Morphometric and Hypsometric Analyses for Watershed Prioritization of Koyna River Basin, Maharashtra, India Using Remote Sensing and GIS

Watershed management is crucial for sustaining water resources, controlling soil erosion, and mitigating flood risks. Prior to management, it is important to understand characteristics of watershed through morphometric analysis, which lays foundation for informed decision-making, conservation strategies, and sustainable land use planning in a watershed. Despite the progress made in watershed management studies, a significant research gap exists in applying an integrated approach of morphometric and hypsometric analyses using high-resolution datasets. This study abridges such gap by integrating morphometric analysis and hypsometric analysis by applying remote sensing (RS) and geographic information system (GIS) in Koyna River basin of Maharashtra, India. Furthermore, this study prioritizes sub-watersheds for soil and water conservation using RS and GIS techniques. The watershed boundary was delineated, and key morphometric parameters, i.e., basin area, stream order, stream length, and drainage density, were derived from high-resolution digital elevation model. The basin was classified as a 6^th order basin with a drainage density of 0.83 km km^-2, indicating a coarse drainage pattern. The elongation ratio (0.8) indicated an elongated basin shape, associated with moderate slopes and differential erosion susceptibility, particularly in the upstream regions. The hypsometric analysis (HI = 0.5) suggested a mature basin condition, reflecting an equilibrium state between erosional and depositional processes. Sub-watershed prioritization revealed that three sub-catchments, i.e., SW9, SW10, and SW5 ranked highest in vulnerability and requires immediate implementation of soil and water conservation measures, while others showed relatively stable conditions. Findings of this study highlighted that accurate watershed delineation, supported by morphometric and hypsometric evaluation in a GIS framework, is essential for effective hydrological assessment and resource management. The approach provides a scientific basis for targeted watershed prioritization, enabling site-specific interventions and supporting long-term sustainability of land and water resources.