Collaborative Research: Conceptualizing and quantifying the function of beaver dams and stormwater ponds on the hydrology and biogeochemistry of urban streams

合作研究：概念化和量化海狸坝和雨水池对城市溪流水文学和生物地球化学的功能

• 批准号: 2024338
• 负责人: Diego Riveros-Iregui
• 金额: $ 10.25万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2024338&HistoricalAwards=false
• 关键词: Collaborative; Research; Conceptualizing; quantifying; function

Cities across the United States are struggling with issues of storm water because buildings and roads cannot soak up rain like soil. Instead, rain that falls on cities runs off the buildings and roads. Cities are spending billions of dollars to manage this extra water. They are investing in green infrastructure, which is infrastructure on the land that can soak up and hold rainwater. One of these green infrastructure approaches is storm water ponds. However, across the southeastern U.S., beaver live in urban streams, and they build ponds, too. Beaver are considered a nuisance species and are often killed, even though their ponds may be similar to storm water ponds for slowing water and improving water quality. The first goal of this project is to compare how well beaver ponds store water during both dry and wet periods compared to storm water ponds. In addition to retaining and slowing the flow of storm water from cities, both beaver and storm water ponds receive nutrients than can feed algae blooms. The second goal of this project is to evaluate if urban beaver ponds increase the storage of nutrients and sediments from water that passes through their dams. This is important because it will improve downstream water quality. The final goal of this project is to map where beaver may be building these ponds in urban areas. This will inform city managers on what to do with the ponds. To determine if the ponds work the same way in different cities, this work will be conducted in Atlanta, GA, Charlotte, NC, and Raleigh-Durham-Chapel Hill, NC. The project will provide multiple broader impacts, including increasing diversity in the geosciences, collaborating with conservation groups, such as Adopt-a-Stream and Chattahoochee Riverkeeper, to educate the general public about the benefits of beaver, and helping local watershed managers to better manage beaver and adopt benefits that might exist from their ponds. In addition, this research will be done at multiple minority serving institutions by a diverse group of investigators. The multi-institution project will allow students to collaborate across institutions. This project will test a conceptual model of how the physical features of urban beaver and stormwater ponds impact streamflow attenuation and water quality. Cities are spending billions of dollars on installing green infrastructure to capture stormwater runoff, when cities in the southeastern U.S. may have infrastructure that fills a similar role already in beaver ponds. The functioning of beaver ponds compared to stormwater ponds has not been systematically studied anywhere. This project aims at (1) quantifying the nutrient and sediment retention of beaver and stormwater ponds, (2) quantifying the transit time of water through beaver and stormwater ponds and floodplain-stream reconnection around dams at both high and low flow, and (3) using remote sensing products and GIS to estimate the total number of beaver ponds in cities and scale-up quantification of retention to the whole-city scale. The hypothesis for objectives 1 and 2 is that the hydrologic and nutrient retention response of the pond will be driven by the hydrologic source of the water—specifically inflows dominated by surface or groundwater—and readily quantifiable metrics of pond geomorphology. The hypothesis for objective 3 is that identified ponded water from aerial imagery can be combined with the drivers of beaver habitat, including stream slope and vegetation, to pinpoint locations of beaver activity. The project entails conducting field work on urban beaver dams and stormwater ponds in the Piedmont cities of Atlanta, GA, and Charlotte and Raleigh, NC to compare influent to effluent mass fluxes of nutrients and total suspended solids (TSS) over two years, sample hyporheic waters in the dam and floodplain to understand nutrient cycling in the sediments and quantify travel time distributions of water through beaver ponds and how they compare to engineered stormwater ponds. The proposed research will develop a conceptual framework through rigorous testing using intensive field studies that will yield new and transformative knowledge within the field of urban hydrological science. The study will be carried across a range of factors, including pond size, watershed land use, sediment, geology, and infrastructure age to assess controlling drivers and predict the response in other systems. In addition, larger-scale mapping of these systems will help to evaluate landscape-level impacts on entire cities.In addition to the intellectual merits, this project will increase diversity in STEM by recruiting underrepresented students to complete M.S. degrees at minority serving institutions, mentored by a diverse group of faculty. The project will also entail public outreach on the ecological benefits of beaver leveraging existing relationships with non-profit conservation groups. Beaver are considered a nuisance species, and thus to reap the benefits their ponds may have on hydrologic and nutrient retention, conversations between watershed managers and beaver pond neighbors must be facilitated to allow for science-based decisions on the fate of these ponds.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.

