INTERNATIONAL JOURNAL OF GEOMATICS AND GEOSCIENCES Volume 3, No 3, 2013

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1 INTERNATIONAL JOURNAL OF GEOMATICS AND GEOSCIENCES Volume 3, No 3, 2013 Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0 Research article ISSN Morphometric analysis using Geographic Information System (GIS) for sustainable development of hydropower projects in the lower Satluj river catchment in Himachal Pradesh, India G. B. Pant Institute of Himalayan Environment and Development, Himachal Unit, Mohal-Kullu (H.P.), India jckuniyal@gmail.com ABSTRACT Remote Sensing and Geographic Information System techniques are effectively being used in recent times as an important tool in determining the quantitative description of morphometry of a basin. This technique characterizes very high accuracy of mapping and measurement of morphometric analysis. The aim of the present study is therefore to analyze the GIS based morphometric activities of the Lower River Satluj catchment including parts of Kinnaur, Shimla, Kullu, Mandi and Bilaspur districts in Himachal Pradesh, India. Morphometric analysis of drainage system requires delineation of all existing streams. Based on GIS morphometric assessment, buffer zone of 10 km either of the River Satluj was identified. This area is lying from northeast to southwest from Nathapa village in Kinnaur district to Bilaspur town in Bilaspur district. The total length of River Satluj included under present study was 165 km. The total length of stream segments is maximum under first order streams and this length decreases as the stream order increases. It is also observed that there is a decrease in stream frequency as the stream order increases. It is observed that low drainage density is in the lower Satluj catchment. With the help of GIS, it is observed that highest number of streams shows the maximum opportunities for the hydroelectric power projects in the middle Satluj catchment. While the lower drainage density indicates that the catchment has permeable sub-soil. Keywords: Morphometric classification, Drainage density, Stream orders, Hydropower projects, Geographic Information System 1. Introduction Morphometric analysis with the help of drainage pattern in a basin is an important indicator about the process of landform development (Horton, 1932; Miller, 1953; Schumm, 1956; Melton, 1958; Smith, 1958; Morisawa, 1962; Strahler, 1964). It is an ideal unit for understanding the geo-morphological and hydrological processes like run-off pattern of the streams (Horton, 1932). The four great rivers namely the Indus, Satluj, Ghagra and Tsangpo originate from one region- the Kailas Mansarover Lake in the southern Tibet. The source area lies at an altitude of about 5000m above mean sea level and across the m high in the Himalayan barrier. When these antecedent rivers pass through these mountain barriers, these make different type of shapes which is measured by morphometric analysis. Morphometry is the measurement and mathematical analysis of the configuration of the earth s surface, shape and dimension of its landforms (Ashor, 1986; Agarwal, 1998; Reddy et al. 2002; Chopra et al. 2005). While for some scholars, it is purely descriptive or genetic which enables spatial analysis of geometric variables to analyse and interpret the landform (Al Muliki and Basavarajappa, 2008). Earlier some studies show the use of remote sensing Submitted on September 2012published on March

2 techniques for morphometric analysis (Ashor, 1986; Agarwal, 1998; Vittala et al., 2004; Pankaj and Kumar, 2009), different hydro-geomorphological units like very shallow weathered pediment, structural hills/ residual hills/ inselbergs with very poor ground water prospects, and moderately weathered pediplains and valley fills (Nag and Chakraborty, 2003). Based on morphometric parameters like bifurcation ratio, drainage density, stream frequency, form factor, circulatory ratio, elongation ratio, drainage texture and length of overland flow, and prioritization of mini-watersheds were attempted (Chaudhary and Sharma, 1998; Biswas et al. 1999). Moreover, morphometric analysis is also made to evaluate linear, relief and aerial morphometric parameters and analyze soil parameters like porosity, permeability, texture, infiltration, run-off and land erosion conditions (Nag, 1998). Rao et al. (2010) carried out morphometric analysis of the Gostani basin in Andhra Pradesh using spatial information technology. In reference to assess natural hazards vulnerability assessment, morphometric parameters at Dabka River Basin in the northwestern part of Nainital town in the Central Himalaya with the help of Geographic Information System (GIS) in the third order sub-basin (TOSBs) was analysed (Rawat et al., 2011). Pingale et al. (2012) studied the land use characteristics using GIS of the Maun watershed in the Central Himalaya through morphometric analysis. GIS technique is nowadays used for assessing various terrain and morphometric parameters of the drainage basins and watersheds. They provide a flexible environment and a powerful tool for manipulation and analysis of spatial information within the present study stream numbers. Stream order, frequency, density and bifurcation ratio are derived and tabulated on the basis of areal and linear properties of drainage channels using GIS on drainage lines as represented over the Survey of India (SOI) topographical maps (1:50,000). GIS based morphometric analysis of the Satluj catchment area mainly provides a quantitative description of the drainage system and its appropriateness for upcoming hydropower development (Figure 1). Source: Figure 1: Study area in the Satluj river catchment 465

