Prediction of Prediction of Climate Change Impacts on Kharkeh Dam Reservoir Inflows with Using of CMIP5-RCP Scenarios

The objective of this research was to investigate the effects of climate change on precipitation and temperature parameters of Karkheh Basin and inflow to Karkheh dam reservoir. This was conducted by applying 21 GCM models under CMIP5 scenarios. The error indices of R2, RMSE and MAE models with the observed precipitation and temperature data were examined to find the appropriate GCM model, MRI-CGCM3. The outputs of this model under RCP2.6 and RCP8.5 scenarios were used to predict precipitation and temperature in future periods (2020-2040 and 2040-2060). With change factor downscaling of MRI-CGCM3 outputs, the precipitation decrease and temperature rise was 2.8% and 1°C under the RCP scenario of 2.6, 6.8% and 1.5°C under the RCP8 scenario, respectively in the period of 2020-2040. IHACRES model was used to study the effect of climate change on basin runoff and inflow to Karkheh Dam reservoir. Runoff simulation results show that overall runoff reduction is 10.2% under RCP2.6 and 20.1% under RCP8.5 scenarios in 2020-2040 compared to baseline period. These results indicate the inappropriate future situation of Karkheh Dam reservoir, which will have an impact on the water supply required for agriculture and electricity of the region.