Impacts of Urbanization on Stormwater Pollutant Loadings and River Water Quality

雨水/融雪径流将积聚在道路和其他城市表面的人为和自然污染物冲入雨水下水道，然后进入接收水体，对水质和生态系统构成重大威胁。对于加拿大和美国北部的市政当局来说尤其如此，在那里，冬季使用的大量道路除冰盐/砂可能会在春季径流到接收水体时产生冲击效应，据报道氯化物浓度高达加拿大急性暴露指南的600%。在快速城市化和气候变化的背景下，这些威胁将进一步加剧和复杂化。该项目的长期目标是揭示和量化城市化和气候变化对接收水体的耦合影响，并研究创新方法来提高城市和河流/湖泊的可持续性和弹性，以最大限度地减少这种影响。在接下来的5年里，我将以埃德蒙顿和北萨斯喀彻温河为例，重点研究城市化对雨水污染物负荷和接收河流水质的影响。该计划提出了两项研究。目标1将研究较少报道的常见但重要的污染物（营养物，沉积物，盐类）的雨水负荷的时空变异性，未报道的城市化水平与负荷的关系，以及在春季径流期间被忽视的负荷对接收河流的潜在冲击效应。目标2将首次量化城市雨水中新出现的污染物（微塑料，MPs）的负荷，并调查未开发的流体动力学对MPs在河流中的运输和命运的影响。建议在Aim 1选定的暴雨出水口进行现场监测，并在Aim 2进行MP加载。在第二个目标中，将进行实验室实验，研究在不同的水动力条件下和不同的MP特性（材料/密度、尺寸和形状）下，MP在水槽中的迁移和再悬浮。基于粒子图像测速法、粒子跟踪测速法和平面激光诱导荧光法，将发展一种新型的粒子速度和浓度测量技术。我们将对Aim 1的污染物负荷和河流水质进行数值模拟，并对Aim 2的污染物运输和再悬浮进行数值模拟。提案中列出的所有主要设备/软件都可供ufa水资源组使用。拟议的研究将产生关于城市雨水污染物负荷、运输和水中MPs命运的创新、原始知识。研究结果也将有助于加拿大三级政府制定/调整许多关于城市发展和河流/湖泊最大总污染物负荷的计划/政策，以及除冰盐/沙和雨水管理。这项研究将在咨询公司、公用事业公司和政府部门非常需要的领域培养7名HQP。

Stormwater/snowmelt runoff flushes anthropogenic and natural pollutants accumulated on roads and other urban surfaces into storm sewers and then into receiving water bodies, posing significant threats to the water quality and ecosystem. This is particularly true for municipalities in Canada and the northern US where the large amounts of road de-icing salts/sands used in winter can potentially have a shock effect during spring runoff to the receiving water bodies, with chloride concentration reported as high as 600% over the Canadian acute exposure guideline. In the context of fast urbanization and climate change, such threats will be further intensified and complicated. The long-term goals of this program are to reveal and quantify the coupled impacts of urbanization and climate change to receiving water bodies and to research innovative ways to enhance the sustainability and resiliency of both cities and rivers/lakes to minimize such impacts. In the next 5 years, I will focus on urbanization impact to stormwater pollutant loadings and receiving river water quality using Edmonton and the North Saskatchewan River as an example. Two studies are proposed in the program. Aim 1 will research the less-reported temporospatial variability of stormwater loadings of common yet important pollutants (nutrients, sediments, salts), the un-reported relation of urbanization level with the loadings, and the overlooked potential shock effect of the loadings to receiving rivers during spring runoff. Aim 2 will quantify, for the first time, the loading of an emerging pollutant (microplastics, MPs) in urban stormwater, and investigate the unexplored hydrodynamic impact to MP transport and fate in rivers. Field monitoring is proposed at selected storm outfalls for Aim 1 and MP loading in Aim 2. Lab experiments will be conducted for Aim 2 on MP transport and re-suspension in a flume under different hydrodynamic conditions and with different MP properties (materials/densities, sizes and shapes). An innovative measurement technique for MP velocity and concentration will be developed based on particle image velocimetry, particle tracking velocimetry and planar laser-induced fluorescence. Numerical modeling will be conducted for pollutant loadings and river water quality in Aim 1, and MP transport and re-suspension in Aim 2. All the major devices/software listed in the proposal are available for use in the Water Resources Group at the UofA. The proposed research will generate innovative, original knowledge on urban stormwater pollutant loadings and transport and fate of MPs in water. The research results will be also useful in Canada's three levels of governments in making/adjusting numerous plans/policies on urban development and maximum total pollutant loadings to rivers/lakes, as well as on de-icing salts/sands and stormwater management. The research will train 7 HQP in areas that are highly desirable by consulting firms, utility companies and government sectors.