Simulation of Climate Change Impacts Using Fifth Assessment Report Modelsunder RCP Scenarios on Water Resources in the Upper Basin of Salman FarsiDam

This research aims to assess the potential impacts of climate change on water resource in the headwater basin of Salman Farsi dam in Fars province using Soil and Water Assessment Tool (SWAT). Climate projections from three Global Circulation Models (GCMs) under two Representative Concentration Pathways (RCP2.6 and RCP8.5) during future period (2020-2050) were incorporated into the calibrated SWAT model and changes in simulated runoff, blue water, green water flow, and green water storage were compared to the baseline period (1978-2008). SWAT model efficiency in simulating hydrological response of the basin was confirmed by performance evaluation indices in Tang-e-Karzin hydrometric station which is located at the outlet of basin in the calibration (NSE=0.77, R2=0.80) and validation (NSE=0.57, R2=0.67) periods. The GCMs projections indicate increasing the frequency of severe precipitation events and reducing precipitation events with low intensity in the future as compared to the baseline period, and also increasing the minimum and maximum temperature in the basin. These changes lead to an annual increase in runoff and blue water due to increase in extreme events and flood producing potential of the basin, as well as an annual increase in green water flow due to increase in temperature and precipitation over future.The findings of this research can be helpful for water resource managers and policymakers to provide management plans and strategies to encountering climate change.