An AHP-based GIS and Remote Sensing Approach for Mapping the Flood Risk in the Kuya River Basin, Birbhum, West Bengal, India

In recent years, flooding has become more frequent and severe. This has made assessing and reducing flood risk essential. Various human activities and climate change have increased the risk of flooding in many areas globally. Every year, floods cause significant damage to infrastructure and property and result in the loss of hundreds of lives. The Kuya River basin in eastern India faces a continuous and serious threat from flooding, especially during the monsoon season. This study uses a decision-making approach that combines the Analytic Hierarchy Process (AHP) and Geographic Information Systems (GIS) to assess and map flood risk in the area. The methodology includes three main components: hazard, vulnerability, and exposure. Each component's spatial indicators were weighted via AHP pairwise comparisons to reflect flood relevance. The weighted indicators were transformed into thematic layers and processed in a GIS environment (ArcMap v10.8). This created individual maps for hazard, vulnerability, and exposure. These maps were then combined using a weighted linear combination technique to produce a flood risk map. To ensure its reliability, the final map was validated with historical flood data. This validation indicated a strong link between predicted high-risk areas and locations that experienced past floods. The final output divides the Kuya River basin into five flood risk zones. The results revealed that 8.43%, 16.23%, 33.79%, 27.49%, and 14.09% of the total study area are classified as very high to very low risk classes, respectively. The AHP-based approach guides flood mitigation, early warning, and sustainable land use planning, supported by historical data, which enhances resilience and informed decision-making in the basin.