水沙变异条件下的多沙河流梯级水库水沙联合优化调度研究

Based on the accumulative effect of the sediment process and the principal of superposition of regulation mode under the condition of cascade reservoirs, the flow and sediment process have changed significantly, which directly impact on the development of reservoir’s synthetic benefit and downstream reservoir. This study is based on the technology and key problems of the coupling mechanism between scouring and silting evolution of reservoir-river channel downstream, and optimal operation of cascade reservoirs. In view of the action of runoff and sediment variations and current situation of regulation mode, the sedimentation characteristics and evolution trend of sandy rivers cascade reservoirs will be revealed. By means of data analysis, physical simulated test, numerical simulation and theoretical analysis of the typical river, the coupling relationships of sediment and scour, water-sediment joint optimal scheduling model and flood discharging capacity will be analyzed. This study combines hydrokinetics and the multiphase flow theory, system theory and optimization theory, the indicator system combines of water-sediment will be established, the simulation model and analysis method will be established, water-sediment joint optimal scheduling model is established. The sediment control demand and solution technique of model are put forward, and the disintegration evolution will be revealed between reservoir regulation, sediment and scour, reservoir’s synthetic benefit and discharge capacity of downstream channel. Based on research above, the reservoir water-sediment joint operation will be realized. Furthermore, the theoretical and experimental investigation achievements will help to enrich the theory of silt regulation theory and promoting the development of water conservancy discipline.

由于多沙河流梯级水库泥沙运动过程的累积性和调度方式的叠加性，水沙条件变异显著，严重影响了水库综合效益的发挥和下游河道的过洪能力。本项目立足于库区-河道冲淤演变与梯级水库常规调度间的耦合机制这一科学问题，针对来沙减少和梯级水库联合优化调度现状，通过实测资料分析、实体物理模型、数值模拟和理论分析的方法，研究多沙河流梯级水库泥沙冲淤特性和演变规律，解析泥沙冲淤、调度方式、水库效益、河道过洪能力之间的耦合机制，并将水沙动力学和系统理论、优化理论相结合，建立水沙调度指标体系，构建水库水库-河道互馈的梯级水库水沙联合优化调度模型，提出梯级水库水沙调控需求和调度模型求解技术，揭示水库水库调度方式、泥沙冲淤、综合效益和河道过洪能力互馈动力过程演化规律，实现水沙变异条件下多沙河流梯级水库水沙联合调度。项目研究对丰富梯级水库水沙调控理论，促进水利科学发展具有重要的实践意义和科学价值。

本项目立足于库区-河道冲淤演变与梯级水库常规调度间的耦合机制这一科学问题开展研究工作。针对流域水沙演变规律和内在驱动机制复杂的问题，采用黄河中游重要水文控制站实测多年水沙资料，建立了不同重现期下年径流量和年输沙量不同遭遇组合概率的二维Copula函数水沙关系联合分布模型，研究进入黄河下游水沙系列时空变异特征与演变趋势，阐释了水沙协调度的内涵，提出了水沙协调度的计算方法。针对水库排沙过程中泥沙运动与河道边界条件的物理机制交互作用复杂的问题，基于一维水沙数学模型和水动力学模型，以典型淤损水库为例，明晰不同输沙流态下水库排沙机理与河道高效输沙机制。针对水库调度、泥沙淤积和下游河道河床演变难以相互协调的问题，建立了水库-河道互馈的梯级水库水沙电生态多目标优化调度耦合模型，揭示水库综合效益和河道过洪能力互馈的动力过程演化规律。针对求解多目标水库调度模型问题时存局部搜索能力较差的问题，提出了一种基于改进逐次逼近方法的快速非支配排序遗传算法的调度模型求解技术（SA-NSGA-Ⅱ），系统的研究了不同水沙条件下的梯级水库多目标优化调度模型的Pareto最优解，为多沙河流梯级水库多目标优化调度的研究提供了一种全新的思路。