CAREER: Flood Attenuation as an Ecosystem Service: Does it Scale Upward through Catchment-Scale River Restoration?

泛滥平原提供了一项重要的生态系统服务，通过减缓洪水在泛滥平原表面流动时的流速来减弱下游洪水的强度。从某种意义上说，泛滥平原是保护流域内人类发展的自然基础设施。不幸的是，全球各地的河流和泛滥平原已经发生了广泛的变化，这主要是因为通过修建堤坝、大坝和其他防洪措施，工程努力限制了河流系统的动态性质。不幸的是，这些河流工程项目可能会增加洪水的风险，因为失去了泛滥平原提供的天然减洪服务。然而，通过大规模实施河流恢复可以改善洪水衰减，尽管在理解战略上分散的恢复、河流-泛滥平原的相互作用和河网特征如何增强洪水衰减的生态系统服务方面仍然存在差距。这项研究的重点是通过实地研究和模型工作相结合的方式，建立关于这些相互作用的基础知识，以检验如何在改善洪泛区生态系统服务的同时降低人类对洪水的风险。该项目包括一个综合研究和教育计划，旨在指导第一代学生，增加公众对河流科学的接触，并重新开发和传播本科和研究生课程，以纳入可持续河流-泛滥平原工程和管理的概念。这项研究将增强对洪水衰减如何由河网结构和泛滥平原环境的物理特征来调节的理解。流域结构(大尺度)和物理洪泛区特征(小尺度)在控制通过流域的洪水运动方面的复杂的跨尺度依赖关系仍然不清楚。这项研究将探讨流域尺度恢复、河流-洪泛区相互作用和河网组织在增强洪水消减生态系统服务方面的重要性，这些共同构成了自然洪水管理的基础。这项工作的主要智力成果将包括：1)一个新的跨尺度概念模型，描述河网结构、泛滥平原特征和洪水衰减程度之间的关系；2)加深对流域尺度河流恢复在可持续水资源管理和加强泛滥平原生态系统服务方面的作用的理解；3)一个新的水文模拟框架，可用于产生关于河流恢复战略对大规模泛滥平原生态系统服务影响的可转移知识。这项研究将为社会如何在河流流域内和谐地融合河流恢复和自然洪水消减的好处提供更多的洞察力。此外，开发的模型可能会被纳入国家水模型，美国地质调查局使用该模型来监测全国各地的洪水。该项目将对工程和河流科学教育产生积极影响，方法是支持科罗拉多州立大学第一代学生的成功，向年轻人介绍以定位为基础的课程，并将研究成果纳入该项目的所有教育和宣传部分。该项目将通过科罗拉多州立大学斯科特本科生研究体验项目支持多名第一代学生的参与。同样，该项目将扩大女孩推进科学进步暑期计划，并通过基于地点的学习促进人们对河流科学的兴趣。这个项目中的实地数据收集和河流监测活动将被纳入两门课程，这两门课程将被重新开发，使学生能够学习数据收集方法、建模方法，以及在水资源管理中支持集水区尺度河流过程的重要性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Floodplains provide an important ecosystem service of attenuating downstream flood magnitudes by slowing flow velocities as water moves across floodplain surfaces. In a sense, floodplains are a natural infrastructure that protect human development within a river basin. Unfortunately, rivers and floodplains have been extensively altered around the globe, largely due to engineering efforts to restrain the dynamic nature of river systems, through the construction of levees, dams, and other flood control measures. Unfortunately, these river engineering projects have likely increased the risk of flooding due to loss of natural flood reduction services provided by floodplains. Flood attenuation may be improved, however, by implementing river restoration at large scales, though gaps still remain in understanding of how strategically dispersed restoration, river-floodplain interactions, and characteristics of river networks can enhance the ecosystem service of flood attenuation. This research focuses on building fundamental knowledge of these interactions through a combination of field studies and modeling efforts that examine how human risk to flooding can be reducing while improving floodplain ecosystem services. This project includes an integrated research and education program aimed at mentoring first- generation students, increasing public exposure to river science, and redeveloping and disseminating undergraduate and graduate curriculum to include concepts of sustainable river-floodplain engineering and management.This research will enhance understanding of how flood attenuation is regulated by both the structure of a river network and the physical characteristics of floodplain environments. The complex cross-scale dependencies of catchment configurations (large scale) and physical floodplain characteristics (small scale) in controlling flood movement through a river basin is still not understood. This research will investigate the importance of catchment-scale restoration, river-floodplain interactions, and the organization of river networks in enhancing the ecosystem service of flood attenuation, which together comprise the foundations of natural flood management. The principal intellectual outcomes of this work will include: 1) a new cross-scale conceptual model describing the relationships between river network structure, floodplain characteristics, and degree of flood attenuation; 2) advanced understanding about the role of catchment-scale river restoration in sustainable water resource management and the strengthening of floodplain ecosystem services; and 3) a novel hydrologic modeling framework that can be used to generate transferrable knowledge about the impacts of river restoration strategies on large-scale floodplain ecosystem services. This research will provide greater insight into how society can harmoniously blend the benefits of river restoration and natural flood attenuation within river catchments. In addition, the model developed potentially may be incorporated into the National Water Model, which is used by the USGS to monitor flooding around the nation. This project will positively impact engineering and river science education by supporting the success of first-generation students at Colorado State University, introducing youth to river science with a placed-based curriculum, and integrating research results into all education and outreach components of this project. The project will support the involvement of multiple first-generation students through the Scott Undergraduate Research Experience program at CSU. Similarly, this project will expand the Girls Advancing Scientific Progress summer program and promote interest in river science through place-based learning. Field data collection and river monitoring activities in this project will be incorporated into two courses that will be redeveloped, enabling students to learn data collection methodologies, modeling approaches, and the importance of supporting catchment-scale river processes in water resources management.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.