Chen Xunhong, Shu Longcang
Conservation and Survey Division, University of Nebraska-Lincoln, 68588, USA.
Ground Water. 2002 May-Jun;40(3):284-90. doi: 10.1111/j.1745-6584.2002.tb02656.x.
Numerical modeling techniques were used to simulate stream-aquifer interactions from seasonal ground water pumping. We used stream-aquifer models in which a shallow stream penetrates the top of an aquifer that discharges ground water to the stream as base flow. Because of the pumping, the volume of base flow discharged to the stream was reduced, and as the pumping continued, infiltration from the stream to the aquifer was induced. Both base-flow reduction and stream infiltration contributed to total stream depletion. We analyzed the depletion rates and volumes of the reduced base flow and induced stream infiltration during pumping and postpumping periods. Our results suggested that for a shallow penetrating stream with a low streambed conductance, base-flow reduction accounts for a significant percentage of the total stream depletion. Its residual effects in postpumping can last very long and may continue into the next pumping season for areas where recharge is nominal. In contrast, the contribution of the induced stream infiltration to the total stream depletion is much smaller, and its effects often become negligible shortly after pumping was stopped. For areas where surface recharge replenishes the aquifer, the residual effects of base-flow reduction and thus its depletion volume will be significantly reduced. A stream of large conductance has a high hydraulic connection to the aquifer, but the relationship between stream conductance and stream depletion is not linear.
采用数值模拟技术来模拟季节性地下水抽取过程中河流与含水层之间的相互作用。我们使用了河流 - 含水层模型，其中一条浅河流穿透含水层顶部，含水层以基流形式向河流排放地下水。由于抽水，排放到河流的基流量减少，并且随着抽水持续进行，诱导了从河流到含水层的入渗。基流减少和河流入渗都导致了河流总耗竭。我们分析了抽水期间和抽水后阶段减少的基流和诱导的河流入渗的耗竭速率和量。我们的结果表明，对于河床传导率低的浅穿透河流，基流减少在河流总耗竭中占很大比例。其在抽水后的残余影响可能持续很长时间，对于补给量较小的地区，可能会持续到下一个抽水季节。相比之下，诱导的河流入渗对河流总耗竭的贡献要小得多，并且其影响在抽水停止后不久通常就可以忽略不计。对于有地表补给补充含水层的地区，基流减少的残余影响及其耗竭量将显著减少。传导率大的河流与含水层有很高的水力联系，但河流传导率与河流耗竭之间的关系不是线性的。
