Drought is one of the climate features in sense of shortage in water resources to the normal level of water that is likely to occur in all climate regions but with different characteristics from one region to another. The drought index, comprising a set of parameter such as: rainfall, snowfall, river stream, air mass, et al., is used to understanding the drought and its environmental influences in order to make clarification on this phenomenon. In this study, we tried to analyze the meteorological drought by using the percent of normal rainfall and climate data gathered from synoptic stations in Zabol. According to this study during the period from 1972 -2013, this region experienced a 5-year, weak dry spell during the period from 1985 to 1990 and a 10-year wet spell during the period from 1990 to 2000 according to the five-year moving average. In the beginning of 2000 dry period occurred again, but with more severity this time. Among diverse statistical functions examined for developmental embedding test and choosing the best distribution for mentioned synoptic station’s precipitation data, Log-Pearson type 3 Distribution presented the best embedding graph and therefore drought severity calculated through this probability distribution function in reoccurrence interval.

Full text: IJEIR_1078_Final.pdf