Central Mountain Range while Tembeling River has its origin at the Besar Mountain Range. The Pahang river system begins to flow in the south east and south directions from the north passing along such major towns as Kuala Lipis, Jerantut and Temerloh, finally turning eastward at Mengkarak in the central south flowing through Pekan town near the coast before discharging into the South China Sea. The main highland areas situated within the basin are the Central Mountain Range along its western side and the East Coast Range in the north-east between Kuantan River and the Tembeling River. These upland areas are highly dissected and generally range from 1,000 m to 1,500 m in elevation with some peaks reaching more than 2,000 m. The topography is less rugged towards the main drainage lines in the central part of the basin, where most of the land is below an elevation of 75 m and consists of low hills. The mountainous areas are covered with virgin jungle while rubber, oil palm and some paddy are planted in the undulating terrains and lowlands. The eastern coastal plain is 30 to 40 km wide in the vicinity of the Pahang River. The coastal plain is flat and mostly swampy. Granite is found in the mountainous terrains in the east and west. The granitic soil in this region consists of fine to coarse sand and clay. Its depth seldom exceeds about half a metre except in areas where intense weathering has taken place and the soil layer can be as deep as 9 m. In the central portion of the catchment lies a wide valley where quartzite, schist, shale stone and limestone are the predominant rock types. This area, especially along the larger rivers such as Pahang River and Tembeling River is mainly covered with alluvium which varies from less than 1 m to more than 1 8 m in depth. The basin has an annual rainfall of about 2,170 mm, a large proportion of which occurs during the North-East Monsoon between mid October and mid January. The mean annual temperature at Kuantan is 26.4 C with mean relative humidity of 86%. The mean flow of Pahang River measured at Lubok Paku is 596 m3/s. 148

157 China-Il 2. Geographical Information 2.1 Geological Map Ternary- shale, sands lone.conglomeraie Sl traa<x coal seami Qualenary- clay.silt. saod pen with mines gra^-el AEid Inlmsives/ Imenuediate intrusives lundinérenliated) Tnassic - Intertiedded aondstone. silisione end sbale Peinuon - Phvllite, dale and shale wilh subordínale sandstdoe and schiil volcanic«basic mtru5i\«b, mainly gabbrti 2,2 Land Use Map Legend: 011 Palm Wetland Forest Association Forest ^ IB ^ f UHian & Associ&ted Areas Paddy Virgin Forest Rubber 149

158 Malaysia Characteristics of River and Main Tributaries No Name of river Pahang River (Main river) Jelai River (Tributary) Tembeling River (Tributary) Length [km] Catchment area [km , , ,050 Highest peak [m] Lowest point [m Mt. Tahan (2,187 m) River mouth (0 m) MtSiku (1,916 m) Mt. Besar (790 m) Land use [%] (1997) F (73.2), U (0.1), L (10), OP (4), R (10), P (2.2), A (0.5) F (85), OP (2), R (4), L(9). F (66), OP (12), R(13),L(9) A: Other agricultural field (vegetable, grass) F: Forest L: Lake, River, Marsh P: Paddy field U: Urban R: Rubber OP: Oil Palm. 3. Climatológica] Information 3.1 Annual Isohyetal Map and Observation Stations 150

159 Malaysia List of Meteorological Observation Stations No.11 Station Elevation [ml Location Observation period Mean annual precipitation [mm] Observation items ' Brinchang Mountain, CHighlands - N 04 31' 00" E ' 00" (Man) present (Auto) 2697 ( ) 2328( ) (P)SM (P) PAT Kg. Telang - N 04" 14' 55" E ' 50" ( ) (P)SM Merapoh - N 04 40' 40" E ' 30" ( ) (P)SM Kg. Merting - N 04 14' 35" E ' 00" (Man) present (Auto) 2345 ( ) 2300( ) (P)SM (P)PA Ulu Atok - N 04 03' 35" E ' 10" present 1500( ) (P)SM Kg. Dong Raub - N 03 54' 20" E ' 40" present 2000 ( ) (P)SM Stor JPS Raub - N 03 48' 20" E ' 50" (Man) present (Auto) 2000( ) 2000( ) (P)SM (P)PA Bukit Fraser - N 03 42' 50" E ' 05" ( ) (P)SM Lemb. Ujian Sg. Tekan 1 - N 03 53' 50" E ' 05" ( ) (P)PA Sg. Lembing PCCL Mill - N 03" 55' 00" E ' 10" present 2500( ) (P)PA Janda Baik - N 03 19' 35" E ' 45" present 2000 ( ) (P)SM Ldg. Sg. Kawang - N 03 28' 00" E ' 35" present 2100( ) (P)SM Ldg. Sg. Tekal - N 03 39' 20" E ' 00" present 2050( ) (P)SM JKR Mentakab - N 03 29' 00" E ' 05" present 1900( ) (P)SM Rumah Pam Pahang Tua, Pekan - N 03 33' 40" E ' 25" present 2800 ( ) (P)SM JKR Kg. Manchis - N 03 12' 10" E ' 45" present 2200 ( ) (P)SM Simpang Pelangai - N 03 10' 30" E ' 50" present 2500( ) (P)PA Pos Iskandar - N 03 01' 40" E ' 30" present 1800( ) (P)PA Sg. Cababg Kanan - N 03 17' 55" E ' 20" present 2100( ) (P)PA Kg. Batu Gong - N 03 23' 25" present 2300( ) E ' 35" 1) Serial number used by Department of Irrigation and Drainage, Malaysia. 2) (P): Precipitation, SM: Secondary Manual, PAT: Primary Auto telemetric, PAET: Primary auto, evaporation and telemetric, SA: Secondary Auto, SAT: Secondary auto telemetric, PA: Primary Auto (P)PA 151

160 Malaysia Monthly Climate Data Observation item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Kuantan Precipitation [mm] Ldg. Jeram, Kuantan , Evaporation [mm] Pekan , Duration of sunshine [hr] Kuantan Long-term Variation of Monthly Precipitation Sg. Cabang Kanan, Pahang ( ) Annual Mean: mm SD: mm 37-month moving averages Year Ldg. Teh Sg. Palas, Cameron Hidhlands, Pahang ( ) Annual Mean: mm SD: mm 37-month moving averages 152

161 Malaysia-5 4. Hydrological Information 4.1 Map of Streamflow Observation Stations LEGENDS : V Water Level station 0?0 4P km KILOMETER 153

162 1 37-Month Malaysia List of Hydrological Observation Stations No.* Station Location Catchment area (A) [km ] Observation period Observation Ítems1' (frequency) Lubok Paku N03 30'45" E ' 30" 25, present WL/Q (A), SS(Wk),WQ (Wk) Temerloh N03 26'40" E ' 45" 19, present WL/Q (A), SS(Wk),WQ (Wk) Sg. Yap N04 0r55" E ' 30" 13, present WL(A) No.* Q2) [m3/s] Qmax3) [m3/s] Qmax4' [m'/sl Qmin5* [m3/s] Q/A [m3/s/100km2 Qmax/A [m3/s/100km2] Period of statistics ,318 6,377 2,657 2, *: Serial number used by Dept. of Irrigation and Drainage Malaysia. 1)Q: Discharge; WQ: Water quality ; WL: Water Level; D: Daily manual; A: Automatic Wk: 2 weekly ) Mean annual discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge 4.3 Long-term Variation of Monthly Discharge o o Jan Pahang Lubok Paku ( 25,600 km2 ) Mean: nrt/s SD : m3/s movng average added Jan-78 Jan-98 Jan

163 Malaysia Annual Pattern of Discharge Pahang Lubok Paku Daily Discharge of \ 1 Flow Duration /Curve / Qpeak= 5388 cumecs J/T E O) <n g h V l\^-^j\a A» «Qmean = 956 cuinecs s^v^v^^y ^ a/ ^ w\^ v ^^^j Day Annual Maximum and Minimum Discharges Year Maximum" Date [m3/s] Minimum ' Month (m3/sl Year Maximum1' Date [m3/sj Minimum2' Month [m3/s] /12 4, /11 1, /05 1, /12 3, /12 3, /12 4, /12 1, /11 2, , /12 5, /12 1, , /12 4, /08 1, /12 1, /10 2, , /12 1, , /12 4, / , , /01 3, , /12 3, , , , / / ), 2) Instantaneous observation by recording charts 155

164 i i i Malaysia Hyetographs and Hydrographs of Major Floods Stn Lubok Paku, Pahang (1993) ' 1 PII uuooououccc Ot-t-t-OICMCMCXOOO lin in" npii" " Il -2! Ml "e ym\ 1 "JJ" 18 Dec 1993 ra ""!~ "T g 4000 / / '''*''><+./] *^- ' 1000 T u 5454 cumecs? 28 Dec ' 5ii r i * \ 3 \ s i\ ta Water Resources 5.1 General Description Unlike Kelantan River in the northern state which meets the irrigation demand of four major granary (paddy) areas totalling more than 30,000 Ha, Pahang River, via the effort of DID Malaysia, provides water only to numerous small scale paddy irrigation schemes. For instance, in Lipis River basin there are 26 extraction points along the river drawing a total of 290 million litres per day (mid) of water during paddy planting season. Similarly, water are drawn from Jelai, Triang, Lepar and the lower reaches of Pahang main river for irrigating the paddy fields. A number of these paddy cultivation schemes have been operating since the 1930's. Total amount of water extracted from more than 70 locations for these small paddy irrigation schemes stands at about 750 mid or 8.7 cumecs which represents only a small fraction of the available water from the Pahang River. Water from Pahang River also supports the needs of other agricultural activities such as rubber and oil palm plantations. In contrast, due to extensive farming activities water scarcity is being experienced in the headwaters of the Bertam and Telum rivers in the Cameron Highlands (in the north-western mountain range) that stands at more than 1600 m above sea level. This is the most important highland fresh vegetable producing area of the country and is also an important vegetable source for the people of the neighbouring country - Singapore. The highlands are also home to some of the largest tea plantations in the country which have been operating since the British colonial time. In addition, Pahang River delivers more than 120 mid of water, via the Public Works Department to meet the demand of domestic and industrial sectors, particularly in urban regions. 5.2 Major Floods and Droughts No major drought has been experienced in Pahang River basin in the past. 156

165 Malaysia-5 Major Floods Date Water level [m] Meteorological al cause Dead and missing Major damages [Districts affected] Pekan Heavy rainfall - village and roads were flooded and damages Sg. Paku Heavy rainfall 4 died 3,082 people were evacuated, roads, bridge side drain and culvert were flooded and damages. Damages costrm3,191, Sg Yap Heavy rainfall people were evacuated Heavy rainfall people were evacuated Sg Yap Temerloh Heavy rainfall - 3 people were evacuated 10 people were evacuated Temerloh Heavy rainfall people were evacuated, road and structural damages RM Socio-cultural Characteristics The State of Pahang belongs to Eastern Region and is one of the eleven States in Peninsular Malaysia. The State of Pahang, normally divided into North and South Pahang, is composed of ten Districts. Kuantan is the capital of Pahang situated near the mouth of Kuantan River which is not part of the Pahang River basin. It is the development centre of North Pahang. Major towns found in the Pahang River basin include Pekan, Marang, Temerloh, Jerantut, Kuala Lipis, Raub and Bentung. According to historical records Kuala Lipis was once the administrative center of the Pahang Sultanate empire. Raub has the commercially lucrative gold mining industry of the country while Bentung was one of the major tin producing towns in the 1960's till the 1980's. A number of nationally and internationally wellknown recreation and tourist destinations are found in the Pahang River basin. Taman Negara or the National Park of Mt Tahan is a national heritage area where tens of thousands of tourists from inside the country and abroad trek the virgin jungle of Mt Tahan enjoying the fascinating bio-diversity and nature's wonders each year. The basin also houses the three most popular highland resorts, namely Cameron Highlands, Fraser' s Hill and Genting Highlands where temperatures of 18 C to 22 C during the day are the norm. They are the perfect getaway destinations for city dwellers from the bustling and burning heat of urban areas in the lower altitudes. In addition, the only two natural lakes in Peninsula Malaysia are found in the Pahang River basin. They are Chini Lake and Bera Lake. Tasik (Lake) Chini, consisting of a series of 12 lakes, is located about 100 km south west of Kuantan town, and is formed from the natural damming of a river valley. Legend has it that within the deep water of Tasik Chini lies an ancient kingdom that once ruled the areas around the lakes. The story told by the local indigenoues tribes, such as the Jakun, is that during the imminent advancement by the powerful Khmer regime in the early 51 century the ancient city of gold was deliberately flooded to avoid invasion. To this date, this mysterious underwater city of an ancient kingdom remains elusive from mankind. The Jakun people still live off the land around the lakes; hunting, gathering jungle produce, fishing and carrying out some agricultural activities. Tasik Bera or Bera Lake is situated at about 80 km south-west of Tasik Chini. This natural freshwater lake system is 35 km long and 20 km wide and is much larger than Tasik Chini. It drains northward to join the main trunk of Pahang River via the Bera River. Tasik Bera is a swampy wetland that is not only home to a diverse range of fauna and flora, but also sustains the livelihood of the Semelai, the aboriginal inhabitants of the area. It has been protected under an international treaty - the Ramsar Convention, which allows traditional and wise use of the area to continue. Tasik Bera Ramsar site was declared in 157

166 Malaysia-5 November Like Tasik Chini is a sanctuary habitat for hundreds of bird, mammal and fish species including some endangered species such as tiger, tapir and elephant. The population of Pahang is 1,000,000 as recorded in Malays are the majority ethnic group followed by Chinese who largely live in the urban areas. The major economic activities in Pahang are tourism, timber harvesting and forest products, mining and agriculture. Agriculture consists mainly of the cultivation of paddy, rubber, oil palm and cocoa plantations. Fishing (fresh water) and livestock farming are important occupations found in this area too. 158

167 New Zealand New Zealand-6: Motueka River 159

168 Introduction New Zealand is situated in the Southwest Pacific Ocean, between latitudes 34 to 47 S and longitudes 166 to 179 E. It consists of three main islands, North, South and Stewart Islands, and a number of smaller isles. The country is long, 1,500 km, and narrow, average width 180 km, with altitudes, ranging up to 3,764 m in the Southern Alps of the South Island. New Zealand lies on a rather unstable portion of the boundary between the Indo-Australian and Pacific tectonic plates. Consequently the landscape is young, vigorous and tectonically active. Earthquakes are not uncommon and there is an active volcanic zone. Rivers are short, steep and can carry high sediment loads. The climate exhibits a marked maritime influence. The weather is a mixture of anticyclones that bring clear skies, depressions in the form of frontal rainfall from the west and south, and the occasional cyclone that moves down over the country from the north. Most of New Zealand gets between 600-1,500 mm of rain per year. In the South Island, warm wet westerly winds are cooled and condensed as they rise over the Southern Alps to form orographic conditions. On the western side of the Alps rainfall can exceed 10,000 mm per year. The mean annual sea-level air temperature varies from 15 C in the north to 9 C in the south. Much of New Zealand receives over 2,000 hours of sunshine per year. Winter snowfall can occur at higher elevations in the North Island, and down to sea level in parts of the South Island. About 50% of the land area is in pasture and 30% in protected-indigenous and commercial forests. The population is a little over 4 million, of which about 3 million live in the North Island. The New Zealand river catalogued in this volume is the Motueka River. This river basin is in the north of the South Island, about 40 km west of the city of Nelson (population 41,500 (2001)). The Motueka River drains 2,076 km and provides the major freshwater flow into Tasman Bay, a productive, shallow water body of high economic, ecological and cultural significance. The elevation range is from sea level to 1,875 m at Mt Owen, in the Arthur Range on the catchment's western boundary. There is a strong rainfall gradient across the catchment, ranging from 3,500 mm in the west to about 950 mm in the east. Mean annual rainfall is around 1,600 mm with marked wet (winter) and dry (summer) seasons. The river has a mean annual runoff of 844 mm and a mean annual flow of 59 m3/s, as measured at Woodstock, 36 km upstream from the mouth. There is a dominance of mountainous and hilly terrain within the catchment, with limited, but agriculturally important areas of flat terraces and flood plains. Land-use is dominated by indigenous (35%) and commercial (25%) forests, and pastoral farmland (20%). Horticulture occupies a small (0.6%), but expanding area, and is a major user of both surface and groundwater, particularly during late summer. Over much of the catchment demand for water exceeds supply, resulting in competition between land-uses, i.e., horticulture and forestry, and between out-of-stream uses and maintenance of in-stream values. The Motueka catchment is the focus of a 6-year research programme aimed at improving the management of land and water resources by adopting an integrated catchment management (ICM) approach. The major resource management issues within the Motueka include water resource allocation, water quality and quantity, habitat quality and land and coastal productivity. The ICM approach takes a "ridge top to the sea" perspective to provide a framework for understanding the cumulative interactions of past, present, and possible future uses of land, freshwater and marine resources. Acknowledgements Alex Watson, from Landcare Research (Lincoln), compiled this report, with the help of Tim Davie, Les Basher and James Barringer of the same organisation. Data has been sourced from published material (see Section 7) and the Landcare Research archives. We would like to thank: Martin Doyle of Tasman District Council, Richmond, for generously allowing access to their meteorlogical and hydrological data-bases, Roger Young of Cawthron Institute, Nelson for the water quality data in Section 5.5. This report has been funded by the Foundation for Research, Science and Technology, under contracts C09X0014 and C09X

