ERI: Effects of urban water infrastructure and proximate soil profiles on coupled surface-subsurface hydrology

城市洪水和水质问题给城市供水基础设施带来压力。在接下来的二十年里，数千亿美元将投资于修复和改善废水，雨水和联合下水道系统，以应对美国城市化和气候变化带来的挑战。这种基础设施是“渗漏的”，因此与周围的土壤和水循环相互作用。然而，相关的水文过程，即，饮用水、雨水和地下水的地下流动在城市流域研究中常常被忽视或特征不充分。漏水的卫生和雨水管道是否从流域中补充或排放水？从灰色雨水基础设施到绿色雨水基础设施的转变将如何影响地下有渗漏下水道的流域的雨水保留？解决缺乏关于城市水基础设施如何影响地表-地下水文过程的基本科学知识的问题，对于进行有效和有复原力的水基础设施投资至关重要。这项工作的目的是评估城市土壤剖面和水分配和收集基础设施对城市水平衡的影响，改进城市水文模型，以更好地量化基础设施修复的成本和效益，并最终促进发展有弹性和可靠的城市供水系统的目标。该项目将为城市排水和水文社区提供一个有效的建模工具，加强中西部排水和水资源方面的产学研合作，并制定“城市水文和雨水管理”明尼苏达大学校园的本科生和研究生都可以使用的课程。城市水系统的可持续性和恢复力受到对地下水文的理解不足的限制控制洪水生成的过程以及它们如何受到城市土壤剖面和水分配和收集基础设施的影响。这些饮用水，雨水，废水和地下水的地下流动的特点是在大多数水文研究和城市水文模型。因此，有一个迫切需要量化地下水文过程及其相互作用与地表入渗径流分配在城市流域。该项目将量化城市土壤剖面和水分配和收集基础设施对事件规模径流产生和长期水平衡的影响。这将通过将土壤剖面调查与水文模型模拟相结合来实现。首先，这项工作将通过土芯取样和水力剖面分析，确定配水和集水系统管道附近土壤剖面的特征。然后，这项工作将开发一个表面-地下水文模型参数化，可以代表水基础设施和非饱和/饱和区之间的渗透和渗出通量。最后，这项工作将评估土壤剖面和下水道管道条件和布局对洪水响应和长期水平衡的相对影响，通过假设模拟在很多和集水规模。本研究重点关注威斯康星州密尔沃基的城市流域，而方法和结果也适用于美国其他城市流域。该奖项反映了NSF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进行评估，被认为值得支持审查标准。

Urban flooding and water quality issues are putting pressure on urban water infrastructure. In the next two decades, hundreds of billions of dollars will be invested in the repair and enhancement of wastewater, stormwater, and combined sewer systems to address challenges arising from urbanization and climate change in the United States. This infrastructure is “leaky” and, therefore, interacts with the surrounding soils and the water cycle. However, the associated hydrologic processes, i.e., subsurface flows of drinking water, stormwater, and groundwater, are often overlooked or insufficiently characterized in urban watershed studies. Do leaky sanitary and storm sewers recharge or discharge water from the watershed? How will a shift from gray to green stormwater infrastructure impact stormwater retention in watersheds with leaky sewers underneath? Addressing the lack of fundamental scientific knowledge on how urban water infrastructure affects surface-subsurface hydrologic processes is imperative to making effective and resilient water infrastructure investments. The purpose of this work is to evaluate the effect of urban soil profiles and water distribution and collection infrastructure on urban water balances, improve urban hydrologic models to better quantify the costs and benefits of infrastructure rehabilitation, and ultimately contribute to the goal of developing resilient and reliable urban water systems. The project will provide an efficient modeling tool to the urban drainage and hydrology community, enhance industry-research collaboration in drainage and water resources in the Midwest, and develop an “Urban Hydrology and Stormwater Management” curriculum that is available to undergraduate and graduate students across the University of Minnesota campuses.The sustainability and resilience of urban water systems is limited by poor understanding of subsurface hydrologic processes that control flood generation and how they are impacted by urban soil profiles and water distribution and collection infrastructure. These subsurface flows of drinking water, stormwater, wastewater, and groundwater are less characterized in most hydrologic studies and urban hydrologic models. Therefore, there is an urgent need to quantify subsurface hydrologic processes and their interaction with surface infiltration-runoff partitioning in urban watersheds. This project will quantify the effects of urban soil profiles and water distribution and collection infrastructure on event-scale runoff generation and longterm water balances. This will be achieved by integrating soil profile surveys with hydrologic model simulations. First, this work will characterize the soil profiles near water distribution and collection system pipes through soil core sampling and hydraulic profiling. Then, this work will develop a surface-subsurface hydrologic model parameterization that can represent infiltration and exfiltration fluxes between water infrastructure and the unsaturated/saturated zones. Lastly, this work will evaluate the relative effects of soil profiles and sewer pipe conditions and layouts on flood response and long-term water balances through hypothetical simulations at lot and catchment scales. This study focuses on urban watersheds in Milwaukee, WI, while the approach and results are applicable across other urban watersheds in the United States.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.