■这项研究有三个空间尺度:全球(0.5°),宏观区域,和国家规模。干旱事件数据库为每个宏观区域和国家都有特定的条目。
■我们建立了一个1951年至2016年的气象干旱事件数据库,现在由欧盟委员会联合研究中心的全球干旱观测站主办。根据对不同累积尺度(3至72个月)的标准化降水-蒸散指数(SPEI)和标准化降水指数(SPI)的单独分析,在宏观区域和国家尺度上检测到事件,使用全球降水气候学中心(GPCC)和气候研究单位(CRU)时间序列数据集作为输入。该数据库包括大约4800个基于SPEI-3的事件和4500个基于SPI-3的事件。每个事件都由其开始和结束日期来描述,持续时间,强度,严重程度,峰值,干旱的平均和最大面积,和一个特殊的分数来分类52特大干旱。
■我们得出了干旱频率和严重程度的趋势,分别对于SPI和SPEI在12个月的积累规模,这通常与水文干旱有关。结果表明,在过去的几十年中,有几个干旱热点地区:亚马逊,南美洲南部,地中海地区,非洲大部分地区,中国东北和,在较小程度上,中亚和澳大利亚南部。在北美,中欧,中亚,澳大利亚,最近的气温上升超过了降水的增加,导致更频繁和严重的干旱。
UNASSIGNED: This study has three spatial scales: global (0.5°), macro-regional, and country scale. The database of drought events has specific entries for each macro-region and country.
UNASSIGNED: We constructed a database of meteorological drought events from 1951 to 2016, now hosted by the Global Drought Observatory of the European Commission\'s Joint Research Centre. Events were detected at macro-regional and country scale based on the separate analysis of the Standardized Precipitation-Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI) at different accumulation scales (from 3 to 72 months), using as input the Global Precipitation Climatology Centre (GPCC) and Climatic Research Unit (CRU) Time Series datasets. The database includes approximately 4800 events based on SPEI-3 and 4500 based on SPI-3. Each event is described by its start and end date, duration, intensity, severity, peak, average and maximum area in drought, and a special score to classify 52 mega-droughts.
UNASSIGNED: We derived trends in drought frequency and severity, separately for SPI and SPEI at a 12-month accumulation scale, which is usually related to hydrological droughts. Results show several drought hotspots in the last decades: Amazonia, southern South America, the Mediterranean region, most of Africa, north-eastern China and, to a lesser extent, central Asia and southern Australia. Over North America, central Europe, central Asia, and Australia, the recent progressive temperature increase outbalanced the increase in precipitation causing more frequent and severe droughts.