Study on the effect of climate change on maximum precipitations and probable maximum flood in the Karoon River zone of Iran

Climate change is one of the challenges which affect different areas of the human’s life on the earth, one of which is its effect on extreme events such as flood and drought. Today, one of the most important topics being discussed is that how the intensity of heavy precipitations and flood will change in future compared to that of the present values. In the present study, we try to investigate the effect of this phenomenon on the extreme precipitation and maximum probable flood (PMF) in the Shaloo Bridge region of the Karoon River in Iran. For such purpose, future temperature and precipitation between 2011 and 2030 is simulated with HadCM3 model based propagation scenarios of A1B, A2, B1 and small-scale exponential and statistical model LARS-WG. For simulation of the flood in the region, rainfall-runoff model HEC-HMS model is applied and for simulation of snowmelt, SRM model is considered. Results of this research shows that under the A1B scenario, in the time period from 2011 to 2030, the maximum precipitations in the region is reduced by 5 percent compared to that of the present time; on the contrary, A2 and B1 scenarios show an increase of 5 and 10 percent each. Also, it can be predicted that the flood as result of snowmelt in the climate change condition is increased in all the three scenarios. Also, the maximum probable flood at the area is decreased upon the A1B scenario, but it is increased in the A2 and B1 scenarios; however, the intensity of change is much higher in the last one.