APPLICATION OF GIS AND REMOTE SENSING IN DISASTER PRONE AREAS: A CASE STUDY IN COASTAL KERALA DISASTER Disaster is an unpleasant event than occurs with little or no warning which results in economic disruption, loss of property and loss of life require external help. The word s root is from astrology, which implies that when the stars are in a bad position, a bad event is about to happen. Natural disasters have their greatest impact at local level, especially on the livelihood of poor people. Manjush Koshy, Aneesh A and Jayalekshmi A.B Geomatics Lab, Centre for Earth Science Studies Thiruvananthapuram-695031 Email: manjushkoshy@yahoo.com DISASTER MANAGEMENT Disaster management can be defined as the discipline and profession of applying science, technology, planning and management to deal with extreme events, that can injure or kill large numbers of people and cause extensive damage to property. In India importance is given to post-disaster activities compared to the developed countries where huge funds are spent towards pre-disaster preparedness and mitigation activities which considerably reduces the impact of a disaster by making the people more disaster resilient. CRISIS INFORMATICS Crisis Informatics is an emerging field showcasing the application of information communication technology (ICT) in Disaster Management. GIS, Remotely Sensed data, GPS and other databases can be integrated to develop a better crisis management support system. Geographic information system (GIS) is a effective tool in disaster management activities like preparedness, mitigation and disaster response. GIS IN DIFFEERENT STAGES OF DISASTER MANAGEMENT HIGH RESOLUTION SATELLITE IMAGERY IN DISASTER MANAGEMENT Use of high resolution imagery is imperative in Disaster Management. It provides vital information to disaster managers for strategic planning. Satellite image taken after a catastrophe reveals the existing state of the area, blocked roads, vulnerable areas, alternative evacuation routes, the settlements that need immediate attention can be located and emergency personnel can be re directed to the area. Pre disaster and post disaster images can be used for change detection and the damage assessment can be done more effectively and quickly. 1
This satellite image shows Kalutara, Sri Lanka, before the Dec. 26, 2004 tsunami. Source: http://www.itc.nl/library/tsunami.asp#free_images. Source: http://www.itc.nl/library/tsunami.asp#free_images. This satellite image shows Kalutara, Sri Lanka, before the Dec. 26, 2004 tsunami hit the coast. Source: http://www.itc.nl/library/tsunami.asp#free_images This satellite image shows Kalutara, Sri Lanka, flooded after the Dec. 26, 2004 Tsunami.. STUDY AREA The study area is the 8 coastal wards of Alleppey Municipality in Alleppey district in Central Kerala. This satellite image shows Kalutara, Sri Lanka, flooded after the Dec. 26, 2004 Tsunami hit the coast. Source: http://www.itc.nl/library/tsunami.asp#free_images. QUICKBIRD IMAGE OF 0.6 METER RESOLUTION The area stretches up to 5.41 sq.km and lies between 9027 46 and 9031 19 north latitude, 76018 41 and 76020 05 east longitudes. In the 8 wards there are a total of 6,150 houses which contain 29,573 people. 2
RESULTS METHODOLOGY QuickBird image of 0.6 meter resolution was used as the base map to develop disaster preparedness and response mapping system for the coastal wards in the municipality. Thematic layers generated from the QuickBird image and the cadastre were integrated and geographically analyzed to derive meaningful information on vulnerability of the coastal settlements using ArcGIS software. The QuickBird imagery was geo-referenced using the WGS84 coordinates and the Image-image referencing of Cadastry and the QuickBird image was carried out using Erdas Imagine. Using this digital database, Coastal Regulation Zone (CRZ) was demarcated. The 200m and 500m regulation lines were drawn uniformly along the coast from the High Tide Line (HTL). Different point, line and polygon shape files were generated using ArcGIS. Different thematic layers extracted from the QuickBird image include location of individual households, roads and land use. Cont.. The individual parcels were extracted from the Cadastre. SETTLEMENT VULNERABILITY MAPPING The study area was divided into grids of 12.5m interval. Different vulnerability ranks were assigned to these grids depending on criteria like presence or absence of settlements in a grid, road connectivity to a grid, coastal proximity of the grids and the proximity to inland water bodies. These ranked grids were intersected into the centroids of the grids and based on the IDW interpolation technique using the 3D Analyst extension of ArcGIS, a 3D raster model was developed in GIS. Resultant data set was used to develop a decision support system using Map Objects and VB.NET that will help figure out the Shortest path to the settlements at risk and the nearest evacuation shelter. This system could be used by the emergency responders like fire and rescue, police, medical personnel and the local authorities. 3
RESULTS Air lift capabilities need to be used in areas that are not directly accessible after the catastrophe. Two Indian Air Force emergency landing centers were identified near the beach in the Alleppey town, which will help in rapid disaster response activities. The Police ground and the SD College ground were identified. Safe locations situated at safer distance from tsunami vulnerable coastline such as open spaces, public and community assets with were identified, where evacuated people can be relocated. LEO 13 School, SDV School and the ST.Michel School were identified. QUANTUM GIS INTERFACE OSGIS - OPEN SOURCE GEOGRAPHIC INFORMATION SYSTEM Proprietary GIS software is costly for community level preparedness plans. OSGIS promotes the use of geo-information for community preparedness through Public Participatory Geographic Information System (PPGIS) workshops and meetings. Quantum GIS (QGIS) is a user-friendly desktop-gis software released under the General Public License (GPL) and is available for Linux, and Windows and Mac OS. ADVANTAGES OF OPEN SOURCE GIS IN DISASTER MANAGEMENT OSGIS could be used for community level disaster preparedness activities like setting up an evacuation route, organizing mock drills and making the people aware of the area they live in. The objective is to bridge the gap between several levels of local administration and common people through an extensive knowledge workshop that ensured public participation. The local knowledge on disasters is highly important, OSGIS helps in taking technology to the common people. CONCLUSION This study gives an idea on the advantage of using high resolution satellite imagery and GIS in disaster management. The present study emphasizes the purpose of assessment of an area during a coastal disaster like tsunami or storm surges with special preference given to early evacuation routing and community preparedness. Use of OSGIS is a cost effective method for local level community preparedness and public participatory geographic information sharing. CONCLUSION This system can be used for generating community preparedness plans, thus empowering the people to think and act spatially, thereby having a proper understanding of the area they live in and the risk they are exposed to. The quality and timeliness of response services during a disaster can be improved using this system. Disaster management plans are to be integrated within the mainstream planning and development activities of local authorities. GIS needs to be deliberately infused into these activities for a better disaster resilient society. 4
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