Multi-criteria-based sub-basin prioritization and its risk assessment of erosion susceptibility in Kansai–Kumari catchment area, India

Abstract

Environmental processes are interrupted by the water action like soil erosion, mass movement as well as siltation on the dam in the undulating catchment area. Soil erosion is one of them and degraded the basin potentiality. This paper demonstrates that erosion susceptibility status in the 13 sub-basins of Kansai–Kumari catchment area has been determined depending upon its morphometric, lithology, geomorphic, land use/land cover (LULC), slope and soil characteristics used by integrated micro-watershed prioritization rank which is based on susceptible capacity under geographical information system platform. Risk assessment of soil erosion was measured by hypsometric characteristic (Hi) and denudation rate (tu) to assess the geological stage of landform and risk status for conservative practices. The result shows that SB13, 2 have a high risk (tu > 90 t/km2/year) due to the presence of low priority rank of morphometric, geomorphic, slope, soil and high priority rank of lithological set-up and LULC but reached under the late mature geological stage (Hi > 0.35). SB3, 4, 10 have a low risk (tu < 83 t/km2/year) due to the presence of high priority rank of morphometric, geology, geomorphic, slope and soil types under the mature stage of geological setting (Hi > 0.5). But SB7, 8, 9 have the medium risk (tu < 85 t/km2/year) due to the presence of erosion-prone LULC patterns like cropland and laterite cover but having low final priority rank and old geological stage (Hi < 0.35). Therefore, erosion susceptibility does not depend on morphometric aspects but also depends on other determinant themes at the sub-basin level.