169 New Zealand-6 Motueka River Map of River 161

170 New Zealand-6 Table of Basic Data Name: Motueka River Serial No. : New Zealand-6 Location: Nelson Region, New Zealand S 41 05' ' E ' ' Area: 2,076 km2 Length of main stream: 1 16 km Origin: Red Hills, in SE of catchment Outlet: Tasman Bay Highest point: Mt. Owen, 1,875 m Lowest point: River mouth, 0 m Main geological features: Complex geology of: basement igneous, ultramafic and sedimentary rocks, young sedimentary rocks, clay-bound gravels and small, but hydrologically significant areas of younger alluvium. Main tributaries: Wangapeka, Motupiko, Baton, Upper Motueka, Tadmor, Dove, Stanley Brook. Main lakes: None Main reservoirs: None Mean annual precipitation: 1,600 mm Mean annual runoff: 844 mm Population: 12,000 Main cities: Motueka (7,000) Land use: Agriculture (pastoral, horticultural) and commercial forestry on lowland and hill areas. Protected Indigenous forests in the mountains. 1. General Description -2. The Motueka River drains 2,076 km of dominantly mountainous and hilly terrain located about 40 km west of the city of Nelson, South Island, New Zealand. The catchment elevation range is from sea level to 1,875 m. The river rises in the southeast of the catchment and flows north for about 116 km to Tasman Bay. The Motueka is joined by a series of small and medium-sized tributaries that drain hilly alluvial terrain to the east, and by a series of much larger tributaries originating in a complex assemblage of sedimentary and igneous rocks which form the mountainous terrain of the Arthur Range on the western boundary of the catchment. Rainfall is strongly seasonal. Catchment mean annual rainfall is around 1,600 mm. Average monthly maximum temperature (29 C) and average monthly maximum pan evaporation (180 mm) occurs in December and January, respectively. Frosts can occur between April and October and snow can fall during all months at higher elevations. Mean annual sunshine hours (2,407) are among the highest in New Zealand with mean monthly values ranging from 265 to 134 hours in January and June, respectively. The Motueka River basin is geologically and pedologically very complex. The wide variety of rock types include, complex basement rocks, ultramafic and old sedimentary rocks, granites, young sedimentary rocks, clay-bound gravels and small, but hydrologically significant areas of recent alluvium. The characteristics of the wide variety of soils are closely related to geology, landform and climate. The Motueka Catchment is largely rural. The major productive land uses are commercial forestry (25%), sheep and beef farming (19%) and limited, but increasing dairying. Horticulture, mainly pipfruit, berry-fruit, hops and market gardening, occupies a small, but expanding area, and is a major surface and groundwater user. The largest areas of indigenous forest are found in the Kahurangi National Park situated in the headwaters of the western tributaries, and in Mt. Richmond Forest Park, in the upper catchment. 162

171 New Zealand-6 2. Geographical Information 2.1 Geological Map 163

172 New Zealand Land Use Map Map of landcower types recorded in the LarxJ Cover Database (source Ministry for the Environment). Legend Locattora mentlonttd In twtt ^^1 HotUcuJUral I Indigenous Forest I ExoUc Forest I Tussock/Sciub 164

173 New Zealand-6 (E0Oo 2.3 Characteristics of River and Main Tributaries No Name of river Motueka (Main river) Wangapeka (Tributary) Motupiko (Tributary) Baton (Tributary) Upper Motueka (Headwaters) Tadmor (Tributary) Dove (Tributary) Stanley Brook (Tributary) Length [km] Catchment area [km2] 116 2, Highest peak [m] Lowest point [m] 1, , , , , , A: Agricultural {pastoral, horticultural) F: Forest (indigenous, commercial) S: Scrub/Tussock 2.4 Longitudinal Profiles Baton /.Stanley Brook Tadmor/ / ^y* Towns Land use [%] population (2001) (2001) Motueka F 60 7,000 A 20 F 80 None A 10 F 85 None A 10 F 90 None A5 F 60 None S 40 F 50 None A 45 F 45 None A 50 F 60 None A 35 Motueka Whangapeka y frw%/ j Motu pi ko I Distance (km)

174 New Zealand-6 3. Climatological Information 3.1 Annual Isohyetal Map and Observation Stations Map of spatial dtetributton of mean annual rainfall in tne Motueka Catchrrient (source Tasman District Council) and active primary rainfall sites. Legend tocattons rrwntxxio«! m t«xt Primary Fkiw/Aclive HamtBM Acíi^fít fí^tnt^íf Annual Rainfall (mm> ^^t 1000 dd E S00 I >3000 Primary Flow/Active Rainfall means that both flow and rainfall are being measured at the location. Active Rainfall means that only rainfall is being measured. 166

175 New Zealand List of Meteorological Observation Stations No. Station Elevation [m] Location Period of record Mean annual rainfall [mm] Period of record Mean annual evaporation1' [mm Other Items2' G12191 Motueka 8 S 41 06' E ' Jan 1943 Jun ,376 Jan 1971 Sep ,050 P, T, TS, SR 1 ) Raised pan. 2) P = Precipitation, T = Temperature, TS = Total Sunshine, SR = Solar Radiation 3.3 Monthly Climate Data Observation item Observation station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature PC] Motueka Apr 1956 Jun 2003 Precipitation [mm] Motueka ,376 Jan 1943 Jun 2003 Evaporation [mm] Motueka ,050 Jan 1971 Sep 1996 Solar radiation [MJ/m2/d] Motueka Apr 1995 Jun 2003 Duration of sunshine [hr] Motueka ,407 Jan 1965 Jun Long-term Variation of Monthly Precipitation Motupiko Monthly rainfall 12 month mean 250 Jan-80 Jan-82 Jan-84 Jan-86 Jan Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Date 167

176 New Zealand-6 4. Hydrological Information 4.1 Map of Streamflow Observation Stations 168

177 New Zealand List of Hydrological Observation Stations No.* Station Location Catchment area (A) [km2] Observation period Observation items1' (frequency) Woodstock S 41 16' El 72 49' 1, Q, P (15m, lh) Walters Peak S 41 20' E ' Q,P(15m, lh) Christies S 41 37' E ' Q,P(15m, lh) Flats S 41 19' El 72 43' Q,P(15m, lh) Upper Gorge S 41 38' E ' Q, P (15m, lh) Mudstone S 41 27' E ' Q,P(15m, lh) Stanley Barkers S 41 19' E ' Q,P(-,-) No.* Q2) lm3/s) Qmax3' lm3/s] Qmax4' [m3/s] Qmin5' [rn3/s] Q/A m3/s/100km2l Qmax/A m3/s/100km2] Period of statistics , *: New Zealand stream gauging site numbers. 1)Q: Discharge P: Precipitation 15m: 15 minutes, lh: 1 hour 2) Mean annual discharge 3) Maximum daily discharge 4) Mean maximum daily discharge 5) Mean minimum daily discharge 169

178 New Zealand Long-term Variation of Monthly Discharge Motueka at Woodstock 250 Monthly discharge ~ ~ 1 2 month mean Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Date 4.4 Annual Pattern of Discharge Motueka at Woodstock 500 Daily discharge Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date 170

179 , ; New Zealand-6 Motueka at Woodstock1'' 2) ^ 300 a E Median flow 0 C % of time flow greater than 1) Located 36 km upstream from the river mouth. 2) Contributing area = 1,750 km 4.5 Annual Maximum and Minimum Discharges Motueka at Woodstock11, 2) Year 1970 Maximum ' Date Flow [d/m] [m3/s 1/ Minimum4' Date Flow [d/m] [m3/sl 21/ Year 1986 Maximum ' Date Flow [d/ml [m3/s] 26/ Minimum4' Date Flow [d/ml [m3/sl 14/ / / / / / / / / / / / / /4 1,013 1/ /8 1,355 15/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /7 1,442 23/ / / / / / / / / ) Located 36 km upstream from the river n 2) Contributing area = 1,750 km2 3), 4) Daily mean values 171

180 New Zealand Hyetographs and Hydrographs of Major Floods Motueka at Woodstock vv'jvyvi Jul-83 8-M-83 9-JuI-83 9-M Jul Jul-83 ll-jul-83 ll-jul Jul-83 Date 5. Water Resources 5.1 General Description By New Zealand standards the Motueka is a reasonably large river with a long-term mean annual flow of 59 m3/s (7-day running mean at Woodstock) and a measured flow range of 6 m /s to greater than 2,100 m3/s. River flow is lower than the long-term mean annual flow about 70% of the time. Like rainfall, mean monthly flow shows a distinct seasonal fluctuation, with higher values in winter and spring, and lower values during the summer months. This seasonality is more marked for low flows. River flow generation is controlled by rainfall distribution and geology. The largest contributors to flow in the lower Motueka are the west and southeast mountain catchments (Wangapeka, Baton, Upper Motueka). Collectively they cover a large area, have the highest rainfall and are underlain by basement rocks that provide sustained water yields of up to 0.05 m3/s/km2. These catchments provide a large proportion of the mean annual flow for the Motueka as measured at Woodstock. Periodic large floods are a characteristic feature of the hydrology of the Motueka River basin, and were a severe hazard to transport and land use prior to the implementation of the Motueka Catchment Control Scheme, which was initiated in The largest post-european-settlement flood occurred in February It caused many landslides, widespread erosion and sedimentation, and changed the character of the river in many areas. The maximum flow at Woodstock was estimated to lie between 2,500-3,500 m3/s. Other large historical floods occurred in January 1895, July 1929, June 1954 and April No significant natural or man-made water storage facilities exist in this river basin. The Tadmor River summer flows are heavily used for horticultural irrigation and have been augmented by diverting water from the Hope River, a tributary of the Buller River (see: Catalogue of Rivers for Southeast Asia and 172

181 New Zealand-6 Pacific-Volume I (1995)). The Hope River diversion scheme, operational from October through to April, can contribute up to 0.5 m3/s. 5.2 Map of Water Resource Systems Not applicable. 5.3 List of Major Water Resources Facilities Major Reservoirs There are no reservoirs in this river basin. Major Interbasin Transfer Name of transfer line Names of rivers and places connected From To Length [km] Maximum capacity [m3/s] Purpose1' Year of completion Hope River Diversion Hope River, Subcatchment of Butler River Tadmor River, Subcatchment of Motueka River H,N. Scheme proposed ) H: Horticultural use N: Maintenance of normal flows 5.4 Major Floods and Droughts Major Floods Recorded at Woodstock1'' 2) Date Mean daily discharge [m3/s] Rainfall duration [mm] Meteorological cause Dead and missing Major damages to 10 July , h No details 0 Property 13 August , h No details 0 Property 17 April , h No details 0 Property 7 April , h No details 0 Property 6 October h No details 0 Property 1) Located 36 km upstream from the river mouth. 2) Contributing area = 1,750 km2 173

182 New Zealand-6 Major Droughts. Flows Recorded at Woodstock1*' ' Year3' Flow4' (m3/s) Return Period (yrs) Rainfall5' (mm) Return Period (yrs) Days below 1 0 yr. low flow6' Major damages and counteractions Dry streams in eastern catchments, Motueka river warm, irrigation water rationed Dry streams in eastern catchments, Motueka river warm, irrigation water rationed Dry streams in eastern catchments, irrigation water rationed Dry streams in eastern catchments, irrigation water rationed Dry streams in eastern catchments, irrigation water rationed. 1) Located 36 km upstream from the nver mouth. 2) Contributing area = 1,750 km 3) Year from 1 August to 31 July. 4) 7 day running mean low flow. 5) 3 month total. 6) The 1 0 year, 7 day running mean low flow = 6.4 mv 5.5 River Water Quality As part of the ICM programme, an environmental sampling network was initiated to provide an improved understanding of the influence of land-use and geology on the variation in water quality throughout the catchment. The sampling sites, arranged to cover the longitudinal profile of the river, are located in the key geological and land-use types. Water quality is generally high throughout the catchment, though much depends on adjacent land use. Faecal coliform bacteria and increased nitrate and phosphate levels are associated with the increased agricultural land use in the lower catchment. Nutrient and suspended sediment concentrations tend to be relatively low when compared to other New Zealand rivers. Although any increase in suspended sediment concentrations is often associated with commercial forestry activities, particularly harvesting. Water clarity is high in streams draining indigenous or commercial forests, but tend to be lower in streams draining pasture and horticultural land. Clarity is also lower in streams draining the catchments underlain by granite. Water quality and clarity are particularly high in rivers draining the western ranges and in the headwater-rivers of the upper catchment. 174

183 New Zealand-6 Motueka River Water Quality at Woodstock1'' 2) from October 2000 to September 2001 Date of observation 18 Oct 15 Nov 13 Dec 11 Jan 13 Feb 13 Mar 9 Apr 16 May 11 Jun 11 Jul 14 Aug 18 Sep ph Turbidity [NTU E. coli [cfu/100ml] TSS3' [g/m3l NO3-N lg/m3l Discharge4' m3/s] ) Located 36 km upstream from the river mouth 2) Contributing area = 1,750 km2 3) Total Suspended Solids 4) Discharge on the date of observation 6. Socio-cultural Characteristics There are approximately 12,000 people living within the Motueka River basin. The main population centres are the town of Motueka (7,000) and the villages of Tapawera, Tadmor and Brooklyn. The rural population density is about 2/km. The median age is 38 years, with 13% of the population being older than 65 (retirement age) and 12% younger than 15 (minimum school leaving age). Life expectancy is around 78 years. About 96% of the inhabitants identify themselves as European and 7% as Maori. Some people claim dual ethnicity. Population growth is estimated to be about 2% per annum. The median annual income is $NZ16,100. For those fully employed, the primary source of income is from salary and wages (57%) and from self-employment (23%). A further 23% of the population receive some form of Government assisted benefit. The unemployment rate in the area is approximately 4%. For people over 15 years, 53% are married, 24% have never married, 7% are divorced, 6% are widowed and 3% are separated. The information above was extracted from the 2001 New Zealand Census. 7. References, Databooks and Bibliography The Motueka and Riwaka Catchments, 2003: A technical report summarising the present state of knowledge of the catchment, management issues and research needs for integrated catchment management. Compiled by L.R. Basher, Lincoln, Canterbury, New Zealand.: Landcare Research New Zealand. 120 p. Rattenbury, M.S.; Cooper, R.A.; Johnston, M.R., 1998: Geology of the Nelson area. Institute of Geological and Nuclear Sciences 1 :250,000 geological map 9. Institute of Geological and Nuclear Sciences, Wellington, New Zealand. 175

