Bioretention for enhancing urban stormwater management

雨水是加拿大水道的一个主要污染源，因为雨水在到达受纳沃茨之前，会带走大量沉积在陆地表面的总悬浮固体、营养物质、有机物、重金属和其他污染物。低影响开发技术（LID）是现代雨水管理方法，可以改善雨水水质，减少雨水量。生物滞留技术就是其中之一，它涉及在陆地表面的洼地种植植被。** 自90年代首次使用以来，生物滞留得到了广泛的实施，但主要是以临时方式在温和和温暖的气候地区实施，这在加拿大的大多数气候区是不典型的。去除污染物的基本过程的知识仍然缺乏，因此，可预测的生物滞留设计所需的实用工具。为了使工程从业者有信心在加拿大使用这种技术，生物滞留在管理雨水的数量和质量的好处需要明确量化，并设计生物滞留的实用工具需要开发。拟议的研究项目将把联合收割机计算机模拟与在不同规模（空间尺度）和两个不同气候区建立的生物滞留设施上收集的观察结果结合起来，以回答下列问题：（一）控制生物滞留中污染物（特别是营养物）去除的基本过程是什么？ii）如何比较和评估不同水文条件（如不同规模的降雨事件）和不同污染物负荷下的生物滞留性能？（三）如何利用从不同规模的生物滞留设施获得的知识开发预测工具？（四）生物滞留在加拿大不同气候条件下的表现如何？这些问题的答案将导致可靠的方法来预测生物滞留的好处和优化生物滞留设计的发展。该项目的结果将不仅提供有用的和明确的生物滞留技术信息，但生物滞留设计所需的实用，有用的工具。**

Stormwater is a major source of pollution in Canadian waterways because it picks up high amounts of total suspended solids, nutrients, organic matter, heavy metals and other pollutants that are deposited on the land surface, before reaching the receiving waters. Low Impact Development technologies (LIDs) are modern stormwater management methods that can improve stormwater quality and reduce stormwater quantity. Bioretention, which involves vegetated depressions in the land surface, is one of these technologies. ** Since its initial use in the 90's, bioretention has seen widespread implementation but primarily in an ad hoc manner and in regions of mild and warm climates, which are atypical of most climate zones in Canada. The knowledge of the underlying processes to remove pollutants is still lacking and hence, so are the practical tools necessary for predictable bioretention design. In order to equip engineering practitioners with the confidence to use such a technology in Canada, the benefits of bioretention in managing stormwater quantity and quality need to be clearly quantified, and the practical tools for designing bioretention need to be developed. The proposed research project will combine computer modelling with observations collected on bioretention facilities developed at different sizes (spatial scales) and in two different climate zones, to answer the following questions: i) What are the underlying processes controlling the removal of pollutants (especially nutrients) in bioretention? ii) How can bioretention performance under different hydrologic conditions (such as different size rain events) and different pollutant loads be compared and evaluated? iii) How can knowledge obtained from bioretention facilities at very different scales be used to develop predictive tools? iv) How does bioretention perform under varying Canadian climate conditions? The answers to these questions will lead to the development of reliable approaches for predicting the benefits of bioretention and optimizing bioretention design. The results from this project will not only provide useful and definitive technical information on bioretention, but the practical, useful tools necessary for bioretention design. **