Sodium chloride has long been used for winter deicing, although its legacy use has resulted in rising chloride concentrations in urban watersheds. Persistently high chloride levels impair drinking water resources and threaten the health of aquatic life and vegetation. In urban areas, chloride fate and transport is impacted by human modification of the environment, including increased impervious surface cover and disconnection of stream corridors from riparian groundwater. We couple continuous streamflow records with weekly chloride concentration data over two water years to create continuous chloride load estimates at three locations along a degraded, urban stream in upstate New York with contrasting channelized and intact reaches. Our results show that degraded reaches characterized by channelized, armored banks and minimal groundwater connection deliver chloride loads closer to chloride application rates in the surrounding watershed. In contrast, stream–groundwater interactions in intact reaches adjacent to riparian floodplains, including surface water losses to subsurface flow paths, result in stream chloride loads that are 50% less than those delivered from upstream channelized reaches. These findings show that longitudinal chloride load estimates along a stream channel can be valuable in identifying the timing and magnitude of chloride sources and sinks, which may be common but less apparent in urban environments.

长期以来，氯化钠一直被用于冬季除冰，尽管其遗留用途导致城市流域中氯化物浓度上升。持续高浓度的氯化物会损害饮用水资源并威胁水生生物和植被的健康。在城市地区，氯化物的归宿和运输受到人类环境改造的影响，包括不透水地表覆盖增加和河流走廊与河岸地下水的断开。我们将连续河流流量记录与两年内每周氯化物浓度数据结合起来，以在纽约州北部退化的城市河流沿线的三个位置创建连续的氯化物负荷估计，对比渠道化和完整河段。我们的结果表明，退化的河段以通道化为特征，装甲堤和最小的地下水连接使氯化物负荷更接近周围流域的氯化物施用率。相比之下，与河岸漫滩相邻的完整河段中的河流-地下水相互作用，包括地表水流失到地下流动路径，导致河流氯化物负荷比上游渠道化河段输送的氯化物负荷低 50%。这些发现表明，沿河道的纵向氯离子负荷估计对于确定氯离子源和汇的时间和大小很有价值，这在城市环境中可能很常见但不太明显。包括地表水流失到地下流动路径，导致河流氯化物负荷比上游渠道化河段输送的氯化物负荷低 50%。这些发现表明，沿河道的纵向氯离子负荷估计对于确定氯离子源和汇的时间和大小很有价值，这在城市环境中可能很常见但不太明显。包括地表水流失到地下流动路径，导致河流氯化物负荷比上游渠道化河段输送的氯化物负荷低 50%。这些发现表明，沿河道的纵向氯离子负荷估计对于确定氯离子源和汇的时间和大小很有价值，这在城市环境中可能很常见但不太明显。