This paper presented in MAPASIA 2010 in 26-28 July, Kuala Lumpur- Malaysia Theme: Connecting Government & Citizen Through Ubiquitous GIS 1
Paper Reference Number: 6 Name: ADIPANDANG YUDONO Author (s) Affiliation:Department of Urban and Regional Planning, Faculty of Engineering, Brawijaya University, INDONESIA Mailing Address: Dept. of Urban and Regional Planning Building, Faculty of Engineering, Brawijaya University, Jl. MT.Haryono no.167 Malang - East Java, INDONESIA 65145 Email Address: adipandang@ub.ac.id or adipandang@yahoo.com Telephone number (s):+62341-587710 or +62341-587711 Fax number (s):+62341-551430 Brief Biography (100 words): I graduated from Department of Geography-University of Indonesia in 2004 as Bachelor Degree of Science (Geography) and Program of Urban and Regional Planning, School of Built Environment-University of South Australia in 2007 as Master degree of Urban and Regional Planning. Currently I work in Department of Urban and Regional Planning, Faculty of Engineering, Brawijaya University, Malang-INDONESIA as Lecturer. Since 2009 I ve got promotion as Head of Planning Information System Lab. I teach Land Use Planning Management, Watershed Management, Coastal Management, Transport Planning and Planning Information System. My Research interests are Disaster Management, Urban Growth Modeling and Transport System Modeling. 2
Name: JAROT MULYO SEMEDI Author (s) Affiliation:Department of Geography, Faculty of Mathematic and Natural Science, University of Indonesia Mailing Address: Dept. of Geography Building, Faculty of Mathematic and Natural Science, University of Indonesia Campus, Depok - West Java, Indonesia 16424 Email Address: jms_gis@yahoo.com Telephone number (s):+6221-7873067 Fax number (s):+6221-7873067 Brief Biography (100 words): Born in Semarang 20 May 1981 and graduated from Department of Geography - University of Indonesia in 2005 as Bachelor Degree of Science. Enrolled as Student in Master of Science in Information Technology for Natural Resources Management Program in Bogor Agriculture University. Since 2002 actively working in Department of Geography as Lab work Instructor and Assistant Lecturer in GIS course. Since September 2009 until present day listed as guest lecturer for Cartography, GPS, GIS, and Remote Sensing course in International Program of Information System, Faculty of Science and Technology - Syarif Hidayatullah Islamic State University.Joined the Center for Applied Geography Research as reasearch assistant in 2007. 3
Spatial Analysis for Flood Risk Assessment in North Jakarta by Adipandang Yudono 1), Jarot Mulyo Semedi 2) adipandang@yahoo.com; jms_gis@yahoo.com 1) Department of Urban and Regional Planning, Fac. of Engineering, Brawijaya University 2) Department of Geography, Fac. of Science and Mathematics, University of Indonesia ABSTRACT- The North Jakarta has characteristics as alluvial soil, flat area, the land altitudes closed to sea mean level, compact urban land uses within domestic well in each land parcel, decrease of groundwater by pumping it in a huge volume, and land dredging to fulfill building development. Due to these phenomena, most of the north Jakarta area has high risk for land subsidence. Furthermore, global warming raises temperature by effects of melting of Ice in Ice Mountains that indirectly contributes to increase sea mean level globally. Hence, the North Jakarta has high risk of the common natural disaster called flood. The purpose of this research is to identify flood risk areas based on historical flood data and the physical condition of North Jakarta using Remote Sensing and Geographical Information System and finding the best location for temporary evacuation shelters. The flood risk assessment will give an input to the decision maker to formulate strategies for future development based on prone areas. Keywords: GIS, Remote Sensing, Flood Hazard, Risk Assessment 1. Introduction 1.1 Background and Purpose of Research Jakarta as The Capital City of Indonesia has the role as the central government of Indonesia. The existing area has 661,52 km 2 and population is 8.725.630 people with population density is 13.150 people/ km 2 (Indonesia Bureau Statistic 2005). Furthermore, the city has the role as multiple central functions region such as the central of trade and commercial city and the central of public service city. Topographically, Jakarta has characteristics as alluvial soil, flat area, and located near coastal area. 4
The increasing urban activities has consequences decrease or the worst thing is ignore environmental sector, one example is the land subsidence in northern Jakarta because of the compact urban land uses within domestic well in each land parcel encourage decrease of groundwater hence pumping it in a huge volume, also land dredging to fulfill building development. The impact, as the result of the land subsidence, is in the rain season, the northern Jakarta area get flood. The background of the Jakarta Phenomena encourage why this thesis occurred. The focus of study are identifying flood risk areas based on historical flood data and the physical condition of North Jakarta and finding the best location for temporary evacuation shelter using Remote Sensing (RS) and Geographical Information System (GIS) with any disaster management concepts. 1.2 Research Area The North Jakarta is part of Jakarta Province which located in the northern Jakarta faces to Java Sea. Based on GIS analysis, the percentage of land use in study area are categorized into settlement by 40%, Green Space by 23%, Industry by 21%, Lake 10%, and Commercial areas by 8%. Topographically, it has the highest elevation is 9 m from above sea level. 1.3 Research Method Through sorting up of the original materials and the investigation and study of the current environment, comprehensive analysis is made on the causes, characteristics and rules of historical flood disaster in the North Jakarta. On this basis, the identification from time series aerial photograph identified the flood in study area. Then from land use characteristic also building function parcel, determining temporary shelter for evacuation. The final is determining massive evacuation routes using the existing road into safer areas from flood. 5
