Assessment of climate change uncertainty and its effects on the probability of the Jamishan dam inflow frequency

In order to assess the uncertainty of climate change and its effect on the discharge into the Jamishan dam located in the northwestern province of Kermanshah changes in temperature and precipitation parameters in the periods 2020-2039 and 2040-2059 were calculated using a combination of weighted average seven climate model output under three emission scenarios A1B, B1 and A2 respectively, The daily rainfall and temperature forecasts for future periods under each climate scenario was entered to rainfall-runoff calibrated and validated model ‘IHACRES’ and the daily runoff of future periods under each scenario was predicted. In order to determine periods of high-water and water shortage in the status quo and future periods, using Markov chain transition probability matrix, the Frequency months of wet, normal and drought were calculated. The results showed that in the period 2020-2039, annual rainfall decreases and temperature increases. In the period 2040-2059 the annual temperature changes are most severe between -0.66 and °C. A1B and B1 scenarios show annual rainfall and runoff reduction and increase in the A2 scenario.