This study investigated the space-time drought incidence in the northeastern highlands of Ethiopia using monthly rainfall data. It also aims to predict drought events for 100 years. The Standardized Precipitation Index (SPI) was used to compute the drought severity classes of rainy months and seasons at 1-, 4- and 8-months timesteps. The Mann-Kendall’s test and Sen’s slope estimator were used to analyze the trends of drought events and to determine the magnitude of change. Inverse Distance Weighted spatial analysis tool was used to illustrate the spatial patterns of the drought risk events. The study detected extreme severe droughts in the belg rainy months in March 2008 and April 1984. However, during the belg season, the year 1999 was the driest for the recorded periods. On the other hand, the extremely severe droughts were observed during the kiremt rainy months of July 1987 and 2015, August 1984, and September 2009. In general, 1984, 1987 and 2015 were the driest years recorded in the kiremt season. The study noted that the drought risk events of months in the belg season were threefold greater than that of the months in kiremt season under moderate drought intensity class. Equally, the drought risk events of months in kiremt season were threefold greater than that of the belg season under extreme drought intensity class. Complex spatial variations of drought risk events were also observed in 1-, 4- and 8-months timesteps. During the belg seasons, the southern half was subjected to more frequent drought risk events while the northern half experienced more frequent drought risk events during kiremt season. Almost the eastern half of the livelihood zones experienced higher drought frequency events than the other parts in the 8-month timestep. The observed space-time drought risk event analysis has shown a potential threat to the rainfed agricultural practices that have a great influence on the livelihoods of smallholder farmers. Hence, documentation and assessment of drought risk events based on the livelihood zones are essential for drought risk management, early warning responses, local-scale planning and food security management. Finally, the study recommended further research on additional indices of climatic variables such as evapotranspiration and soil water content.

中文翻译：

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埃塞俄比亚东北高地的时空干旱发生率分析

这项研究使用月度降雨数据调查了埃塞俄比亚东北高地的时空干旱发生率。它还旨在预测100年的干旱事件。标准化降水指数（SPI）用于计算1个月，4个月和8个月时间步骤的雨季和雨季的干旱严重程度等级。使用Mann-Kendall检验和Sen斜率估算器来分析干旱事件的趋势并确定变化的幅度。逆距离加权空间分析工具用于说明干旱风险事件的空间格局。该研究在2008年3月和1984年4月的比利时雨季中发现了极端严重的干旱。但是，在比利时季节，1999年是有记录以来最干旱的年份。另一方面，在1987年7月和2015年，1984年8月和2009年9月的科里姆雨季，观测到了极为严重的干旱。总的来说，1984年，1987年和2015年是科里姆特季节中最干旱的年份。研究指出，在中等干旱强度等级下，比利时季节数月的干旱风险事件比kiremt季节数月的干旱风险事件大三倍。同样，在极端干旱强度等级下，基瑞姆季节几个月的干旱风险事件比比利时季节的干旱风险事件大三倍。在1、4和8个月的时间步长中也观察到了干旱风险事件的复杂空间变化。在比利时季节，南部地区在kiremt季节遭受更频繁的干旱风险事件，而北部地区在干旱季节遭受更频繁的干旱风险事件。在8个月的时间步中，几乎生计区的东半部经历了比其他地区更高的干旱频率事件。观察到的时空干旱风险事件分析表明，雨养农业生产方式有潜在威胁，对小农的生计有很大影响。因此，基于生计区的干旱风险事件的记录和评估对于干旱风险管理，早期预警，地方规模规划和粮食安全管理至关重要。最后，该研究建议进一步研究气候变量的附加指标，例如蒸散量和土壤含水量。观察到的时空干旱风险事件分析表明，雨养农业生产方式有潜在威胁，对小农的生计有很大影响。因此，基于生计区的干旱风险事件的记录和评估对于干旱风险管理，早期预警，地方规模规划和粮食安全管理至关重要。最后，该研究建议进一步研究气候变量的附加指标，例如蒸散量和土壤含水量。观察到的时空干旱风险事件分析表明，雨养农业生产方式有潜在威胁，对小农的生计有很大影响。因此，基于生计区的干旱风险事件的记录和评估对于干旱风险管理，预警响应，地方规模计划和粮食安全管理至关重要。最后，该研究建议进一步研究气候变量的附加指标，例如蒸散量和土壤含水量。当地规模的规划和粮食安全管理。最后，该研究建议进一步研究气候变量的附加指标，例如蒸散量和土壤含水量。当地规模的规划和粮食安全管理。最后，该研究建议进一步研究气候变量的附加指标，例如蒸散量和土壤含水量。