The selection of the best from climate change model in the estimation of climatology variables for east region of the country by use fifth report data

Climate change is nowadays a major cause of concern in water related fields because it may cause more severe, shortened or prolonged droughts or floods in the future. In this research was tried to the best model of climate change is determined from the climate change models to determining the minimum temperature, maximum temperature and precipitation for the Birjand synoptic station. For this reason, 35 models of GCM were determined for each of variables of the minimum temperature, maximum temperature and precipitation. Initially, for each of the weather variables, the values ​​of each of the fifth report models for the base period and the synoptic station of Birjand were determined and compared with the results of the synoptic station in Birjand. Results showed that the rainfall data of GISS-ES-R, CNRM-CM5, CSIROMKMK3.6 models are most similar to the data of the Birjand synoptic station. For maximum temperature, GISS-ES-R, CNRM-CM5, CSIROMKMK3.6 models and for the minimum temperature, the GISS-ES-R, GFDLCM3 and MIROC-ESM models have the minimum error values and results of these models had the best similarity with the observed data. From comparison of model data with synoptic station data showed that the highest percentage of relative error of rainfall, minimum temperature and maximum temperature is shown for 1(January), 2(February) and 5(May) months, respectively. In comparing the differences between GCM models and Birjand station data for precipitation, the maximum temperature and minimum temperature are the fifth (May), third (March) and first (January) months, respectively, than the rest of the months.