Author(s): Kashish Sadhwani; Ti Eldho; Subhankar Karmakar

Linked Author(s): Kashish Sadhwani

Keywords: Climate change impacts; GCM; Hydrological modelling; SWAT

Abstract: Hydro-climatologic processes are analyzed in climate models to predict future climate data. These data are used in the hydrological model to predict the hydrological behavior of watersheds which are very helpful in water resource management. In this study Soil and Water Assessment Tool (SWAT) is used with statistically downscaled General Circulation Model (GCM) climate data to estimate the streamflow in Periyar River Basin, Kerala in South India. Periyar River basin is a complex river basin located in the sub-tropical region that is also subjected to anthropogenic impacts with three major reservoirs in the watershed that alters the natural flow. The SWAT model was calibrated for monthly streamflow with a coefficient of determination (R-square), Nash-Sutcliffe efficiency (NSE), and Percent Bias (PBIAS) 0.92, 0.84, and 6.5% during the calibration period (1998-2004) and 0.85, 0.67, and 11.8% during validation period (2006-2012) respectively. It was then used to predict future streamflow till 2100 using MPI-ESM-MR GCM data under Representative Concentration Pathways (RCP) 4.5 scenario. To analyze the climate change impact, the time duration was divided into three scenarios near future (2021-2040), mid future (2041-2070), and far future (2071-2100). The results suggested a possible increment in streamflow in the near, mid, and far future till 2100 with maximum change in sub-basins near the river channel.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022140

Year: 2022