Understanding anthropogenic impacts on water storage and water flow pathways in catchments is an ongoing challenge in hydrology. Here, we study the dynamics of subsurface storage and residence time of water in a catchment in Berkeley, California, that is within a regional park but contains diverse land use within its perimeter, including a periodically irrigated golf course. Our study combines several isotopic tracers with water budget data to examine sources of water in a stream draining the site. Irrigation water, applied to a small area of the watershed, is a minor component of the water budget. However, geochemical tracers reveal that irrigation water is a significant fraction of stream flow downstream of the golf course during baseflow and during precipitation events. Isotopic tracers indicate that the watershed has a preference to release young water for stream flow generation, resulting in contrasting tritium ages for stream water and groundwater of 1.3 ± 0.5 year and 8.2 ± 1.7 year, respectively. We determined that the older water is a very small component (0.7%) of the stream water in the tail of an assumed exponential distribution. We used the seasonal variation of stable water isotopes in precipitation and stream water over two water years to explain the damping of the isotopic signature of stream water, which yields information about the catchment's response to the input signal. The methods described here may be applicable to other urban or suburban headwater catchments in areas with a component of non‐natural recharge from, for example, leaky infrastructure, storm water routing or dry season irrigation.

中文翻译：

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在定期灌溉的流域中的集水区存储和停留时间

了解人为对流域蓄水和水流路径的影响是水文学中一项持续的挑战。在这里，我们研究了加利福尼亚州伯克利市一个流域的地下蓄水和水滞留时间的动态，该流域位于一个区域公园内，但周边包含多种土地用途，包括定期灌溉的高尔夫球场。我们的研究将几种同位素示踪剂与水预算数据结合起来，以检查流经该场地的溪流中的水源。灌溉水只用于流域的一小部分，是水预算的一小部分。但是，地球化学示踪剂显示，在基流和降水事件期间，灌溉水是高尔夫球场下游水流的重要组成部分。同位素示踪剂表明，该流域倾向于释放年轻水来产生水流，导致stream水和地下水的tri年龄分别为1.3±0.5年和8.2±1.7年。我们确定，在假定的指数分布的尾部，较旧的水仅占溪流水的很小一部分（0.7％）。我们使用了两个水年中降水和溪流水中稳定水同位素的季节性变化来解释溪流水同位素特征的衰减，从而得出有关集水区对输入信号响应的信息。此处描述的方法可能适用于其他地区的市区或郊区源头集水区，这些地区的自然补给成分来自例如泄漏的基础设施，