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

申请方提议研究冲积河道中河床沉积物在开阔水域和冰层覆盖条件下的迁移、侵蚀和沉积情况。这项研究有大量的直接应用。这类应用的例子包括控制河流洪水、河流水利结构的安全设计和运行、水资源规划和管理以及鱼类生境的恢复和保护。这些都是加拿大全国人民、工程师和决策者面临的重要问题。拟议的研究计划表明，它在追求以科学合理的方式解决这些问题方面具有相关性。由于流动的水和下面的移动的河床之间复杂的相互作用，河床沉积动力学问题知之甚少。冬天的冰几乎覆盖了加拿大所有的河流。然而，目前有关冰对沉积动力学的影响的知识是非常不完整的。在这项提案中，申请人打算开发有效和具有成本效益的计算机模型，用于预测湍流河流中的泥沙输移、侵蚀和沉积。这些模型将通过将模型预测与现场方案和实验室实验的测量结果进行比较来验证。*拟议研究计划的长期目标是：1）开发建模和分析策略，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）开发可靠且具有成本效益的预测工具，用于现场和实验室数据。短期目标是：1）改进现有的预测方法; 2）开发和验证预测开放水域和冰封河流中沉积物动力学所需的新方法; 3）提高三维建模能力，并有助于提高对复杂流动床河流的认识。所提出的研究的独创性和创新性方面在于区分边界层流动直接以上的移动的河床自由流进一步以上，并在引入计算效率的混合技术内的计算机模型的沉积动力学。申请人将探索将分析/半分析函数与守恒方程的数值解相结合的混合技术，以加强对近边界流的描述。这项拟议的研究计划将有可能作出更广泛的贡献，以改善跨学科的水力和水文建模，促进系统预测河流和邻近环境，并了解人类活动和不断变化的自然条件对环境的影响。该计划将为培养博士和硕士水平的研究生创造机会。**

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.**