Climate change impact assessment on extreme daily rainfalls in Kermanshah

One of the potential impacts of climate change is the change on extreme rainfalls frequency and magnitude. For active adaptation strategy, it is required to assess the impacts of climate change on heavy rainfalls. Many downscaling methods have been developed, however most of them are not adequate for assessing climate change impact on extreme rainfalls. Among them, the NSRP rainfall model, which is generally ignored in previous studies, have considerable capabilities for climate change impact assessment on extreme rainfalls. In this paper, capability of the NSRP for daily rainfall series generation and climate change impact assessment on extreme rainfalls in Kermanshah is evaluated. The results indicated that NSRP can realistically simulate daily rainfall series containing extreme rainfalls; and can be used for climate change impact assessment on extreme rainfalls. Using the model, 100 series of daily rainfall of length 30 years were generated under each of the future A2, B1 and A1B scenarios from the CGCM3 model. Based on the results, magnitude of annual maximum rainfall of durations of one to five days will increase in future. Seasonal cycles of monthly means and accordance of extreme rainfalls will change. Long-term average of rainfall will decrease while extreme rainfall magnitude will increase. So it can be concluded that change in rainfall averages in monthly or yearly timescales cannot provide credit information about change in rainfall extremes. Respect to the results, for the future plans which are impressible of heavy rainfalls, the climate change impacts on heavy rainfalls should be considered.