河网型分流河道的分流分沙规律研究

There were always large numbers of anastomosing rivers in large river network. The movement characteristics of water and sediment are hard to grasp for the complex stream structure and the intervention of human events. At present, the flow and sediment diversion characteristics in anastomosing river had not been studied systematically and profoundly, and the research on complex sediment division models which restricted the simulation of complex river network are rare. .To research the mechanism of flow division and sediment division, the theoretical analysis and conceptual flume experiment were conducted. Water and sediment movement characteristics, including sediment division ratio, flow division angle, sediment gradation, height deviation of riverbed and width ratio of main and branch. The computational methods of sediment division in complex river network were extracted and applied to Jingjiang River-Dongting Lake system. The research results would promoted the development of river dynamics and rising the accuracy of the complex river network simulation. The theoretical value and application prospect of research results is important..Two key problems should be solved in this study: (1)Water and sediment movement characteristics and mechanism of anastomosing rivers in different boundary conditions. (2)Mathematical description for sediment diversion ratio in complex river network.

大型河网内具有数目众多的分流河道，其复杂的水系结构决定了复杂的水沙运动机理和分流分沙规律。目前对河网型分流河道的分流分沙规律还缺乏系统、深入的研究，用于河网型分流河道的分沙比计算模式还不多见，为此，本项目拟采用理论分析和水槽试验相结合的方法，研究河网型分流河道的分汊口附近的水沙运动规律，建立分沙比与分流角度、主支汊河床高程差、主支汊宽度比、泥沙级配等多种因素之间的量化关系，揭示影响分沙比的控制性主导因子，从而提炼出模拟复杂河网型分流河道的分沙比计算模式，再将该方法应用到荆江－洞庭湖河网水沙数学模型中进行检验。研究成果可促进河流动力学学科的发展，提高复杂河网水沙模拟的精度，具有重要的理论价值和应用前景。项目拟解决两个关键问题：（1）不同边界条件作用下的分汊口水沙运动规律和机理研究；（2）河网型分流河道分沙比计算模式的合理数学描述。

大型河网内具有数目众多的分流河道，其复杂的水系结构决定了复杂的水沙运动机理和分流分沙规律。目前对河网型分流河道的分流分沙规律还缺乏系统、深入的研究，用于河网型分流河道的分沙比计算模式还不多见，为此，本项目拟采用理论分析和水槽试验相结合的方法，研究河网型分流河道的分汊口附近的水沙运动规律，建立分沙比与分流角度、主支汊河床高程差、主支汊宽度比、泥沙级配等多种因素之间的量化关系，揭示影响分沙比的控制性主导因子，从而提炼出模拟复杂河网型分流河道的分沙比计算模式，再将该方法应用到荆江－洞庭湖河网水沙数学模型中进行检验。研究成果可促进河流动力学学科的发展，提高复杂河网水沙模拟的精度，具有重要的理论价值和应用前景。项目拟解决两个关键问题：（1）不同边界条件作用下的分汊口水沙运动规律和机理研究；（2）河网型分流河道分沙比计算模式的合理数学描述。