Application of Geographic Information System and HEC-RAS in Flood Risk Mapping of a Catchment

Abstract

Flood is one of the catastrophic outbreaks, which ravages the normal functioning of a society whose aftermath is experienced by more or less throughout the world. In this context, the present study has been focussed to analyse the flood risk based on flood hazard and vulnerability using HEC-RAS model in GIS environment for a portion of Ajay River catchment lying in the states of Bihar, Jharkhand and West Bengal. Flood hazard map has been obtained using a multi-criteria evaluation technique. Steady flow analysis has been carried out using one-dimensional hydraulic model HEC-RAS in conjunction with GIS to generate inundation area and classify the hazard map based on the depth of inundation for 10 years, 50 years and 100 years return period. Land use characteristics and population density of the study area have been taken into account for vulnerability analysis. The risk analysis classifies the area into different categories of flood hazard zones for various return periods. The study will help in preparing the strategies for flood preparedness and in turn flood mitigation of the area.