中文摘要：

应用改进的河口海洋数值模式,计算长江河口及其邻近海域水位随时间的变化,利用国际上先进的T_Tide调和常数软件计算得出潮汐的主要调和常数,根据《海道测量规范》（GB12317—1998）理论最低、最高潮面算法,在考虑8个主要分潮M2、S2、N2、K2、K1、O1、P1、Q1的基础上再考虑3个主要浅水分潮M4、M6和MS4,得出长江河口理论最低、最高潮面的空间分布。采用数值模式,设计高分辨的网格,有效解决了潮位站稀少和空间分布不均的不足,提升了理论最低、最高潮面的计算精度。将基于理论最低潮面的2009年长江河口实测地形资料转化为基于85国家高程基面的地形资料,使资料得到了充分应用。

英文摘要：

The improved 3-D estuarine coastal and ocean numerical model ECOM_si is used to simulate the water elevation in the Changjiang Estuary and its adjacent sea. The harmonic constants of the main tidal constituents are calculated by the software T_Tide. According to the algorithm in the ＂Specification for hydrographic survey＂ （ GB12317-1998 ）, and considering the 8 main tidal constituents M2 , S2, N2, K2, K1, O1 , P1, Q1 and 3 shallow water tidal constituents M4, M6, MS4, the distributions of the theoretically lowest and highest tidal levels in the Changjiang Estuary arc given. Using the numerical model and designing high grid resolution, the shortages of spatial asymmetry of limited tidal stations are overcome effectively, and the ealeulation accuracy of the theoretically lowest and highest tidal levels are improved. The data of water depth based on the theoretically lowest tidal level observed in 2009 are converted to those based on 85 national height data, enabling them to be used more effectively.