Assessment of Drought Severity Using Normal Precipitation Index (Case study Sistan and Baluchestan Province)

Water crisis is one of the most important crises in the management of human societies and environment which almost affect all of the development bases in the international, regional and national levels. Drought assessment and its intensity are very different and includes statistical (Standardizatation, probabilities), meteorological (Synoptic, dynamic) and hydrological (water balance) methods. In this research we have used percale normal index to analyze the meteorological drought in Sistan and Baluchestan province which has suffered from severe drought during recent years. According to the results of the present work, the annual precipitation of between 36 to 52 percent of the studied years is higher than mean precipitation of the province. 10 to 23 percent is in the borderline of drought, 3 to 13 percent is exposed to weak drought, 6.7 to 23 percent to moderate drought, 6 to 20 percent to severe drought, and 6.7 to 23 to very severe drought.