Groundwater shapes North American river floods
Groundwater shapes North American river floods
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DOI：
10.1088/1748-9326/acbecc
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发表时间：
2023-03-01
影响因子：
6.7
通讯作者：
Slater, Louise J.
中科院分区：
文献类型：
--
作者：
Berghuijs, Wouter R.;Slater, Louise J.
土壤湿度在引发河流洪水方面的重要性日益得到承认。然而，土壤水分仅代表非饱和带中储存的水的一小部分。相比之下，地下水从较深的饱和区，可能有助于河流流量的显着比例，但其对洪水的影响知之甚少。在这里，我们分析了1981年至2018年北美数千个流域的水文气候记录，以表明基流（即地下水维持的河流流量）影响了从几天到几十年的时间尺度上的年度洪水规模。每年的洪水几乎总是通过高降水（降雨+融雪）和基流的共同发生而产生。洪水量级通常与前期基流的变化比前期土壤湿度和短期（
The importance of soil moisture in triggering river floods is increasingly recognized. However, soil moisture represents only a fraction of the water stored in the unsaturated zone. In contrast, groundwater from the deeper, saturated zone, may contribute a significant proportion of river flow, but its effects on flooding are poorly understood. Here we analyze hydroclimatic records of thousands of North American watersheds spanning 1981-2018 to show that baseflow (i.e. groundwater-sustained river flows) affects the magnitude of annual flooding at time scales from days to decades. Annual floods almost always arise through the co-occurrence of high precipitation (rainfall + snowmelt) and baseflow. Flood magnitudes are often more strongly related to variations in antecedent baseflow than antecedent soil moisture and short-term (