A GIS-based flood risk mapping of Assam, India, using the MCDA-AHP approach at the regional and administrative level

Abstract

Floods are hydrological disasters that can alter the physical, socioeconomic, and environmental settings of a region. The objective of the present study is to develop an efficient and reliable methodology to prepare a flood risk map for Assam, the North-eastern region (NER) of India, by the integration of hazard and vulnerability components. Three indices, namely flood hazard index (FHI), flood vulnerability index (FVI), and flood risk index (FRI), are developed using multi-criteria decision analysis (MCDA) – Analytical hierarchy process (AHP) approach in GIS environment for the regional and administrative level of Assam. The selected hazard and vulnerability indicators define the topographical, geological, meteorological, drainage characteristics, land use land cover, and demographical features of Assam. The results show that more than 70% of the total area lies in the moderate to very high FHI class, 57.37% have moderate to high FVI, and more than 50% have moderate to very high FRI class.