Red River Research Station, Louisiana State University Agricultural Center, 262 Research Station Dr., Bossier City, LA 71112, USA.
J Environ Qual. 2009 Oct 29;38(6):2458-67. doi: 10.2134/jeq2008.0526. Print 2009 Nov-Dec.
The goal of this study was to construct a wetland that would detain runoff from a 162-ha watershed for the purposes of improving water quality. The volume of runoff that needed to be detained was determined to be that amount coming off the 162-ha watershed consisting of 146 ha of cultivated crop land and 16 ha of pasture that exceeded the amount that would have come off of the watershed in its natural, forested state. The Soil Conservation Service (now the Natural Resource Conservation Service [NRCS]) runoff curve number method was used to estimate runoff from the watershed in its natural, forested state and in its current state of cultivated crop land and pasture. The design of the constructed wetland was accomplished using the natural topography of the wetland site and the design criteria for a sediment containment system developed by NRCS. The SPAW (Soil-Plant-Atmosphere-Water Field & Pond Hydrology) computer model was used to model depth and volume in the wetland to determine if the constructed wetland design would accommodate typical runoff events. Construction of the wetland occurred over a 4-mo period. The capabilities of the system were verified when Hurricane Rita deposited above-normal rainfall to the wetland site area. The wetland was able to accommodate this event, allowing flow through the system for 9 d, followed by continued detention of remaining runoff for water quality improvement.
本研究的目的是构建一个湿地，以滞留来自 162 公顷流域的径流，从而改善水质。需要截留的径流量是由 162 公顷流域中超出自然森林状态下流域径流量的部分组成，其中包括 146 公顷耕地和 16 公顷牧场。土壤保持局（现自然资源保护局 [NRCS]）的径流曲线数法被用于估算自然森林状态和当前耕地和牧场状态下的流域径流量。湿地的设计是利用湿地场地的自然地形和 NRCS 开发的泥沙截留系统设计标准完成的。SPAW（土壤-植物-大气-水野外和池塘水文学）计算机模型用于模拟湿地中的深度和体积，以确定构建湿地的设计是否能够容纳典型的径流事件。湿地的建设历时 4 个月。当飓风丽塔向湿地地区带来高于正常水平的降雨量时，对系统的能力进行了验证。湿地能够容纳这一事件，允许水流通过系统 9 天，然后继续截留剩余的径流以改善水质。
