CLIMATE CHANGE IMPACT ASSESSMENT ON STREAMFLOW OF GANJAL RIVER USING SWAT MODEL

Abstract

Hydrological models often predict a changing situation, necessitating further research into models to make water resource management more realistic. This study uses the Soil Water Assessment Tool (SWAT) model to analyse the possible effect of climate change on the future streamflow of the Ganjal river watershed, a sub-basin of the Narmada River, India. The model was calibrated for 1988-2007 and validated for 2008-2015 using monthly discharge data at the watershed outlet. Calibration and validation of the SWAT model were carried out in SWAT CUP using the SUFI-2 algorithm. The coefficient of determination (R2 ) and Nash Sutcliffe efficiency (NSE) were 0.87 in calibration, whereas in validation was 0.85 each. The outcome indicates that the simulated and observed flow have a good match. The calibrated model was then run for the future (2025-52) using climate model output. The study of climate change is completed using the Representative Concentration Pathway RCP 4.5 and 8.5 scenarios from three different GCM. The downscaled output of these GCM from CORDEX has been used in this study after bias correction. The findings demonstrate the significance of climate change's effect on water resources, as it has a significant impact on streamflow.