Efficacy of Bioretention for Treatment of Stormwater in Semi Arid Cold Climates

低影响开发技术(LID)是一种可以改善雨水水质、减少雨水量的现代雨水管理方法。生物保育就是其中一项技术，它涉及到陆地表面的植被洼地。他们也看到了广泛的实施，但主要是以特别的方式和在温和和温暖的气候地区，这是加拿大大多数气候带的非典型。去除污染物的基本过程仍然缺乏知识，因此，可预测的生物保留设计所需的实用工具也是如此。为了使工程从业者有信心在加拿大使用这种技术，需要清楚地量化生物保留在管理雨水数量和质量方面的好处，并需要开发设计生物保留的实用工具。拟议的研究项目将结合在不同规模发展的设施上收集的建模和观测来回答以下问题：i)控制生物保留中污染物(特别是营养物质)去除的潜在过程是什么？Ii)如何比较和评估不同水文条件和不同污染物负荷下的生物滞留性能？三)如何利用从生物保育设施获得的知识来开发预测性工具？该项目的结果不仅将提供有关生物保育的有用和明确的技术信息，还将为生物保育设计提供实用、有用的工具。因此，我们建议：(1)通过对各种土地覆盖类型的实地监测，研究处理城市雨水径流的生物保护系统，特别注重营养物质、沉积物和体积衰减在数量和质量方面的特征；(2)检查这些污染物对这些系统长期性能的影响；(3)开发城市雨水径流的模拟工具；以及(4)利用基于证据的知识制定建议，以加强与城市雨水管理相关的指导方针和标准，以便更好地保护艾伯塔省及其他地区的水源和生态系统。

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. They 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 modelling with observations collected on facilities developed at different scales 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 and different pollutant loadings be compared and evaluated? iii) How can knowledge obtained from bioretention facilities be used to develop predictive tools? iv) How does bioretention perform under varying Canadian climate conditions?  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. Therefore, we propose to: (1) investigate bioretention systems to treat urban stormwater runoff with particular attention paid to the characterization of nutrients, sediment and volume attenuation in terms of their quantity and quality, through field monitoring of various land cover types; (2) examine the impacts of these pullutants on the long term performance of these systems; (3) develop modeling tools for urban storwmater runoff; and (4) develop recommendations using evidence based knowledge for enhancing guidelines and standards associated with urban stormwater management for better protection of our source water and ecosystems in Alberta and beyond.