Hydrological Response to Climate Change Impacts in the Karkheh River Basin

This paper addresses the impacts of climate change on hydrology and water resources in the Karkheh River Basin (KRB). KRB is the third most productive basin in Iran, and has a great potential for hydropower generation. A total potential capacity of reservoirs in this basin is more than 15,000 mcm of which 40 percent has been built. The sensitivity of the KRB to potential climate change is investigated by simulating basin streamflow response under different climate change scenarios. A conceptual rainfall-runoff model (IHACRES) is first calibrated by using hydrological and streamflow observations. The model is then applied by downscaled two general circulation model outputs (CGCM3 and HadCM3) under three emission scenarios (A1B, A2, and B1). Results show that in the short-term, annual mean temperature will increase by about 0.9°C, but the annual amount of precipitation will not change significantly. Also, annual streamflow will decrease 10 to 15 percent. In mid- and long-term, respectively, temperature will increase by more than 2.0°C and 4.0°C, precipitation will decrease by about 15 and 17 percent, and annual streamflow will decrease by about 25 and 32 percent.

کلیدواژه ها:

Climate Change ، Karkheh River Basin ، Rainfall-runoff Model ، Impact Assessment