Hydrological modeling and simulation of water balance components using the SWAT model in the coal mining province of the Mahan River catchment, Central India

The research was employed to simulate the watershed's hydrologic behavior and to predict stream flow in the Mahan River catchment area alongside the effect of six underground (UG) and opencast (OC) mines for the past decades. Following the SWAT model run, the mining area sub-watersheds possess (SW20, SW26, SW28, SW31 and SW38) a comparatively lesser sediment yield of 61.41 Metric Ton/ha than that of non-mining area sub-watersheds 159.40 Metric Ton/ha. Amongst all hydrological components, evapotranspiration with 531.2 mm consumed 39% of the total annual precipitation (1365.3 mm). The total discharge was estimated to be 775.57 mm, which comprises Surface Runoff of about 351.89 mm, Return Flow (402.21 mm) and Lateral flow (21.47 mm), while percolation into the unconfined and confined aquifers as soil and groundwater storage also accounted for 58.86 mm. The statistical indicators and graphs indicate that the model performs satisfactorily for the daily streamflow (R2 = 0.875, p = 0.71, r = 0.76 and NSE = 0.87 during the validation (R2 = 0.817) as that during the calibration period. The model performed satisfactorily during the simulation and the results showed that the mines play a critical role in changing the hydrological regime of the watershed with low recharge and moderate evapotranspiration characteristics. Taken together, the SWAT model appears to be a reliable tool for forecasting stream discharge over long periods of time, in parallel with the likely impacts of mining activity on HRUs.