Journal of Hydrology ( IF 6.4 ) Pub Date : 2021-09-15 , DOI: 10.1016/j.jhydrol.2021.126917 Adam P. Schreiner-McGraw 1 , Hoori Ajami 1
Groundwater is a life-sustaining resource that supplies water to 2 billion people worldwide and is critical for agriculture. Despite the importance of groundwater, understanding of groundwater recovery from meteorological droughts is limited. Here, we utilize daily groundwater observations from unconfined aquifers without active groundwater management across the conterminous United States to illustrate that in response to a multi-year drought, it takes on average, 3 years for shallow aquifers to recover the storage lost during the drought. This recovery time increases with higher drought severity, and is influenced by the time-lag between the initiation (termination) of a meteorological drought and initiation (termination) of a groundwater drought. There is considerable variation in the time-lag duration, up to 15 years in some aquifers, controlled by geographic properties in regions with shallow water tables and precipitation characteristics in regions with deep water tables. A machine learning algorithm finds that the most important controls on the time-lag are the drought intensity at the beginning of the precipitation drought and the mean annual recharge. Projected increases in drought severity could potentially increase groundwater recovery times to droughts in a changing climate.
中文翻译:
在缺乏人为管理的情况下,地下水对多年气象干旱的延迟响应
地下水是一种维持生命的资源,为全世界 20 亿人供水,对农业至关重要。尽管地下水很重要,但对从气象干旱中恢复地下水的了解是有限的。在这里,我们利用来自美国本土没有积极地下水管理的非承压含水层的每日地下水观测来说明,为了应对多年干旱,浅层含水层平均需要 3 年时间才能恢复干旱期间损失的储存量。该恢复时间随着干旱严重程度的增加而增加,并受气象干旱开始(终止)和地下水干旱开始(终止)之间的时间差的影响。时滞持续时间有相当大的差异,在一些含水层中长达 15 年,受浅水位地区的地理属性和深水位地区的降水特征控制。机器学习算法发现,对时滞最重要的控制是降水干旱开始时的干旱强度和年平均补给量。预计干旱严重程度的增加可能会增加地下水在气候变化中恢复干旱的时间。