184 I Philippines Philippines-4: Pasig-Marikina-Laguna de Bay Basins ^ 121 ätaniil^ 1-^^ ts 176

185 Introduction The Philippines lies in the Southeastern Asia, and is an archipelago between the Philippine Sea and die South China Sea. It is composed of about 7,100 islands and islets with a total land area of approximately 300,000 km2, of which about 94% is contained within the 11 principal islands, namely Luzon, Mindanao, Samar, Negros, Palawan, Panay, Mindoro, Leyte, Cebu, Bohol and Masbate. The country is divided into three major island groups, namely Luzon with an area of 141,000 km, Mindanao with 102,000 km2 and Visayas with 57,000 km2. Since it lies in the tropics, near the equator, weather in the Philippines is hot and highly humid. Temperatures vary from 25 C to 35 C. There are two seasons, both directly governed by the monsoon. The southwest monsoon called Habagat blows from June to November, which meets the Philippines in its path and is laden with moisture that consequently produces the rainy season. On the other hand, the northeast monsoon called Amihan from December to May brings rather dry cool temperatures; however from March onwards, the later part of the dry season becomes really hot. The terrain is mostly mountainous with narrow to extensive coastal lowlands. The highest point is Mount Apo in Mindanao with a summit elevation of 2,954 m. Natural hazards in the Philippines include typhoons, cyclonic storms, landslides, active volcanoes, destructive earthquakes and tsunamis. The Philippines has a total of 18 major river basins with at least 1,400 km2 of watershed area. These river basins are the Cagayan, Pampanga, Agno, Abra, Pasig-Marikina-Laguna de Bay, Bicol and Abulug River basins in Luzon Island; the Agusan, Agus, Davao, Cagayan de Oro, Mindanao, Tagum- Libuganon, Tagoloan, and Buayan-Malungun River basins in Mindanao Island; the Panay and Jalaur River basins in Panay Island; and the Ilog-Hilabangan River basin in Negros island. They cover a total area of 108,678 km2 equivalent to 36.2% of the total land area of the Philippines. The Pasig-Marikina-Laguna de Bay Basin, which is catalogued in this volume, is one of the major river basins of the country. It dwells within latitudes of 13 55' to 14 50' N and longitudes of ' to ' E in Luzon Island, Philippines. It is comprised of 2,942.0 km2 of the Laguna de Bay watershed, km2 of Laguna de Bay lake proper, and km2 of the adjacent Metro Manila River sub-basins, for a total drainage area of 4,522.7 km2. Metro Manila which is the main attraction for population migration of the archipelago has a total population of around 1 1 million in the year This is about 13% of the whole population of the country. Other Metro Manila environs contained in the basin include some towns of Bulacan, Cavité, Laguna, Batangas, and Rizal. The estimated population in these adjacent towns as of year 2000 is around 3 million. The Pasig-Marikina-Laguna de Bay basin is classified under two climate types. The major portion of the basin is classified under Type I climate with two pronounced seasons, dry from November to April and wet from May to October. A smaller eastern part (less than 10% of the total area) falls under Type IV climate having an even rainfall distribution throughout the year. The area derives its rainfall mostly from the southwest monsoon and the convergent storm cells associated with the Intertropical Convergence Zone from May to October and the northeast monsoon from October to January. The mean monthly temperature in the region varies from 25 C to 30 C and the mean annual temperature is placed as 27 C. Monthly relative humidity in the basin ranges from 95% in August and September to 55% in March and April with the mean annual relative humidity taken as 76%. Acknowledgements The following organizations are thanked for their provision of hydrological data and for their assistance in the preparation of this work: Department of Public Works and Highways (DPWH), Laguna Lake Development Authority (LLDA), National Hydraulic Research Center, University of the Philippines (UP-NHRC), and Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA). 177

186 Philippines-4 Pasig-Marikina-Laguna de Bay Basins Map of Rivers and Sub-basins ^f--^ (tmfiuítfilvj, /\ HiCií^^ \X >^o^vil^ '-f^j'/c^ /^^^Sy // _ ^V\S^h^ N A ''^^' S larvi aj^^l 1 1^""^^^^^^^^^^^^^^^^^ ^^^^1 f <.> ^ Í ^i-s iwvci^(\iir^^v^^ J^^^^^^^^^^V '*PV \T]iy? Tyy^^yT^/^^^^^^^^^^L ^^B ^f <i^ /'2^^'^ 'ti^ ;M ^ i(ñ/yi^f^f/f^vy ^^^^t^b äl ^^^B\^t' ^**^ÇÏÎ-7 ^ jt^tît^êo S"!fl'!^/iy^iîè~"^S?' ^^^^^ HtomMiri SCAIE /v Qasjn and Lake Boundary /V Main Rivers and Tributaries ^1 Sub-Basin Ovictes Lakes and Reser/oirs 178

187 Philippines-4 Table of Basic Data Name: Pasig-Marikina-Laguna de Bay Basins Serial No. : Philippines-4 Total drainage area: 4,522.7 km Location: Luzon Island, Philippines Lake area: km E ' ' N 13 55' ' Length of the longest main stream: 66.8 Marikina River Highest point: Mt. Laguna (2,188 m) Lowest point: River Laguna lake & Manila bay (0 m) Main geological features: Laguna Formation (Pliocene to Pleistocene) (1,439.1 km ), Alluvium (Halocene) (776.0 km2), Guadalupe Formation (Pleistocene) (455.4 km2), and Taal Tuff (Pleistocene) (445.1 km2) Main land-use features: Arable land mainly sugar and cereals (22.15%), Lakes & reservoirs (19.70%), Cultivated area mixed with grassland (17.04%), Coconut plantations (13.03%), and Built-up area (11.60%) Main tributaries/sub-basins: Marikina river (534.8 km ), andpagsanjanriver(311.8km ) Mean annual precipitation of major sub-basins: Marikina river (2,486.2 mm), and Pagsanjan river (2,170 mm) Mean annual runoff of major sub-basins: Marikina river (106.4 m3/s), Pagsanjan river (53.1 m /s) Main reservoirs: Caliraya Reservoir (1 1.5 km2), La Mesa reservoir (3.6 km2) Main lakes: Laguna Lake (871.2 km ) No. of sub-basins: 29 Population: 14,342,000 (Year 2000) Main Cities: Manila, Quezon City 1. General Description Pasig-Marikina-Laguna de Bay Basin, which is composed of km watershed and km lake, covers the Metropolitan Manila area (National Capital Region) in the west, portions of the Region III province of Bulacan in the northwest, and the Region IV provinces of Rizal in the northeast, Laguna and portions of Cavité and Batangas in the south. The Laguna Lake is centrally located inside the basin and has an average depth of 2.8 m. The lake has traditionally been used as habitat for fisheries and duck-raising, waterway for minor passenger and cargo traffic, source of irrigation water in Laguna province, effluent sink by industries and municipalities, flood-control detention storage, and serves as the lower pool of the Kalayaan Pumped- Storage Hydro-Electric Plant. One of the main sub-basins or tributaries of Pasig-Marikina-Laguna de Bay Basin is the Marikina River, which has an average annual rainfall of 2,750 mm in a drainage area of km2. It runs through the Marikina Valley and a portion of the flow is controlled and diverted by the Manggahan Floodway towards the Laguna Lake. The remaining water is drained to the Manila Bay through Pasig River. Napindan Hydraulic Control Structure regulates the flow between Manila Bay and Laguna Lake by blocking the high-tide inflow of saline and polluted water of Manila Bay-Pasig River and sometimes allowing reverse seaward flow to allow the entrance of saline water for fisheries. Pagsanjan River, which is the other main tributary of the basin and located at the eastern side, has a mean annual rainfall of 2,318 mm and drainage area of km. Pagsanjan River also drains to the Laguna lake and its flow is partially regulated by the Caliraya Reservoir. Aside from the two main sub-basins, there are another 27 smaller tributaries in the Pasig-Marikina- Laguna de Bay Basin. Eight of these originate from upland agricultural, rural and urbanized catchments of Rizal, twelve from lowland-agricultural, rural and urbanized catchments of Laguna, and seven other adjacent rivers in Metro Manila, which are separated from the Laguna Lake Basin by relatively low ridges. The 29 river sub-basin delineations as well as the rivers and river systems of the basin are shown in the figure above entitled "Map of Rivers and Sub-basins ". 179

188 Philippines-4 2. Geographical Information 2.1 Basin Geology The Pasig-Marikina-Laguna de Bay Basin is underlain by rocks of various origin and characteristics consisting primarily of agglomerates, pyroclastics, sandy tuff and cinder beds. These occur in association with other properties in alluvial deposits, reworked tuff and volcanic ash often displaying desirable hydrogeologic properties. Complex tectonic and volcanic events, mainly during the Late Tertiary and Quaternary periods, together with large relative sea level changes have produced the basic structure observable today in the study area. The table below summarizes the surface geology and significant geological features (strata) of the Pasig-Marikina-Laguna de Bay Basin followed by its geological map. Code Geologic Description Land-Use Area (km2) Percentage (%) Kb Kinabuan Formation (Cretaceous to Paleocene) Tmb Maybangin Formations (Paleocene to Oligocène) Tad Antipolo Diorite (Oligocène) Ta Angat Formation (Early Miocene) Tma Madlum Formation (Middle Miocene) Qg Guadalupe Formation (Pleistocene) Ql Laguna Formation (Pliocene to Pleistocene) 1, Qt Taal Tuff (Pleistocene) Qal Alluvium (Halocene) Lk Lake Total 4,

189 Philippines-4 Geological Map N 70 lotometers SCALE tsij= Cntmeaeuslmpemtaeble fsvj' Qu^eirmry VOIctrtcs IQA} = Qu»l«mary ADiMin td Ktnabusn FomMton (Ptleocen«to Oligocène) [C(] Maytiangin Formation (PaleoceneloOigacene) (Cq Antpolo Oofite (Oligooene) (CI) Angst Fonnatior (Early Miocone) [CI] Madum Fomiatior (MitWIe Miocene) (Ci) Guadalupe Fixrration (Pleistocene] [OV) Laguna Fomaton (Pkqcene B P1ei»looene) (OV) Ta«Tufl(Pleistacene) [QV] Alluvium (Hato,ne) (QA) Lake 181

190 Philippines Basin Land-use The table below shows the different types of land-use in the basin and summarizes the area of each land-use as well as its percentage over the total area of the basin. Code Land-Use Description Land-Use Area (km2) Percentage (%) Ic Arable land, mainly cereals and sugar 1, B Built-up area Fdc Closed canopy, mature trees covering > 50 percent Ipc Coconut plantations Imc Crop land mixed with coconut plantation Imo Crop land mixed with other plantation Ec Cultivated area mixed brushland and grassland Ifm Fishponds derived from mangrove Eg Grassland, grass covering > 70 percent L Lakes and Reservoir M Marshy area and swamp Fdo Open canopy, mature trees covering < 50 percent Un Unclassified Total 4,

191 Philippines-4 Land-Use Map N Kilo meters I Arable land, mainly cereals and sugar Biil-up Area I OMed canopy, mature trees covering 50% Coconut plantations Crop ta nd mixed with coconut plantation I Crop bnd mixed with other plantation j Cultivated Area mixed with brushland! Fishponds darr^ed from mangrove j Giassland, grass coveiing 7D% I Open Canopy, mstire trees covering 50% Marshy area and swamp Lake 183

192 Philippines Characteristics of the Sub-basins and Tributaries The Pasig-Marikina-Laguna de Bay Basin is composed of 29 sub-basins, which drain to the Laguna Lake and Manila Bay. A summary of some basin and river characteristics that includes drainage area, length of the main river, and land-use composition of 12 selected sub-basins is shown in the following table. The selection is based on the length of the river and the size of the drainage area. The following figures in Section 2.4 exhibit the longitudinal profiles of these rivers. Sub-basin Code River/Sub-basin Name Length/Drainage area [km] [km2] Code Primary Land-use [km2] Code [km2 Code [km2[ SB1 Sta. Maria River Ec 67.1 Ic 40.7 Imc 28.2 SB2 Siniloan River Ec 28.4 Ic 17.2 Ipc 15.6 SB5 Pagsanjan River Ipc Imc 87.5 Ec 33.5 SB6 Sta. Cruz River Ipc Imc 21.7 Ic 10.9 SB10 San Juan River Ic 98.1 Ipc 44.9 Imc 40.1 SB11 San Cristobal River Ic 82.4 Imc 47.7 Ipc 10.6 SB13 Binan River Ic 48.3 Imc 39.0 Ipc 26.0 SB16 Marikina River Ec Ic 78.9 Fdo 76.1 SB19 Morong River Ec 80.7 Ic 30.0 Eg 7.6 SB23 Marilao River Ic B 33.7 Ec 21.5 SB24 Tuliahan River B 40.4 Fdo 19.6 Ic 11.2 SB29 Imus River Basin Ic Imc 23.3 B Longitudinal Profiles w c o 160- <u LU 80 - Sta. Maria River y> 0.0 i I 2.0 I i i i i i i i i i i i i Distance from the River Mouth (km) Sta. Maria River 184

193 i Philippines -4 E(ocro TS g m > Siniloan River ^r i Distance from the River Mouth (km) Siniloan River ^ ^r +~ S^ s-* Balanac River X S^»- ^ -«* ^^S **" _s^ ^ y^ 1 s Pagsanjan River J.S S ^^ Distance from the River Mouth (km) Pagsanjan River ^ ^^^ Sta. Cruz River y / / Maimpis River / / -a»**^*^^ Distance from the River Mouth (km) Sta. Cruz River 185

194 Philippines-4 voeo o(ococ S 240- LU % m San Juan River ^^» Distance from the River Mouth (km) _ San Isidro River ^~^yy^ San Juan River San Cristobal River ^3^ ^ ^^^ / s* / s /s /** Diesmo River Distance from the River Mouth (km) San Cristobal River ^^^***^ ^>^^^ ^y^ Binan River Distance from the River Mouth (km) Binan River 186

195 Philippines-4 E(ero3O EC(O g, g ro > Si LU Ü Montalban River Tanog River» ' Nangka River ^ * / -->* - _y -ir^*" '" Marikina River Distance from the River Mouth (km) ^ Marikina River Morong River Distance from the River Mouth (km) Morong River Marilao River ^_^^^-^^ Distance from the River Mouth (km) Marilao River 187

196 1 1 i I 1 1 t i Philippines-4 Ca í*. El (m oo ro 64 - Tuliahan River ^S"^ Distance from the River Month (km) Tuliahan River %, 400 ^y y g Imus River.X*^ 0 T^ 1 1 r j l I « Distance from the River Mouth (km) Imus River 188

197 Philippines-4 3. Clímatological Information 3.1 Annual Isohyetal Map and Observation Stations e5000 2»S CXW 3ZSO0O I L L 1 1 I I I l_ 1M5000-1B A3S SOSO0O- 19BS0D \ r B50OO locco MOOO GRAPHICAL SCALE ^M (M«ten) 189

198 Philippines List of Meteorological Observation Stations There are fifteen available rainfall stations in the Pasig-Marikina-Laguna de Bay Basin that are being maintained by the PAGASA. Eleven of these stations are climatic, three are synoptic, and the remaining one is an agromet. The table below provides a summary of the types, location in UTM coordinates, mean annual rainfall, and length of records of the stations. Moreover, the figure at Section 3.1 displays the rainfall observation stations as well as the annual isohyetal map generated from the available annual rainfall data from the 15 stations. Station Name Location (UTM) X-Coord Y-Coord Type of Station Mean Annual (mm) Data Available From To Amadeo Climatic 3, Ambulong Climatic 1, Bosoboso Climatic 2, NAIA Synoptic 1, Pakil Climatic 5, Pasig Climatic 1, Port Area Synoptic 1, San Pedro Climatic 1, Science Garden Synoptic 2, Sta. Cruz Climatic 1, Sta. Maria Climatic 2, Tabak Climatic 2, Tayabas Climatic 3, Tipas Climatic 1, UPLB Agromet 2, Monthly Climate Data (Observation Station: UPLB) Observation Item Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period Precipitation (mm) , Evaporation (mm) , Wind Speed (m/s)

199 Philippines Long Term Variation of Monthly Precipitation Series Marikina River Basin monthly rainfall -37-month moving averages Annual Mean : mm Standard Dev. : mm 900 'ro 600 Q. O <U Pagsanjan River Basin monthly rainfall -37-month moving averages Annual Mean : mm Standard Dev. : mm o E E a <u Year 191

200 Philippines-4 San Cristobal River Basin 1500 ~ 'S oe I 900 -monthly rainfall 37-month moving averages Annual Mean : mm Standard Dev. : mm E o 'ro Year 192

201 Philippines-4 4. Hydrological Information 4.1 Map of Streamflow Observation Stations ZP VÍ ffe lli^^^ Í W -P^ /P^^ -1SOSO0O -itaeooo W5000-1S29D0O leoeooo S7S T5O i^(vk2^ ^^^y^yy^ TS ^^^^^^^^H ^^^^^^^^M ff («HM MMn ««MC (Mcier») GRAPHICAL SCALE 193

202 Philippines List of Hydrological Observation Stations Station Name Location (UTM) X-Coord Y-Coord Type of Station Mean Annual (m3/s) Data Available From To Marikina River Stream Mayor River Stream Pagsanjan River Stream San Cristobal River Stream San Juan River Stream Sta Cruz River Stream Station Name Qave [m3/sl Qmax [m3/s] Qmax_ave [m'/s] Qmin_ave lm3/s] Qave/A [m3/s/100km2] Qmax/A [m3/s/100km2] period of statistics Marikina River , , Pagsanjan River Qave = mean annual discharge Qmax =* maximum discharge Qmuvjwe = mean minimum discharge Qmax_avc = mean maximum discharge 4.3 Long Term Variation of Monthly Discharge Marikina River Basin

