Flow-sediment interactions in complex three-dimensional curvilinear river flows

加拿大和世界各地的河流的健全管理对于许多重要目的至关重要，包括尽量减少洪水危害，水力发电，保护河流和河岸基础设施，以及维护健康的渔业和水生生态系统。 河流管理具有挑战性，因为河流会移动沉积物，而沉积物的转移决定了河流本身的形状。由于自然和人类的影响，河流形态可能会发生变化，但预测河道形态的变化仍然是一项具有挑战性的任务。拟议的研究计划包括三个项目，旨在阐明三维湍流和泥沙颗粒夹带和运输的河流之间的关系，以了解和预测河流形态和栖息地。 研究将在实地、实验室和数字上进行。 第一个项目描述了不列颠哥伦比亚省弗雷泽河游荡砾石床的一个大河段的沉积物流动过程。 第二个计画是探讨复杂的三维紊流流场及相关的泥沙输移通过一系列淹没式丁坝在一个渠道弯曲。 淹没式丁坝用于保护侵蚀的河岸，同时为溪流生物提供栖息地。 第三个项目将是研究半冲积河流，在这种情况下，半冲积河流是以冰川沉积物为主的河流。 这些河流在加拿大很常见，但人们对它们知之甚少。在所有三个项目中，高分辨率的空间分布测量的湍流强迫流和相关的泥沙输运将被用来构建改进的河道变化的形态动力学模型。这些模型将作为有价值的工具，实践工程师面临的管理和恢复国家的河流。

Sound management of rivers in Canada and worldwide is essential for many important purposes, including minimization of flood hazard, production of hydroelectricity, protection of in-stream and stream-bank infrastructure, and maintenance of healthy fisheries and aquatic ecosystems. River management is challenging because rivers move sediment, and this transfer of sediment determines the shape of the river itself. River morphology can change due to natural and human influences, yet prediction of changes in channel form remains a challenging task. The proposed research program includes three projects designed to elucidate the relations between three-dimensional turbulent flow and sediment particle entrainment and transport in rivers, in order to understand and predict river morphology and habitat. Research is to be conducted in the field, the laboratory, and numerically. The first project describes sediment-flow processes throughout a large reach of the wandering gravel-bed Fraser River, British Columbia. The second project examines the complex three-dimensional turbulent flow field and associated sediment transport through a series of submerged groynes in a channel bend. Submerged groynes are used to protect eroding river banks while providing habitat for stream organisms. The third project will be a study of semi-alluvial rivers, which in this case are rivers dominated by glacial deposits. Such rivers are common in Canada, but poorly understood. In all three projects, high resolution spatially distributed measurements of the turbulent forcing flow and associated sediment transport will be utilized to construct improved morphodynamic models of river channel change. These models will serve as valuable tools for practicing engineers faced with managing and restoring the nation's rivers.