The effect of climate change on runoff produced in some part of Shiraz

Recently, the effects of climate change on the hydrological cycle and regime have become an important research topic. The results of atmospheric general circulation models (GCMs) together with hydrological models are used to determine the impacts of climate change on hydrologic regime. The daily minimum and maximum temperatures, rainfall and sunshine hours of the Shiraz synoptic station were simulated using the LARSE_WG6.0 statistical model. The efficiency of the model for simulating climate variables was determined using historical data of Shiraz station. To investigate climate change on runoff, two scenarios of the HadGEM2-ES model for two periods were downscaled using the LARSE_WG model. In the next step, runoff was simulated using the SWMM model and its results were compared with the measured runoff. For this purpose, 2 events were used for calibration and one event for validation. Based on coefficient correlation (R), root mean square error (RMSE) and Nash-Sutcliffe efficiency (NSE), the model has a suitable efficiency for simulating runoff. Then, LARSE_WG downscaled data were used in SWMM model and the runoff changes in future periods compared to present. According to RCP4.5 and RCP8.5 climate scenarios, precipitation will increase from 16.10 to 8.88% in 2021-2040 and 14.49% and 19.73% in 2061-2080. Therefore, assuming no change in landuse in Shiraz district 8, the volume of runoff will increase from 13.35 to 21.48 percent.