203 Philippines-4 Pagsanjan River Basin average monthly discharge - 37-month moving averages Monthly Mean : 22.2 m3/s Standard Dev. : m3/s Drainage Area : km2 S Year San Cristobal River Basin 16 average monthly discharge 37-month moving averages Monthly Mean : Standard Dev. : Drainage Area : 1.77 m3/s 1.95 m3/s km J\l KJ L_JV=cfv du4 vj 1 Jtr UJ '*vj \J I UmJ 'LTu' u Lie: WfWJ u Year 195

204 Philippines-4 cd 4.4 Annual Pattern of Discharge E g, i_ nj x: ? CD O) Marikina River Basin (1995) D.A.: km2 -daily discharge -12-month moving mean flow duration curve Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Pagsanjan River Basin (1989) D.A.: km2 -daily discharge -12-month moving mean flow duration curve Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 196

205 1 1 1 í i Philippines Annual Maximum and Minimum Discharges Station: Marikina River [D.A.: km2] Year Maximum Date m3/s Minimum Date m3/s Year Maximum Date m3/s Minimum Date m3/s /11 2, / /25 1, / /9 2, / /1 1, / /1 2, / / / / / /19 1, / / / /23 2, / / / /3 2, / Station: Pagsanjan River [D.A.: km j Year Maximum Date m3/s Minimum Date m3/s Year Maximum Date m3/s Minimum Date m3/s / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / Hyetographs and Hydrographs of Major Floods Major Marikina River Basin (1999) H ui - H H i» -» - a - U s i i \ j îî X Q ^ =1 Cl. CD»< Jul 19-Jul 23-Jul 27-Jul 31-Jul 4-Aug 8-Aug 12-Aug Date

206 Philippines-4 Major Pagsanjan River Basin (1988) 150 LU D r "g j \ Y J 5" ôt ~ [ 800.0, Oct 11-Oct 13-Oct 15-Oct 17-Oct Oct Date 5. Water Resources 5.1 General Description The Pasig-Marikina-Laguna de Bay Basin is composed of 29 sub-basins of which 22 sub-basins collectively known as Laguna de Bay basin drains to the Laguna Lake, while runoffs from the other seven Metro Manila river sub-basins flow to the Manila Bay. River diversions for irrigation systems are made from the Laguna sub-basins before reaching the lake. The lake on the other hand is used for fisheries, duck-raising, navigation, effluent sink by industries and municipalities, flood-control detention storage, lower pool of the Kalayaan Pumped-Storage Hydro-Electric Plant, and earmarked for future source of fresh-water supply. There are two major reservoirs in the Pasig-Marikina-Laguna de Bay Basin i.e. the Caliraya Reservoir and the La Mesa or Novaliches Reservoir. Caliraya Reservoir, which is located at Laguna, has a catchment area of 129 km2 with an effective capacity of 78 million cubic metres (MCM). It is used for power generation, flood control as well as for municipal and industrial use of water. It is also used by the Kalayaan pumped-storage hydropower plant for its cycles of water pumping and releasing between Laguna de Bay and the Caliraya lake. La Mesa Reservoir, which supplies water both for municipal and industrial use for almost the whole of the Metro Manila area has a catchment area of only 27 km. However, the volume of water in the reservoir is augmented by diverting water from the Angat Reservoir to Ipo Dam down to the La Mesa Reservoir through the Ipo Tunnels and Bicti-Novaliches Aqueducts. The Alat Dam with a watershed of 14 km also diverts water to the La mesa reservoir through the Alat-Sapang Kawayan Aqueducts. The gross capacity of La Mesa Reservoir is 45.4 MCM and its effective capacity is 38 MCM. 198

207 Philippines List of Major Water Resources Facilities Major Reservoirs Name of River Name of Dam Catchment Area km ] Gross Capacity [1 x 106 m3l Effective Capacity [lxio'm3] Purpose Caliraya Caliraya M. F, I, P Tuliahan La Mesa M.F,I Wawa Wawa M. F, I, P Purpose: P = Power Generation, F = Flood Control, M = Municipal Use, I = Industrial Use. Major Inter basin Transfer Name of Transfer Line Name of rivers connected From To Length (km) Maximum Capacity [m Is] Purpose Tunnel 1 Ipo Dam La Mesa M Tunnel 2 Ipo Dam La Mesa M Alat Aqueduct Alat Dam La Mesa M 5.3 Major Floods and Droughts From Date To Peak Discharge [m3/s] Rainfall [mm Duration [days] Meteorological Cause 21-Oct Oct-98 2, storm 31-Jul-99 7-Aug-99 2, storm 25-Oct Oct-00 2, storm 6. Socio-cultural Characteristics The inhabitants of the Pasig-Marikina-Laguna de Bay belong to the Tagalog-speaking people of the country and are predominantly Christian (majority are Roman Catholic). There are small segments of cultural minorities living in the eastern mountain ranges. Most of the rural population are farmers (lowland and upland), and lake fishermen. The urban population is engaged in commerce, light to heavy industries, and services. The smallest political units are called "barangays" which compose the municipalities (towns and cities), while the municipalities form the provinces (Metro-Manila, Cavité, Laguna, Batangas, Rizal and Quezon). The latter five provinces are grouped as the "Calabarzon" region which lies directly south of Metro Manila. The language and culture of the people have been molded by the tropical humid environment (farming and fishing), with a strong Spanish influence. The word "Tagalog" is derived from "taga ilog" which means "river dweller". The name of the lake "Laguna de Bay" is formed by the Spanish phrase "Laguna de" (lake of) and the Tagalog word "Bai" (woman). The Tagalog word "Pasig" means sand bar, while Marikina comes from the Spanish name "Mariquina". The Tagalog language is the basis of the national language, Filipino, and is basically Malayan, with a major influx of Spanish words. Spoken Filipino is often interspersed with English, an influence of Americandominated mass media such as TV and cinema. While lowland farmers raise rice, sugar, and coconut as well as ducks, chicken and hogs, upland farmers/foresters grow orchards of fruits and vegetables (including honey), or else extract forest products such as bamboo and rattan. Horses, water buffaloes (carabaos), cattle, and goats are also 199

208 Philippines-4 raised for animal power, meat or dairy products. The native cuisine of the region is thus mainly characterized by rice, fish, coconut, sugar, tubers and other tropical crops. Thus one encounters native rice cakes enriched with coconut meat or coconut milk and sweetened by unrefined brown sugar, beverages such as coconut wine ("tuba") and coconut liquor ("lambanog"), all sorts of coconut confections, and the unique salted egg with the immature duck fetus ("balut") which is a Laguna de Bay cultural icon. Small fishermen make their catch in the open lake waters and lakeshores while commercial aquaculture operators raise milkfish ("bangus") and other brackish-water species inside fish pens and fish cages. However, with the growing urbanization and westernization, the eating habits of the population, as in the rest of the Philippines, are gradually shifting to less rice and more bread, pasta and pizza. Fresh fish, however, remain to be a premium source of protein, compared to the usual pork and chicken. The native dwelling or nipa huts (made of bamboo members and panels, and roofed with palm-leaf shingles) are elevated on stilt posts, with the upper floor raised above the highest flood of experience and are less vulnerable than the more modern bungalows. The old horse-drawn "carretela" has huge wheels which keep the passengers dry and above the water during floods. This wheeled vehicle together with the native dugout boats ("banca"), equipped with outriggers and engined-propellers, are ready substitutes for the motorcars as means of transportation during monsoon floods. The urban workers are employed in commerce, services, manufacturing (electronics, automotive assembly, chemicals, food and beverages, appliances, handicrafts, etc.) and mining. The major service sectors are power utilities, water utilities, irrigation systems, transportation, telecommunications, and tourism. The other government services are military, health, education, social welfare, disaster and environmental management and protection, similar to other regions of the country. Inside Metro Manila, the basic municipal services such as traffic, solid waste and flood management are administered by the Metro Manila Development Authority (MMDA), which coordinates with the local governments of the various cities. Flood-control monitoring and operations in the Pasig-Marikina rivers are also the functions of MMDA, through its Effective Flood Control Operations System (EFCOS). The environmental quality of the Pasig River, in particular, is being improved by the Pasig River Rehabilitation Project (PRRP) under the Office of the President. The natural resource management of the watersheds and lake in the Laguna de Bay Basin, are the functions of a river basin organization, the Laguna Lake Development Authority (LLDA), attached to the Department of Environment and Natural Resources (DENR), which also coordinates with various local governments. Other agencies which develop and maintain infrastructures and provide related services in the region are the Department of Public Works and Highways (DPWH), Metropolitan Waterworks and Sewerage System (MWSS), Local Water Utilities Administration (LWUA), National Irrigation Administration (NIA), National Power Corporation (NPC), Bureau of Soils and Water Management (BSWM), Department of Health (DOH), Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) and Philippine Ports Authority (PPA). 200

209 Thailand Thailand-lO: Chao Phraya River Thailand-11: Sakae Kräng River Thailand-12: Pasak River Thailand-13: Tha Chin River Sakae Kräng River 201

210 Introduction Thailand is situated in the tropical monsoon zone of Southeast Asia and cover an area of 5 13,1 1 5 km from latitudes 5 30' N to 21 00' N and longitudes 97 00' E to ' E. The country is bordered on the west and northwest by Myanmar, on the northeast and east by People's Democratic Republic of Lao, on the southeast by Cambodia and the Gulf of Thailand, and on the south by Malaysia. Thailand has maximum dimensions of about 2,500 km from north to south and 1,250 km from east to west with a coast line of approximately 1,840 km along the Gulf of Thailand and 865 km along the Indian Ocean. The topographic features of Thailand comprise of three main types of landform: highlands, plains and plateaus. The highlands include several mountain ranges covered with forest extending from north to south along the entire western length of the country. The coastal area of the Gulf of Thailand is another part of the highlands. The central part of the country is an extensive alluvial plain, while the northeast region is undulating plateau. Thailand is a warm and semi-humid tropical country. The climate is monsoonal, marked by a pronounced rainy season lasting from about May to September and a relatively dry season for the remainder of the year. The monsoon season rainfall is around 90 percent of the annual rainfall. The mean annual precipitation is 1,400 mm varing from 1,100 mm in the northeast plateau to over 1,800 mm in the southern peninsula. The population in 2003 was approximately 63 million. The hydrological characteristics of Thailand vary from region to region depending on various factors such as the geographical and climatic conditions of each region. Further, the country area is divided into 25 river basins according to the topography. The four rivers catalogued in this volume are the Chao Phraya River, Sakae Krang River, Pasak River and Tha Chin River. All are located in the Central part of the country. The confluence of the Ping, Wang, Yom and Nan Rivers originates the Chao Phraya River at Nakhon Sawan about 200 km north of Bangkok. The Sakae Krang River flows from northwest to southeast and joins the Chao Phraya River at the Krokphra district in U-thai Thani province. It has a catchment area of 5,202 km2. The Pasak River flows from north to the south and joins the Chao Phraya River at Ayuthaya province. It has a catchment area of 15,779 km2. The Tha Chin, a branch of the Chao Phraya River, begins at Chainat province. It flows through Suphanburi and Nakhonpathom province, and drains to the Gulf of Thailand at Samuthsakom province. It has a catchment area of 14,199 km. Acknowledgements The following members of the Hydrological Information Center Sub-Committee of the Thai National Committee for IHP were involved in the compilation and preparation of the information for these four rivers. S. Sasisuwan, Department of Water Resources, M. Srikhajon and R. Krishnamra, Land Development Department, S. Chaiyapruk, The Electricity Generating Authority Thailand, L. Rojanasoonthon and A. Buddhapalit, The Royal Irrigation Department, P. Amornpatawat, Meteorological Department, Y. Chantajitra, Department of Energy Development and Promotion, W. Niyom, Kasetsart University, A. Na Lamphun, Royal Forestry Department, and K. Rachadanurakh, National Research Council of Thailand. 202

211 Thailand-10 Chao Phraya River Map of River.1530 N \ -jô^jt''''^'^'"' r^^ / ^ç^îox fe \ Chai Nal^jJY^^ 'Ov. Ri5iï['*JE 3r ^^\itesfici--t^ yf ü'iri*^ B.i^S ^ 4 Id ïr[iiqws>y 1 *^3ñui( PraEífrtíiSf 3, Km I 203

212 Thailand-10 Table of Basic Data Name: Chao Praya river Serial No. : Thailand-10 Location: Central part of Thailand N13 29' 18" ' 54" E 99 31' 06" ' 30" Area: 21,725 km" Length of Main stream: 712 km Origin: Pak Nam Pho District, Nakhon Sawan Highest point: 284 m Province Outlet: Gulf of Thailand Lowest point: 0 m Main geological features: Phu Kradung and Phra Wihan Formation, Rattburi Formation, Alluvium, Eluvium, Kanchanaburi Formation, Marine Formation, Andesite-Rhyorite, Porphyry and Tuff, Bassalt Main Tributaries: Main Chao Phraya river (21,725 km ), Bung Boraphet (4,902 km ) Main Lake: None Main Reservoir: Chao Phraya Dam (1957) Mean annual Precipitation: 1,487.3 mm. Mean Annual Runoff: m /s at Sang Khla Buri District, Chainat Province Population: 11,710,968(1998) Main Cities: Bangkok, Nakhon Phathom, Ayutthaya, Samut Prakan, Ang Thong, Singburi, Lopburi, Chai Nat, Pathum Thani, Non Thaburi, Nakhon Sawan, Phet Chaboon, Samut Sakhon Land use: Forest 2.1 %, Agriculture & urban area 92.7 %, Water resource 5.2 % 1. General Description The origin of the Chao Phraya River is the confluence of the Ping, Wang, Yom and Nan rivers about 200 km north of Bangkok. From Nakhon Sawan, the river flows through the central plain passing Bangkok toward the Gulf of Thailand. At Ayutthaya about 55 km North of Bangkok, the Chao Phraya river is joined by the Pasak river which rises in the divide between the central alluvial plain and the North-east plateau. The Lower Chao Phraya river basin starts from Nakhon Sawan and has a drainage area of 21,725 km the average annual precipitation is 1,487.3 mm and the average discharge at Sang Khla Buri District, Chainat Province has been m3/s. Chao Phraya reservoir built in 1957 is the largest existing reservoir in this basin. 204

213 Thailand Geographical Information 2.1 Geological Map tí»' - r M* Ritiun ronutan rllfj n AflUII^ rdtnilbfl t3m Source: Geological Map of Thailand too Kb 100»I : Jumchet C. and Javanaphet, 1969, Department of Mineral Resource 205

214 Thailand Land-use Map I I PsddyFidd ^^ Fidd Crop ^1 Forest ^1 Perenntal I Swamp and Oras^land Hj Walet Boch' ^U Urban.Area ^H.Aquaculture Ltod 13 N IDO Km Source: Landuse Map of Central of Thailand, 1998 Landuse Planning Division Department of Land Development 206

215 Thailand Soil Map (T]cutrr i»»i $ htomquint«h Lourr uttiriuvcmt«h E l^ a cu» euviv T PELLUDEPTT* PiLLurrtm CUYIT TKoraouiPT* cutitmidtropaavtrr» CUTI Y UtTKOMm cutviv wtruwuoiii CUTIV ««LCWtTMLI cuttr HAriuiTout LMuv TimrMUM.ri Cl*Tf r TFOPIOMiP* \.o»àn mnutiuft curt r TForuoMP* CUVEV PUUBUULTt curer ruuftuum eutit TK9mMUH.rt «Mirnu. PLiwTMurruLTt loun curir pkleurrvit«puiuttult«14» riliuttuit«eurf» r«.ïuttvt,t» loun fuflmtvilt* KOPf COUPLII 1*W. 100 Kn Source: General Soil Map of Thiland, Soil Survey Division, Department of Land Development. 207

