Collaborative Proposal: Plastic Spiraling In River Networks (Plastic-SIReN): Determining the controls of watershed plastic fluxes using a field and modeling approach

塑料垃圾是一个普遍存在的问题。海洋已积累了高达 2110 万吨塑料，其中大部分通过河流进入。但河流不仅仅是将塑料输送到海洋的管道。相反，当塑料向河流下游移动时，它可能会沉降、破碎或与生物体相互作用。大量塑料可能储存在河流中，但塑料储存的时间和地点以及向下游移动的情况仍然未知。 该研究结合了各种河流尺寸的现场测量和计算机建模，这在塑料研究领域是新颖的。需要这项研究来更好地管理塑料污染、清理重点以及饮用水源是否受到影响。多元化的学生团队将学习如何测量三个不同流域的溪流中的塑料。最重要的研究问题是：“水文的时空变化如何控制河流网络中保留的塑料碎片与向下游输送的塑料碎片的比例？”该项目将确定流量变化、塑性特征和流域特征对塑性运动的作用。耦合场和建模方法将应用于三个大都市区（伊利诺伊州芝加哥；马萨诸塞州波士顿；安大略省多伦多）的流域。现场测量将在每个流域的多个地点进行。在每个地点，我们将测量底部的宏观和微观塑料以及风暴流，以量化塑料浓度、类型、尺寸分布、沉积物中的储存量和通量。应用于三个流域的水文模型将量化河网规模的塑料积累、停留时间和滞留。该团队将与流域团体合作，确定塑料堆积的热点，优先处理塑料废物清理，并将在海洋科学和饮用水会议上发表演讲，塑料污染管理是这些会议的主要关注点。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Plastic litter is a widespread problem. Oceans have accumulated up to 21.1 million tons of plastic, the majority of which enters via rivers. But rivers are not just pipes delivering plastic to oceans. Instead, as plastic moves downstream in rivers it may settle, break into pieces, or interact with organisms. A substantial amount of plastic is likely stored in rivers, but when and where plastic is stored vs. moved downstream remains unknown. The research combines field measurements and computer modeling across a range of stream sizes, which is novel in the field of plastic research. This research is needed to better manage plastic pollution, where to focus cleanups, and whether drinking water sources are affected. A diverse team of students will learn how to measure plastics in streams in three different watersheds. The overarching research question is: “How does spatial and temporal variation in hydrology control the proportion of plastic debris that is retained within river networks vs. transported downstream?” The project will identify the role of flow variation, plastic characteristics, and watershed characteristics on plastic movement. A coupled field and modeling approach will be applied in the watersheds of three metropolitan regions (Chicago, IL; Boston, MA; Toronto, ON). Field measurements will take place at multiple sites in each watershed. At each site we will measure macro- and microplastic at base and storm flows to quantify plastic concentrations, types, size distribution, storage in sediments, and fluxes. A hydrologic model applied to each of the three watersheds will quantify river network-scale plastic accumulation, residence time, and retention. The team will work with watershed groups to identify hotspots of plastic accumulation to prioritize plastic waste cleanups and will present at ocean science and drinking water meetings, where management of plastic pollution is a major interest.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.