Increasing importance of temperature as a contributor to the spatial extent of streamflow drought
Increasing importance of temperature as a contributor to the spatial extent of streamflow drought
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DOI：
10.1088/1748-9326/abd2f0
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发表时间：
2021-02-01
影响因子：
6.7
通讯作者：
Wood, Andrew W.
中科院分区：
文献类型：
--
作者：
Brunner, Manuela, I;Swain, Daniel L.;Wood, Andrew W.
由于跨区域水管理的复杂现实，大范围的径流干旱可能比空间上范围较小的事件造成更大的社会挑战。在气候变暖的情况下，干旱的空间范围可能会随着潜在水文气象贡献者的变化而变化。在这里，我们评估了1981-2018年间美国境内径流干旱空间范围的变化，以及潜在的水文气象贡献者的重要性如何随着时间的变化而变化。我们首先推导出干旱空间范围的月度时间序列，并考察径流干旱空间范围的趋势。然后，我们确定降水干旱、温度异常、雪水当量亏缺和土壤水分亏缺与径流干旱地区的空间百分比重叠，以考察这些因素对空间范围的变化影响。我们的结果表明：(1)干旱的空间范围有所增加，这主要是由于小型干旱程度的增加；(2)径流干旱程度总体上与土壤水分亏缺基本重叠，干旱与降水和温度异常的关系随季节变化而变化；(3)温度作为干旱程度贡献者的重要性随着时间的推移而增加。因此，我们得出结论，全球持续变暖可能会进一步增加干旱程度，需要调整区域干旱管理战略。
Widespread streamflow droughts can pose substantially greater societal challenges than spatially less extensive events because of the complex realities of trans-regional water management. In a warming climate, drought spatial extent may change along with changes in underlying hydro-meteorological contributors. Here, we assess changes in streamflow drought spatial extent over the period 1981-2018 across the conterminous United States, and how the importance of potential hydro-meteorological contributors has changed over time. We first derive a monthly time series of drought spatial extent and look at trends in streamflow drought spatial extent. We then determine the spatial percentage 'overlap' of precipitation droughts, temperature anomalies, snow-water-equivalent deficits, and soil moisture deficits with the area under streamflow drought to look at the changing influence of these contributors on spatial extent. Our results show that (1) the spatial extent of droughts has increased, mainly because of increases in the extent of small droughts; (2) streamflow drought extents overall substantially overlap with soil moisture deficits and the relationship of drought to precipitation and temperature anomalies varies seasonally; and (3) the importance of temperature as a contributor to drought extent has increased over time. We therefore conclude that continued global warming may further increase drought extents, requiring adaptation of regional drought management strategies.