Figure 1. Research Method of thesis study START GIS Data: 1. Topography 2. Road Network 3. Land Use 4. Building Parcel 5. Flood data in time series Identifying Land Use (Open Spaces/Public Spaces and Public building parcels Finding appropriate place for shelters Determining appropriate Land Use for temporary shelter Determining appropriate building parcel for temporary shelter Determining Massive Evacuation Route to temporary shelters End 6
2. The North Jakarta Characteristic 2.1 Topographic of The North Jakarta characteristic The North Jakarta is the lowest part of Jakarta, it has characteristics as alluvial soil, flat area, the land altitudes closed to sea mean level which ranging from -5m to 9m above sea level. 19% of the total areas of North Jakarta are below sea level (submerged land) and 80% are between 0 5 meter above sea level (Van Bemmelen, 1949), making North Jakarta very vulnerable to inundation even in the dry season because of flood tides. The flat areas also contribute the vulnerability parameter of North Jakarta which has more than 95% area with slope less than 2%. 2.2 Economic-Social of The North Jakarta characteristic Based on the book Jakarta Utara in Figures published by the Statistic Office (BPS) in 2009, North Jakarta has 1.201.308 resident in 2008. The densest population located in Koja Sub District with 17.655 resident/km 2 followed by Tanjung Priok Sub District with 12.422 resident/km 2 as one of the busiest port in Indonesia. North Jakarta also very vulnerable in social matters such as gang fights because of the high population that reach 8.609 resident/km 2. In the education level, North Jakarta has 16,32% resident that did not graduate the elementary school, 22,18% were graduated from elementary school, 20,79% graduated from junior high school 32,49 were graduated from high school, and the rest graduated from diploma to bachelor degree. Tanjung Priok as one of the busiest port in Indonesia indirectly contribute on the increasing economic growth in the manufacturing sector that reach 1,53% followed by trade, hotel and restaurant sector and also transportation and communication sector which are 1,03% and 0,71% each. 2.3 Physical Environment of The North Jakarta characteristic The are 14 rivers that flow in Jakarta and all the river have an outlet in North Jakarta (Semedi, 2005). All the 14 river in North Jakarta are: Kali Kamal, Kali Tanjungan, Kali Angke, Kali Pesanggrahan, Kali Grogol, Kali Krukut, Kali Cideng, Kali Cipinang, Kali Sunter, Kali Buaran, Kali Jatikramat, Kali Cakung, Kali Cakung Timur, and Kali Ciliwung. Among all the river, Ciliwung is the biggest river and the main source of flood in Jakarta. Based on the interpretation of IKONOS image of North Jakarta, the building density in North Jakarta are 9 buildings per hectares. The majority building type 7
in North Jakarta is settlement with 120.700 buildings and followed by office buildings with 2.915 buildings. The densest Sub District is in Koja with building density of 18 buildings per hectares and followed by Tanjung Priok Sub District with 14 buildings per hectares. 3. Spatial Analysis for Flood Disaster Identification 3.1 Remote Sensing Interpretation Remote sensing technology for disaster management becomes something that is commonly used nowadays. The ability of remote sensing data in giving detail information is required by the authorities in detecting the damage area and implements the damage mitigation. High resolution imagery such as IKONOS and Quickbird provides very detailed information for urban areas where building parcels can be extracted. In flood disaster management, high resolution imagery can be used for the detection on flood plain area if combined with Digital Terrain Model. (Amini, 2007) The building parcels extracted from the satellite imagery if combined with the inundation or flood area will give result on the number of losses suffered by the resident and determining which building will be suitable for evacuation shelter. 3.2 Historical flood in The North Jakarta (1980 2007) Flood always occur in Jakarta every year, but big flood often comes with the interval of 5 years such as the big flood in 1996, 2002, and 2007. Most of the residents of Jakarta suffered big losses due to floods; the losses are not only covers material losses, but also the trauma of the flooding that occurred. In North Jakarta flood tides also contribute on the vast inundation area. The flood occurrence in 1980, 1996, 2002, and 2007 were used to understand the time series behavior of flood in North Jakarta. 8
Figure 2. Time Series Flood in North Jakarta 3.2.1 Flood area in 1980 Flood in 1980 were caused by more than 500mm of maximum rain intensity on the day of flood with the average of 40 60mm. The flood also affected by tidal floods that occur for four days consecutively with 80cm depth. (Irawati,1987) In North Jakarta the flood covers only 2,3% of the whole North Jakarta with the total of 314,315 Hectares. The flood area mainly located in the wetlands and agriculture area. 3.2.2 Flood area in 1996 Dharmawan (1997) in his research mention that the flood in January 1996 caused by the rain that happens in southern Jakarta with average intensity of more than 50mm and the contribution of tidal floods of 115cm. In February the average rain intensity reach more than 70mm but without the occurence of tidal floods. Although the coverage of flood area in the 1996 only 5,8% of North Jakarta, the losses caused by this flood are quite severe because most of the flood occur in the settlement area. 9