3 The River Satluj originates at Mansarover in Tibet and enters into Himachal Pradesh at Shipkila pass. The study area extends from northeast to southwest from Nathapa village in Kinnaur district to Bilaspur town in Bilaspur district. The total length of River Satluj included under present analysis is 165 km (see figure 1). 2. Methodology The catchment area occupied from the Shiwalik range of the Himalaya to Greater Himalaya stretching from the northeast to southwest from Nathapa village (in Kinnaur district) to Bilaspur town (in Bilaspur district) falling in Survey of India (SOI) toposheets No: 53 E/03, E/04, E/07, E/08, E/10, E/11 and 53 A/15, A/16 on 1:50,000 scale. The total length of River Satluj included under present analysis was 165 km and with the help of the Arc GIS 9.2, the 10 km buffer zone in either of the river bank was demarcated. Within 10 km buffer zone in either of the bank of river has maximum number concentration of tributaries and beyond which topography in the catchment is very harsh and inaccessible. The land use and land cover classifications (LULC) were made under the present selected buffer zone of the River Satluj Catchment area. Morphometric analysis of a drainage system requires delineation of all existing streams. The stream delineation was done digitally in GIS (ArcGIS 9.2) system. All tributaries of different extents and patterns were digitized from Survey of India Toposheets on 1:50,000 scale and the catchment boundary was also determined. Digitization work is carried out to cover entire analysis of drainage morphometry. The order was given to each stream by following a stream ordering technique of Strahler (1964). The attributes were assigned to create the digital data base for a drainage layer of the river basin. The methodology used for morphometric analysis for a River catchment is vividly shown in figure 2. Figure 2: Present approach and methodology 466

4 This map was prepared after detailed ground verification with GPS survey on channel network. The various morphometric parameters such as linear aspects of a drainage network were studied. Stream order (N u ), bifurcation ratio (R b ), stream length (L u ), and stream length ratio (R l ) were within linear aspects. While drainage density (D) and stream frequency (F s ) under areal aspects of the catchment were computed and illustrated with the help of a flow chart. 3. Results and discussion The highest share of LULC of the total buffer zone stood to be 2945 km 2 out of which barren land covered 40.90% (1205 km 2 ). This LULC component of barren land was followed by forest land with 36.48% (1074 km 2 ), agricultural land 21.91% (645 km 2 ) and settlement area 0.71% (21 km 2 ) (Figure 3). Here is a high anthropogenic pressure due to ever increasing human population and continuously upcoming hydropower projects in the catchment. At the time of study, there were 8730 households inhabiting under identified settlement area and there were a number of hydropower projects. The various morphometric parameters of the lower Satluj catchment area were determined and are summarized. Figure 3: Land use and Land cover of the Satluj river catchment 3.1 Linear Aspects of the Channel System The results of linear aspects of a drainage network such as stream order (N u ), bifurcation ratio (R b ) and stream length (L u ) are presented in Table

5 Table 1: Linear aspects of the drainage network of the study area River Basin Stream order (u) Number of streams (N u ) Total length of streams in km (L u ) Lower Satluj Catchment Stream Order (N u ) In the drainage basin analysis, the first step is to determine the stream orders. Under the present study, the channel segment of the drainage basin has been ranked according to Strahler s stream ordering system. According to Strahler (1964), the smallest fingertip streams having no tributaries are designated as order 1. Where two first-order channels join, a channel segment of order 2 is formed and similarly where two stream orders join, a segment of stream order 3 is formed and so on. The trunk stream through which all discharge of water and sediments pass through is the stream segment of the highest order. The present study has up to a 5 th order drainage catchment. According to estimation of stream orders, 636 streams were identified under the 1 st order, 178 streams under 2 nd order, 43 streams under 3 rd order, 7 streams under 4 th order and 1 stream under 5 th order. The first order streams constitute 49.12% ( km) of the total length covered by the streams. While the second order streams constitute 23.52% ( km), the third 14.79% ( km), the fourth 3.24% (53.56 km) and the fifth 9.33% ( km) (Figure 4). Thus, lower the order, higher will be the number of streams which is applied throughout the catchment. Drainage pattern of stream network from the basin is mainly observed as dendritic type. This pattern is characterized by a tree like or fern like pattern with branches that intersect primarily at an acute angle. Figure 4: Drainage pattern of the study area 468

