Multi-criteria-based decision making approach for soil erosion susceptibility modelling of Sali River Basin, Bankura, India

Identification of soil erosion-prone locations is crucial since erosion of soil is a grave issue in semi-arid watershed regions. In this present study, the Sail watershed of Bankura district has been selected for the soil erosion susceptibility investigation. This basin is topographically complex, where there is a coexistence between badlands topography, lateritic capping and fragile soil texture at the western portion and a riverine flood plain at the eastern portion. Apropos to prioritize the sub-watersheds and identify the probable soil loss locations within each watershed, a multiple-criteria decision-making technique has been used. Eleven geo-environmental variables, including slope, soil texture, rainfall, sediment transport index, stream power index, land use and land cover, topographic wetness index, geomorphology, curvature, and lineament density, have been weighted using the analytical hierarchy process. Because undermining of the scarp foot is producing stream headward erosion and gully head slumping in this region, the southwestern portion of the basin has been identified as being particularly vulnerable to erosion. The receiver operating characteristic curve has been applied for validation purposes of the entire assessment. The area under the curve value accounted for 84.3%, which confirms satisfactory accuracy of susceptibility zonation.