Assessing climate change and land management impacts on drought resilience in the Seonath Basin using SWAT

ABSTRACT Droughts are a major hydroclimatic hazard in central India and are projected to intensify under climate change. This study evaluates the effectiveness of land management practices (LMPs) in mitigating drought impacts on watershed hydrology in the Seonath Basin, a key tributary of the Mahanadi River, using the Soil and Water Assessment Tool (SWAT). The model was calibrated (1985–2003) and validated (2004–2017) with satisfactory performance (NSE = 0.86–0.90 during calibration and 0.35–0.87 during validation). Baseline simulations show that evapotranspiration (ET) dominates the water balance, consuming ∼70% of annual rainfall and limiting streamflow and groundwater recharge during drought years. Climate projections under SSP245 and SSP585 indicate a ∼5% increase in precipitation, with runoff and recharge increasing by ∼50% and 300%, respectively, while ET declines by ∼38%. Although total water yield is projected to rise, altered water partitioning increases the risk of both flash floods and seasonal droughts. Simulated LMPs--including conservation agriculture, agroforestry, rice -fallow intensification, and watershed interventions--enhanced hydrological resilience by reducing surface runoff (5–20%), increasing baseflow (4–18%), soil moisture (10–20%), and recharge (5–15%). Without LMPs, future hydrological droughts reduce streamflow by 25–30%, whereas LMPs offset this deficit by 12–18%.