Assessment of climate change using dynamical downscaling of GCM in Gheshlagh dam basin during the coming decades

The process of climate change because of its significant impact on various dimensions of the fitted living beings, in recent decades has been highly regarded. In this study regarding the importance of precipitation and temperature on water saving and increasing kishlak dam water requirement for Sanandaj city, simulation of climate change in Kishlak basin dam in next decade were done by circulation model of the atmosphere. In order to prepare the climatic scenarios in this research, the general circulation model HadGEM2 under RCP4.5 scenario HadGEM2 was used. In order to ensure a high resolution of the general circulation model output, small dynamic model downscaling ‘RegCM4’ were used and total rainfall, maximum temperature, minimum temperature and wind speed parameters for next decade (2015-2020) were simulated. In the verification phase, the historical data simulated by model for 1996-2000 periods with observed data from local stations compared by using correction coefficient and mean square of error. Finally, the spatial distribution of climatic parameters for future decades was obtained by GIS software. The results showed a good performance of model for simulation of the average monthly maximum and minimum temperature parameters, however, average monthly rainfall data with less accuracy were estimated. Also based on RCP4.5 scenario it can be concluded that in the near future in summer the temperature will increase and the total amount of rainfall will decrease and mean annual temperature will increase.