Advances in Computational Models for Simulation of Sediment Dynamics in Alluvial Rivers

申请人建议对开阔水域和冰盖条件下冲积河道中的床沙的输送、侵蚀和沉积进行研究。本研究具有大量的直接应用价值。这类应用的例子包括河流洪水控制、河流水工结构的安全设计和运行、水资源规划和管理以及鱼类栖息地的恢复和保护。这些都是加拿大人民、工程师和全国各地的政策制定者面临的重要问题。拟议的研究方案表明，它在寻求以科学合理的方式解决这些问题方面具有相关性。 由于流水和下伏流动河床之间的复杂相互作用，人们对河床泥沙动力学问题知之甚少。冬季的冰几乎覆盖了加拿大所有的河流。然而，目前关于冰对沉积物动力学影响的知识是非常不完整的。在这项提案中，申请人打算开发高效和具有成本效益的计算机模型，以产生对湍急河流中的泥沙输送、侵蚀和沉积的预测。这些模型将通过将模型预测与现场计划和实验室实验的测量结果进行比较来验证。 拟议研究方案的长期目标是：1)制定建模和分析战略，并将其应用于解决与水资源规划和管理有关的实际问题；2)开发可靠和成本效益高的预测工具，用于现场和实验室数据。短期目标是：1)改进现有预报方法；2)开发和验证预报开阔水域和冰盖河流中泥沙动力学所需的新方法；3)提高三维模拟能力，促进增进对复杂流动河床水流的认识。 这项研究的原创性和创新性在于区分流动河床上方的边界层流动和更上方的自由流动，并在泥沙动力学的计算机模型中引入计算效率高的混合技术。申请人将探索将解析/半解析函数与守恒方程的数值解相结合的混合技术，以增强对近边界流动的描述。 这一拟议的研究计划可能会对改进跨学科的水力和水文模拟、促进对河流和邻近环境的系统预测以及了解人类活动和不断变化的自然条件对环境的影响做出更广泛的贡献。该项目将为博士和硕士研究生的培养创造机会。

The applicant proposes to conduct research on the transport, erosion, and deposition of bed sediments in alluvial river channels under both open-water and ice-covered conditions. This proposed research has a large number of direct applications. Examples of such applications include the control of river floods, safe design and operation of river hydraulic structures, water resources planning and management, and fish habitat restoration and protection. These are important issues facing the Canadian population, engineers and policy-makers across this country. The proposed research program demonstrates its relevance in the pursuit of addressing these issues in a scientifically sound manner. The problem of riverbed sediment dynamics is poorly understood, due to the complex interaction between the flowing water and the underlying mobile riverbed. Winter ice grips virtually all the Canadian rivers. However, the current knowledge concerning ice-effects on sediment dynamics is very incomplete. In this proposal, the applicant intends to develop efficient and cost-effective computer models for generating predictions of sediment transport, erosion and deposition in turbulent river flows. These models will be verified by comparing model predictions with measurements from field programs and laboratory experiments. The long-term goal of the proposed research program is to: 1) develop modelling and analysing strategies and apply them to solving practical problems related to water resources planning and management; and 2) develop reliable and cost-effective prediction tools for use with field and laboratory data. The short-term objectives are to: 1) improve existing predictive methods; 2) develop and verify new methods needed for the prediction of sediment dynamics in open-water and ice-covered river flows; and 3) advance three-dimensional modelling capacities and contribute to improved knowledge of complex mobile-bed river flow. The originality and innovative aspect of the proposed research lies in distinguishing the boundary-layer flow immediately above a mobile riverbed from free-stream flow further above and in introducing computationally efficient hybrid techniques within a computer model of sediment dynamics. The applicant will explore hybrid techniques that couple analytical/semi-analytical functions with numerical solutions to the conservation equations, in order to enhance the description of near-boundary flow. This proposed research program will potentially make broader contributions to improving interdisciplinary hydraulic and hydrological modelling, to facilitating system predictions for the riverine and adjacent environments, and to understanding the impact of anthropogenic activities and changing natural conditions on the environments. This program will create opportunities for training graduate students at both the doctoral and Master’s levels.