216 Thailand-10 E(OQO 2.4 Characteristic of River and Main Tributaries No. 1 2 Name of River Chao Phraya (Main River) Bung Boraphet Length (km) Catchment area (km2) , , Longitudinal Profiles Highest Land-Use Cities Peak (m) [%] (1994) - - Bangkok, Samut Sakhon, Nakhon Phathom, Samut Prakan,, Ang Thong, Forest Singburi, Lopburi, Chai (2.1 %), Nat, Pathum Thani, Agriculture & Non Thaburi, Nakhon Urban Area Sawan, (92.7 %), Water (Phaisari, Nong Bua, Resources Phayuhakhiri, Thatako (5.2 %) District) Nakhon Sawan Province (Chai Dan District) Phet Chaboon Province i i i i i i Bung Borapet 50 0 C ) 100 i. i i i ; i I I I I I I I I I I iiii 400 * i i 500 Distance (km) 208

217 Thailand Climatological Information 3.1 Annual Isohyetal Map and Observation Stations 209

218 Thailand List of Meteorological Observation Station Station No. Station Name Location Observation period Mean annual Precipitation (mm) Observation itemsl) Tha Ta Ko N 15 38' 25" E ' 12" ,074.1 P(S) Nong Bua N 15 51' 47" E ' 50" ,027.9 P(S) Muang, Nakhon Sawan N 15 39' 55" E ' 43" ,068.2 P(S) Phai Sari N 15 35' 41" E ' 39" ,051.4 P(S) Royal Irrigation Department, Bangkok N 13 47' 14" E ' 56" ,459.9 P(S) Pho Thong N 14 38' 31" E ' 42" P(S) Tha Wang N 14 48' 00" E ' 00" P(S) Kok Phra N 15 33' 19" E ' 35" P(S) Muang, Singburi N 14 53' 12" E ' 29" P(S) Muang, Ang Thong N 14 35' 14" E ' 22" ,113.7 P(S) Ayutthaya N 14 21' 49" E ' 34" ,035.0 P(S) Muang, Pha Thumthani N 14 01' 04" E ' 11" P(S) Muang, Nonthaburi N 13 50' 21" E ' 45" ,059.8 P(S) Muang, Samut Prakan N 13 36' 00" E ' 59" ,247.4 P(S) 1) P(S) : Precipitation from standard rain gauge 3.3 Monthly Climatic Data Station: Bang Na, Bangkok Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Period of the mean , , : Temperature [ C] 2 : Precipitation [mm] 3 : Evaporation [mm] 210

219 Thailand Long-term Variation of Monthly Precipitation Series Station: Meteorological Department, Bang Na, Bangkok E ë- 400 To c 300 ñ ^ cccccccccccccccccccccccc cccccccc c Date (Period ) Station: Amphoe Muang, Lopburi Province SCO -I 500 Date (Period ) 211

220 Thailand Hydrological Information 4.1 Map of Streamflow Observation Stations 212

221 Thailand List of Hydrological Observation Stations No. Station Location Catchment area [km2] Observation period Observation items1' Muang District, Nakhon Sawan Province N 15 40' 15" E ' 45" 110, present Q(H1) Huai Kot District, U-Thai Thani Province N 14 35' 05" E ' 12" present Q(H1) Sanphaya District, Chai Nat province N 15 09' 57" E100 11' 32" 120, present Q(H1) No. Q2) [m3/s] Qmax3) [m'/s] Qmax4) [m3/sl QminS) [m'/s] Q/A [m3/s/100km2] Qmax/A [m'/s/100km ,820 2, ,538 2, ) HI : Water level at recording chart 2) Q : Mean annual discharge 3) Qmax : Maximum discharge 4) Qmax : Mean annual maximum Discharge 5) Qmin : Mean annual minimum Discharge Period : Long-term Variation of Monthly Discharge Series Station: at Amphoe Mueang, Nakhon Sawan Province it oc Date (Period ) 213

222 Thailand Station: at Ban Re Raí, Chai Nat Province Date (Period ) 4.4 Annual Maximum and Minimum Discharge Station: Muang District, Nakhon Sawan Province (110,569 km2) Year Date Maximum m'/s 2,601 4,712 3,825 2,959 3,825 1,540 2,930 2,768 1,271 2,827 4,420 2,370 1,310 2,600 1,930 4,355 2,618 1, Date Minimum m'/s Year Maximum Date m'/s 1,412 4,350 1,663 1,600 2,290 1,260 2,142 1,471 1,652 1,916 1,458 1,158 1,440 1,401 1,070 2,539 4,280 3,011 1,318 Minimum Date m3/s

223 Thailand Hyetoghraphs and Hydrographs of Major Floods Before Phumipol Dam Construction J3 03 h 03 Q. 0) Period (6 Aug-16 Dec 1961) (day) O c rr After Phumipol Dam Construction 'linn / A w "I'l"! JU 03 3 h 03. If =\ a 03 < 0.0 Period (11 Sep-16 Nov 1978) (day)

224 Thailand Major Peak Discharge Experiences No. Drainage Area (km2) m3/s Discharge m'/s/km2 Date Period ,569 4, /1/ ,693 4, /5/ Water Quality Point Year PH DO (mg/i) BOD (mg/l) Coliform (MPN/100 ml) Upper Chao Phraya River ,000 Middle Chao Phraya River ,000 Lower Chao Phraya River ,000 Chao Phraya River Muang District, Chainat Province Chumsang District, Nakhonsawan Province Supunburi River AJVluang,Supunburee Water Resources 5.1 General Description The Chao Phraya River Basin is divided into 2 sub-basins. The water level in Chao Phraya River is greatly influenced by the operation of three main dams built in the basin, namely : - Bhumipol dam on Ping River and Sirikit dam on tha Nan River for the reaches downstream from the dams to Nakhon Sawan Province. - Chao Phraya Dam on the Chao Phraya River from the reach from Chaînât Province to Ang Thong province. Flood plains which are fertile for rice cultivation exist on both sides of the Chao Phraya River in the central plain covering an area of 1 million hectares. Flooding in the basin usually occurs during the typhoon season i.e. from July to September. 216

225 Thailand MapofWater Resources Systems -áe (^. nst o «o SOI 5.3 List of Major Reserviors The flows of Chao Phraya River Basin are greatly influenced by the operation of two main dams built in the Ping River basin (Bhumiphol Dam) and Nan river Basin (Sirikit Dam). Chao Phraya Dam was built for irrigation and flood control purposes. 217

226 Thailand Socio-cultural Characteristics The confluence of the Ping, Wang, Yom and Nan rivers at Nakhon Sawan Province is the beginning of Chao Phraya River. Siltation of these four rivers has enriched this river basin making Chao Phraya River basin the most fertile plain of the country. Inhabitants of this river basin earn their living from agricultural production of rice, vegetables and other major economic crops. Water related festivals are Songkhran water festival and the flower float festival. Inhabitants of this river basin are peace loving and very proud of their inherited cultures. The capital city, Bangkok, is located in this basin thus contributing to higher economic and social development than in other river basins. 7. References Department of Mineral Resources, (1969): Geological map of Thailand. Meteorological Department, (2001): Climatological Data of Thailand Royal Irrigation Department, (2000): Hydrology Division: Thailand Hydrological Yearbook Department of Land Development. Soil of the Kingdom of Thailand, (1972): Explanatory Text of the General Soil Map, Soil Survey Division. Electricity Generating Authority of Thailand, (1992): Surface runoff and specific yield of river basin in Thailand, Survey and Ecology Department, Meteorology and Hydrology Division. 218

227 Thailand-11 Sakae Krang River Map of River Table of Basic Data Name: Sakae Krang river Serial No. : Thailand-11 Location: Central part of Thailand N 15 15' 00" ~ 16 08' 00" E 99 00' 00" ~ ' 00" Area: 21,725 km' Length of Mainstream: 427 km Origin: Mokoju range Outlet: Cha Phraya river Highest point: 1,960 m Lowest point: 250 m (Krok Phra District, Makhon Sawan Province) Main geological features: Alluvium, (is it alluvium?) Eluvium, Granite, Kanchanaburi Formation, Rattburi Formatiom, Phu Kradung Formation Main Tributaries: Nam mae Wong (1,060 km^), Klong Pho (1,512 km2), Huai Tap Salao (778 km2), Lower Sakae Krang (1,842 km2) Main Lake: None Main Reservoir: Tap Salao Dam (152 mmc 1988) Mean annual Precipitation: 1,162.1 mm. ( ) At station Nong Kha Yang District, U-thai Thani Province Mean An nual Runoff: m/s ( ) at station Khanu Woralak District, Kam Phaeng Phet Province Population: 427,997(1998) Main Cities: U-thai Thani, Nakhon Sawan, Kham Phaeng Phet Province Land use: Forest 29.0 %, Agriculture & urban area 70.8 %, Water resource 0.2 % 219

228 Thailand General Description Sakae Krang river basin is located in the Central Plain of Thailand. It flows from northwest to southeast in direction, that is from Mae Wong district and Lard Yao district in Nakhon Sawan Province. It then joins Khlong Pho at Sawang Ar-rom district in U-thai Thani province and then joins Huai Thap Salao at Thap Than district of the same province. This river finally joins Chao Phraya river at Rrokphra district in U-thai Thani province. The high and steep mountainous upstream area of Sakae Krang river and flat downstream area before joining the Chao Phraya river causes flash flooding every rainy season. 2. Geographical Information 2.1 Geological Map 220

229 Thailand Land-use Map [~~ PidityFidd H FiddCtop Source: Landuse Map of Central of Thailand, 1998 Landuse Planning Division Department of Land Development N K» 2.3 Soil Map ttm 221

230 Thailand Characteristic of River and Main Tributaries No. Name of River Length (km) Catchment area (km2) Highest Peak (m) Cities Land-Use [%] (1994) Nam Mae Wong Khlong Pho Huai Thap Salao Lower Sa Kae Krang 81 1, , ,842 Mokoju 1,960 1,304 Khao Yai 1,554 Khao Luang 772 Lat Yao District Nakhon Sawan, Kha Woralakburi district Kham Phaeng Phet Province Lat Yao District Nakhon Sawan Province Lan Sak District U-thai Thani Province Thap Than, Nong Chang, Lat Yao, Sawang Arlom, Nong Krayang District, U-thai Thani Province Forest (29.0 %), Agriculture & Urban Area (70.8 %), Water Resource (0.2 %) 5 Sa Kae Krang (main river) 222 5,202 - U-thai Thani, Kham Phaeng Phet Province 2.5 Longitudinal Profiles Sakae Krang Nam Mae Wong Khlong Pho Huai Thap Salao Distance (km)

231 Thailand Climatological Information 3.1 Annual Isohyetal Map and Observation Stations 223

232 Thailand List of Meteorological Observation Station Station No. Station Name Location Observation period Mean annual Precipitation (mm) Observation items1' Ban Pang Ma Ka N 15 54' 10" E 99 28' 15" ,232.4 P(S) Ban Hang Rai N 15 38' 23" E 99 32' 20" ,061.9 P(S) Ban Bung Ai N 15 31' 38" E 99 28' 10" ,276.8 P(S) Lan Sak N 15 27' 00" ,030.1 P(S) San Chao Kai To, Lat Yao N 15 47' 01" E 99 40' 55" ,184.4 P(S) Lat Yao N 15 44' 58" E 99 47' 34" ,040.8, P(S) Muang, U-thai Thani N 15 22' 39" E ' 39" ,051.0 P(S) Nong Kha Yang N 15 21' 46" E 99 55' 56" ,162.5 P(S) Thap Than N 15 27' 27" E 99 53' 41" ,166.2 P(S) Sawang Arlom N 15 34' 56" E 99 51' 49" ,171.7 P(S) Nong Chang N 15 26' 00" E 99 44' 00" ,168.3 P(S) Ban Rai N 15 28' 23" E 99 31' 18" ,311.3 P(S) 1) P(S) : Precipitation from standard rain gauge 3.3 Monthly Climatic Data Station: Muang, Uthaithani Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Period of the mean , , : Temperature [ C] 2 : Precipitation [mm] 3 : Evaporation [mm] 224

233 Thailand Long-term Variation of Monthly Precipitation Series Station: Amphoe Muang, Uthaithani Province 4S0 400 (Ac >i^(da)0«-csdcr>4ijitor^ ixio>c3^<siin^snt }r-itio>q -- ts tn cccccccccccccccccccccccc Í0 10 W Í0 Month (Period ) Station: San Chao Kai To, Lat Yao District, Nakhon Sawan Province 9 cc. iiilkiiilmui {?>{?iotcb90000 Month (Period ) 225

234 Thailand Hydrological Information 4.1 Map of Streamflow Observation Stations 4.2 List of Hydrological Observation Stations No I0S04 station Khanu VVoralakburi District, kham Phaeng Phet Province Lat Yao District,.Nakhon Sawan Province Lan Sak District, U-thai Thani province San Chao Kai To, Lat Yao District, Nakhon Sawan Province Location N 15 54' 10" E 99 28' 45" N 15 38' 23" E 99 32' 20" N 15 31' 38" E 99 28' 10" N 15 47' 01" E 99 40' 55" Catchment area (A) [km^l ,246 Observation period present present present Observation items'' (frequency) Q(H1) Q(H1) Q(H1) Q(H1) 226

235 Thailand-11 R No Q2) [m3/s] Qmax3' [m3/s] ) HI : Water level at recording chart 2) Q : Mean annual Discharge 3) Qmax : Maximum Discharge 4) Qmax: Mean annual maximum Discharge 5) Qmin : Mean annual minimum Discharge Qmax [m3/s] Qmin5' Q/A [m3/s] [m3/s/100km Long-term Variation of Monthly Discharge Series Station: at Ban Pang Makha, Kamphaeng Phet Province (0 *»^ n E Qmax/A [m3/s/100km2] Period O CO 3" CO 3 rsj CO 3 ro CO 3 S 3 m CO CO 3 CO CO 3 Oï CO 3 O en 3 Ol 3 rnj Ol 3 ro as 3 s 3 m en 3 vo en 3 r^ en 3 00 en 3 en 3 O O 3 O 3 Month (Period ) 227

236 Thailand Annual Maximum and Minimum Discharge Station: Khanu Woralakburi District, Kham Phaeng Phet Province (938 km2) Year Maximum Date m3/s Minimum Date m3/s Year Maximum Date m3/s Minimum Date m3/s Hyetoghraphs and Hydrographs of Major Floods I 300.0!fc n n I ^T W / \ ' i m 30.0 ET % 70.0 w an r\ Period (11-26 Oct 1988) (day) 228

237 Thailand Major Peak Discharge Experiences No. Drainage Area (km2) m3/s Discharge m3/s/km2 Date Period of year /09/ /20/ /18/ , /09/ Water Quality Point Year PH DO (mg/l) Bod (mg/l) Coliform (MPN/100 ml) 1) Wong River Khao Chon Kan Ban Kaeng Kao Yai Ban Tha Yu Sawang Arlom ) Sawang Arlom Thap Than District Nong Kha Yang District Muang District 3) Huai Thap Salao 4) Nam Mae Wong 5) Sakae Krang River ) Sakae Krang River Water Resources 5.1 General Description The Tha Chin River basin is divided into 5 sub-basins. Most of the areas in the river basin are field crop and paddy field. The water resource is utilized mainly for paddy irrigation. Thap Salao Dam is the only existing impounding reservoir in the basin which has the gross capacities and effective capacities of 160 x 106 m3 and 152 x 106 m3 respectively. 229

238 Thailand Map of water Resources Systems 1»00 KWOO tj A ResenioT M^ 0 Wier / ^^ Dam ' 1 \ hmoo i \. / «00- L ' 4mw»m ^, \ Ç fc- v^> V r»&n S (_ AT»Wa*L«Q*M «^\,. 1 "* ""^ * Tt*»mSt^ 1"'' ) ^>^ Km -isoo'.,., s» 00 too 00 I 1 ( < 5.3 List of major Reserviors Name of River Name of Reservior Catchment area [km2 Gross Capacity 10' m3] Effective Capacity llo'm3] Purpose'* Year of completion Huai Thap Salao Thap Salao A, F, I, P, W ) A: agriculture, F: flood control, I: Industry, P : Hydropower, W: Munucipal water supply 230

