Forecasting climate change effects on drought using the decadal climate prediction project in arid and semi-arid regions of southeastern Iran

The southeastern region of Iran is typified by arid climatic conditions, which have resulted in severe droughts and water scarcity in recent years. To investigate the occurrence of droughts and predict their future behaviour in this region, this study employed the Standardized Precipitation Evapotranspiration Index (SPEI) and outputs from the MPI-ESM1-2-HR model of the Decadal Climate Prediction Project (DCPP). The run theory was subsequently employed to analyze the characteristics of droughts in the study area, including their severity, duration, intensity, and frequency. The model results indicate a forecasted decrease in precipitation across most months over the next five years compared to the observed period. This predicted decline is estimated to be approximately 17%. The minimum and maximum temperatures are forecasted to increase in all months, with an average increase of 1.1 °C for both parameters. Consequently, the SPEI is expected to increase significantly in a substantial portion of the study region, affecting all drought characteristics. The frequency of drought is forecasted to increase considerably in stations including Nehbandan (32%), Zahedan, Zahak, Kerman, Qeshm Island, and Minab (30%), and Zabol (26%). The most pronounced increases in drought severity are projected in Bandar Lengeh, Anar, and Zahedan, with the SPEI index values rising by 0.35, 0.17, and 0.16, respectively, compared to the observed period. Overall, the findings of this study indicate that southeastern Iran will experience intensified droughts in the near future, necessitating the urgent implementation of effective management strategies across sectors such as agriculture, water, and energy.