Climate Change Impact on the Future Inflow of the Doroodzan Reservoir in the Province of Fars

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change presents four general circulation models under the SRES emission scenarios of A2 and B1. The take-home message of these documents is the expected change in the atmospheric temperature, which undoubtedly would affect the hydrology of watersheds. These warnings dictate the necessity of prediction of the future change in the flow of rivers and the vulnerability of the people who depend on them for their water supplies. Results indicated that the average temperature variations are from -0.13 to 0.96°C and 0.72 to 1.85°C for 2016-2038 and 2039-2061 periods, respectively. Furthermore, the average monthly rainfall variations in the baseline period in comparison to the observed period (1988-2010) are from -3.5 to 182% and -20.7 to 123 % for those two periods, respectively. The daily rainfall- runoff simulation using the IHACRES model yielded the R2 of 0.684 and 0.635 for the calibration and validation stages, respectively. Overall, the mean volume of annual runoff into the Doroodzan Reservoir would decrease by 8.4 and 28.15 % as compared with the baseline period for the 2016-2038 and 2039-2061, respectively. Furthermore, the most decrease in the mean volume of monthly runoff of the basin in comparison with the baseline period has been predicted for November to be 42.34 and 54.13 % for those two periods, respectively.