The river situation in a dry or semi-dry area is extremely affected by climate change and precipitation patterns. In this study, the impact of climate alteration on runoff in Kashafrood River Basin (KRB) in Iran was investigated using the Soil and Water Assessment Tool (SWAT) in historical and three future period times. The runoff was studied by MIROC-ESM and GFDL-ESM2G models as the outputs of general circulation models (GCMs) in the Coupled Model Intercomparison Project Phase 5 (CMIP5) by two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP8.5). The DiffeRential Evolution Adaptive Metropolis (DREAM-ZS) was used to calibrate the hydrological model parameters in different sub-basins. Using DREAM-ZS algorithm, realistic values were obtained for the parameters related to runoff simulation in the SWAT model. In this area, results show that runoff in GFDL-ESM2G in both RCPs (2.6 and 8.5) in comparing future periods with the historical period is increased about 232–383% and in MIROC-ESM tends to increase around 87–292%. Furthermore, GFDL-ESM2G compared to MIROC-ESM in RCP2.6 (RCP8.5) in near, intermediate, and far future periods shows that the value of runoff increases 59.6% (23.0%), 100.2% (35.1%), and 42.5% (65.3%), respectively.

干旱或半干旱地区的河流状况受到气候变化和降水模式的极大影响。在这项研究中，使用土壤和水评估工具（SWAT）在历史和未来三个时期研究了气候变化对伊朗Kashafrood流域（KRB）径流的影响。MIROC-ESM和GFDL-ESM2G模型通过两个代表性浓度路径（RCP）情景（RCP2.6和RCP8），在耦合模型比较项目阶段5（CMIP5）中研究了径流作为普通循环模型（GCM）的输出。 5）。差分演化自适应大都市（DREAM-ZS）用于校准不同子流域的水文模型参数。使用DREAM-ZS算法，获得了SWAT模型中与径流模拟有关的参数的实际值。在这方面 结果表明，与未来时期相比，两个RCP（2.6和8.5）中GFDL-ESM2G的径流量增加了约232–383％，而MIROC-ESM中的径流往往增加了约87–292％。此外，GFDL-ESM2G与RCP2.6（RCP8.5）中的MIROC-ESM在近期，中期和远期相比，显示径流值分别增加59.6％（23.0％），100.2％（35.1％）和分别为42.5％（65.3％）。