Abstract Somalia is one of the most drought prone countries both in Africa and globally. Drought events usually develop gradually unnoticed, causing tremendous effects on both agriculture and environment. This study evaluated the spatio-temporal variations of drought occurrences in Somalia for the period between 1980 and 2015 as quantified by Standardized Precipitation Evapotranspiration Index (SPEI). The intensities, frequencies and trends of drought occurrences were analyzed using SPEI for the multiple timescales of 1-, 3-, 6-, 12-, and 24-month. The temporal variations in drought showed decreasing trends in severity and increasing trends in drought duration as the SPEI timescales increases. The major drought event as identified by SPEI 12 occurred during the period between May 2011 and January 2013 lasting for a period of 12 months with an intensity of −0.55. Furthermore, drought count was generally high in the southern parts of Somalia and entire country had suffered droughts ranging from moderately dry to severely dry conditions. An average drought duration of between 2 and 3 months was recorded for most (81%) of the locations. The results of this study could be used to support the water resources management, and to promote the realization of environmental protection and crop production in future.

中文翻译：

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基于 SPEI 的索马里干旱时空评估

摘要 索马里是非洲和全球最容易发生干旱的国家之一。干旱事件通常会在不知不觉中逐渐发展，对农业和环境都造成巨大影响。本研究评估了 1980 年至 2015 年期间索马里干旱发生的时空变化，该变化由标准化降水蒸散指数 (SPEI) 量化。使用 SPEI 分析了 1、3、6、12 和 24 个月的多个时间尺度的干旱发生的强度、频率和趋势。随着 SPEI 时间尺度的增加，干旱的时间变化显示出严重程度降低和干旱持续时间增加的趋势。SPEI 12 确定的重大干旱事件发生在 2011 年 5 月至 2013 年 1 月期间，持续 12 个月，强度为 -0.55。此外，索马里南部地区的干旱次数普遍较高，整个国家都遭受了从中度干旱到严重干旱的干旱。大多数（81%）地点的平均干旱持续时间为 2 至 3 个月。本研究结果可用于支持水资源管理，促进未来环境保护和农作物生产的实现。大多数（81%）地点的平均干旱持续时间为 2 至 3 个月。研究结果可用于支持水资源管理，促进未来环境保护和农作物生产的实现。大多数（81%）地点的平均干旱持续时间为 2 至 3 个月。本研究结果可用于支持水资源管理，促进未来环境保护和农作物生产的实现。