Abstract The practice of stormwater infiltration is widely used to reduce the amount of urban stormwater runoff delivered to drainage systems and receiving waters. In theory, the practice recharges groundwater, leading to increased urban stream baseflow. In reality, however, little is known about the fate of infiltrated stormwater. Because urban groundwater pathways are numerous and the interactions with subsurface infrastructure (e.g. trenches, pipes, etc.) are highly complex, the spatial and temporal variability of the contribution of infiltrated stormwater to baseflow is difficult to predict. We tracked the fate of infiltrated stormwater out of an 1800 m2 infiltration basin (3.5% of its 5-ha impervious catchment) using a network of piezometers for over three years. We found that groundwater levels downslope of the basin were increased (up to 4 m) while water levels in an array of reference piezometers lateral to the basin showed no change (dry at depths ranging 2–4 m). Monthly water balance calculations indicated that in summer, most of the infiltrated stormwater was evapotranspired by the vegetation downslope of the basin, and thus did not reach the receiving stream. In the colder months, some infiltrated stormwater did reach the stream as plant water use declined. Anthropogenic disturbances (a sewer pipe and stream re-alignment) interacted with the upper part of the plume of infiltrated stormwater, locally lowering the water table. The study provides evidence that the fate of infiltrated stormwater is complex, and that infiltrated stormwater does not always reach receiving streams as baseflow as is often assumed.

中文翻译：

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渗入的雨水去了哪里？与植被和地下人为特征的相互作用

摘要 雨水渗透的实践被广泛用于减少输送到排水系统和接收水体的城市雨水径流量。从理论上讲，这种做法可以补给地下水，导致城市河流基流增加。然而，实际上，人们对渗入的雨水的命运知之甚少。由于城市地下水路径众多且与地下基础设施（例如沟渠、管道等）的相互作用非常复杂，因此难以预测渗透雨水对基流的贡献的时空变异性。三年多来，我们使用渗压计网络跟踪了 1800 平方米渗透盆地（其 5 公顷不透水集水区的 3.5%）中渗透雨水的命运。我们发现盆地下坡的地下水位增加（高达 4 m），而盆地侧面的一系列参考压力计中的水位没有变化（在 2-4 m 的深度干燥）。月度水量平衡计算表明，在夏季，大部分下渗雨水被流域下坡植被蒸发蒸腾，未到达受纳溪流。在较冷的月份，随着植物用水量下降，一些渗入的雨水确实到达了溪流。人为干扰（下水道和河流重新调整）与渗透的雨水羽流的上部相互作用，局部降低了地下水位。该研究提供的证据表明渗透的雨水的命运是复杂的，