Evaluation of the Impact of Climate Change on Streamflow Using SWAT Model

Abstract

The Soil and Water Assessment Tool (SWAT) model was applied in this study to simulate stream-flow in the Oyun River Basin. The model was calibrated and validated using monthly stream-flow data for the basin. Model performance was satisfactory for calibration and validation with a coefficient of determination (R2) of 0.69 and 0.88, respectively. Climate change impact on Oyun River was assessed by driving the SWAT model with climate parameters obtained from two global climate models (HadGEM2-ES and BCC-CCSM1-1M) based on RCP 2.6 for 2050 – 2059 and 2080 – 2089 periods. With respect to a baseline period of 2000 – 2009, HadGEM2-ES predicted a 4.62% decrease in total stream-flow while the BCC-CSM1-1M predicted stream-flow increase by 6.18% for the 2050 – 2059 period. However, both HadGEM2-ES and BCC-CCSM1-1M predicted stream-flow to increase by 18.92% and 11.25% respectively for the 2080 period. The HadGEM2-ES model showed consistency in relating future rainfall predictions with future discharge trends for the periods under study. Model results show the need for adaptive measures to mitigate climate change impacts on the water resource system.

Keywords

• swat model
• climate change
• stream-flow
• hadgem2-es
• bcc-ccsm1-1m