Development of phosphorus loading control strategies for urbanizing watersheds

磷负荷和富营养化加速对人类和环境健康造成负面影响，并产生重大的潜在经济影响。据报道，在加拿大的几个地区，藻类水华的发生频率有所增加，来自城市和农村的非点源磷负荷被怀疑是主要原因。水系统中营养状态的变化影响了将水资源用于娱乐目的的能力，增加了水处理成本，并降低了水生生物多样性。目前，仅基于磷负荷的考虑，加拿大几个地区对新的开发项目施加了限制。在城市化的分水岭内，雨水可能是接收水体的主要磷来源。由于其低维护要求、弹性和美观吸引力，处理湿地已被确定为一种可能的工具来减轻城市雨水中的磷负荷。然而，关于雨水湿地中磷的去向，尤其是在凉爽的气候中，人们对磷的去向有很大的认识差距。这项研究计划的短期目标是确定雨水处理湿地的磷保留机制，并开发创新的设计和运行方法，用于优化凉爽气候湿地系统的磷去除。该研究计划将包括受控实验室实验、涉及全尺寸雨水湿地系统的实地研究，以及开发一种新的、凉爽的气候、基于过程的湿地模型。研究活动将重点放在一个湿地系统上，该系统从哈利法克斯的一个新的城市开发项目中接收雨水，该系统将作为一个“生活实验室”。不同的学生将接受博士、硕士和本科水平的培训，并将获得使用最先进的环境监测仪器的经验。这项研究将导致开发可供雨水工程师和市政规划者直接使用的工具和设计建议，以确保保护宝贵的水生资源。**

Phosphorus loading and accelerated eutrophication have negative effects on human and environmental health, and significant potential economic impacts. Increases in the frequency of algal blooms has been reported in several regions of Canada, with phosphorus loading from non-point urban and rural sources as suspected primary causes. Changes in trophic state within a water system influences the ability to use the water resource for recreational purposes, increases water treatment costs, and degrades aquatic biodiversity. Restrictions are currently being placed on new development in several regions of Canada based solely on phosphorus loading concerns. Within urbanizing watersheds, stormwater can be a major source of phosphorus to receiving water bodies. Treatment wetlands have been identified as a possible tool for mitigating phosphorus loading from urban stormwater due to their low maintenance requirements, resiliency, and aesthetic appeal. However, there are significant knowledge gaps with respect to the fate of phosphorus within stormwater wetlands, especially in cool climates. The short term goals of this research program are to identify mechanisms of phosphorus retention with stormwater treatment wetlands, and develop innovate design and operation approaches that can be used to optimize phosphorus removal in cool climate wetland systems. The research program will involve controlled laboratory experiments, field studies involving full scale stormwater wetland systems, and the development of a new, cool climate, process-based wetland model. The research activities will focus on a wetland system receiving stormwater from a new urban development in Halifax, that will serve as a "Living Laboratory". A diversity of students will be trained at the doctoral, masters and undergraduate levels, and will gain experience using state-of-the-art environmental monitoring instruments. This research will lead to the development of tools and design recommendations that can be directly used by stormwater engineers and municipal planners to ensure protection of valuable aquatic resources. **