Analysis of Spatial Drought Patterns Using the SPI Index in Golestan Province

Scarcity in precipitation along with great variability is the most feature of climate in Iran. Drought as a phenomenon of climate, leaving behind undesirable effects every year in Iran. The purpose of this study was investigation of the spatial characteristics of drought using SPI index in monthly scale in Golestan province. Therefore, the 35-year rainfall data from 23 climate stations were used. Monthly Moving Average chart reviews showed that withincreasing time scales, the severity of the drought is reduced while the drought duration is increased.The highest intensity and frequency of droughts were occured in the northeast stations in Golestan province. Zoning map was also showed the drought prone zone increases while changing time scales from 3-month to 24-month.