Saharwardi Md Saquib, Dasari Hari Prasad, Hassan Waqar Ul, Gandham Harikishan, Pathak Raju, Zampieri Matteo, Ashok Karumuri, Hoteit Ibrahim
Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia.
Climate Change Center, National Center for Meteorology, Jeddah, 21431, Saudi Arabia.
Sci Rep. 2025 Jan 11;15(1):1711. doi: 10.1038/s41598-025-85863-w.
The Arabian Peninsula (AP) has been reported to experience increasing drought in recent decades. With this background, this study evaluates best performing Climate Model Intercomparison Project 6 (CMIP6) Global Climate Models (GCMs) for historical (1985-2014) simulations and future drought projections across the AP until 2100, using the standardized precipitation index (SPI) and standardized precipitation-evapotranspiration index (SPEI). We assess uncertainties from model differences, scenarios, timescales, and methods. Our findings reveal the limitations of most models in reproducing precipitation, leading to uncertainties in SPI projections. Nonetheless, CMIP6-GCMs better capture the increase in the current-day potential evapotranspiration (PET) and therefore the SPEI, which is dominated by PET. The Hargreaves based PET is identified as the most suitable method for SPEI projections. The rate of increase in PET surpasses that of precipitation in all scenarios by fivefold. Consequently, SPEI indicates projected increase in future droughts with greater changes in SSP585 and SSP370 scenario compared to SSP245 and SSP126. In general, drought will exacerbate in the AP despite uncertainties from indices selection, scenarios, and inter-model variability, followed by methods and timescales which predominantly impacts drought magnitude. Over findings emphasize the need for more reliable representation of the AP precipitation in climate models for improved drought projection over the AP to enhance planning and adaptation strategies.
据报道，近几十年来阿拉伯半岛（AP）干旱情况不断加剧。在此背景下，本研究使用标准化降水指数（SPI）和标准化降水蒸散指数（SPEI），评估了表现最佳的气候模式比较计划第6阶段（CMIP6）全球气候模式（GCMs）对历史时期（1985 - 2014年）的模拟以及到2100年整个阿拉伯半岛未来干旱情况的预测。我们评估了模型差异、情景、时间尺度和方法带来的不确定性。我们的研究结果揭示了大多数模型在再现降水方面的局限性，导致SPI预测存在不确定性。尽管如此，CMIP6 - GCMs能更好地捕捉当前潜在蒸散量（PET）的增加情况，进而更好地捕捉由PET主导的SPEI。基于哈格里夫斯方法的PET被确定为最适合用于SPEI预测的方法。在所有情景中，PET的增加速率比降水增加速率高出五倍。因此，SPEI表明未来干旱情况预计会增加，与SSP245和SSP126情景相比，SSP585和SSP370情景下的变化更大。总体而言，尽管存在指数选择、情景以及模型间变率等方面的不确定性，阿拉伯半岛的干旱仍将加剧，其次是方法和时间尺度，这些主要影响干旱程度。我们的研究结果强调，气候模型需要更可靠地再现阿拉伯半岛的降水情况，以改进对该地区干旱的预测，从而加强规划和适应策略。
