DRAINAGE MORPHOMETRY-BASED SUB-WATERSHED PRIODRAINAGE MORPHOMETRY-BASED SUB-WATERSHED PRIORITIZATION OF THE TAPI RIVER BASIN (TRB) USING GEOSPATIAL TECHNOLOGIESRITIZATION OF THE TAPI RIVER BASIN (TRB) USING GEOSPATIAL TECHNOLOGIES

Abstract

The present study utilized drainage morphometry to characterize the sub-watersheds of the Tapi River Basin (TRB) and prioritize them for groundwater recharge, bank erosion, and flood hazard assessment. Streams were extracted from the 30 m Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). From the same SRTM DEM, drainage density, lineament density, and slope maps were generated. Land use/land cover (LULC) was classified from the 10 m Sentinel-2 image. Furthermore, geological, geomorphological, and fault dataset were downloaded from the Bhukosh portal of the Geological Survey of India. The linear, areal, and relief parameters were calculated for nine sub-watersheds (SB1–SB9) using a geographic information system (GIS). The sub-watersheds varied significantly concerning the physical features, which affect the hydrological behavior of the watershed. In terms of groundwater potential, SB9, SB7, and SB3 were found to have the highest potential; while, the bank erosion and flood hazards were the highest in SB4, SB2. The sub-watersheds (SB7) and (SB9) were more vulnerable to climate change than others. Overall, a groundwater potential zone (GWPZ) map was prepared using seven thematic layers (geology, geomorphology, drainage density, lineament density, LULC, soil, and slope). The very good class, good class, moderate class, low class, and very low class were recorded by 5.03%, 51.36%, 18.99%, 13.73%, and 10.89% of the basin area, respectively. It is suggested to implement water management practices in such sub-watersheds to optimize groundwater potential, minimize erosion and flood hazards, and build resilience capacity against predicted climate change impacts in the TRB region.