Collaborative Research: Urban Watershed Evolution - Novel Temporal Perspectives on the Hydrologic Impacts and Positive Unintended Consequences of Failing Municipal Infrastructure

合作研究：城市流域演化——关于水文影响和市政基础设施故障的积极意外后果的新的时间视角

• 批准号: 2055536
• 负责人: Jay Banner
• 金额: $ 61.87万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2055536&HistoricalAwards=false
• 关键词: Collaborative; Research; Urban; Watershed; Evolution

Municipalities are increasingly challenged to use aged and failing infrastructure to deliver a continuous supply of clean water, and to return and treat wastewater, yet little is known about when, where, and how infrastructure failures were initiated or how they progressed. This project has three main scientific goals including: 1) determining the fate of municipal water after it leaves the engineered system and enters the natural hydrologic system, 2) unravel when, and under what conditions, infrastructure failure began, and 3) understanding how this failure and its impacts on water resources have progressed over time. The primary project activities comprise using naturally-occurring chemical tracers in stream water and trees to reconstruct a history of water quality, and using historical data to reconstruct a history of infrastructure development. We expect our approach will be transferrable to other urban systems with aging infrastructure. Most broadly, this project will leverage our network of stakeholders to help inform city-level planning efforts to implement resilient infrastructure while accommodating rapid expansion of urban populations in the 21st century. Results from this project will be incorporated across the sustainability curriculum at the University of Texas at Austin, which includes interdisciplinary degrees and 24 courses that emphasize field experiences and engage 800 students per year in on-campus environmental research along one of the proposed stream study sites, as well as geoscience graduate programs at UT Austin and the University of Arizona. Graduate and undergraduate student training will emphasize inclusion of underrepresented minorities.At the onset of infrastructure failure in each Austin watershed, municipal water was introduced by leakage into relatively pristine natural hydrologic systems. We hypothesize that the distinct chemical compositions of these anthropogenic water sources were recorded in bald cypress trees at the onset of failure and in subsequent years as failure progressed. This project comprises a novel application of natural isotopic tracers to examine the impacts of urbanization on natural hydrology and stream ecology in three watersheds in the same hydrogeologic terrain. The primary variable among the watersheds is the extent of urbanization. We will analyze elemental, and Sr isotope variations in stream water, and develop methods for high resolution measurements of the Sr isotopes in the growth rings of bald cypress trees growing adjacent to those streams. We posit that the growth rate and isotopic composition of the tree rings encode a hydrologic history of the progressive failure of infrastructure. We will apply these data using hydrogeochemical models to: 1) trace the evolution of municipal water during its transmission through the natural hydrologic cycle in anthropogenically compromised watersheds; and 2) use dendrochemical variations to reconstruct decadally-resolved temporal changes in municipal water input to streams. These results will be used to identify, for the first time, both the timing of the onset of infrastructure failure and temporal changes in the magnitude and impacts of the failure. We will compare this temporal record of municipal water input with the history of urban development in the same watersheds to determine the threshold for the extent of urbanization, above which hydrologic and ecological impacts of failing infrastructure are manifested. This award is co-funded by the Hydrologic Sciences, Environmental Sustainability, and Environmental Engineering programs.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.

市政当局面临着越来越大的挑战，需要利用老化和失效的基础设施来持续供应清洁水，并返回和处理废水，但人们对基础设施失效的时间、地点、方式和进展知之甚少。该项目有三个主要科学目标，包括：1）确定城市水离开工程系统并进入自然水文系统后的命运，2）弄清楚基础设施故障何时以及在什么条件下开始，以及3）了解这是如何发生的随着时间的推移，失败及其对水资源的影响不断发展。主要项目活动包括使用溪流和树木中天然存在的化学示踪剂来重建水质历史，以及使用历史数据重建基础设施发展历史。我们预计我们的方法将可以转移到其他基础设施老化的城市系统。更广泛地说，该项目将利用我们的利益相关者网络来帮助为城市级规划工作提供信息，以实施弹性基础设施，同时适应 21 世纪城市人口的快速增长。该项目的成果将纳入德克萨斯大学奥斯汀分校的可持续发展课程中，其中包括跨学科学位和 24 门课程，这些课程强调实地经验，每年吸引 800 名学生沿着拟议的流研究地点之一进行校园环境研究以及德克萨斯大学奥斯汀分校和亚利桑那大学的地球科学研究生课程。研究生和本科生培训将强调包容代表性不足的少数群体。在每个奥斯汀流域的基础设施开始出现故障时，市政用水通过渗漏进入相对原始的自然水文系统。我们假设，这些人为水源的独特化学成分在秃柏树开始衰竭时以及随后几年随着衰竭的进展而被记录下来。该项目包括天然同位素示踪剂的新颖应用，以研究城市化对同一水文地质地形的三个流域的自然水文和河流生态的影响。流域之间的主要变量是城市化程度。我们将分析溪流水中的元素和锶同位素变化，并开发对溪流附近生长的秃柏树的年轮中的锶同位素进行高分辨率测量的方法。我们假设树木年轮的生长速度和同位素组成编码了基础设施逐渐失效的水文历史。我们将使用水文地球化学模型将这些数据应用于：1）追踪城市用水在人为破坏的流域中通过自然水文循环传输过程中的演变； 2）利用树化学变化来重建市政供水流入溪流的十年间解析的时间变化。这些结果将首次用于确定基础设施故障发生的时间以及故障严重程度和影响的时间变化。我们将把市政用水的时间记录与同一流域的城市发展历史进行比较，以确定城市化程度的阈值，超过该阈值，失败的基础设施的水文和生态影响就会显现出来。该奖项由水文科学、环境可持续性和环境工程项目共同资助。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。