Impact of climate change on the hydrology of a semi-arid river basin of India under hypothetical and projected climate change scenarios

Climate change impact on the hydrology of the Betwa river basin, located in the semi-arid region of Central India, was assessed using the Soil and Water Assessment Tool (SWAT), driven by hypothetical scenarios and Model of Interdisciplinary Research on Climate version 5 (MIROC5) Global Circulation Model projections. SWAT-Calibration and Uncertainty Programs (SWAT-CUP) was used for calibration and validation of SWAT using multi-site streamflow data. The coefficient of determination, Nash-Sutcliffe efficiency, RMSE-observations standard deviation ratio and percent bias during calibration and validation period varied from 0.83-0.92, 0.6-0.91, 0.3-0.63 and -19.8-19.3, respectively. MIROC5 projections revealed an increase in annual mean temperature in the range of 0.7-0.9 degrees C, 1.2-2.0 degrees C and 1.1-3.1 degrees C during the 2020s, 2050s, and 2080s, respectively. Rainfall is likely to increase in the range of 0.4-9.1% and 5.7-15.3% during the 2050s and 2080s, respectively. Simulation results indicated 3.8-29% and 12-48% increase in mean annual surface runoff during the 2050s and 2080s, respectively. Similarly, an increase of 0.2-3.0%, 2.6-4.2% and 3.5-6.2% in mean annual evapotranspiration is likely during the 2020s, 2050s and 2080s, respectively. These results could be used for developing suitable climate change adaptation plans for the river basin.