Document Type : Research Paper
Department of Climatology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
Department of Geography, Faculty of Humanities, Zanjan University
Global warming have led to an increase in the frequency of severe weather events, including droughts. Monitoring and predicting spatio-temporal behavior phenomenon is very important to prevent negative socio-economic consequences and environmental planning. There has been no comprehensive long-term assessment of drought spatial analysis for Iran. In this way, first a decade of droughts with the PDSI index from 1980 to 2020 were extracted and then analyzed spatially. The results showed that the intensity of Palmer drought index in Iran increased from -2.12 to 1.45 to -5.73 to 1.34 and changed from dry to extremely dry.
The elliptical direction showed three standard deviations in each of the four decades studied northwest and southeast, which was in the direction of unevenness, following the direction of Iran's rainfall. To explain the spatial pattern of Gates statistics calculated in the first decade showed the case range of hot spots (severe drought clustering)
In small parts of central Iran and on low rainfall and desert provinces showed in the second decade in southwestern Iran, including Bushehr and Khuzestan provinces in the third decade in many parts of central Iran, including Tehran, Semnan, Isfahan, Fars and Kohkiluyeh and Boyer Ahmad in the fourth decade of the southern and southeastern part of Iran, including Hormozgan province and Sistan Baluchestan, showed its significant cluster patterns.
The spatial distribution of drought intensities indicates the displacement and intensity of rainfall systems over the decades, indicating that all parts of the country may be at risk of drought. Such research can identify areas at high drought risk and be used in environmental planning.