Sensitivity of Braided River Morphodynamics to Sediment Supply

辫状河形态动力学对泥沙供给的敏感性

• 批准号: 1147942
• 负责人: Joseph Wheaton
• 金额: $ 27.08万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-15 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1147942&HistoricalAwards=false
• 关键词: Sensitivity; Braided; River; Morphodynamics; Sediment

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.

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响应，该模型将允许进行数十至数百年的预测实验。该项目通过开发过去二十年来许多研究人员呼吁的模型，解决了当前预测河流建模能力的缺陷。我们已经有了该模型的试点版本，我们将扩展、完善和严格测试该模型，然后再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见解，以及我们提供新建模工具的计划，可能会开辟新的实验和发现途径。辫状河是指水流被分成多个平行河道的河道，这些河道在大坝（沉积物沉积物）周围不断分裂和返回，就像一根绳子缠绕在一起一样。辫状河代表了一些最具活力和快速发展的环境，通常是生物多样性的热点，也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，但工程和河流管理一直在努力阻止辫状河的出现。恢复河流的努力越来越多地认识到有时提倡编织的重要性。气候变化引起的洪水变化和上游沉积物（例如砾石和沙子）的数量可能会将许多河流推回辫状状态。尽管辫状河很重要，但我们预测其行为和了解其功能的能力充其量还不成熟。 该项目旨在推动两者的发展。 除了研究的科学价值外，该项目还可以帮助为负责处理和/或恢复辫状河的河流管理者和恢复从业人员提供指导。这些专业人士正在寻求合理的定量预测来管理辫状河。该项目通过为本科生提供研究机会和为 K-12 学生提供新体验等举措，扩大了代表性不足群体的参与。该项目通过与其他组织资助的工作（其中一些组织得到了 NSF 的支持）合作，利用了各种现有资源（例如现场数据、计算资源、外展计划、门户网站）。最后，作为本研究的一部分开发的建模方法可以帮助推进对预测气候变化影响和/或环境管理感兴趣的其他领域的模拟建模工作。