Abstract
Abstract
The 2022 monsoon season triggered one of the most devastating floods in recent memory along the Rapti River in Balrampur district, Uttar Pradesh, inundating nearly 38% of the district's geographical area and affecting over 1.2 million residents. This paper completes a geospatial analysis of the event, integrating Sentinel-1 Synthetic Aperture Radar (SAR), Sentinel-2 optical imagery, CHIRPS rainfall data and SRTM 30 m digital elevation model in a geographical information system (GIS). Inundation extent was determined using a thresholding approach on the synthetic aperture radar (SAR) backscatter (VV polarization), which was validated against optical Normalized Difference Water Index (NDWI) values, as well as photographs collected in the field from twelve village clusters. The study found that 4,400 hectares of land had been inundated between August 14 and August 26, of which 65% cropland, built-up area shares were at almost 19%, while the rest was fallow land and orchards. Tehsil-wise vulnerability zonation, derived by combining flood depth, elevation, drainage proximity, and population density, classified 27.4% of the district as "severe to very high" vulnerability zone. Critical examination of pre- and post-event imagery identifies embankment breaches near Pachpedwa and Utraula as primary flood amplifiers. The paper concludes with five targeted management strategies early warning enhancement, riparian afforestation, regulated land-use zoning, community-based rescue infrastructure, and integrated basin-level governance offering a transferable framework for flood-prone districts of the Indo-Gangetic plain.
Keywords
Rapti River; flood inundation; Sentinel-1 SAR; GIS; vulnerability zonation; Balrampur; disaster management
Author Affiliations
Research Scholar M.L.K. P.G. College, Balrampur (Affiliated to- Siddharth University, Kapilvastu, Siddharth Nagar, Uttar Pradesh)