239 Thailand Socio-cultural Characteristics The source of the Sakae Krang river is in a mountain watershed in the north and central regions of Thailand in U-thai Thani, Kam Paeng Phet and Nakhon Sawan provinces. The people living in the river basin grow crops for their livelihood. They have their own local dialects. Water related festivals are food offering to monks day in July in U-thai Thani province and folk music festival and first harvest celebration in Kam Phaeng Phet province. In general inhabitants of this river basin are nice and calm and enjoy their active participation in the annual festival. Tourist attractions in this river basin invite tourists to visit all year round. The richness of natural resources and tourist destinations in this river basin fuels economic wealth in many provinces. 7. References Department of Mineral Resources, (1969): Geological map of Thailand. Meteorological Department, (2001): Climatological Data of Thailand Royal Irrigation Department, (2000): Hydrology Division: Thailand Hydrological Yearbook Department of Land Development. Soil of the Kingdom of Thailand, (1972): Explenatory Text of the General Soil Map, Soil Survey Division. Electricity Generating Authority of Thailand, (1992): Surface runoff and specific yield of river basin in Thailand, Survey and Ecology Department, Meteorology and Hydrlogy Division. 231

240 ThaiIand-12 Pasak River Map of River N S iw) ^ ^^ \ Petchab)^^ i ^ilf ^ ^ y-äj»'^aryhulci:^^ Km 232

241 Thailand-12 Table of Basic Data Name: Pasak river Serial No. : Thailand-12 Location: Central part of Thailand N 14 21' 44" ' 02" E ' 40" ' 56" Area: 15,779 km2 Length of mainstream: 1,039 km Origin: Phetchaboon range Highest point: 1,746 m (Dan Sai District, Loei Province) Outlet: Cha Phraya river Lowest point: 3 m (Uthai District, Ayutthaya Province) Main geological features: Phu Kradung, Phu Phan and Phra Wihan Formation, Ratburi Formation, Alluvium, Eluvium, Marine Formation, Andesite-Rhyorite, Porphyry and Tuff, Basalt and its equivalents, Granite, diorite and quartz diorite Main Tributaries: Upper Pasak (1,465 km2), Huai Nam Pung (655 km2), Second part of Pasak (2,205 km2), Third part of Pasak (4,717 km2), Huai Kao Kaew (520 km2), Lam Sonthi (1,410 km2), Lower Pasak (4,152 km2), Huai Muak legk (655 km2), Main Lake: None Main Reservoir: Pa Sak Cholasist Dam (764 million m, 1999) Mean annual Precipitation: 1,207.6 mm. ( ) At station Wichienburi District, Phetchaboon Province Mean Annual Runoff: m/s ( ) at station Kaeng Khoi District, Saraburi Province Population: 1,785,424(1998) Main Cities: Phetchaboon, Lopburi, Saraburi and Ayutthaya Province Landuse: Forest 19.4%, Agriculture & urban area 80.4%, Water resource 0.2 % 1. General Description The origin of the Pasak River is in the highlands of Phetchaboon Province and flows through hundreds of kilometers of the central plain of Lopburi, Saraburi and joins the Chao Phraya River at Ayutthaya Province. This river flows from the mountainous north to the south. There are short tributaries from the east and the west joining the river as it flows to Chao Phraya River. 233

242 Thailand Geographical Map 2.1 Geological Map ' «ü PtM plkm Md Ptn IWtOT FonwMn rwpnjff fwbwt Fonuton r^^^ N Sir '\/W l taum nd ta «qi^nlht w IF Onnik.Aorta and quarti dmh / ^JtS nmv PTw Kmkng romton llakia FormMn y i il 1 ^\ tí '.V''^^^» <; Km Source: Geological Map of Thailand : Jumchet C. and Javanaphet, 1969, Department of Mineral Resources. 234

243 Thailand Land-use Map Ml $ Km Source: Landuse map of Central of Thailand, 1998 Landuse Plaiming Division Department of Land Development 235

244 Thailand Soil Map m B H 1 toioq <ê r^^ SmOV QUWTTZIf UUIUtHTS CUtVCY PELLUDERTS CLAYEY CHROHVSTEirrS ClATEY TKOfMUErrs cuiyty gstnorerrs CLAYEY CUCtUSTOLLB cuerrt tmplurrolls LOMIYTKOPItQtMlFS LOJUIY PIU,eUtTU.PG -16 M CLAYEY HAPLUSTKIFS «KELCTAl HAPlUtTALFG LOAMY PALCAQUULTS SHLETli PLIWTHUSTULTS LCUUIV PALEUSTVLTS CLAWCY PAieUSTULT? -WOO H SLOPE GKELFTAL PALEUSTULTS LOAMY PALEUSTULTSi SKELETAL HAPIUSTVLTS SKELETAL PLINTHUrrULTiy LOAMY PAlE*«i;ULT» couriex Water 100 Km 236

245 Thailand Characteristic of River and Main Tributaries No Name of River Pasak (main river) Upper Pasak Huai Nam Pung Second part of Pasak Third part of Pasak Huai Kao Kaew Lam Sonthi Lower Pasak Huai Muak legk Length (km) Catchment area (km2) , , , , , , Highest Peak (m) 1,746 m 1,235 m 1,746 m 1,279 m 677 m 600 m 846 m ,078 m Cities Population (1998) Phetchaboon, Lopburi, Saraburi and Ayuthaya Province Lorn Sak, Lom Kao, Nam Nord District, Phetchaboon Province Lom Sak, Lom Kao District, Phetchaboon Province, Dan Sai District, Loei Province Muang, Khao Ko, Lom Sak, District, Phetchaboon Province Srithep, Wichienburi, Nong Phai, Muang, Bungsamphan District, Phetchaboon Province Srithep District, Phetchaboon Province Chaibadan, Kokcharoen District, Lopburi Province Lam Sonthi, Chaibadan District, Lopburi Province Muak Legk District, Saraburi Province. Wichienburi District, Phetchaboon Province Si Kue, Dankhuntot District, Nakhon Ratchasima Province Thepsatit District, Chaiya Phum Province Muak Legk, Kaeng Khoi, Muang, Phraphutabath, Sao Hai, Wang Muang, Ban Mor, Nong Done District, Saraburi Province Chaibadan, Tha Luang, Pattananikhom District, Lopburi Province Nakhon Luang, Tha Rua District, Ayuthaya Province Muak Legk, Wang Muang, District, Saraburi Province Pak Choung District, Nakhon Ratchasima Provincee Land-Use [%] (1994) Forest (19.4%), Agriculture & Urban Area 80.4 (%), Water Resource 0.2(%) 237

246 ThaUand-12 E 2.5 Longitudinal Profiles r o () L / ] J J^ -^ Distance (km) Upper Part Nam Pung Second Part Third Part Huai Kok Kaew Lam Sonthi Lower Part MuakLek 238

247 Thailand Climatological Information 3.1 Annual Isohyetal Map and Observation Stations IE 00 woo 239

248 Thailand List of Meteorological Observation Station Station No Station Name Lom Kaod Lom Sak Muang Phetchaboon Khao Ko Ban Wang Dee Sri Thep Bua Chum Chaibadan Nong Phai Wichiengburi Ban Tha Yium Chaibadan Kaeng Hkoi Muang Saraburi Sao Hai Chaibadan Pu Kae Phutabaht Location N 16 53' 02" E ' 00" N 16 46' 25" E ' 48" N 16 26' 00" E ' 00" N16 13' 00" E ' 00" N 15 59' 50" E ' 28" N 15 28' 15" E ' 10" N 14 15' 50" E ' 13" N 15 59' 13" E ' 53" N 15 41' 20" E ' 40" N 15 20' 21" El 01 22' 30" N 14 36' 54" E ' 56" N 14 31' 32" E ' 50" N 14 32' 56" E ' 48" N 15 12' 17" E ' 06" N 14 40' 05" E ' 15" N 14 44' 44" E ' 56" Observation period Mean annual Precipitation (mm) 1, , , , , , , , , , , , , , , ,183.8 Observation items,) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) P(S) Pattananikhom Nong Done Muak Legk N 14 51' 16" E ' 32" N 14 38' 00" E ' 00" N 14 39' 20" E ' 07" , ,201.9 P(S) P(S) P(S) 1 ) P(S) : Precipitation from standard rain gauge 3.3 Monthly Climatic Data Station: Wichien Buri District, Phetchaboon Province Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Av. monthly Av. annual Period , , : Temperature [ C] 2: Precipitation [mm] 3: Evaporation [mm] 240

249 Thailand Long-term Variation of Monthly Precipitation Series Station: Wichien Buri District, Phetchaboon Province Month (Period ) Station: Ban Mee District, Lopburi Province Month (Period ) 241

250 Thailand Hydrological Information 4.1 Map of Streamflow Observation Stations N 10100' PctchMli Wùt^r Lrval Station 100 Km 242

251 Thailand List of Hydrological Observation Stations No. Station Location Catchment area (A) [km* Observation period Observation items ' (frequency) Nong Phai N 15 59' 50" E ' 28" present Q(H1) Ban Tha Yium N 15 20' 21" E ' 30" present Q(H1) WQ Ban Na Sonr Chaibadan N 15 13' 24" E ' 51" 1, present Q(H1) WQ Ban Pang Sua Hue Chaibadan N 15 06' 05" E ' 11" Q(H1) WQ Keang Khoi N 14 37' 33" E ' 00" 14, present Q(H1) WQ Muak Legk N 14 38' 04" E ' 37" Q(H1) No. Q2) lm3/s] Qmax3) [m3/s] Qmax4) [m5/s] Qmin5' [nrvs] Q/A [m3/s/100km2 Qmax/A m3/s/100km2] Period , ) HI : Water level at recording chart 2) Q : Mean annual discharge 3) Qmax : Maximum discharge 4) Qmax : Mean annual maximum discharge 5) Qmin : Mean annual minimum discharge 4.3 Long-term Variation of Monthly Discharge Series Station: at Ban Muang Nua,Keang Khoi District, Saraburi Province Month (Period ) 243

252 Thailand Annual Maximum and Minimum Discharge Station: Ban Muang Nua, Kaeng Khoi District, Saraburi Province (14,374 km2) Year Maximum Date m3/s Minimum Date m3/s Year Maximum Date m3/s Minimum Date m3/s , , , Hyetoghraphs and Hydrographs of Major Floods 244

253 Thailand Major Peak Discharge Experiences No. Drainage Area (km2) m3/s Discharge m3/s/km2 Date Period /8/ /9/ , /9/ /9/ ,374 3, /10/ /9/ Water Quality Point Year PH DO (mg/l) BOD (mg/1) Coliform (MPN/100 ml) 1) Pasak River , ,000 2) Pasak River ,500 3) Pasak River Lom Sak Muang Phetchaboon Water Resources 5.1 General Description The Pasak River includes both the central alluvial plain and North-east plateau. It is divided into 9 subbasins. The river basin contains both urban and agricultural areas with the water resource being utilized mainly for paddy irrigation. Pasak Cholrasist Dam is the only existing impounding reservoir in the basin which has gross and effective capacities of 780 x 106 m3 and 764 x 106 m3 respectively. 245

254 Thailand Map of Water Resources Systems «IM -II M A a Roovior Wier nam -«Tt»' 5.3 List of major reservoirs Name of River Name of Reservoir Catchment area km2 Gross Capacity [10* m3] Effective Capacity [10* m3] Purpose'* Year of completion Pasak Pasak Chonrasist 14, A, F, 1, W ) A: agnculture, F: Flood control, I: Industry, P : Hydropower, W: Municipal water supply 246

255 Thailand Socio-cultural Characteristics The population of northern culture are found in the upstream while central culture are found in the downstream part of the river basin. Water related cultures are the Songkran festival, flower float or Loy Kratong festival and long rowing boat racing while the non water related cultures are rice harvest, general merit giving and flower offering to monks festivals. Phetchaboon Province is the main tourist attraction of this river basin because of its mountains and highlands thus providing it an economic advantage. 7. References Department of Mineral Resources, (1969): Geological map of Thailand. Meteorological Department, (2001): Climatological Data of Thailand Royal Irrigation Department, (2000): Hydrology Division: Thailand Hydrological Yearbook Department of Land Development. Soil of the Kingdom of Thailand, (1972): Explanatory Text of the General Soil Map, Soil Survey Division. Electricity Generating Authority of Thailand, (1992): Surface runoff and specific yield of river basin in Thailand, Survey and Ecology Department, Meteorology and Hydrology Division. 247

256 Thailand-13 Tha Chin River Map of River 248

257 Thailand-13 Table of Basic Data Name: Tha Chin River Serial No. : Thailand-13 Location: Central part of Thailand N 17 05' 00" ' 00" E 98 54' 00" ~ 99 58' 00" Area: 14,199 km" Length of Main stream: 439 km Origin: Doi Luang Highest point: 1,390 m Outlet: Gulf of Thailand Lowest point: 0 m (Muang District, Samut Prakan Province) Main geological features: Granite, Kanchanaburi Formation, Ratburi Formation, Phu Kradung Foemation, Alluvium, Eluvium, Gneiss and Schist, Basalts and its equivalents Main Tributaries: Huai Kra Sieo (1,788 km2), Tha Chin Plain (12,41 1 km2) Main Lake: None Main Reservoir: Kra Sieo Dam (201 nunc, 1977) Mean annual Precipitation: 1,390.6 mm. ( ) At station Ban Rai District, U-thai Thani Province Mean Annual Runoff: 3.70 m/s ( ) at station Ban Thap Khrai, Ban Rai District, U-thai Thani Province Population: 1,817,708(1998) Main Cities: Suphanburi, Chainat, Nakhon Phathom, Samutsakhon, Nakhon Sawan and U-thai Thani Province Land use: Forest 7.5 %, Agriculture & urban area 90.8 %, Water resource 1.7 % 1. General Description Tha Chin, a branch of the Chao Phraya River, begins at Makham-Thao subdistrict, Wat Singh District of Chainat Province. It flows through Suphanburi, Nakhonpathom and drains to the Gulf of Thailand at Samuthsakorn Province. The lower river basin is connected to the Mae Klong River basin. Major tributaries of this river are Huai Krasieo and Supanburi rivers. 249

258 Thailand Geographical Map 2.1 Geological Map - laoo 14«Samiit Sakhon 76 Km l_ Source: Geological Map of Thailand : Jumchet C. Javanaphet, 1969, Department of Mineral Resources. 250

259 Thailand Land-use Map Al E fi^ 5 n lo V ^^^^ g^^ Lj ^^ Soplmnbiirl rn Paddy Field ^H Field Crop ^H Forest ^^M Perennial ^^ \X _ñ^ m^ Svranip and Grassland i 1^4 \ ^ ^M Water Body ^H Urban Area H~H~H 0 76iaii 1 «Off- i4ocrr-;:'^:^- Samut Soktioo Source: Landuse map of Central of Thailand, 1998 Landuse Planning Division Department of Land Development 100^00 251

260 Thailand Soil Map tt ^^^^ LO*«CUVFVtUir*ÛUEM' y ^^^H^ /^ " 1 t 1 Cl»VEV KïDRAQUCWTS ^^^ W^g ^^1 SAMOT 0UAPT7i >&MWErrrs ^^^H Â ^^1 lomirustifiimentb ^^H^ ^ ^H CLATCv PEiiurrtHTs ^^^ \ ^^1 CUTEY TROPAOUCm M^^^B ^^1 cuyrrmiotrof^auerrs ^bv ii 1 to««0vïtbowptb S««LETM. 0VSTROKPT3 ^^^I^I^BÍ ^^H ClAVEY HAPOQUOLLS ^^1 ClAYEY TROFAQumiFR ^^^^^^^H ^^^^L^^^^l HH LOAUY HAm«TM.rS ^B^^^l ^H ] } 1 lo**rym*piu>t»lf8/lo»mypaieustult» ^^1 LOMIY PM.EUSTU1T3 ^H ClATTr PM.CUtnK.T3 ^^1 Mdimi PM.IUSTULTS ^^1 lomiypmeustutvf SKEICTM. HAPVUBTUIT«^^1 310PÍ COWPIEI 0 76 Km imm' f 252

261 Thailand Characteristics of the River and the Main Tributaries No Name of River Tha Chin River Huai Kra Sieo Tha Chin Plain Length (km) Catchment area (km ) , , ,575 Highest Peak (m) Lowest Peak (m) 1,390 1, Cities Population (1998) Suphanburi, Chainat, Nakhon Phathom, Samutsakhon, Kanchanaburi and U- thai Thani Province Sam Chuk, Dermbang Nangbuad District, Suphanburi Province Ban Rai District, U-thai Thani Province Muang, Krathumban District, Samutsakhon Province Samphan, Nakhon Chaisri, Bang Lane, Putamonthon, Kamphaengsaen District, Nakhon Phathom Province Sawankaburi District, Chainat Province Sripachan, Muang, Songpinong, U-thong, Bangprama, Don-j-di, Samchuk District, Suphanburi Province Thamaka, Phanom tuan, Lao-Khuan District, Kanchanaburi Province Land-Use [%] (1994) Forest (9.2%), Agriculture & urban area (90.8 %), Water resource (1.7%) 2.5 Longitudinal Profiles 600 -i ^ î m ( J Distance (km) J i 300 -^Tha Chin Huai Kra Sieo i

