在正交坐标系下，建立了能较好拟合长江口边界的平面二维潮流和全沙数学模型。应用１９９６年洪、枯两季大、中、小潮水文泥沙资料和１９９５年、１９９６年地形及８３１０和８６１５台风暴潮引起的南北槽淤积资料，对长江口的潮位、流速、流向、含沙量特别是南北槽的地形变化和航道回淤进行了验证，结果表明该全沙数学模型较好地复演了长江口流场、含沙量场和地形变化。 Under the orthogonal coordinate system, a planar two-dimensional tidal current and total sand mathematical model that can well fit the boundary of the Yangtze Estuary is established. Based on the data of hydrological and sediment hydrological, mantle and tide hydrology and sediment in the floods and wilts of 1996 and the sediment data of north and south trenches caused by the terrain in 1995 and 1996 and the storm surges of 8310 and 8615 in 1996, the tidal level, velocity, flow direction, The results show that the whole sand mathematical model can reproduce the flow field, sediment concentration field and topographic change of the Yangtze Estuary well.