Collaborative Research: Dynamic connectivity of river networks as a framework for identifying controls on flux propagation and assessing landscape vulnerability to change

河流网络通过促进水、沉积物和营养物等环境通量的运输和分配，在塑造景观方面发挥着关键作用。这些网络不仅为淡水物种提供了栖息地，而且还成为可能导致严重疾病的水传播病原体的通道。研究人员将开发一个预测框架，该框架将提供对河网的拓扑(结构连通性)、几何(河道长度、坡度等)和紧急特征(例如，河道短暂性)如何在稳定和瞬变条件下影响通量运动动力学的定量理解。这一框架将有可能评估气候和土地利用变化等不同的变化情景如何影响河流网络在整个地貌中输送水文、生态和生物地球化学通量的能力的未来。这一框架还可以为有关管理河网的决策提供信息，以减少其洪水潜力和频率，以及病原体在流域内关键位置的集中。该项目将向K-12、本科生和研究生的不同受众传播有关河网及其运输模式和特性的基础和应用知识，重点是河网与水文、工程和地球科学的相关性。拟议的研究采用整体(数学-物理-观测)的方法，通过将静态、动态和紧急连通性属性整合到一个单一框架内来了解河流网络上的流量动态，该框架提供了评估气候和土地利用变化等不同变化情景如何影响河流网络未来的可能性，因为它们在整个景观中传输水文、生态和生物地球化学通量的能力。它利用网络理论、遥感和现场观测、水文学原理和数值模拟的优势，破译控制河流网络上通量传输动态模式的关键拓扑、几何和紧急控制。特别是，研究人员的目标是(I)揭示河流网络对运输过程中的通量聚集施加的最相关的控制，(Ii)量化它们与外部强迫(如气候和人类行动)的关系，以及(Iii)提出确定变化热点的脆弱性指标。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。

River networks play a critical role in shaping landscapes by facilitating the transport and distribution of environmental fluxes such as water, sediment, and nutrients. These networks not only provide habitats for freshwater species but also serve as conduits for water-borne pathogens that can cause severe diseases. Researchers will develop a predictive framework that will provide quantitative understanding of how the topological (structural connectivity), geometric (channel length, slope, etc.), and emergent features (e.g., channel ephemerality) of river networks influence the dynamics of flux movement under both steady and transient conditions. This framework will have the potential to assess how different scenarios of change, such as climate and land use change, may affect the future of river networks in their capacity to transport hydrological, ecological, and biogeochemical fluxes throughout the landscape. This framework can also inform decisions about managing river networks to reduce their flooding potential and frequency, as well as the concentration of pathogens at critical locations within a basin. The project will disseminate fundamental and applied knowledge about river networks and their transport patterns and properties, with a focus on their relevance to hydrologic, engineering and earth sciences, to a diverse audience of K-12, undergraduate, and graduate students. The proposed research takes a holistic (mathematical-physical-observational) approach to understanding the flux dynamics on river networks by integrating static, dynamic and emergent connectivity attributes within a single framework that offers the potential to assess how different scenarios of change, such as climate and land use change, may affect the future of river networks in their capacity to transport hydrological, ecological, and biogeochemical fluxes throughout the landscape. It leverages the strengths of network theory, remote sensing and field observations, hydrologic principles and numerical modeling to decipher the key topological, geometric, and emergent controls that govern dynamic patterns of flux transport on river networks. In particular, the researchers aim to (i) unveil the most relevant controls imposed by river networks on the aggregation of fluxes during the transport process, (ii) quantify their relation with external forcing such as climate and human actions, and (iii) propose vulnerability indicators for identifying hot spots of change.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.