Geospatial modelling for sub-watershed prioritization in Western Himalayan Basin using morphometric parameters

Geographical information system and remote sensing are proven to be an efficient tool for locating water harvesting and recharge structures, groundwater potential, runoff, watershed prioritization through morphometric analysis. The management and conservation of watershed require scientific evaluation so that appropriate strategies can be implemented by the policymakers and stakeholders. This study evaluates the Parvati River Basin for prioritization of sub-watershed. We use analytical hierarchical approach with pairwise comparison matrix for ranking the parameters which has been derived through morphometric analysis of the watersheds. The linear (stream order, stream length, mean, stream length, stream length ratio, bifurcation ratio, rho coefficient), relief (basin relief, relief ratio, ruggedness number) and areal morphometric parameters (drainage density, stream frequency, texture ratio, form factor, circulatory ratio, elongation ratio, length of overland flow, constant channel maintenance) have been used for prioritization of watershed in the Basin. The results revealed that the basin comprises of complex topography with mountainous and hilly relief structures which results into high run-off. The prioritization of sub-watershed suggests that the largest watershed comprising of 36.09% total watershed area falls into medium category for water potential. The total area under very high to high category is 5.36% and 8.44% respectively. The relationship between morphometric parameter and watershed prioritization shows that the sub-watersheds SW1 and SW8 falls under very high to high category having high water holding capacity.