Using spatially-identified effective impervious area to target green infrastructure retrofits: A modeling study in Knoxville, TN
Using spatially-identified effective impervious area to target green infrastructure retrofits: A modeling study in Knoxville, TN
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DOI：
10.1016/j.jhydrol.2019.05.062
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发表时间：
2019-08
影响因子：
6.4
通讯作者：
Thomas H. Epps;J. Hathaway
中科院分区：
文献类型：
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作者：
Thomas H. Epps;J. Hathaway
有必要加强对分布式、渗透式绿色基础设施（GI）实践的选址指导，特别是在改造成本高昂的密集开发的城市流域。为了最大限度地发挥地理标志实践对城市河流的水文效益，将有效不透水区域（EIA）或与雨水网络水力连接的不透水区域断开连接已被确定为一种预计会产生最大影响的战略管理方法。空间识别环境影响评价的全断连对流域水文的总体影响是不确定的，因为这种全断连很少全面实施。在本研究中，采用空间环境影响评价识别方法，利用美国环境保护署的雨水管理模型（SWMM）对城市径流模型进行参数化。校准后的模型用于评估地理标志实践通过不同的布局策略（包括空间信息和非空间信息）分布在流域中的径流减少。利用生物滞留细胞对空间识别的环境影响评估进行全面处理，并将其与处理同一区域不透水表面的两种方案进行比较，但随机放置在所有不透水区域或集中放置在高不透水区域。模型结果表明，通过针对EIA可以实现更高的径流量减少，使用该战略选址，在1.27至20.7 mm的风暴事件中，径流量减少的中位数比其他处理方案高出近30%。在优化分布式渗透GI实践位置方面需要进一步改进，针对空间识别的EIA似乎是增加通过流域尺度实施实现的水文改善的可行方法。
There is a need for enhanced guidance in siting distributed, infiltrative green infrastructure (GI) practices, especially in densely developed urban watersheds where retrofits come at a high cost. To maximize the hydrologic benefit of GI practices on urban streams, the disconnection of effective impervious areas (EIA), or those impervious areas hydraulically connected to the stormwater network, has been identified as a strategic management approach that is expected to have the greatest impact. The overall effect of full disconnection of spatially-identified EIA on watershed hydrology is uncertain because this type of full disconnection is rarely brought to full-scale implementation. In this study, spatial EIA identification is used to parametrize an urban runoff model using the United States Environmental Protection Agency’s Storm Water Management Model (SWMM). The calibrated model is used to assess runoff reductions resulting from GI practices distributed through the watershed via different placement strategies, both spatially-informed and not. Full treatment of the spatially-identified EIA using bioretention cells was compared to two scenarios treating the same area of impervious surfaces, but with random placement either among all impervious areas or placement focused in areas of higher imperviousness. Model results indicate that substantially higher runoff reduction could be realized by targeting EIA, with a median runoff reduction of nearly 30% more than other treatment scenarios across storm events ranging from 1.27 to 20.7 mm using this strategic siting. Further improvements in optimizing distributed infiltrative GI practice placement are needed and targeting of spatially-identified EIA appears to be a viable method for increasing the hydrologic improvements realized through watershed scale implementations.