3.2.3 Flood area in 2002 The 2002 floods begin with the rain intensity of 180cm in the southern Jakarta. In the second day the flood area become wider because of the rain in the Jakarta itself and reulting of 101 flood location with the total area of 16.777,67 Hectares for all Jakarta (Rachmawati, 2004) The big flood in 2002 covers 84% (11485.424 hectares) of North Jakarta and paralyzed the area for several days. 3.2.4 Flood area in 2007 Based on the meteorological station around Jakarta, the 2007 floods were caused by the rain that occurs in 1-2 February. The stations recorded that the average rain intensity reaches 235mm in 2 February, this rain intensity are equivalent with the 100 year periodical flood with the occurrence probability of 20%. In North Jakarta the coverage of flood area are decreasing compare to the 2002 floods. The area of floods are 7042.902 hectares or 51,5% of total North Jakarta. 4. Spatial Analysis for Flood Risk Assessment 4.1 Identifying The Spots for Emergency Temporary Shelters In this study, there are three criteria to find appropriate spots for shelters, namely finding higher elevation where save from flood, doing classification of land use and building parcel. Finding high elevation that saves from the flood may analysis from elevation data which represented by contour then overlaying with flood areas which has already identified in part 3, the result is the area which never had the flood become high priority. The next step is visualizing the saver area by making 3D model from contour become Digital Terrain Model (DTM) then overlaying with the depth of the flood. The second criterion is land use classification. The aim of this part is determining the public areas where appropriate to build emergency temporary shelters. The public areas in this thesis defined of huge areas of open spaces where appropriate to build tents for flood victims can stay for temporary. The open spaces in case might be classified into field, such as soccer field, golf range and urban forest 10
Figure 3. Appropriate land use classification for shelters The last criterion is building parcel classification. The purpose of this activity is similar with the land use classification, the difference both of them is Building parcel layer using the public existing buildings. Based on any experiences during disasters in Indonesia, the usual public buildings where allow used for shelters are the worship house such as (mosques, churches) and school. Therefore, this study uses both types of public buildings. 11
Figure 4. Appropriate building parcels classification for shelters 4.2 Determining Massive Evacuation routes In this activity, determining massive evacuation routes would use network analysis model. The existing road layer has been chosen for the purpose. To execute network analysis successfully, the road layer must be build topology first. Building topology has the aim to create spatial relationships between connecting and or adjacent features in geographic data layers. A requirement for massive evacuation route based on Indonesia standard procedure for disaster management is deciding minimum road width has 3-4 meters. Hence, the next step is classifying the existing hierarchical road class into three classes, namely arterial roads, collector roads and local roads. From these three road classes, there are two groups required for the evacuation road: Arterial roads which minimum road width is 3.5 m and collector roads which minimum road width is 3 m. Two road classes in the road layers are categorized separately to become a new GIS layer, called Evacuation routes. 12
The activity after road classification to choose appropriate evacuation routes is doing network analysis of the route. In network analysis, the layer created point to point adjacency matrix, then advance analysis is from the matrix would searching saver area from flood using shortest path algorithm. The shortest path has been chosen in this thesis as evacuation route no more longer 1000 meters. This distance route could be reached by flood victims by human mean speed (50 until 60 meters/minutes) no longer 20 minutes. Figure 5. Massive Evacuation Routes 5. Conclusion Remote sensing technology and GIS analysis are able to provide the analysis in determining shelters and evacuation routes for flood disaster. By having detailed information about population and street network will enhanced the model and helps the authority to manage how the flood victims to be distributed to the available shelters. 13
6. References Amini, J. 2007. Generating Floodplain map using Ikonos Image and DTM. Proceedings. 4 Th International Conference in Recent Problems in Geodesy and Related Fields with International Importance, Bulgaria. BPS, 2009. Jakarta Utara in Figures. BPS-Statistics Jakarta Utara Municipality, Jakarta Dharmawan, A. 1997. Flood in Ci Liwung Watershed on 6 7 January 1996 and 10 11 February 1996. Department of Geography, University of Indonesia. Irawati, N. 1987. Flood in Western Jakarta. Department of Geography, University of Indonesia. Purnomo, AB, 2009. Quantity technique for Architecture and Urban Design, Rajawali Press, Jakarta Rachmawati. 2004. Flood in year 1996 and year 2002 in Ci Liwung watershed. Department of Geography, University of Indonesia. Semedi, J.M. 2005. Flood Risk Level in Jakarta Year 2002. Department of Geography, University of Indonesia. Van Bemmelen, R.W, 1949; The Geology of Indonesia Vol. IA General Geology. Government Printing Office, The Hague. 14