Conn Ruel Michael, Fiedler Fritz R
J-U-B Engineers, Inc., Coeur d'Alene, Idaho, USA.
Water Environ Res. 2006 Dec;78(13):2514-23. doi: 10.2175/106143006x101944.
The treatment efficiency of wetlands depends primarily on the residence time of the polluted storm water (Walker, 1998). Because of this, increasing hydraulic residence times (HRTs) at various flow levels will increase the treatment efficiency of constructed wetlands. In this research, the effects of characteristic bottom topographic features that increase HRT were explored through the use of a two-dimensional hydrodynamic model. Based on numerical simulations of rectangular test wetlands, relationships were made between topographic features and their effects on HRT. Results from the simulations showed that creating baffled wetlands with multiple vertical-scale topography can markedly increase HRT, as is illustrated in a design example. When compared (using the hydrodynamic model) with a wetland having no bottom topography, the design example wetland increased HRT by 113% for the low-flow (142 L/sec) peak flood, and 39% for the 2-year flood event (1700 L/sec).
湿地的处理效率主要取决于受污染雨水的停留时间（Walker，1998年）。因此，在不同流量水平下增加水力停留时间（HRT）将提高人工湿地的处理效率。在本研究中，通过使用二维水动力模型探索了增加HRT的特征底部地形特征的影响。基于矩形试验湿地的数值模拟，建立了地形特征与其对HRT影响之间的关系。模拟结果表明，创建具有多个垂直尺度地形的折流湿地可显著增加HRT，如一个设计示例所示。当（使用水动力模型）与没有底部地形的湿地进行比较时，设计示例湿地在低流量（142升/秒）洪峰时HRT增加了113%，在两年一遇洪水事件（1700升/秒）时增加了39%。