6 Morphometric analysis shows that the first order streams have the largest share. However, these in lean period remain sometimes ephemeral in nature. So the 2 nd and 3 rd order streams have opportunities for identifying the locations for HEPs in the Sutlej basin. However, the vulnerability is observed to increase as the order of streams increase. At the same time, as the stream orders increase, the opportunities for geographical location of HEPs decrease which is vividly shown in figure Bifurcation Ratio (R b ) Bifurcation Ratio is defined as the number of streams in a low order to the number of streams in the next high order (Horton, 1945) and is given by R b = N u /N u +1, R b = 636/178 R b = Where R b = bifurcation ratio, N u = number of segment in a low order, and N u +1 = number of segment in the next higher order. If within a unit, bifurcation ratios are equal, it is called Horton s net. Such values usually ranged between 3.0 and 5.0 for catchment in which the geological structures do not distort the drainage pattern (Strahler, 1964). Strahler (1957) demonstrated that bifurcation ratio shows a small range of variation for different regions or the different environments. According to Strahler (1964), the geological structure does not distort the drainage pattern if the Bifurcation Ratio (R b ) values stand between 3.0 and 5.0 for a catchment. The mean bifurcation ratio obtained for the present study region was 5.2 (Table 2) indicating distorted geological structures and low permeability (Pankaj and Kumar, 2009). Table 2: Calculative value of Bifurcation ratio and mean Bifurcation ratio Bifurcation Ratio Mean Bifurcation 1 st order/ 2 nd order/ 3 rd order/ 4 th order/ Ratio 2 nd order 3 rd order 4 th order 5 th order In our study area, these values stood to be 3.57 under 1 st and 2 nd order streams, 4.14 under 2 nd and 3 rd order, 6.14 under 4 th order and 7 under 5 th order indicating 1 st and 2 nd order streams with ample opportunities for identifying geographical location of HEPs Stream Length Ratio (R l ) According to Horton (1945), the cumulative mean lengths of stream segments of each of the successive orders in a catchment tend closely to approximate a direct geometric series in which the first term is the mean length of streams of the first order. The stream Length Ratio is therefore calculated with the help of the following formula as under:- (R l ) = L u /L u -1 (R l ) = N u -1 / N u (R l ) = / (R l ) = Where (R l ) = stream length ratio, N u = length of an order, and N u -1 = length in the next higher order. 469

7 The mean stream length ratio is 1.29 for the study area (Table 3). Table 3: Calculative value of stream length ratio and mean stream Length ratio Stream Length Ratio (R l ) Mean Stream Length Ratio 2 nd order/ 1 st order 3 rd order/ 2 nd order 4 th order/ 3 rd order 5 th order/ 4 th order The measurement of stream length Ratio (R l ) also helps in identifying the geographical location of HEPs. Table 3 shows that R l value under 2 nd and 1 st orders was While total length of streams (L u ) was measured as km under 1 st order, km under 2 nd, km under 3 rd order, km under 4 th order and km under 5 th order (see Table 1). The value of Lu decreased as the stream orders increased. 3.2 Areal aspects of the drainage catchment The area of a basin (A) is an important parameter in quantitative morphology of morphometric analysis. The area of the catchment is defined as the total area projected upon a horizontal plane contributing to cumulative area existing in all the order of streams within a catchment. Perimeter is the length of the boundary of a basin which can be drawn from the topographical maps. The areal aspects of the drainage catchment such as drainage density (D) and stream frequency (F s ) were calculated in Table 4. Table 4: Areal aspects of the study area Morphometric parameters Symbol Results Area (km 2 ) A 2945 Drainage density (km/km 2 ) D 0.56 Stream frequency (stream/km 2 ) F s 0.29 Stream length (km) N Drainage Density (D) According to Horton (1932), drainage density is an expression to indicate the closeness of spacing of channels. It is thus defined as the total length of stream of all orders per drainage area. Langbein (1947) recognized the significance of drainage density varying between 0.55 and 2.09 km/km 2 in humid region with an average density of 1.03 km/km 2. In other words, density factor is an outcome of prevailing climate, type of rocks, relief, infiltration capacity, vegetation cover, surface roughness and run-off intensity index. Morphometric analysis of the drainage density (km/km 2 ) is calculated with the help of the following formula as under:- D = L u /A, D = /2945 D = 0.56 km/km 2 Where D = Density, L u = Total stream length of all orders, and A = Drainage Area (km) The drainage density (D) of the catchment area is 0.56 km/km 2 indicating low drainage density. The low drainage density indicates highly permeable sub-soil and relatively better or 470

