CAREER: Science and Education for Connecting Urban Irrigation Efficiency to Streamflow in Semi-Arid Cities

半干旱的美国城市在缺水地区迅速发展。环境可持续性的一个主要挑战是通过确保城市、农业和环境共同实现水安全，帮助半干旱社区繁荣发展。一个成功证明的办法是，通过提高效率减少城市用水量，以同样的供水量满足日益增长的用水需求。城市草坪灌溉现在是减少城市用水的主要目标，因为它在许多半干旱城市的年度用水中占主导地位。通过提高灌溉效率减少城市用水量可以在缺水的河流流域发挥关键作用，但目前受到径流减少和地下水流入河流的潜在意外后果的限制。如果我们改变半干旱城市，减少户外用水，城市溪流会干涸吗？流经半干旱城市的主要河流是否会变成涓涓细流，从而对生态、娱乐和下游水资源造成破坏？缺乏基本的科学知识，城市灌溉如何影响径流限制了水效率的城市灌溉系统在美国的半干旱地区的部分实施这项工作的目的是预测减少城市灌溉对径流的影响，提高城市地区管理稀缺水资源的能力，并最终有助于繁荣，可持续的半干旱社区的目标。该项目将为对水事业感兴趣的少数民族学生建立一个指导计划，并让这些学生参与城市水研究。该项目由水文科学计划和环境可持续性计划共同资助，减少城市灌溉可以在水资源稀缺的河流流域实现水安全和可持续性方面发挥关键作用。城市灌溉可以通过智能，高效的灌溉系统或草坪转换为干旱和不透水的表面来减少。这项工作将量化目前的贡献草坪灌溉小，半干旱城市流域的径流。这将在美国科罗拉多丹佛地区实现，方法是开发和应用一种新方法，将水同位素作为自来水的示踪剂与供水商报告相结合，并在实验流域进行监测。然后，利用灌溉地块和综合地下-地表-地表水文模型，本研究将确定减少城市灌溉对半干旱地下水补给和地表径流的影响。最后，这项工作将评估目前和减少城市灌溉的河流流量在半干旱城市走廊的一个大流域的水文意义。这项研究将与教育计划紧密结合，以实现科罗拉多州城市供水劳动力的多元化。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审查标准进行评估，被认为值得支持。

Semi-arid U.S. cities are growing rapidly in regions where water is scarce. A major challenge for environmental sustainability is to help semi-arid communities thrive by ensuring that cities, agriculture, and the environment are jointly water-secure. One successfully demonstrated option to meet growing water demands with the same water supply is reducing urban water use through efficiency. Urban lawn irrigation is now the primary target for reducing urban water use, as it dominates annual water use in many semi-arid cities. Cutting urban water use through irrigation efficiency could play a critical role in water-scarce river basins, but is presently limited by the potential unintended consequences of streamflow reduction from less runoff and groundwater flowing into streams. If we transform semi-arid cities to use less water outdoors, will urban streams run dry? Will major rivers flowing through semi-arid cities become trickles, with all the associated damage to ecology, recreation, and downstream water availability? The lack of fundamental scientific knowledge on how urban irrigation affects streamflow has limited the implementation of water-efficient urban irrigation systems in some parts of the semi-arid U.S. The purpose of this work is to predict the effects of reduced urban irrigation on streamflow, enhance the capacity of urban areas to manage scarce water resources, and ultimately contribute to the goal of thriving, sustainable semi-arid communities. The project will establish a mentoring program for underrepresented minority students interested in water careers and engage these students in hands-on urban water research. This project is co-funded by the Hydrologic Sciences Program and the Environmental Sustainability Program.Reducing urban irrigation could play a critical role in achieving water security and sustainability in river basins where water is scarce. Urban irrigation may be reduced through smart, efficient irrigation systems or lawn conversion to xeriscaping and impervious surfaces. This work will quantify the present contribution of lawn irrigation to streamflow in small, semi-arid urban watersheds. This will be achieved in the Denver, Colorado, U.S. area by developing and applying a novel method combining water isotopes as a tracer of tap water with water provider reports, and monitoring in experimental watersheds. Then, using irrigation plots and integrated subsurface-surface-land surface hydrologic modeling, this research will determine the effects of reduced urban irrigation on semi-arid groundwater recharge and surface runoff. Lastly, this work will evaluate the hydrologic significance of present and reduced urban irrigation on streamflow in the semi-arid urban corridor of a large river basin. This research will integrate tightly with an education plan to diversify the urban water workforce in Colorado.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.