Effect of climate and land use change on discharge in the Betwa River basin, India, using SWAT based on CMIP6 and the Land Change Modeler model projections

ABSTRACT

Assessment of hydrological flux under climate and land use change is critical. For the Ken-Betwa river-linking project underway in central India, a pre-assessment of land use land cover (LULC) and climate change effects on the hydrology of the Betwa River basin becomes essential. Land Change Modeler suggests a sustained expansion in open forests and built-up land. Agricultural land area shows a decline for 2030 and 2050. Model performance measures such as Nash–Sutcliffe efficiency, R2, PBIAS, and RSR for calibration (1987–1999)/validation (2000–2018) were 0.66, 0.67, 1.2, 0.59, and 0.64, 0.65, 9.2, and 0.60, respectively, based on the historical climate (1984–2018) and land use map. SSP245 scenarios (MRI-ESM2-0 and ACCESS-ESM1-5) and LULC 1990, 2010, 2030, and 2050 show a decreasing trend in the average annual discharge. Average annual river discharge declined with the MRI-ESM2-0 model under SSP245 and LULC 2010 scenarios, while a more optimal decline was observed under SSP245 and LULC 1990 scenarios. There is a substantial decline in average annual river discharge with ACCESS-ESM1-5 under SSP245 and LULC 2050, whereas the least projected decline is under SSP245 and LULC 1990. Both models exhibited a decreasing trend in average annual discharge at the outlet from mid-century.