8 thick vegetative cover and low relief (Nag, 1998). However, under the present case, the former is most prominent. During field survey, it is observed that high water density results in high siltation. This feature does not provide conducive environment for the development of HEPs. However, it is irony that maximum concentrations of these HEPs are at such a place where there is high drainage density. One of the reasons for being high concentration of these projects at a place is that the mountain areas provide the natural walls between valley and peak topographic features for dam construction Stream Frequency (F s ) Stream frequency is the number of stream segments per unit area (Horton, 1932; 1945). The stream frequency is calculated with the help of the following formula as under:- (F s ) = N u /A (F s ) = 865/2945 (F s ) = 0.29 streams/km 2 Where N u = the number of stream segments, and A = Drainage Area (km) For the present study, the stream frequency value of the catchment is 0.29 streams/km 2. The relation between Drainage Density and Frequency (F s ) is directly proportional to D, thus drainage frequency is double the value of drainage density. This variation occurs due to rainfall, relief, infiltration rate, initial resistivity of terrain to erosion and total drainage area of the basin. The value of F s indicates poor stream networks and high values indicate denser networks in the catchment area. 4. Conclusion / Suggestions/ Findings The study, in a nutshell, reveals that GIS based approach in evaluation of drainage morphometric parameters and their influence on landforms, soils and eroded land characteristics in a river catchment is more appropriate than the conventional methods. GIS based approach facilitates analysis of different morphometric parameters and explores the relationship between the drainage morphometry and properties of landforms, soils and eroded lands. In this study, drainage density and stream frequency are the most useful criteria for the morphometric classification of drainage catchment which certainly alert to control the run-off pattern, sediments yield and other hydrological parameters of the drainage catchment where HEPs are to be developed. According to the law of streams, lower the stream orders, the higher would be the number of streams. The total length of the stream segments is maximum under present first order streams and decreases as the stream order increases. In a nutshell, the study has mainly shown that the present catchment has higher number of 1 st order streams indicating sometimes ephemeral in nature during lean period, bifurcation ratio (5.2) indicating distorted geological structures and low permeability, stream length ratio (1.29) which usually change in the basin indicating variation in slope and topography, and low drainage density (0.56 km/km 2 ) indicating the areas of highly resistant or highly permeable sub-soil. These morphometric features suggest that the topography, in general, is fragile in nature which needs strategic approach for hydropower development in this region or any other having similar morphometric landform features in the mountains. 471

9 Acknowledgement The authors are thankful to the Director, G.B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora, India for providing facilities in Himachal Unit of the Institute which could make this study possible. 5. References 1. Al Muliki M.M., and Basavarajappa H.T., (2008), Morphometric analysis of Rasyan valley basin- A case study in the republic of Yemen, using remote sensing and GIS techniques, Earth Science, 59(2), pp Agarwal C.S., (1998), Study of drainage pattern through aerial data in Naugarh area of Varanasi district, U.P., Jour. Indian Soc. Remote Sensing, 26, pp Ashor M.M., (1986), Methodological morphometric analysis for river network, Journal of Faculty of Humanities Science and Social Science, Qatar University, 9, pp Biswas S., Sudhakar S., and Desai V.R., (1999), Prioritization of sub-watersheds based on morphometric analysis of drainage basin: A remote sensing and GIS approach, Journal of Indian Society of Remote Sensing, 27(3), pp Chopra R., Dhiman R., and Sharma P.K., (2005), Morphometric analysis of subwatersheds in Gurdaspur district Punjab using remote sensing and GIS technique, Jour. Indian Soc. Remote Sensing, 33(4), pp Chaudhary R.S., and Sharma P.D., (1998), Erosion hazard assessment and treatment prioritization of Giri river catchment, North western Himalayas,Indian Journal of Soil conservation, 26, pp Horton R.E., (1932), Drainage basin characteristics, Trans. Amer. Geophys. Union, vol. 13, pp Horton R.E., (1945), Erosional development of streams and their drainage basins: Hydro-physical approach to quantitative morphology, Bulletin of Geological Society of America, 5, pp Langbein W.B., (1947), Topographic characteristics of drainage basins, US Geological Survey Water-supply paper, 986(c), Melton M.A., (1958), Correlation structure of morphometric properties of drainage system and their controlling agents, Journal of Geology, 66: Miller V.C., (1953), A quantitative geomorphic study of drainage basin characteristics in the clinch mountain area, Technical Report 3, Department of Geology, Columbia University. 12. Smith K.G., (1958), Standard for grading texture of topography, American Journal of Sociology, 5(298): Morisawa M.E., (1962), Quantitative geomorphology of some watershed in the Appalachian plateau, Geological Society Bulletin, 73,

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