Global trends and patterns of drought from space
Global trends and patterns of drought from space
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DOI：
10.1007/s00704-013-1019-5
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发表时间：
2014-08-01
影响因子：
3.4
通讯作者：
AghaKouchak, Amir
中科院分区：
文献类型：
--
作者：
Damberg, Lisa;AghaKouchak, Amir
本文分析了过去三十年来干旱地区的变化，并改变了我们对南半球（SH）和北方半球（NH）干旱幅度和频率差异的理解。与以往大多数基于气候模型的全球尺度研究不同，这项研究是基于卫星雨量计调整的降水观测。在这里，我们表明，干旱的幅度和频率方面的更多的变化在SH比NH的土地。结果表明，在过去的三十年里，干旱地区的土地没有显着的趋势。然而，调查后的土地在NH和SH分别，结果表现出显着的积极趋势，在干旱的土地在SH的面积，而没有显着的趋势是观察到在NH的土地。我们调查了过去三十年的干湿空间格局，我们发现，一些地区，如美国西南部，得克萨斯州，亚马逊河的部分地区，非洲之角，印度北方和地中海地区的部分地区，表现出显着的干燥趋势。全球趋势图表明，中非、西南亚部分地区（如，泰国、台湾）、中美洲、澳大利亚北方和东欧部分地区在同一时间段内显示出湿润趋势。这项基于卫星的研究结果与几项基于模型的研究结果不一致，后者表明陆地上的干旱一直在增加。另一方面，我们的发现与一些基于观察的研究一致。
This paper analyzes changes in areas under droughts over the past three decades and alters our understanding of how amplitude and frequency of droughts differ in the Southern Hemisphere (SH) and Northern Hemisphere (NH). Unlike most previous global-scale studies that have been based on climate models, this study is based on satellite gauge-adjusted precipitation observations. Here, we show that droughts in terms of both amplitude and frequency are more variable over land in the SH than in the NH. The results reveal no significant trend in the areas under drought over land in the past three decades. However, after investigating land in the NH and the SH separately, the results exhibit a significant positive trend in the area under drought over land in the SH, while no significant trend is observed over land in the NH. We investigate the spatial patterns of the wetness and dryness over the past three decades, and we show that several regions, such as the southwestern United States, Texas, parts of the Amazon, the Horn of Africa, northern India, and parts of the Mediterranean region, exhibit a significant drying trend. The global trend maps indicate that central Africa, parts of southwest Asia (e.g., Thailand, Taiwan), Central America, northern Australia, and parts of eastern Europe show a wetting trend during the same time span. The results of this satellite-based study disagree with several model-based studies which indicate that droughts have been increasing over land. On the other hand, our findings concur with some of the observation-based studies.