Analyzing and Forecasting Drought Using the Standardized Precipitation Index (SPI) in Cities of Golestan Province

Drought is a natural and global phenomenon typically defined as a period of water scarcity relative to normal levels and is considered one of the most significant meteorological hazards. In many regions worldwide, both the frequency and intensity of droughts have dramatically increased. Drought refers to the reduction in water availability over a specific period and area. This study analyzes drought fluctuations during the period 1971 to 2019 and forecasts its status for 2019 to 2044 across various cities in Iran.The SPI was calculated at different time scales (1, 3, 6, 12 months). The SPI is an index based on the probability of precipitation deficits over a given period. SPI values are calculated using long-term precipitation records (30 years or more) for a specific region. Positive SPI values indicate above-average precipitation, while negative SPI values indicate below-average precipitation.The results reveal severe fluctuations in SPI in cities like Aliabad and Gorgan, which have experienced alternating periods of drought and wet conditions. In contrast, regions such as Hashemabad and Incheh-Borun showed predominantly positive SPI values, indicating consistently wet conditions and regular rainfall. However, cities like Kalaleh and Maraveh Tappeh faced severe droughts. Forecasts for 2019 to 2044 suggest increased severe fluctuations and recurrent droughts in cities like Bandar-e-Turkmen and Gonbad-e-Kavus, while Gorgan and Hashemabad are expected to maintain relative stability.These findings underscore the urgent need for effective water resource management and climate planning to address potential droughts and climate change impacts. Overall, this study highlights the necessity of adopting preventive measures and establishing early warning systems to optimize water resource management and tackle future challenges associated with climate variability.