Prioritization of Sub-watersheds of Kosi River Basin Using Morphometric Analysis and Geospatial Tools

Abstract

This study aimed to use remote sensing (RS) and geographic information system (GIS) geospatial tools for morphometric investigation of a mid-Himalayan Kosi river basin in Uttarakhand, India. The sub- watersheds (SWs) were identified and prioritized into high, medium, and low level of priority based on the compound factor analysis for conservation of natural resources in the watershed, leading to sustainable watershed management. Total of 10 morphological parameters related to drainage network, basin geometry, and drainage texture were used for compound factor analysis. The drainage network of the river basin was dendritic in nature and exhibited homogeneity in texture and lack of structural control that helped in analysing terrain parameters as drainage density, infiltration capacity, runoff, bedrock nature, which control underground water movement. The stream-order estimated using the digital elevation model (DEM) having 12.5 m × 12.5 m spatial resolution ranged from first to seventh order streams. During prioritization of sub-watersheds using compound factor values, higher priority was assigned to sub- watersheds which yielded lowest compound factor and vice-versa. Sub-watersheds SW5 to SW7 covering an area of 396.18 km2 were noted to have highest priorities for soil erosion conservation measures; SW2, SW3 and SW8 had medium priorities; and SW1, SW9, and SW4 were assessed with lowest priorities. It is anticipated that the prioritization of sub-watersheds would be useful to planners, decision makers, and relevant stakeholders for implementation of soil and water conservation interventions for sustainable natural resources management within watershed.