Evaluation of the Efficiency of Statistical Downscaling Model (SDSM) In Simulation and Forecast of Climatic Parameters (Case Study: Karaj Synoptic Station)

The increase in the world's population, the use of more than fossil fuels, landuse change, the increasing expansion of industrial activities to provide the welfare and needs of the planet's population has led to gradual changes in the climate after the Industrial Revolution The Earth is the most significant of which is the increase in the average temperature in Korea, the increase of extreme climatic phenomena such as floods,storms,rising sea levels, melting of polar ice and Drought.In this research, SDSM model was used for quantitative estimation and investigation of climate change in Karaj region. The simulation results, on average, in the scenario A2, in the first periods(2020-1999),second(2021-2050) and third(2051-2080) for rainfall were about 0.1, 0 and 0.2mm in comparison with the base period and in the case of temperature is about 0.1, 0.4 and 0.2C, respectively, relative to the base period of increase. Under scenario B2, the time periods mentioned for rainfall were about 0, 0.1 and 0.2 millimeters, respectively, and about 0.2,0.1 and 0.1 centigrade, respectively Shows the increase relative to the base period.Changes in rainfall will lead to significant changes in the quality and quantity of water resources, which require careful planning in order to utilize water resources.