Prioritization of watersheds based on a picture fuzzy analytic hierarchy process and linear assignment model

Soil erosion is one of the most dangerous natural dangers, causing a great deal of harm in many parts of the world. In the presented study, the Gusru river watershed in Indi was divided into 14 sub-watersheds, and then 14 morphometric parameters were calculated, including drainage density (D d ), bifurcation ratio (R b ), streams frequency (F s ), average slope (S a ), form factor (R f ), circulatory ratio (R C ), elongation ratio (R e ), relative relief (R h ), ruggedness number (R N ), bifurcation ratio (R b ), texture ratio (T), length of the overland flow (L o ) compactness coefficient (C C ) and hypsometric integral (HI) were derived for each sub- watershed. Afterward, the combination of picture fuzzy-analytic hierarchy process and picture fuzzy-linear assignment model were used to assign weights to selected morphometric criteria and to rank the sub-watersheds based on the level of soil erosion susceptibility. The results of the study showed that sub-watersheds 11 and 2 were the most susceptible sub watersheds, while sub-watersheds 13 and 14 had the lowest susceptibility to soil erosion. Prioritization and ranking of sub-watersheds from the perspective of soil erosion susceptibility can be used as a powerful tool for prevention and mitigation measures.