GIS-based Flood Risk Mapping: The Case Study of Kosi River Basin, Bihar, India

Flood risk mapping aims to create an easily read and rapidly accessible map prioritize the mitigation effects. This study presents empirical approach flood through integration of Analytical Hierarchy Process (AHP) Geographic Information System (GIS) techniques. SRTM 30m DEM is processed using ArcGIS 10.3 software. The methodology includes selection area, identification factors responsible for collection required data, generation desired thematic layers, their produce map. Geomorphic, hydrologic, socio-economic analyses are carried out generate namely slope, district`s distance active stream, highest elevation, drainage density, rainfall, population land use-land cover. AHP used determine relative impact weight layers. influence each layer scale values provided based on weights score calculated by integrate layers in GIS environment prepare Consistency ratios determined from judgment process validate reliability proposed results. classified area falling basin under different zones with Purnia Madhepura having large areas high risk. may aid decision policymakers evaluation rapid assessment flooding phenomena region.