CAREER: The Role of Groundwater Storage in Earth System Dynamics; Research to Improve Understanding of Current Hydrologic Regimes and Future Climate Response

地下水是美国乃至全世界的重要水资源。它与地表水的自然相互作用有助于稳定河流和生态系统。尽管地下水在水平衡中发挥着核心作用，但它很难被发现，这导致了它的可用性存在很大的不确定性。因此，它在全球模式中被简单地描述，并且在水文学界之外经常被误解。尽管在全球模型中更好地计算地下水储存的必要性已得到广泛承认，但我们对地下水储存如何在大空间尺度和长时间内发挥作用的理解仍然存在重大差距。必须解决这种不确定性，以严格评估新的建模方法，并改进我们用全球模型进行的水文预测。该项目探索地下水储存在大型模型中的作用，并开发工具来验证大型耦合系统中的地下水行为。该项目将进一步开发各种方法，以改善对公众关于地下水的有效沟通。我们将利用我们的建模平台作为一种资源，让K-12学生参与到与当地相关的水问题有关的计算机科学中来。拟议的研究将量化大规模储存动态在水和碳循环中的作用，这是我们目前地球系统预测的一个已知弱点。更具体地说，该项目旨在了解存储动态如何控制水文制度，以及存储变化在未来水文制度转变中可能发挥的作用。研究将利用美国大陆第一个完全集成的地下水地表水模型，与其他大规模建模方法进行直接比较，并在不同空间分辨率下简化地下水在大空间范围内的表示。这将为过程表征和空间分辨率对全球水和碳预测的影响提供独特的见解，这是以前的方法无法做到的。本研究的主要成果将：(1)表征最敏感的水文地质环境，以简化地下水近似和空间分辨率；(2)绘制美国各地的时空“地下水制度”并分析空间控制；(3)分析现有的全球模型储量基准；(4)量化地下水配置与气候变化响应之间的关系；(5)确定最容易受到地下水储量变化影响的地区。在取得这些技术成果的同时，该项目将提高公众对地下水可持续性的理解和参与。广播气象学家已经定期向公众传播水文信息。这个项目将向这一群体提供有关地下水系统的培训和广播资源，与直接向公众宣传相比，它将接触到更多和更多样化的受众。亚利桑那大学的本科生将通过现有的科学传播课程帮助开发广播材料，从而也为水文学以外的学生提供接触水文学的机会。最后，这里使用的模拟平台将作为一种工具，在学习计算机科学和编码技能的同时，让高中生参与当地的分水岭问题。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。

Groundwater is a critical water resource across the US and world-wide. Its natural interactions with surface water help stabilize our rivers and ecosystems. Despite its central role in the water balance, groundwater is hard to see, leading to much uncertainty on its availability. As a result, it is simply characterized in global models, and often misunderstood outside the hydrologic community. Though the need for better accounting of groundwater storage in global models has been widely acknowledged, there are still critical gaps in our understanding of how groundwater storage functions across large spatial scales and over long time periods. This uncertainty must be addressed to rigorously evaluate new modeling approaches and improve the hydrologic projections we make with global models. This project explores the role of groundwater storage in large scale models and develops tools to validate groundwater behavior in large coupled systems. The project will further develop ways to improve effective communication about groundwater to the public. We will use our modeling platforms as a resource to engage K-12 students in computer science with locally relevant water issues. The proposed research will quantify the role of large-scale storage dynamics in water and carbon cycles, which is an identified weakness of our current earth systems projections. More specifically, this project seeks to understand how storage dynamics control hydrologic regimes, and what role storage changes could play in future hydrologic regime shifts. Research will leverage the first fully integrated groundwater surface water model of the Continental US to develop direct comparisons with other large-scale modeling approaches and simplified groundwater representations over large spatial extents at varying spatial resolutions. This will provide unique insights on the impact of process representation and spatial resolution on global water and carbon projections not possible with previous approaches. The key outcomes of this research will (1) characterize the most sensitive hydrogeologic settings for simplification of groundwater approximations and spatial resolution, (2) map spatiotemporal ‘groundwater regimes’ across the US and analyze spatial controls, (3) analyze existing global model storage benchmarks, (4) quantify relationship between groundwater configuration and response to climate change, and (5) identify regions that are the most vulnerable to groundwater storage changes. In parallel with these technical outcomes this project will improve public understanding and engagement around groundwater sustainability. Broadcast meteorologists already regularly communicate hydrologic information with the general public. This project will provide training and broadcast resources on groundwater systems to this group, reaching a much larger and more diverse audience than would be possible through direct public outreach. Undergraduates at the UA will help develop broadcast materials through existing science communication courses, thus also providing exposure to hydrology for students outside of hydrology. Finally, the simulation platforms used here will be leveraged as a tool to engage high school students in local watershed issues while learning computer science and coding skills.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.