Spatiotemporal changes in droughts in Iraq for shared socioeconomic pathways

Abstract

Semiarid climate has made Iraq one of the most vulnerable regions to droughts. With temperatures rising and precipitation falling, projected climate models indicate a possible aggravation of droughts in the country. Iraq's shared socioeconomic pathways (SSPs) are the focus of this study, which uses CMIP6 climate models to examine the spatiotemporal variation of drought. The historical simulations of 21 GCMs were evaluated to choose a selection of GCMs. A support vector machine was used to downscaled the simulations of the selected GCM to 0.5° resolution. Downscaled simulations were used to estimate droughts employing standardized precipitation evapotranspiration index (SPEI) for the near (2020–2059) and far future (2060–2099) periods in comparison to the reference period (1975–2014). EC-Earth3-Veg, BCC-CSM2-MR and ACCESS-CM2 performed the best in simulating Iraq's climate. Historical simulation of droughts revealed northern Iraq as most prone to droughts of all severities and time scales. The projections of droughts revealed a decline in drought frequency in the near but a large rise in the late period. SSP 2-4.5 and SSP5-8.5 saw a greater decline in the near future and a rise in the far future. In both scenarios, drought frequency decreased between 0 and 40% in the near future, while an increase of up to 45% in moderate and severe droughts in the far future. In contrast, most scenarios showed a decrease in extreme droughts up to 30% in the drought-prone northern region, signifying a shift in the extreme drought-prone zone in Iraq.