中文摘要：

基于逆流的特征，沉积运动的一个二维的数学模型被建立。在主要溪流和支流的融合的水路边界的复杂性用边界试穿被处理直角的坐标系统。与使用直角的曲线的坐标系统联系的二维的全部的沉积负担模型，数字计算格式，和关键问题的基本方程被讨论。在长江的重庆活动范围的水和沉积流动被模仿。计算的水水平，流动速度分发， silting 的数量并且搜索，并且冲积分发被发现与测量数据一致，它显示数字模型和计算方法是合理的。模型能在一个相对复杂的河网络被用于流动的计算。

英文摘要：

Based on the characteristics of backflow, a two-dimensional mathematical model of sediment movement was established. The complexity of the watercourse boundary at the confluence of the main stream and the tributary was dealt with using a boundary-fitting orthogonal coordinate system. The basic equation of the two-dimensional total sediment load model, the numerical calculation format, and key problems associated with using the orthogonal curvilinear coordinate system were discussed. Water and sediment flow in the Chongqing reach of the Yangtze River were simulated. The calculated water level, flow velocity distribution, amount of silting and scouring, and alluvial distribution are found to be in agreement with the measured data, which indicates that the numerical model and calculation method are reasonable. The model can be used for calculation of flow in a relatively complicated river network.