Flood susceptibility prioritization in Dimoria block Assam using GIS and analytical hierarchy process

Abstract Assam is highly susceptible to frequent flooding, which significantly affects socio-economic conditions. Despite the widespread application of Geographic Information System (GIS) based Analytical Hierarchy Process (AHP) models for flood susceptibility assessment, there remains a lack of micro-spatial analyses focused on semi-urban and rural fringe regions such as Dimoria Block. Existing regional-scale assessments often overlook local variations in topography, land cover, and hydrological conditions, limiting their applicability for site-specific planning. The present study integrates GIS and AHP to delineate flood susceptibility zones in Dimoria Block using eleven flood-conditioning parameters. Multicollinearity analysis was conducted, followed by weighted overlay and sensitivity analyses. Rainfall and land use/land cover (LULC) emerged as the most influential factors. The results indicate that 54.75% of the study area falls within the high flood susceptibility zone, 36.72% within the moderate zone, and 8.52% within the low zone. The final flood susceptibility map was validated using both quantitative and qualitative approaches. The receiver operating characteristic (ROC) analysis yielded an area under the curve (AUC) value of 0.936, indicating high predictive accuracy. Validation using field surveys and official flood records further supports the robustness of the model. This study presents a localized flood susceptibility assessment framework for Dimoria Block and demonstrates the applicability of GIS–AHP approaches in data-scarce environments. The findings provide useful inputs for flood mitigation planning, land-use management, and disaster risk reduction strategies at the local level.