Flow processes and river dynamics

水流过程和河流动力学

• 批准号: 2657-2008
• 负责人: Roy, André
• 金额: $ 3.79万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=473619
• 关键词: Flow; processes; river; dynamics

Alluvial rivers are complex and fundamental components of the natural environment and a key resource for human activities and for wildlife. Although river systems have been extensively studied in the past, their dynamics and response to environmental changes, both natural and anthropogenic, are still far from being understood. Numerous spectacular examples of major and unforeseen impacts on the shape, size and pattern of alluvial channels have been caused by severe floods or by periods of drought such as those recently witnessed in Europe, North America, and elsewhere. In order to understand the behaviour of rivers we need to advance our knowledge on the fundamental mechanical processes that drive the river system. This research program focuses on the relationships, feedbacks and mutual adjustments between flow structure, sediment mobility and the resulting adjustments of the bed (form and bed material distribution) in rivers. The particular scope of the research is on the role of flow turbulence (i.e. smaller scales of motion in fluid flow) in these relationships. The objectives of the research program are to: develop a better model of the properties, origin and evolution of large-scale turbulent flow structures in uniform and non-uniform river flows; to quantify and understand changes in flow structures as flow stage changes; to integrate turbulence in the characterisation of the variability of patches and to assess the role of turbulence on fish behaviour; quantify the relations between flow structures and bedload sediment transport; determine the effects of bed morphology on bed particle movements at the reach scale. These objectives will be met through interconnected projects that will rely on both classical and innovative methods and experimental designs. The experiments will be conducted in rivers in eastern Québec at a selection of field sites, some of which have permanent installations for the measurements of flow, bed topography and particle displacements. The results of this research will be used to improve current models on the development of turbulence and on the effects of turbulence on fish behaviour and sediment transport.

冲积河流是自然环境的复杂和基本组成部分，也是人类活动和野生动物的关键资源，尽管过去对河流系统进行了广泛的研究，但它们的动态和对自然和人为环境变化的响应仍然相距甚远。严重的洪水或干旱时期对冲积河道的形状、大小和格局造成了许多重大和不可预见的影响，例如最近在欧洲、北美和其他地方发生的情况。河流的行为我们需要增进对驱动河流系统的基本机械过程的了解。该研究项目的重点是水流结构、沉积物流动性以及由此产生的河床调整（形态和河床物质分布）之间的关系、反馈和相互调整。研究的具体范围是流动湍流（即流体流动中较小尺度的运动）在这些关系中的作用。大型湍流结构均匀和非均匀河流流；量化和理解流动阶段变化时的流动结构变化；将湍流整合到斑块变化的特征中，并评估湍流对鱼类行为的作用；和河床沉积物输送；确定河段尺度上河床形态对河床颗粒运动的影响。这些目标将通过依赖经典和创新方法以及实验设计的相互关联的项目来实现。魁北克精选这项研究的结果将用于改进当前的湍流发展模型以及湍流对鱼类行为和沉积物的影响。运输。