Geospatial Techniques for Hydro-Geomorphic Assessment of the August 2026 Bhote Koshi Mega- flood in Rasuwa District,Nepal

Abstract Himalaya is a highly susceptible region for avalanche and flash floods due to steep topography as well as fragile lithology. The present study aims to investigates the catastrophic meghaflood of Bhote Koshi and Trishuli river of the greater Himalayin region of Rasuwa District of the Nepal. The research aims to assess the sediment source region and valley-floor deposition, and channel dynamics for the landscape transformation.Sentinal-2A satellite imagery, DEM,GIS based investigations are integrated to delineate erosion and deposition zones and evaluate changes in channel morphology and valley-floor configuration.The meghaflood resulted into channel widening,bank erosion, debris accumulation.The research findings highlight the role of hydro-geomorphic processess responsible for channel modification.It also highlights the critical role of hydro-geomorphic thresholds and sediment connectivity in transforming high-mountain river systems during extreme flood events.Geospatial techniques are utilized to assess the channel modification of Bhothe Koshi- Trishuli river