Fluid and sediment dynamics in sand-bedded river systems

沙层河流系统中的流体和沉积物动力学

• 批准号: 341862-2012
• 负责人: Venditti, Jeremy
• 金额: $ 2.33万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572388
• 关键词: Fluid; sediment; dynamics; sand; bedded

The objective of this research program is to advance our knowledge of the mechanics of sand-bedded river channels and, in particular, to develop physically-based tools to assist in the prediction of sediment movement between their source and ultimate sink in the ocean. The program uses the sand-bedded reach of the lower Fraser River as a natural laboratory to investigate and quantify processes. The Fraser also serves as inspiration (and in some cases the prototype) for more detailed observations in the River Dynamics Laboratory (RDL) flume channel at SFU. The mechanisms responsible for moving sediment through the 85 km river reach that passes through British Columbia's Lower Mainland are understood only conceptually, but the dynamics of the sediment control how the river responds to flood flows and the quality of aquatic habitat in the channel, delta, and tidal flat environments. Empirical methods for estimating sediment movement based on historical data collection programs are no longer reliable because of ongoing adjustment of the river to dredging required to maintain the Port of Vancouver. A physically-based modeling approach for sediment routing is required to make reliable predictions of how the sand-bedded channel and the delta environments will respond to various perturbations (e.g. a warmer climate, changes in water flux, changes in sediment flux associated with land use practices and contemporary variation in sea level). This research focuses on establishing methods to monitor suspended sediment delivery to the sand-bedded lower Fraser River, development of models for predicting suspended sediment transport based on the physical interactions between large-scale turbulent motions in the water column and examination of bedform response to variable flows (hydrographs or tides). There is a pressing need to make predictions of sediment transport in sand-bedded rivers that empty into the sea, such as the lower Fraser River, because they are often sites of intense urban development world-wide and the dynamics of these natural landscape processes significantly affect the socio-economic viability of this development.

这项研究计划的目的是推进我们的知识的机制砂层河道，特别是开发物理为基础的工具，以帮助在其源和最终汇在海洋之间的沉积物运动的预测。该计划利用弗雷泽河下游的砂层河段作为自然实验室，以调查和量化过程。弗雷泽也作为灵感（在某些情况下原型）在河流动力学实验室（RDL）水槽通道在SFU更详细的观察。负责移动沉积物通过85公里的河段，通过不列颠哥伦比亚省的低陆平原的机制只理解概念上，但沉积物的动态控制河流如何应对洪水流量和质量的水生栖息地的通道，三角洲和潮滩环境。基于历史数据收集程序估算泥沙运动的经验方法不再可靠，因为需要对河流进行疏浚以维护温哥华港。需要一种基于物理的沉积物路径模拟方法，以可靠地预测砂层河道和三角洲环境将如何应对各种扰动（例如，气候变暖、水通量变化、与土地利用做法相关的沉积物通量变化以及当代海平面变化）。本研究的重点是建立方法来监测悬浮泥沙输送到砂层较低的弗雷泽河，预测悬浮泥沙输运模型的基础上的物理相互作用的大规模湍流运动在水柱和检查床形响应变量流量（水文或潮汐）。有一个紧迫的需要，使泥沙输运的预测砂层河流，空入海，如较低的弗雷泽河，因为它们往往是激烈的城市发展的网站，这些自然景观过程的动态显着影响这种发展的社会经济可行性。