Determining the Uncertainty of Evaporation from Reservoir by Considering the Climate Change Conditions (Case Study: Dez Dam Reservoir)

Human activities have led to increased greenhouse gas emissions in the atmosphere area and it caused internal climate changes. These influences are effective on the climate parameters, which increases the temperature rate and, consequently, elevates the rate of evaporation from the free surfaces. The reservoirs of dams are influenced directly by this temperature rise as the main place of water storage, causing the annual loss of a large amount of water in them due to the evaporation phenomenon. In this research, the effect of climate change on the evaporation from Dez dam reservoir was studied considering the uncertainty of climate change scenarios. Also, the changes occurring in temperature ranges and evaporation rates in future periods were examined under climate change scenarios. The results suggested that in the coming period of 2020-2044, the annual evaporation rate will increase in all three greenhouse gas emissions scenarios, and with a probability of occurrence of 90%, the highest evaporation rate would occur in May under the A1 scenario.