Assess the Impact of Climate Change on the Hydrological Drought in Southern Khorasan Province, Iran

Drought is a natural disaster causes the most environmental damage, the government and the different types of people in a community silently and slowly. Climate change induced by increasing greenhouse gases, which have negative impacts on human societies in the 21st century, is one of the important issues. Climate change can have different effects on different systems. Because of the critical role of water inhuman life, its negative effects on the severity and frequency of drought in the region are very important. In this paper, we assess the impact of climate change on drought conditions in Southern Khorasan province, using standardized precipitation index (SPI). So after downscaling output of the HadCM3 model under four emission scenarios A1, A2, B1, B2 by IDW, to construct a time series of climate scenarios for the period of thirty years, the method of change factor was used. Then, the 24-month time scale in dices were calculated for future periods and the Probability of moderate and severe droughts in various regions of the province were determined. Comparison results show that probability of severe droughts in the near future is more in the west. In the Intermediate future and distant Future occurrence of the severe drought in western and northeast areas, respectively, will increase. The highest probability of moderated rough during the coming period is in the northern half of the province.