Future Precipitation and Temperature Projection over Eastern Provinces of Iran using Combined Dynamical –Statistical Downscaling Technique

This study aims to provide a perspective of the climate of the eastern provinces of Iran at the end of 21st century to be usd in longterm planning, adoption and mitigation of climate change. This study uses a combined dynamic-statistical approach for downscaling of CanESM global climate model using RegCM4.5 as a dynamic model and change factor as a statistical method over eastern provinces of Iran, including Khorasan Razavi, South and Sistan and Baluchestan. After configuration of the RegCM regional model, the output of the RegCM was statistically downscaled by change factor method over two period of near future (2021-2049) and the distant future (2071-2099) under two IPCC scenarios of RCP4.5 and RCP8.5. The results indicate an annual increase of 4.2oC and 5.5 oC under RCP4.5 and RCP8.5 scenario in near future period (2021-2049) and 8.9oC to 5.5 oC in far future period of 2071-2099, respectively. If in the combined combined dynamical-statistical ownscaling process, the average scenario is considered as the most probalble scenario, then the decrease in precipitation in the east of the country in the near future will be between -11 to -15 percent and in the distant future between -8 to + 149 percent compared to the observation period. Although a small number of scenarios have predicted an increase in precipitation for the region, but due to the relatively large increase in temperature, any effects of increased precipitation will be ineffective due to the prrojected temperature increase in the region and the region will be subject to water stress that requires adaptation sterategy and reducing the consequences of global warming in the region.