In order to understand the influence of tide on sand exchange between an estuary and adjacent coastal region, three estuaries around North West England were chosen for detailed study using an open-source numerical morphological model system, TELEMAC. The source code of model was modified to customize tidal conditions and bed sand sizes. An "input- reduction" method was used to model sediment transport under several tides. "Morphological representative tide" was further achieved for long-term morphological modelling. It is clear that the dominant hydrodynamic processes of an estuary are influenced by tidal asymmetry. Local sediment transport is affected by seabed bathymetry and tidal asymmetry. Furthermore, shape and bathymetry of an estuary can influence tidal elevation and velocity. Tidal range can change transportation of the tidal wave which further changes the range of sediment transport.%通过二维数值模拟研究了位于英国西北海岸的利物浦湾在潮汐单独作用下的水动力以及泥沙输运情况.使用开源软件TELEMAC, 在对模型的源程序进行修改以后能够根据研究需要定制边界条件和初始条件.模型采取输入精简法对利物浦湾中长期的潮汐状况进行分类, 并对每种潮汐作用下的水动力与泥沙输运分别进行对比和分析, 最终确定了对利物浦湾的泥沙输运最相关的潮汐作为代表潮汐, 进而简化了潮汐作用下地形演变的长期计算.研究表明, 利物浦湾内河口海岸的水动力在潮汐作用下主要表现为非对称的涨落潮过程, 而泥沙输运会受到非对称潮汐和当地地形的显著影响.此外, 河口宽度和当地地形还会影响涨落潮的潮位和流速.潮差还会改变涨落潮流速、转流时间、输沙强度和输沙范围.
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