Assessment of Climatic Drought and Its Economic Effects (Case Study: South Khorasan Province)

In this research Standardized Precipitation Index (SPI) in a period of 22 years (1990 to 2011) was used for zoning of climatic and agricultural drought in South Khorasan province, Iran. Rainfall data of six synoptic stations were collected and used for evaluation of meteorological drought. Also, reports of some local offices such as natural resources, agriculture, regional water and environment department were provided to study the effect of agricultural economic drought. At first, the elevation-precipitation regression of each period was obtained then this relationship was applied on Digital Evaluation Model (DEM) layer using ArcGIS 9.3 software. The result showed that the most severity droughts occurred in 2008, 2000, 2006 and 2011 respectively. In 2008 more than 66% of the study area were classified as extremely drought class. The result of agricultural drought showed that the total annual rangelands forage production of South Khorasan province that expected to be 625000 tons reduced to 250000 tons during period of 2007 to 2011. Also the agricultural production was faced with 45% reduction and caused rising poverty and unemployment, immigration from rural area to urban, in evacuated villages.