Sensitivity of Braided River Morphodynamics to Sediment Supply

该项目旨在预测砾石辫状河将如何应对沉积物供应的变化，这可能是预期的气候变化的结果。 它旨在通过将苏格兰和新西兰辫状河前所未有的高分辨率数据与新的模拟模型相结合，更好地预测辫状河对洪水状况和沉积物供应变化的反应，该模型将允许数十至数百年的预测实验。该项目通过开发一个许多研究人员在过去二十年中呼吁的模型，解决了当前预测河流建模能力的不足。我们有一个试点版本的这个模型的工作，我们将扩展，完善，并严格测试这个模型，然后将其提供给更广泛的研究和河流管理社区。从我们计划的实验中获得的洞察力，以及我们提供新建模工具的计划，可能会开辟实验和发现的新途径。辫状河是指水流被分成多个平行的河道，这些河道围绕着大的沙洲（沉积物）反复分裂和汇合，就像一根相互缠绕的绳子。辫状河代表了一些最具活力和快速演变的环境，经常是生物多样性的热点，是鲑鱼和其他高价值物种的重要栖息地。 辫状河在历史上更为常见，但工程和河流管理已努力阻止辫状河。恢复河流的努力越来越认识到有时促进编织的重要性。很可能是气候变化引起的洪水和沉积物数量的变化（例如，上游提供的碎石和沙子）可能会使许多河流回到辫状状态。尽管辫状河的重要性，我们预测其行为和理解其功能的能力充其量是不成熟的。 该项目旨在促进两者。 除了研究的科学价值外，该项目还有助于为负责处理和/或恢复辫状河的河流管理人员和恢复工作者提供指导。这些专业人士正在寻求合理的定量预测管理辫状河。该项目通过为本科生提供研究机会和为K-12学生提供新体验的举措，扩大了代表性不足群体的参与。该项目利用各种现有资源（例如，现场数据，计算资源，外展计划，门户网站），通过与其他组织的资助工作进行合作，其中一些由NSF支持。最后，作为本研究的一部分开发的建模方法可以帮助推进模拟建模工作在其他领域有兴趣预测气候变化的影响和/或环境管理。

This project seeks to predict how gravel braided rivers will respond to changes in sediment supply, which may be expected as a result of climate change. It seeks to better predict the response of braided rivers to changes in flooding regimes and sediment supply by combining unprecedented high-resolution data from braided rivers in Scotland and New Zealand with a new simulation model that will allow predictive experimentation over tens to hundreds of years. The project addresses a deficiency in current predictive river modeling capability by developing a model many researchers have called for over the past two decades. We have a pilot version of this model working and we will extend, refine, and rigorously test this model before making it available to the broader research and river management communities. The insight gained from our planned experiments, as well as our plan to make the new modeling tool available, may open up new avenues of experimentation and discovery. Braided rivers are those in which the flow is divided into multiple parallel channels that split and come back together around large bars (sediment deposits) repeatedly like the intertwined strands of a rope. Braided rivers represent some of the most energetic and rapidly evolving environments and are frequently hotspots for biodiversity and serve as vital habitat for salmon as well as other highly valued species. Braided rivers were historically much more common, but engineering and river management have worked to discourage braiding. Increasingly, efforts to restore rivers are recognizing the importance of sometimes promoting braiding. It is likely that climate-change-induced shifts in flooding and the amount of sediment (e.g., gravel and sand) supplied from upstream could push many rivers back to a braided state. Despite the importance of braided rivers, our ability to predict their behavior and understand their function is immature at best. This project aims to advance both. Aside from the scientific value of the research, the project can help provide guidance to river managers and restoration practitioners charged with working with and/or restoring braided rivers. These professionals are seek reasonable quantitative predictions for managing braided rivers. The project broadens the participation of underrepresented groups through initiatives involving research opportunities for undergraduates and new experiences for K-12 students. The project leverages a variety of existing resources (e.g., field data, computational resources, outreach programs, web portals) by pursuing collaborations with funded efforts of other organizations, some supported by NSF. Finally, the modeling approaches developed as part of this research could help advance simulation modeling efforts in other fields interested in forecasting climate change impacts and/or environmental management.