Prioritization of sub-watersheds of Teesta River according to soil erosion susceptibility using multi-criteria decision-making in Sikkim and West Bengal

Identification of the areas vulnerable to soil erosion through the prioritization of watersheds can help in the planning and execution of suitable conservational measures. In this study, prioritization for soil erosion of 14 sub-watersheds of the Teesta was determined through morphometric parameters using the analytical hierarchical process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The relative weights of various parameters were determined using AHP. For the evaluation of soil erosion hazard, 10 factors are used: bifurcation ration ( R b ), circulatory ratio ( R c ), basin length ( L ), stream frequency ( F s ), drainage density ( D d ), basin perimeter ( P ), basin width ( W ), shape factor ( B s ), drainage texture ( D t ), and elongation ratio ( R e ). The results demonstrate that sub-watersheds 1 and 4 have been ranked 1 and 2 in terms of highest closeness ( cl i + ) to an ideal solution with 0.774 and 0.434 respectively. These sub-watersheds must be given the highest priority for soil conservation measures, to ensure future sustainable agriculture.