Quantitative geo-morphometric and land cover-based micro-watershed prioritization in the Tons river basin of the lesser Himalaya

Across the Himalaya, lesser Himalayan watersheds are the most vulnerable to environmental degradation. It is due to fragile conservational disposition, increasing developmental pressure and tourism. Micro-watershed prioritization is the best scientific option for managing the natural resources while maintaining pace of development. In this study, a typical sub-watershed of the lesser Himalaya (Tons sub-watershed: TSW) has been selected for prioritizing its micro-watershed and proposing a suitable and sustainable site for a small hydro-water plant installation. Micro-watershed prioritization is based on the integrated analysis of geo-morphometric, land use/land cover, lithological and soil type parameters associated with tools of remote sensing and geographical information system. This study characterized four micro-watersheds in TSW: 2C6C1a1, 2C6C1a2, 2C6C1a3 and 2C6C1a4 and assessed the risk and vulnerability of natural resources degradation. Individual category parameter for each micro-watershed has been evaluated, compared and ranks have been assigned based on their capacity to induce erodibility. Integrated theme-based rankings have been determined for each micro-watershed and final (composite) prioritization has been done accordingly. The results reveal that micro-watersheds 2C6C1a2 and 2C6C1a3 fall under medium priority, micro-watershed 2C6C1a4 indicates low priority, while micro-watershed 2C6C1a1 falls in high priority zone in the study area. The developed methodology and the results presented here will be imperative to prepare a comprehensive micro-watershed management planning. The results will be utilized to understand the topography, nature of the basin and demarcation of suitable site for the installation of a small multi-purpose hydropower plant in the study area.