Assessment of Flood Susceptibility in the Cachar District of Assam Using Gis Based Multi-Criteria Decision Making and Analytical Hierarchy Process

Abstract

Abstract Assam experiences significant floods every year, that causes damage to both people and infrastructure. By acquiring and analysing data which is required for hydrological research, geographic information systems and remote sensing technologies can assist to comprehensive flood management. A collection of 10 parameters, including elevation, slope, distance from the river, distance from road, drainage density, flow accumulation, land use and land cover, and Normalised Difference Vegetation Index derived from Landsat 8 OLI/TIRS images, the Environmental System Research Institute’s land cover and the Shuttle Radar topographic Mission’s Digital Elevation Model data from the United States Geological Survey have been used. The Barak basin of Assam's Cachar District was selected as our study area. After the selection of all the components, weights were assigned to each component through the Analytical Hierarchy Process. The influence value of the Topographic Wetness Index was assigned the highest weight in the final weighted overlay analysis that combined all the components. The output zones were divided into five flood prone zones as very low, low, moderate, high, and very high. The results show that 22.67% of the total area is characterized by high-flood zones, while extremely high flood-risk areas cover 0.01% of the area. The high flood-risk zones are densely populated. The Silchar town of Cachar falls under a very high-risk zone, with the highest population density. This work will help policymakers, planners, researchers and emergency responders with disaster preparedness and management.