Soil Erosion Assessment Under Changing Climate Using CMIP6 GCMs Integrated with SWAT

Soil erosion poses a significant threat to agricultural productivity and water resource sustainability, particularly in monsoon-dominated semi-arid basins. This study estimates soil erosion in a sub-basin of the Upper Krishna River (UKR) using the Revised Universal Soil Loss Equation (RUSLE) within the Soil and Water Assessment Tool (SWAT) model. The Indian Meteorological Department (IMD) historical climate data from 1991 to 2021 was used for the calibration and validation of the SWAT model, and the annual average soil loss was found to be 105 tons/ha. Future projections were evaluated using climate data from two General Circulation Models (GCMs), CanESM5 and EC-Earth3, under SSP2 and SSP5 scenarios, to assess changes in annual average soil erosion until mid-century (2049). The results of the study indicate an increased average annual precipitation, which affects the soil erosivity and results in increased soil erosion. Under SSP2-4.5, projected soil erosion is 127.45 tons/ha for CanESM5 and 93.22 tons/ha for EC-Earth3, whereas under SSP5-8.5, the values rise to 208.69 tons/ha and 122.58 tons/ha, respectively. The results of the study highlight the impact of climate change on the soil erosion dynamics and identify the erosion hotspots in the study area to help policymakers and planners for sustainable land management practices.