Assessment of the Impact of Land Use and Land Cover Change on Hydrological Components of the Upper Watershed of Subarnarekha River Basin, Jharkhand, India Using SWAT Model

This study investigated the impact of LULC changes on several hydrological components of the upper watershed of the Subarnarekha river basin, Jharkhand, India. Several hydrological components of the water balance were simulated using the Soil and Water Assessment Tool (SWAT). Three scenarios were generated using a combination of climatic data for the years (1997–2020) and LULC data for the years (2000, 2012, and 2020). The model was run successfully for the calibration and validation period using monthly stream flow data. Sixteen model parameters were applied for sensitivity analysis. RCHRG_DP and ALPHA_BF were found to be the most sensitive parameters. The components of the water balance were calculated accurately. The outcome of this study shows the decrease in evapotranspiration, recharge to deep aquifer and shallow aquifer, and the increase in surface runoff due to urban development and negative change in forest cover over the study area. A significant increase in surface runoff is viewed as a negative impact on watersheds or river basins that balances the hydrological process. In general, the increased surface runoff may intensify the environmental problem by accelerating erosion and sedimentation. The findings of this study will be beneficial to the hydrological community, water resource managers, and decision-makers active in agricultural water management and soil conservation as well as those working to mitigate increased surface runoff and floods from the perspective of LULC transformation and climate change.