Hydrodynamics of fluvial wakes past large in-stream natural objects and their implications for riverbed morphology

经过大型河内自然物体的河流尾流的流体动力学及其对河床形态的影响

• 批准号: 411877768
• 负责人: Dr. Alexander Sukhodolov, Ph.D.
• 金额: --
• 依托单位: Department of Civil and Environmental Engineering
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/411877768?language=en
• 关键词: Hydrodynamics; fluvial; wakes; past; large

The diversity of natural river environments is presently understood throughout the degree of spatial heterogeneity in abiotic factors controlled by river flow structures. Central to this topic is flow heterogeneity produced by natural in-stream obstructions such as boulder clusters, log jams, patches of riparian and aquatic vegetation and their various combinations. Specific flow types forming around and downstream of in-stream obstructions are called wakes, which dynamics are still incompletely understood because of complexities in natural environments and processes. The proposed research aims at the improvement in knowledge of wake flows hydrodynamics by providing fundamental theory-based insight into controlling factors and their implications for river morphology. In this project, complex environmental flows generated in shallow, rough-bedded river environments by porous in-stream obstructions will be assessed directly in the field at a range of hydrological conditions. Dynamics of these wake flows then will be further understood by comparing field observations with the results of lab experiments, which up-scaling issues will be examined by carrying out scale-independent field-based experiments and numerical simulations. These studies will be also complemented by in-situ surveys of porosity in natural obstructions and sampling of the riverbed substrate. These surveys will deliver presently unavailable knowledge on fundamental properties of in-stream obstructions and direct quantification of erosion/deposition processes due to fluvial wakes. Furthermore, the collected data will estimate the wakes’ contribution into the bulk hydraulic characteristics at a river reach scale.

天然河流环境的多样性目前被理解为河流水流结构控制的非生物因子的空间异质性程度。该主题的核心是由天然河道内障碍物（如巨石群、原木堵塞物、河岸和水生植被斑块及其各种组合）产生的水流异质性。在流中障碍物周围和下游形成的特定流类型被称为尾流，由于自然环境和过程的复杂性，其动力学仍然不完全理解。拟议的研究旨在提高知识的尾流流体动力学提供基础理论为基础的洞察控制因素及其对河流形态的影响。在本项目中，将在一系列水文条件下直接在现场评估多孔流内障碍物在浅、粗床河流环境中产生的复杂环境流。这些尾流的动力学，然后将进一步了解通过比较现场观测与实验室实验的结果，其中放大的问题将进行规模独立的基于现场的实验和数值模拟检查。这些研究还将辅之以天然障碍物孔隙度的现场调查和河床基底取样。这些调查将提供目前无法获得的知识，在流障碍物的基本属性和直接量化的侵蚀/沉积过程，由于河流尾流。此外，所收集的数据将估计尾流的贡献，在一个河流河段尺度的整体水力特性。