Document Type : Original Article
Authors
1
Doctoral student of Climatology, Department of Geography, Ahar Branch, Islamic Azad University, Ahar, Iran,
2
Department of Geography, Ahar Branch, Islamic Azad University, Ahar, Iran
3
Department of Civil Engneerin, Ahar Branch, Islamic Azad University, Ahar, Iran
Abstract
Khorasan Razavi province is one of the provinces prone to drought in Iran. This study has assessed the spatio-temporal changes in the drought events in Khorasan Razavi province using the Standardized Precipitation Evapotranspiration Index (SPEI). For this purpose, initially, the IPSL-CM6, MRI-ESM2-0, GFDL-ESM4, and MIROC6 models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) were examined on an annual scale. The results showed that among the models, GFDL-ESM4 has a higher correlation with temperature and precipitation data from synoptic stations. Therefore, this model was selected and then downscaled using the CMHyd software, and the results of this model were used to calculate drought. In this research, the delta change factor (DCF) method was used for downscaling precipitation and temperature. Also, the intermediate scenario (SSP2-4.5) was used for drought projecting. The intensity and frequency of meteorological drought during the historical period from 1990 to 2014 and the future period from 2026 to 2050 were examined. The results indicated that drought in Khorasan Razavi province is subject to significant changes; such that the maximum annual frequency of drought during the historical period is 25%, and under the SSP2-4.5 scenario, it reaches 31%. The frequency and intensity of drought in the future, especially during the spring and summer seasons, will significantly increase. Geographically, the intensity of drought in all seasons is highest in the north and east of the province.
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