Pumping‐Induced Drawdown and Stream Depletion in a Leaky Aquifer System
Pumping‐Induced Drawdown and Stream Depletion in a Leaky Aquifer System
复制标题
渗漏含水层系统中抽水引起的水位下降和水流枯竭
DOI：
10.1111/j.1745-6584.2006.00272.x
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发表时间：
2007
期刊：
影响因子：
2.6
通讯作者：
V. Zlotnik
中科院分区：
文献类型：
--
作者：
J. Butler;Xiaoyong Zhan;V. Zlotnik
地下水抽水对附近河流的影响通常使用相互关联的河流-含水层系统的分析模型来估计。这些模型的一个共同的假设是，抽水含水层是由一个不透水的地层。已经开发了一种新的水位下降和河流枯竭的半分析解决方案，不需要这种假设。该解表明，通过下伏弱透水层的抽水诱导流（渗漏）可能是许多溪流含水层系统的重要补给机制。这种补给源的相对重要性随着抽水井和河流之间的距离而增加。渗漏成为抽水引起的补给的主要成分的距离取决于含水层、弱透水层和河床的具体性质。即使弱透水层的渗透性比含水层低几个数量级，渗漏也可能是一种重要的补给机制，因为渗漏发生的表面积很大。如果不考虑弱透水层渗漏，可能会导致对抽水产生的水位降深和河流枯竭对抽水引起的补给的贡献的大大高估。对水资源管理和水权裁决的影响可能是重大的。一个假设的例子有助于说明这些观点，并表明应更多地注意估计弱透水层下伏河流-含水层系统的属性。这里提出的解决方案应该作为一个相对简单但通用的工具，实际评估抽水引起的河流-含水层相互作用。但是，如果没有表明抽水导致弱透水层渗漏的特定场地数据，则不应将该解决方案用于此类评估。
The impact of ground water pumping on nearby streams is often estimated using analytic models of the interconnected stream‐aquifer system. A common assumption of these models is that the pumped aquifer is underlain by an impermeable formation. A new semianalytic solution for drawdown and stream depletion has been developed that does not require this assumption. This solution shows that pumping‐induced flow (leakage) through an underlying aquitard can be an important recharge mechanism in many stream‐aquifer systems. The relative importance of this source of recharge increases with the distance between the pumping well and the stream. The distance at which leakage becomes the primary component of the pumping‐induced recharge depends on the specific properties of the aquifer, aquitard, and streambed. Even when the aquitard is orders of magnitude less transmissive than the aquifer, leakage can be an important recharge mechanism because of the large surface area over which it occurs. Failure to consider aquitard leakage can lead to large overestimations of both the drawdown produced by pumping and the contribution of stream depletion to the pumping‐induced recharge. The ramifications for water resources management and water rights adjudication can be significant. A hypothetical example helps illustrate these points and demonstrates that more attention should be given to estimating the properties of aquitards underlying stream‐aquifer systems. The solution presented here should serve as a relatively simple but versatile tool for practical assessments of pumping‐induced stream‐aquifer interactions. However, this solution should not be used for such assessments without site‐specific data that indicate pumping has induced leakage through the aquitard.