262 Thailand Clîmatological Information 3.1 Annual Isohyetal Map and Observation Stations /-^^«^^^ÎV 1200 ^ m^^^:/ v-^-^-nv ^^ ^ ty^r ^U^ W X ^^f^v^' n^v 1 ""/ytí* y^^ ^\aw '"^T'f/ffsiv y^ñ/oíu \\. Á. fyrr 1 i'*^^ j^~> ^sfwof yi ^ )íl ^ a/ '^ñ^eit^y^m ^SopllMUwri 3j, S^S^i P^^SffyK ^f ' ^^^^ *w«a^ N-n-S ^ M Hi v^^'^^^'^^^^^^r ^^^^^^B W^^i 0 7ftX>«^Hi 1il T^^* «00- ^JKwCli Saimt Saklwm 99(,3ff 10<\00 ^ösp 254

263 Thailand List of Meteorological Observation Stations Station No. Station Name Location Observation period Mean annual Precipitation (mm) Observation items1' Ban Rai N 15 04' 49" E 99 31' 34" ,390.6 P(S) Dan Chang N 14 49' 05" E 99 41' 55" P(S) Muang Suphanburi N 14 28' 00" E ' 00" ,130.7 P(S) Wat Sing N15 15' 22" E ' 51" ,018.8 P(S) Han Kha N 14 58' 50" E ' 03" P(S) Song Pi Nong N 14 13' 16" E ' 27" ,039.1 P(S) Derm Bang Nang Buad N 14 50' 34" E ' 59" P(S) U-thong N 14 22' 25" E 99 53' 40" P(S) Sam Chuk N 14 45' 14" E ' 49" P(S) Sri Prachan N 14 37' 02" E ' 51" P(S) Bang Pueng N 14 19' 00" E 99 55' 00" ,129.1 P(S) Kra Turn Ban N 13 39' 00" E ' 00" ,136.6 P(S) Phanom Tuan N 14 07' 39" E 99 42' 07" P(S) Nakhon Chaisri N 13 47' 54" E ' 23" ,058.7 P(S) Kam Phaeng Saen N 13 59' 01" E 99 59' 42" P(S) Sam Phan N 13 43' 22" E ' 12" ,101.4 P(S) Bang Lane N 14 01' 25" E ' 34" ,061.6 P(S) Muang Samutsakhon N 13 31' 00" E ' 00" ,067.9 P(S) Bang pama N 14 24' 01" E ' 29" P(S) Don-j-di N 14 38' 00" E ' 27" ,011.7 P(S) Lao Kuan N 14 35' 25" E 99 46' 25" P(S) Don Tum N 13 57' 36" E ' 04" P(S) Sand Noi N 13 58' 31" E ' 05" ,032.4 P(S) 1) P (S) : Precipitation from standard rain gauge 255

264 Thailand Monthly Climatic Data Station: Muang district, Suphan Buri province Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Monthly Annual Period of the mean , , I; Temperature [ C] 2: Precipitation [mm] 3: Evaporation [mm] 3.4 Long-term Variation of Monthly Precipitation Series Station: Muang District, Suphanburi Province Date {Period ) 256

265 Thailand Hydrological Information 4.1 Map of Streamflow Observation Stations 257

266 Thailand List of Hydrological Observing Stations No. Station Location Catchment area (A) [km2] Observation period Observation items1' Derm Bang Nang Buad N 14 51' 44" E 99 39' 10" 1, Q(H1) Dan Chang N 14 49' 03" E 99 41' 51" 1, Q(H1) Ban Rai N 15 03' 06" E 99 35' 18" Q(H1) No. Q2) [m3/s] Qmax3' [m3/s] Qmax4) [m3/sl Qmin5' [m3/s] Q/A [m3/s/100km2l Qmax/A Im3/s/100km2] Period ) HI : Water level at recording chart 2) Q : Mean annual discharge 3) Qmax : Maximum discharge 4) Qmax : Mean annual maximum discharge 5) Qmin : Mean annual minimum discharge 4.3 Long-term Variation of Monthly Discharge Series Station: at Ban Dan Chang, Suphan Buri Province 258

267 Thailand Annual Maximum and Minimum Discharge Station: Kha Woralakburi District, Kham Phaeng Phet Province (938 km ) Year Maximum Date m3/s Minimum Date m3/s Year Maximum Date m /s Minimum Date m3/s Hyetoghraphs and Hydrographs of Major Floods Station: Ban Thap Krai, Amphoe Ban Rai, Uthaithani Province Date (Period 4 Sep - 30 Oct 1996) 4.6 Major Peak Discharge Experiences No. Drainage Area (km2) m3/s Discharge m3/s/km2 Date Period of year /10/ Water Quality Point Year PH DO (rag/i) BOD (mg/l) Coliform (MPN/100 ml) Upper Tha Chin ,000 Middle Tha Chin ,700-20,000 Lower Tha Chin ,

268 Thailand Water Resources 5.1 General Description The Tha Chin River basin is divided into 3 sub-basins. Most of the areas in the river basin are field crop and paddy field. The water resource is utilized mainly for paddy irrigation. Huai Krasieo Dam is the only existing impounding reservoir in the basin and has the gross and effective capacities of 240 x 10^ m^ and 201 x 10*' m^ respectively. 5.2 Map of Water Resources Systems *li^b. II ltf*<" 'y.n9^ 13 A D Rtservior Win- nv. Dam wxx. 76 Kin I«' «wmf 1 260

269 Thailand List of Major Reserviors Name of River Name of Reservior Catchment area [km2] Gross Capacity [106m3] Effective Capacity 106 rn3] Purpose1' Year of completion Huai Krasieo Huai Krasieo Dam 1, A, F, I, W ) A: agriculture, F: Flood control, I: Industry, P: Hydropower, W: Municipal water supply 6. Socio-cultural characteristics The Tha Chin River basin covers most parts of Supanburi Province. Cultures of the basin inhabitants are in common with those who live in the central plain of the country having Songkhran water festival, Loy Kratong, general merit making festival, Don Chadi Fair as annual festive activities. These activities attract tourists from all over the country as well as foreign visitors to visit all year round. 7. References Department of Mineral Resources, (1969): Geological map of Thailand. Meteorological Department, (2001): Climatological Data of Thailand Royal Irrigation Department, (2000): Hydrology Division: Thailand Hydrological Yearbook Department of Land Development. Soil of the Kingdom of Thailand, (1972): Explanatory Text of the General Soil Map, Soil Survey Division. Electricity Generating Authority of Thailand, (1992): Surface runoff and specific yield of river basin in Thailand, Survey and Ecology Department, Meteorology and Hydrology Division. 261

270 Viet Nam Viet Nam-7: Chay River Viet Nani-8: Huong River Baslriof Chay RJver < -^1 p^bmí^gm$ i r * * \ ""^K \^y ^^^ _^.^.v"'"*^ AT^to Basin of Huong Rher ^i^^^? W-I-I f y.^'^al * *.yy-ê it wc V ^ Kb

271 Introduction Viet Nam is located in the inter - tropical zone, on the eastern part of the Indochina Peninsula. The total area of the country is 331,000 km, three quarters of which consist of mountain and hill, and the remainder alluvial plain, most of which lies in the Red River and Mekong Delta. The country is influenced by tropical monsoon climate with two clear cut rainy (April/May to October/ November) and dry seasons. Mean annual precipitation is 1960 mm varying from 4,760 mm in Bac Quang (in the north part) to 650 mm in Phan Rang (Central Viet Nam). Annual river runoff volume in Viet Nam is 835 km of which 525 km3 is generated outside Viet Nam and only 310 km3 generated in Viet Nam (or 980 mm runoff, 4,630 m3 per capita). The urban flow for Vietnamese territory is 936,000 m3/year/km2 or m3/s/km2. Most Vietnamese Rivers are of small and medium sizes except the Red River and the Mekong River. The forest cover is about 26% (1992, Ministry of Forestry). The urban population makes about 15% of the nation's total. The two rivers, Chay and Huong, described in this volume, belong to medium rivers in Viet Nam. The Chay River is located in the northern and the Huong River in the central part of Viet Nam. The Chay River has the basin of 6,500 km2 (of which 1920 km2 is in China); its average altitude is 858 m. The Chay River water resources are used for hydropower production, for water supply in the downstream, for aquaculture and water-borne navigation. The Thac Ba hydropower plant on the Chay River at Thac Ba started the construction in 1962 and has been operated since 1972, The main problem in the Chay River is the protection of Thac Ba reservoir environment and ecological landscape. The Huong River is located in the region abundant of rainfall. Due to large and concentrated rainfalls and steep basin slope, the floods in the basin fluctuate very fast. Heavy rainfalls create flash floods in the upper and middle reaches and inundation in the downstream. Especially large floods also cause bank collapses and create new river mouths in the seacoast. The Hue city - township of Thua Thien Hue province is situated on the Huong River bank, with more than 300,000 populations, used to be the former Viet Nam capital and has been recognised by UNESCO as world cultural heritage. Acknowledgements The working group for the preparation of this volume of River Catalogue consists of: Mr. Le Van Sanh, Technical Secretary of the group, Dr., Ass. Prof. Tran Thanh Xuan, Institute of Meteorology and Hydrology, Mrs. Tran Bich Nga, Mrs. Doan Thanh Hang, Mrs. Dao Thi Quy, Institute of Meteorology and Hydrology. The organisations that have contributed to the work are: Hydro-Meteorological Data Center, and Institute of Meteorology and Hydrology (Ministry of Natural Resources). 263

272 Viet Nam-7 Chay River Map of River Table of Basic Data Name: Chay River Serial No. : Viet Nam-7 Location: Dong Bac Province, Viet Nam N 21 30' ' E ' ' Area: 6,500 km2 Lengthof main stream: 319 km Origin: Mt. Ha Tao Highest point: Mt. Tay Con Linh (2,419 m) Outlet: Lo River (Doan Hung) Lowest point: Main geological features: Gneiss, Amphibole - biotite schist, Amphibolite, Migmatite. Biotite granite. Binary granite. Shale, Chert, Limestone, Rhyolite, Orthopyre, Manganese, Iron ore. Main tributaries: Nam Khoc River (105 km2), Ma Le Ha River (299 km2), Pai Ho River (145 km2), Moc Kouen River (1 16 km2), Ngoi Phong River (260 km2), Nghia Do River (223 km2), Ngoi Biec River (342 km2) Main lakes: None Main reservoirs: Thac Ba reservoirs (2,940 x 1 0 m), N=108MW Mean annual precipitation : 1, mm at Bac Ha ( ~ 2002) Mean annul runoff: 140 m3/s (4.42 x 10* km3) at Bao Yen (4,960 km2) Population: about 579,600(1999) Main cities: Yen Bai Land use: Forest (18.3 %), Rice paddy (3.22 %), Other agriculture ( %) 264

273 Viet Nam-7 1. General Description The Chay River is the second largest tributary of the Lo River. It originates from Ha Tao and passes in the western slope of the Tay Con Linh mountain range that has a peak height of 2,419 m, in the Hoang Su Phi district. Ha Giang province. The river flows towards to the west in the upstream, to the southeast in the middle and lower reaches and finally enters the Lo River at Doan Htmg. The Chay River basin lies between high mountain ranges: in the north is a range of 1,500-2,000 m height, on the west is the Con Voi mountain range and on the east and south east is the Tay Con Linh range (the highest range in the northeast of Vietnam). The Chay River basin is wider in the upstream reaches and tapers to an elongated shape in the middle and lower reaches The basin falls from the north and northwest to southeast. More than 60% of the basin is higher than 400 m. Some characteristics of the Chay River basin are: basin area is 6,500 km2 (1,920 km2 of this is located in China); river length is 3 19 km; basin width is 26 km; the average basin altitude is 858 m; mean basin slope is 24.6 %; and the river network density is 1.09 km/km2. Annual rainfall varies from 1,500 mm to 3,000 mm in the basin. Rainfall is higher on the southeast and southwest slopes of the Tay Con Linh moiuitain range and lower than 1,500 mm in the river valley of the upstream area. Rainy season starts in May and ends in October; rainfall in the wet season makes up % of the total yearly amount. 2. Geographical Information 2.1 Geological Map 265

274 Viet Nam Land User Map 2.3 Cliaracteristics of River and Main Tributaries No. Name of river Length [km] Catchment area [km j Highest peak [m Lowest point [m[ Cities Population Land use [%] 1 2 Chay (Main river) Nam Khoc (Tributary) 319 6, ,419 2,200 A (19.3) F (18.3) P (3.22) 3 Ma Le Ha (Tributary) ,950 4 Pai Ho (Tributary) Moc Kouen (Tributary) ,275 6 Ngoi Phong (Tributary) Nghia Do (Tributary) Ngoi biec (Tributary) A: Other agriculture land F: Forest G; Grass P: Paddy field

275 1 1 1 Viet Nam Longitudinal Profiles 1 (it Ele r s () Climatological Information Nam Khoc. Ma Lo Ha// /Moc Kouen/ / / Ngoi Phong/ it ill 7 1 /Pai Ho / 1 1 ~7/_iJJl\ ^^-^Ngoi B.ec ^ Chav R ver Distance from river mouth (km) 3.1 Annual Isohyetal Map and Observation Stations 23'00'N f*y^\. g yyy^ ^^^^^yy^--\^ LU 8 J^ryooo 'N 1600\ k\ j /Yls' \ l\ eßu Hfei N S 1600N. *í% BjbYerK^ N. ^$3\ ( \ \ N^LucYdjV 22'00'N Ä n jitation Obs Station ^N^v^fi Meteorological \v3i Observation Station \^ >000 l } 1800 \ Nsoo 22'0O,l C^^> BASIN OF CHAY RIVER 0 km b-^* ^ 8 y 267

276 Viet Nam List of Meteorological Observation Stations No. Station Elevation [ml Location Observation period Mean annual precipitation mm Mean annual evaporation [mm Observation items 48/31 Hoang Su Phi 553 N: 22 45' E: ' (P) 1961 ~ (E) 1961 ~ 1, DS, E, P - Muong Khuong 772 N: 22 46' E: ' (P, E) 1961 ~ , DS, E, P 48/30 Bac Ha 957 N: 22 32' E: ' (P) 1961 ~ (E) 1961 ~ 1, DS, E, P Pho Rang N: 22 14' E: ' (P) 1975 ~ (E) , DS, E,P 48/35 Luc Yen N: 22 06' E: ' (P) 1961 ~ (E) 1961 ~ 2, DS, E, P DS: Duration of sunshine observed by Helioscope E: Evaporation by Picbe tube P: Precipitation observed by Pluviometer 3.3 Monthly Climate Data Station: Hoang Su Phi Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] ~ Precipitation [mm] , Evaporation [mm] Duration of sunshine [hi] , Station: Bac Ha Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Precipitation [mm] ,731.2 mi Evaporation [mm] ni Duration of sunshine [hr] ,445.1 mi- Station: Pho Rang Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period for Annual the mean Temperature [ C] Precipitation [mm] , Evaporation [mm] Duration [hr] of sunshine ,

277 Viet Nam-7 Station: Luc Yen Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period for Annual the mean Temperature [ C] Precipitation [mm] , Evaporation [mm] Duration of sunshine [hr] , Long - term Variation of Monthly Precipitation 700 Chay River (VN7) at Bac Ha Station month moving averages added Annual Mean = SD = mm/month mm/month Time (year)

278 Viet Nam-7 4. Hydrological Information 4.1 Map of Streamflow Observation Stations 23"00'N 22WN T Discharge Station V Water Level Station <0> BASIN OF CHAY RTVER o km List of Hydrological Observation Station No. Station Location Catchment area (A) [km2 Observation period Observation items ' (frequency) 156 Chung Thinh N:22 45' E: ' H 157 CocLy N:21 31' E: ' 3, H,Q Bao Yen N: 22 10' E : ' 4, H,Q,S 159 Luc Yen N: 22 06' E: ' 5, ~ 1973 * H,Q,S Thac Ba N:21 44' E: ' 6, H, Q, S, WQ 161 Vinh Yen N: 22 22' E: ' H, Q, S Note: * Indicate missing data in some years 270

