长江干线宜昌—浏河口段一维河网水流数学模型

One-dimensional flow mathematical model of river network from Yichang to Liuhekou of the Yangtze River

根据河道水流特点及模型计算精度和效率,长江干线一维水流数学模型通常以大通为界,将宜昌以下河道分为宜昌—大通、大通—浏河口两段,分别建立径流和潮流模型。而在当前新水沙条件及新型复杂江湖河网关系下,传统的两分段模型难以整体解决长河段复杂河网的水流模拟问题。针对该问题,研发了基于高精度、高性能有限体积法的一维河网水流数学模型,其采用SLIC的数值格式求解相邻单元交界面通量,在处理河网交汇方面以控制体为计算单元,简化求解复杂河网系数矩阵。该模型物理过程更为清晰明了,计算更加方便快捷。将研发的一维河网水流数学模型应用于宜昌—浏河口段,结果表明该模型稳定性强、精度高,有效解决了长江干线宜昌以下数模一体化难题。

According to the characteristics of river flow and the calculation precision and efficiency of the model, the one-dimensional flow mathematical models of the Yangtze River usually divide the river channel below Yichang into two sections with Datong as a boundary. The runoff model is built from Yichang to Datong and the tidal current model is built from Datong to Liuhekou. However, under new water and sediment conditions and complex river and lake networks, the traditional two-section model can hardly simulate the long river section of complex river networks as a whole. In response, a one-dimensional flow mathematical model for the river network is built based on the high-precision and high-performance finite volume method. It solves the interface flux of adjacent units by SLIC and simplifies the calculation of coefficient matrix with the control body as the calculation unit for the intersection of complex river networks. The physical process of the model is clear with convenient and fast calculation. The one-dimensional flow mathematical model is applied to the section from Yichang to Liuhekou. The results show that the model is stable with high precision and effectively realizes the digital-model integration of the trunk line of Yangtze River below Yichang.