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生境，而且也是可导致严重疾病的水媒病原体的通道。研究人员将开发一个预测框架，该框架将提供对拓扑（结构连通性），几何（通道长度，斜率等），和紧急特征（例如，在稳态和非稳态条件下，河网的变化（河道短暂性）都影响着流量的动态变化。该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景观中输送水文、生态和生物地球化学通量的能力。该框架还可以为管理河流网络的决策提供信息，以减少其洪水的可能性和频率，以及病原体在流域内关键位置的集中。该项目将传播有关河流网络及其运输模式和属性的基础和应用知识，重点是它们与水文，工程和地球科学的相关性，面向K-12，本科生和研究生的不同受众。 该研究建议采取整体通过在一个单一框架内综合静态、动态和紧急连通性属性，了解河网通量动态的（生态-物理-观测）方法，该框架有可能评估气候和土地利用变化等不同变化情景如何影响河网未来的水文、生态、和地球化学通量。它利用网络理论，遥感和实地观测，水文原理和数值模拟的优势，破译关键的拓扑，几何和紧急控制，管理动态模式的流量传输的河流网络。特别是，研究人员的目标是（i）揭示在运输过程中河流网络对通量聚集施加的最相关的控制，（ii）量化它们与气候和人类活动等外部强迫的关系，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学术价值和更广泛的影响评审标准。

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.