Event scale hydrograph responses highlight impacts of widespread stream burial and urban infrastructure failures
Event scale hydrograph responses highlight impacts of widespread stream burial and urban infrastructure failures
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DOI：
10.1002/hyp.14584
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发表时间：
2022-05
影响因子：
3.2
通讯作者：
R. Forgrave;E. Elliott;D. Bain
中科院分区：
文献类型：
--
作者：
R. Forgrave;E. Elliott;D. Bain
城市地区对风暴的快速水文响应通常归因于不透水面的高百分比;然而，影响城市风暴响应的另一个因素是渠道掩埋。以前的研究没有记录风暴事件在掩埋流的反应，尽管在城市地区流掩埋是多么常见，一些美国城市有超过75%的所有源头渠道被掩埋。了解事件动态尤其重要，因为气候变化预测表明高强度风暴和城市洪水的频率增加。这项研究使用了6.5年内15分钟的降水和流量数据，对Nine Mile Run的风暴事件响应进行了分类，Nine Mile Run是宾夕法尼亚州匹兹堡的一个城市流域，98%的渠道都被掩埋。广泛的流掩埋导致较低的流域保持能力，并导致更快的风暴事件的反应相对于其他城市流具有可比的不透性。此外，城市水补贴的形式下水道溢流，消防栓冲洗，或水管破裂可以有可测量的流量事件响应的贡献，并导致看似不可行的径流率。这项研究表明，新的流域径流响应系统占主导地位的地下基础设施，在城市水平衡中发挥着关键作用。此外，这项研究强调了一个事实，即流恢复是不是一个普遍的解决方案，城市流闪光，因为下游恢复不能解决上游埋葬的影响。
Fast hydrologic responses to storms in urban areas are often attributed to high percentages of impervious surfaces; however, another factor affecting urban storm response is channel burial. No previous studies have documented storm event responses in buried streams despite how common stream burial is in urban areas, with some US cities having over 75% of all headwater channels buried. Understanding event dynamics is particularly important as climate change predictions suggest an increase in frequency of high intensity storms and urban flooding. This study used 15‐min precipitation and discharge data over a period of 6.5 years to categorize storm event responses in Nine Mile Run, an urban watershed in Pittsburgh, Pennsylvania where 98% of all channels are buried. Extensive stream burial led to lower watershed retention capacity and resulted in faster storm event responses relative to other urban streams with comparable imperviousness. Additionally, urban water subsidies in the form of sewer overflows, hydrant flushing, or water line breaks can have measurable contributions to flow event responses and result in seemingly unfeasible runoff ratios. This study demonstrates novel watershed runoff responses in systems dominated by subsurface infrastructure, which play a key role in urban water balance. Additionally, this study highlights the fact that stream restoration is not a universal solution to urban stream flashiness because downstream restoration cannot resolve the impacts of upstream burial.