强潮河口的潮滩形态、底床浮泥及河口工程结构物等特征与河口泥沙输移动力过程及地形演变动态平衡，对港口航道管理及近海生态保护有至关重要的作用。现有河口泥沙输移相关研究中，缺乏对潮滩形态、底床浮泥及结构物的细化考虑。本项目选取强潮高浊度的杭州湾海域，以细颗粒泥沙为例，通过对潮滩近底层水沙过程、潮滩形态、底床浮泥与结构物的现场观测与取样分析，结合能有效模拟强潮高浊度河口泥沙动力过程的三维泥沙输移数值模型实验，研究强潮高浊度河口泥沙输移动力过程时空分布特征，揭示泥沙输移动力过程主导影响因素及作用机理，重点立足于潮滩形态、底床浮泥与结构物等边界条件，研究河口陆地边界（潮滩、底床）变化与泥沙输移动力过程的互馈影响特征，揭示互馈作用机理。项目预期研究成果将完善强潮高浊度河口泥沙输移动力过程方面的理论体系，加深对河口陆地边界变化与泥沙输移动力过程的互馈机理的理解，具有重要的科学和实践意义。

The characteristics of tidal flats and the structures of bottom boundary interact with sediment dynamics and geomorphology in estuaries, and is important to navigation management and environment protection. However, the characteristics of tidal flats and bottom structure are seldom considered in current studies of sediment dynamics in macro-tidal estuaries. In this study, we take fine sediment in Hangzhou Bay as an example. The characteristics of tidal flats and bottom structure are studied through field observation, sampling and remote sensing data. The sediment model is built and is calibrated, which coupling sediment and water density, fluid mud and tidal flat. The characteristics and mechanism of sediment dynamics and the dominant factors for sediment dynamics in macro-tidal Hangzhou Bay are studied using field data and numerical model results. The interactions between land boundary conditions and the sediment dynamics in estuaries are investigated using numerical experiments. This study would contribute to the theory of sediment dynamics in macro-tidal estuary.