EAR-PF: Quantifying the effects of flow transience on sediment transport

EAR-PF：量化流动瞬变对沉积物输送的影响

• 批准号: 1349776
• 负责人: Colin Phillips
• 金额: $ 8.7万
• 依托单位: Phillips Colin B
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1349776&HistoricalAwards=false
• 关键词: EAR; PF; Quantifying; effects; flow

Dr. Colin Phillips has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and educational outreach plan at the University of Minnesota. He will investigate the process of gravel transport in response to transient and intermittent flooding. Gravel rivers represent the rate limiting step in the incision of mountains and also provide critical habitat and breeding grounds to numerous aquatic species. These experiments will form the basis for understanding how potential changes in climate and land use will affect gravel streams. In addition these experiments will provide a quantitative framework for stream managers regulating flow releases below dams and stream restoration projects. The results from these experiments will be turned into interactive online tools for stream restoration practitioners. Furthermore, the knowledge gained from this project will be transferred to young scientists through classes and experiments during the National Center for Earth Surface Dynamics 2 (NCED2) Summer Institute, and to future young scientists by collaborating with NCED2 REU students.A large majority of our understanding of gravel river dynamics comes from flume experiments under constant or slowly varying floods. Many of the theories developed under steady flow provide reasonable predictions of the dynamics of gravel rivers when averaged over numerous floods, however due to the stochastic nature of sediment transport it remains unclear whether these predictions break down due to flow unsteadiness or granular phenomena. Through the use of laboratory experiments he will test the relative importance of flood shape and sequence to determine how an unsteady flow drives sediment transport. This project will compare the dynamics of gravel transport at the particle level through the tracking of several populations of marked particles under a variety of single and sequences of flows of varying magnitude and duration, but equivalent impulse (time-integrated momentum above the threshold of particle motion).

科林菲利普斯博士已被授予美国国家科学基金会地球科学博士后奖学金，在明尼苏达大学开展研究和教育推广计划。他将研究砾石运输的过程，以应对瞬时和间歇性洪水。砾石河流代表了山脉切割的速度限制步骤，也为许多水生物种提供了重要的栖息地和繁殖地。这些实验将为了解气候和土地利用的潜在变化将如何影响砾石流奠定基础。此外，这些实验将提供一个定量的框架流管理人员调节流量释放以下的水坝和河流恢复项目。这些实验的结果将变成交互式在线工具，供河流恢复工作者使用。此外，从这个项目中获得的知识将转移到年轻的科学家通过类和实验在国家中心地球表面动力学2（NCED2）夏季研究所，并通过与NCED2 REU学生合作，未来的年轻科学家。稳定流下开发的许多理论提供了合理的预测砾石河流的动态时，平均在许多洪水，但由于泥沙输运的随机性，它仍然不清楚这些预测是否打破由于流动不稳定或颗粒现象。通过使用实验室实验，他将测试洪水的形状和序列的相对重要性，以确定如何不稳定流驱动泥沙输运。该项目将通过跟踪在各种大小和持续时间不同但冲量相等（时间积分动量高于粒子运动阈值）的单一和连续流动下的若干标记粒子群，比较粒子一级的砾石运输动态。