GIS Based Flood Hazard and Risk Assessment Using Multi Criteria Decision Making Approach in Rapti River Watershed, India

The flood is a catastrophic event that causes losses in life and property. The magnitude of food-related losses has prompted researchers to place a greater emphasis on robust and comprehensive modelling techniques for mitigating food damage. Recently developed multi-criteria decision making (MCDM) techniques are extensively used to make decision-making processes more collaborative, logical, and efficient. The Rapti River is among the most flood-prone rivers in North-Eastern Uttar Pradesh, where numerous villages and towns are annually inundated by monsoon flooding. The present study is undertaken with an aim to identify and map areas of flood hazard and risk in the Rapti River watershed by employing MCDM based analytical hierarchy process (AHP) approach within GIS interface. Flood hazard analysis was carried out by considering eight hazard indicators namely Height above nearest drainage, distance from river, elevation, land use land cover, slope, soil type, drainage density and rainfall. The analysis of flood risk was performed by employing flood hazard layer, population density, and land use land cover as risk indicators. A weighed overlay approach was implemented to prepare flood hazard and risk maps of the study area. The results of the analysis showed that around 57.61% and 62.67% of the study region fall within the moderate category of flood hazard and risk intensity respectively. Furthermore, significantly high i.e., 27.57% and 12.75% of the study region fall into the category of high hazard and risk intensity respectively. The findings of this study suggest that the integration of AHP and GIS techniques provides an effective tool for decision making procedures in flood hazard and risk mapping, as it enables a coherent and effective use of spatial data.