279 Viet Nam-7 No. Q2) [m3/s] Qmax3) m3/s] Qmax4' [m3/sl Qmin5' [m'/s] Q/A [m3/s/100km2 Qmax/A [m3/s/100km2l Period of statistics , , , , H P 0 S WQ Water lever Precipitation (daily) Discharge Sediment concentration Water quality 2} Mean annua! discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge 4.3 Long- term Variation of Monthly Discharge Chay River (VN7) at Bao Yen Station (4960 km2) ^ =500 - a Ï month moving verages added Mean =140 m/s SD = 121 mvs Time (Year) 4.4 Annual Pattern of Discharge Chay River (VN7) at Bao Yen (4960 km ) Daily in

280 Viet Nam Annual Maximum and Minimum Discharge At Bao Yen [4,960 km2 Year Maximum '' Date [m3/sl Minimum ' Month [m3/s] Year Maximum1' Date [m3/sl Minimum ' Month m3/s] , , , , , , , , , , , , , , , , , , , At Thac Ba [6,170 km2l Year Maximum1' Date [m3/s) Minimum2' Month (m3/s) Year Maximum1' Date [m3/sl Minimum ' Month [m3/sl , , , , , , , , , , , , , ), 2} Discharge rated according to manual observation of water level 272

281 1 ^*^ Viet Nam Hyetographs and Hydrographs of Major Floods Chay River (VN7) at Bao Yen (4960km2), July 1986 \W 1 ' \ \ i Í " M S Q Il ? /' ^"^X ' ' ' 5 ET ^ <**~j ßV~s luly 23 July 25 July 27 July 30 July 1 August Date 5. Water Resources 5.1 General Description Multiyear average values of the specific annual discharges are unevenly distributed in the basin and vary from 0.02 m3/s/km2 in the upstream valley to 0.07 m3/s/km2 in the Tay Con Linh west and southeast slopes. The multiyear average runoff of the river is about 6.62 x 10 mvyear corresponding to the basin average specific discharge of m3/s/km2 and annual runoff depth of 1,020 mm. The runoff varies irregularly in the year and with the seasons. The flood season extends from June to October and contributes 70-80% of the yearly amount. Highest monthly runoff values are in July and August. The average specific minimum discharge varies from m3/s/km2 in the upstream valley to m /s/km on the southeast slopes of the Tay Con Linh mountain range. Observed data show the following maximum discharges; 2,520 m /s (Momax= m /s/km2) on the Chay River occurred on 15 August 1995 at the Bao Yen station (Area = 4,960km ); 3,590 m3/s (MomM= m3/s.km2) at the Thac Ba station (Area 6,170 km2) on August 1971; 374 m3/s (Mgmax = 2.71 m3/s.km2) on 13 July 1997 at the Vinh Yen station on the Nghia Do River (Area 138 kin). The Chay River water resources are used for hydropower generation, water supply for irrigation in the downstream area, for aquaculture and for waterborne navigation improvement. 273

282 Viet Nam Map of Water Resource Systems 23WN $ 3 yy, / Yi f 7 cyt^ài^ - t 23'00'N N W*A*E S 22'00'N \ ^C li4 ^v, 22 00'N <^~") BASIN OF CHAY RIVER Okm UJ 8» 'BIN Hi ^* 5.3 List of Major Water Resources Facilities Name of river Name of dam (Reservoir) Catchment area [km Gross capacity (106m3l Effective capacity [10 m 1 Purpose Year of completion Chay Thac Ba 6,170 2,940 A: Agriculture I: Industrial use N: Maintenance of normal flows W: Municipal water supply - A, I, N, W Major Flood and Droughts Date Peak discharge [m3/s[ Rainfall [mm] Duration Meteorological cause Dead and missing Major damages (Districts affected) , Typhoon , Typhoon Water quality Multiyear average value of suspended sediment concentration varies from g/m on tributaries to 500-1,000 g/m3 on the mainstream. Annual mean of water river mineralization is about

283 Viet Nam-7 mg/l, ph value is from 7 to 8. The river water belongs to hydrocarbonate class, calcium 1 group; the HCOî- concentration makes superiority among the anions, and the Ca makes superiority among the cations. In general, the Chay River water and the Thac Ba reservoir water are still clean, but at some locations in the reservoir the water becomes polluted. 6. Socio - cultural Characteristics In the Chay River basin there live many ethnic people, such as: Viet (Kinh), Tay, Dao, Nung, Thai, Muong, Cao Lan, Kho Mu, Phu La, Giay, H'Mong. The Thac Ba reservoir surface of 234 km2 with more than 1,000 small islands covered with diverse vegetations, ecological landscapes and plentiful caves create beautiful landscapes attracting many tourists. 7. References, Data Books and Bibliography General Department of Tourist, Vietnamese Culture. General Statistical Office: Statistical Yearbook 1999, Statistical Publishing House. Institute of Meteorology and Hydrology (1985): Main Morphometric Features of Viet Nam Rivers, Hanoi. Tran Tuat, Tran Thanh Xuan and Nguyen Due Nhat (1987): Hydrogeography of Viet Nam Rivers, Science and Technique Publishing House. Tran Tuat and Nguyen Due Nhat (1980): Hydrogeographic Characteristics of Rivers in Viet Nam, Institute of Meteorology and Hydrology. 275

284 Viet Nam -8 Huong River Map of River Table of Basic Data Name: Huong River Serial No. : Viet Nam-8 Location: Thua Thien Hue Province, Viet Nam N 16 00' ' El 07 07' ' Area: 2,830 km" Lengthof main stream: 104 km Origin: Mt. A Tin (1,298 m) Highest point: Mt. Nui Mang (1,712 m) Outlet: Gulf of Bac Bo (Thuan An Mouth) Lowest point: 0 m Main geological features: Sand loam. Pebble, Grave, Detrital shell. Coral limestone. Shale, Sandstone, Andesine, Conglomerate, Sandstone, Siltstone, Shale, Limestone. Main tributaries: Khe Hai Nhut River (75.3 km'), Ca Rum Ba Ram River (219 km'), Khe Co Moc River (88.3 km'), Huu Trach River (729 km'). Bo River (938 km') Main lakes: None Main reservoirs: Duong Hoa reservoirs (435 x 1 0 m )* Mean annual precipitation: 2,833.5 mm at Hue (1977 ~ 2000) Mean annul runoff: 198 m7s (6.25 x 10 m ) Population: about 660,000 (1999) Main cities: Hue City Land use: Forest (42.7 %), Rice paddy (10.3 %), Other agriculture (5.91 %) : Under construction 276

285 Viet Nam-8 1. General Description The Huong River, the largest river in Thua Thien Hue Province, has a length of 104 km and a basin area of 2,830 km2. It has three main tributaries, namely the Ta Trach, the Huu Trach and the Bo. The Ta Trach River, the Huong River mainstream, originates from the more than 1,700 m height mountain on the northwest of the Bach Ma mountain range. The river then flows in the general direction of southeast to northwest, passing the City of Hue, discharges into the Tam Giang lagoon and finally flows to the sea at the Thuan An mouth. The mean basin altitude is 330 m; the mean basin slope is 28.5%; the mean basin width is 44.6 km; and the mean basin river network density is 0.6 km/km. Before reaching the sea, the Huong River basin has many branches flowing to lagoon systems that extends about 70 km along the coastline. The lagoons include the Tam Giang lagoon, the Thuy Tu lagoon and the Cau Hai little bay. Besides the Thuan An estuary the lagoon systems have some smaller river mouths linking with the sea. Rainfall in the Huong River basin is very abundant; about 2,500 mm in coastal areas to 3,500 mm in the upper part of the basin. The rainy season usually lasts from September to December. Rainfall in the wet season contributes 67-75% of the total yearly amount of 8.52 km. 2. Geographical Information 2.1 Geological Map 1ÍASIN OF HUONG RIVER okmio

286 Viet Nam Land User Map 16'30W LEGEND ] P3dd> rice I Natural forest I Planted forest Grass with shrub River, stream Annual crops Pcrcmal mdustrial tree Residential land *"? LAO C ^ BASIN OF HUONO RIVER ^-^0^ Characteristics of River and Main Tributaries No. Name of river Length [km] Catchment area [km^] Highest peak [m] Lowest point [m] Cities Population Land use [%] 1 2 Huong (Main river) Khe Hai Nhut (Tributary) 104 2, ,712 1,000 Hue - A (5.91) F (42.7) P(10.3) 3 Ca Rum Ba Ram (Tributary) ,200-4 Khe Co Moc (Tributary) Huu Trach (Tributary) ,000-6 Bo (Tributary) ,774 - A: Other agriculture land F: Forest G: Grass P: Paddy field 278

287 Viet Nam Longitudinal Profiles Bo Oo (mel 1500 y^ /Hmi^ach ^ '^^^'TÍuong River C Distance from river mouth (km) Climatological Information 3.1 Annual Isohyetat Map and Observation Stations 279

288 Viet Nam List of Meteorological Observation Stations No. Station Elevation [m Location Observation period Mean annual precipitation [mm] Mean annual evaporation [mm Observation items Hue N: 16 26" E: ' (P) * (E) 1960 ~ * 2, DS, E, P ALuoi 550 N: 16 12' E: ' (P) (E) , DS, E, P Nam Dong N: 16 10' E: ' (P)1977~ (E) , DS, E,P DS: Duration of sunshine observed by Helioscope E: Evaporation by Piche tube P: Precipitation observed by Pluviometer Note: * Indicate missing data in some years 3.3 Monthly Climate Data Station: Hue Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [T] Precipitation [mm] , Evaporation [mm] Duration of sunshine [hr] , Station: Nam Dong Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Precipitation [mm] , Evaporation [mm] Duration of sunshine [hr] , Station: A Luoi Observation items Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Period for the mean Temperature [ C] Precipitation [mm] Evaporation [mm] Duration of sunshine [hr] ,

289 Viet Nam Long-term Variation of Monthly Precipitation month moving averages added _ Huong River (VN8) at Hue Station I Annual Mean = mm/month SD = 311.3mni/month I \r tlv Time (year) Hydrological Information 4.1 Map of Streamflow Observation Stations 281

290 _ 1 1 i 1 Viet Nam List of Hydrological Observation Stations No. Station Location Catchment area (A) [km2] Observation period Observation items1' (frequency) Thuong Nhat N: 16 07' 25" E: ' 14" H,Q,S No. Q2) [m3/s Qmax3) [m'/s] Qmax4) [m'/s] Qmin5) [m'/s] Q/A [m'/s/100km2 Qmax/A [m3/s/100km2] Period of statistics , )H: P: Q: S: Water lever Precipitation (daily) Discharge Sediment concentration 2) Mean annual discharge 3) Maximum discharge 4) Mean maximum discharge 5) Mean minimum discharge 4.3 Long-term Variation of Monthly Discharge J\ w J \A Ta Trach River (VN8) at Thuong Nhat Station (208 km ) 37- month moving averages added ft' i i i L -ft tf u ^Iean = 16.4 m'/s SD = l!i.5mj/s I ]_r WH \\ Year j Annual Pattern of Discharge ^ 250 Vi í~ 200 B r 150 oo j 100 o a 50 Q Flow 1 duration V curve Ta Trach River (VN8) at Thuong Nhat (208 km) Daily in 1997 Q =16.5m3/s Ia l M M J J A Month 282

291 1 1 1 "* Viet Nam-8 D(/ 4.5 Annual Maximum and Minimum Discharge At Thuong Nhat [208 km' Year Maximum1' Minimum Date m3/s] , , Month ; 9 7; [m'/s] ), 2) Discharge rated according to manual observation of water level. Year Hyetographs and Hydrographs of Major Floods Maximum Minimum Date [m'/sl Month m'/s Ta Trach River (VN8) at Thuong Nhat (208 km2), October 1984 Wir 1 1 H A l 4 4; 5; ; 9 8; ; =? y\ ^ ^ T" Oct 11 Oct 12 Oct 13 Oct 14 Oct 15 Oct 16 Oct 17 Oct Date L

292 Viet Nam-8 5. Water Resources 5.1 General Description Annual specific discharge is unevenly distributed in the basin, varying from mvs/km^ in the coastal plain to more than m^/s/km^ in the mountainous regions. Long term average annual runoff is about 6.25x10' m^ or mvs/km^ and the basin runoff depth is 2,210 mm. Flood season lasts for 4-5 months from September-October to December. Flood volume makes up % of total annual runoff The maximum monthly flow usually occurs in November every year. Heavy rainfall and steep basin slopes generate great fluctuations in floods. The maximum discharge Qmax is rather large. Observed data at the Thuong Nhat station on the upstream of the Ta Trach River shows that Qmax = 1,330 mvs on the 13 of October In the historical flood in November 1999 the flood peak discharge was 5,320 m^/s (MQmax = 9.3 mvs/km^) at Binh Dien on the Huu Trach River, and 14,000 mvs on the Huong River at Kim Long (Hue City). Also, the historical flood in 1953 was very large with Qmax = 12,500 mvs at Kim Long; 4,000 mvs (MQmax = 5.26 mvs/km^) at Co Bi on the Bo River; Qmax = 4,000 mvs (MQmax = 7.1 mvs/km^) at Binh Dien on the Huu Trach River and Qmax = 8,000 mvs at Tuan on the Ta Trach River. The low flow period lasts for 7-8 months from January to August-September. In the low flow period there are usually small floods (called "tieu man") in May and June. Hence, the three month low runoff season is not at a fixed time. It may be before or after the "tieu man" flood season, in other words in February to April or June to August. The long term minimum monthly runoff usually occurs in July or August. The long term minimum specific discharge is about mvs/tonl Rainfall in the basin is very abundant, for example, the rainfall total from 1st to 6th of November 1999 was more than 2000 mm in the province. In Hue it was 2,288 mm and at A Luoi 2,270 mm. The maximum daily rainfall in this period at Hue was 978 mm and 758 mm at A Luoi. The maximum 24h rainfall at Hue (from 7h on 2nd of November to 7h on 3rd of November 1999) was 1,384 mm. That is the highest value recorded in Viet Nam up to now. Intense rainfalls usually generate flash floods in the upper and middle reaches and flooding in the downstream reaches. The flooding depth may surpass 10 m. Large floods may cause bank collapses in rivers and seacoasts and may create new river mouths. In the low flow season, long periods of hot weather may result in the river ceasing to flow. This allows salt water to penetrate further up the river resulting in a lack of fresh water for domestic use and for production. 5.2 Map of Water Resources Systems 284

293 Viet Nam List of Major Water Resources Facilities Name of river Ta Trach Name of dam (Reservoir) Duong Hoa* Catchment area [km 720 Gross capacity 106m'] 435 Effective capacity I106m'] - Purpose A, F, P, I Year of completion - A: Agriculture F: Flood Control I: Industrial P: Hydropower *: Under construction 5.4 Major Flood and Droughts Date Peak discharge [m'/s] Rainfall ]mm Duration Meteorological cause Dead and missing Major damages (Districts affected) ,250 1, Typhoon Typhoon Typhoon Typhoon Typhoon Typhoon Hue City Hue City Hue City Hue City Hue City Hue City 5.5 Groundwater and Water Quality Annual mean suspended sediment concentration is g/m3. In general, water quality is still good, but in the Hue City reach of the Huong River the water is polluted by domestic waste and industrial waste that discharge directly into the river without any treatment. Also, river water in the coastal plain is polluted by salinity in the low flow period. Salinity may intrude further than 20 km up the river. 6. Socio - cultural Characteristics In the river basin there live ethnic people like Viet (Kinh), Ta Oi, Ca Tu, Van Kieu, and so on. Hue City, the main township of Thua Thien Hue Province, is located on the Huong River bank with a population of more than 300,000 people. Hue is the former capital of Viet Nam. Hue province has been recognised by UNESCO as a world cultural heritage area. Besides, Huong River and Hue City have many beautiful landscapes. 7. References, Data Books and Bibliography General Department of Tourist, Vietnamese Culture. General Statistical Office: Statistical Yearbook 1999, Statistical Publishing House. Institute of Meteorology and Hydrology (1985): Main Morphometric Features of Vietnam Rivers, Hanoi. Tran Tuat, Tran Thanh Xuan and Nguyen Due Nhat (1987): Hydrogeography of Vietnam Rivers, Science and Technique Publishing House. Tran Tuat and Nguyen Due Nhat (1980): Hydrogeographic Characteristics of Rivers in Viet Nam, Institute of Meteorology and Hydrology. 285

294 i *. 1 BE Cmt. CfÊttytJa^ ty fltbilé m Sf^CXfnáuaitn