Spatial Zonation of Flood Hazards Using GIS Coupled with AHP

Abstract

Floods are among the most frequent and devastating natural hazards, occurring globally except in polar regions. They pose significant threats to human life, infrastructure, and ecosystems. The increasing frequency and intensity of floods are largely attributed to climate change and anthropogenic land-use changes, which alter river morphology and exacerbate channel stress. Effective flood risk management and policy interventions are essential to minimize these impacts. This study focuses on assessing flood hazards and mapping inundation-prone areas in the Balasore district and adjacent coastal regions of Odisha, which are highly susceptible to flooding. Key flood-contributing factors considered in the analysis include slope, elevation, drainage density, annual precipitation, Normalised Difference Vegetation Index (NDVI), land use/land cover (LULC), and the Topographic Wetness Index (TWI). These parameters were integrated using a Geographic Information System (ArcGIS) and analyzed through the Analytical Hierarchy Process (AHP) to generate a comprehensive flood hazard zonation map. The results indicate that approximately 36.50 ha, 5,073.23 ha, 27,362.54 ha, 301,622.30 ha, and 32,937.77 ha fall under very low, low, moderate, high, and very high flood hazard zones, respectively. The AHP-based GIS model demonstrated high reliability and can be replicated in other flood-prone regions for effective planning and disaster risk reduction. This approach supports proactive flood prediction, early warning systems, and sustainable flood management practices that local and national authorities can institutionalize.