Flood hazard mapping using GIS-based AHP approach for Krishna River basin

Abstract

Flood hazard mapping is an essential tool for determining the risk and susceptibility of flood-prone locations. This constitutes various criteria and factors that require a methodical and comprehensive decision-making framework. The analytic hierarchy process (AHP), the popular multi-criterion decision-making (MCDM) technique, which deals with the complicated problems, including qualitative and quantitative factor, is utilized in this study for developing flood hazard maps in integration with geographic information system (GIS). Flood hazard maps are developed for the Krishna River basin using AHP-GIS. Digital elevation model, rainfall data, soil data and Landsat images are used to extract the various hazard indicators. Nine hazard indicators are employed in this study to prepare the thematic layers, which includes Topographical Wetness Index, elevation, slope rainfall, LULC, Normalized Difference Wetness Index, distance from river, soil type and drainage density. The thematic layers are combined in Arc GIS using weighted overlay method to prepare the flood hazard zonation maps. The hazard maps are classified in three categories as low, moderate and high hazard zones. For the Krishna River basin, 30 percent area was found in high hazard. The outcomes derived from the AHP-GIS method are validated by comparing them with situational reports pertinent to the area, showcasing a robust agreement with the available dataset.