Flood Risk Assessment of Kanhan River Using HEC-RAS and QGIS

Abstract

Floods are among the most destructive natural hazards, threatening lives, infrastructure, and economies. The Kanhan River in Maharashtra, a tributary of the Wainganga, experiences recurrent flooding due to monsoonal rains, unregulated floodplain development, and land-use changes. This study conducts a flood risk assessment using Geographic Information Systems (QGIS) and the Hydrologic Engineering Center’s River Analysis System (HEC-RAS). High-resolution DEMs, LULC data, rainfall records, and river cross-sections were processed in QGIS to generate inputs for hydraulic modeling. HEC-RAS simulated unsteady flows for multiple return periods, with outputs integrated into QGIS for floodplain mapping. The combined approach enabled spatial visualization of inundation extents, depths, and velocities, highlighting vulnerable zones. The resulting hydraulic model has 0.4036% error which provide actionable insights for disaster management, including early warning systems, embankment reinforcement, and land-use regulation. This integrated framework demonstrates the value of geospatial and hydraulic tools in enhancing resilience and guiding flood mitigation strategies in data-scarce regions.