美国各地的城市都在努力解决雨水问题，因为建筑物和道路不能像土壤那样吸收雨水。相反，落在城市上的雨水会从建筑物和道路上流下来。城市正在花费数十亿美元来管理这些额外的水。他们正在投资绿色基础设施，这是在土地上的基础设施，可以吸收和储存雨水。其中一种绿色基础设施是雨水池。然而，在美国东南部，海狸生活在城市的溪流中，它们也会建池塘。海狸被认为是一种讨厌的物种，经常被杀死，尽管它们的池塘可能类似于雨水池塘，可以减缓水的速度，改善水质。这个项目的第一个目标是比较海狸池塘在干旱和潮湿时期与雨水池塘相比储存水的能力。除了保留和减缓城市雨水的流动，海狸和雨水池塘都能获得营养物质，而这些营养物质可以滋生藻类。该项目的第二个目标是评估城市海狸池塘是否增加了流经其水坝的水的营养物质和沉积物的储存。这很重要，因为它将改善下游的水质。这个项目的最终目标是绘制河狸可能在城市地区建造这些池塘的位置。这将告知城市管理者如何处理这些池塘。为了确定池塘在不同城市的工作方式是否相同，这项工作将在佐治亚州的亚特兰大、北卡罗来纳州的夏洛特和北卡罗来纳州的罗利-达勒姆-教堂山进行。该项目将产生多种更广泛的影响，包括增加地球科学的多样性，与保护组织合作，如收养溪流和查塔胡奇河守护者，向公众宣传海狸的好处，帮助当地流域管理者更好地管理海狸，并利用他们的池塘可能存在的好处。此外，这项研究将在多个少数民族服务机构进行，由不同的调查小组进行。多机构项目将允许学生跨机构合作。该项目将测试一个概念模型，以了解城市海狸和雨水池塘的物理特征如何影响水流衰减和水质。城市正在花费数十亿美元安装绿色基础设施来收集雨水径流，而美国东南部的城市可能已经有了在海狸池塘中发挥类似作用的基础设施。海狸池的功能与雨水池的功能相比，在任何地方都没有系统的研究。本项目旨在(1)量化河狸和雨水塘的营养和泥沙淤积；(2)量化河狸和雨水塘中水在高、低流量条件下的穿越时间以及大坝周围洪泛平原-河流的重新连接；(3)利用遥感产品和GIS估算城市河狸池总数，并将截留量量化扩大到整个城市尺度。目标1和2的假设是，池塘的水文和营养保留反应将由水的水文来源驱动-特别是以地表水或地下水为主的流入-以及池塘地貌的易于量化的度量。目标3的假设是，从航空图像中识别出的池塘水可以与海狸栖息地的驱动因素（包括溪流坡度和植被）相结合，以确定海狸活动的位置。该项目需要在亚特兰大、北卡罗来纳州夏洛特和罗利的皮埃蒙特城市进行城市海狸水坝和雨水池的实地工作，比较两年来流入和流出的营养物质和总悬浮固体（TSS）的质量通量，对水坝和洪漫平原的潜流水进行取样，以了解沉积物中的营养循环，量化水通过海狸池塘的旅行时间分布，以及它们与工程雨水池的比较。拟议的研究将通过使用密集的实地研究的严格测试来制定一个概念性框架，这将在城市水文科学领域产生新的和变革性的知识。该研究将涉及一系列因素，包括池塘大小、流域土地利用、沉积物、地质和基础设施年龄，以评估控制驱动因素并预测其他系统的响应。此外，对这些系统进行更大规模的测绘将有助于评估对整个城市的景观级影响。除了智力上的优势，该项目还将通过招募代表性不足的学生在少数族裔服务机构完成硕士学位，在不同的教师群体的指导下，增加STEM的多样性。该项目还将利用与非营利性保护组织的现有关系，向公众宣传海狸的生态效益。海狸被认为是一种讨厌的物种，因此为了获得它们的池塘在水文和营养保留方面可能带来的好处，流域管理者和海狸池塘邻居之间的对话必须得到促进，以便对这些池塘的命运做出基于科学的决定。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

The Nonpoint Sources and Transport of Baseflow Nitrogen Loading Across a Developed Rural‐Urban Gradient

发达城乡梯度基流氮负荷的非点源和传输

• DOI: 10.1029/2021wr031533
• 发表时间: 2022
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Delesantro, Joseph M.;Duncan, Jonathan M.;Riveros‐Iregui, Diego;Blaszczak, Joanna R.;Bernhardt, Emily S.;Urban, Dean L.;Band, Lawrence E.
• 通讯作者: Band, Lawrence E.