【作者】 孔俊；

【导师】 宋志尧； 夏云峰；

【作者基本信息】 河海大学 ， 港口、海岸及近海工程， 2005， 硕士

【摘要】 由于长江口与杭州湾存在密切的水沙交换，本文建立了正交曲线坐标系下长江口、杭州湾二维水沙数学模型，利用数学模型探讨长江口、杭州湾的水沙交换特性，并从机理上对长江口、杭州湾水沙交换进行初步分析。 在水流和悬沙数学模型中分别采用DSI方法和Euler-Lagrange模式建立了相应的计算模式，同时在悬沙模型中尝试应用枚举方法确定挟沙能力公式中的模型系数，取得了较好的效果，相比于传统方法该方法使挟沙能力公式的精度和相关系数得到明显的提高，模型计算结果与实测吻合较好。 分析了影响长江口、杭州湾水沙交换的各种水动力因素，通过对潮流动能的分析并结合波浪作用，从机理上初步阐述了南汇边滩洪淤枯冲的特性，通过比较Euler余流和Lagrange余流在南汇附近的不同运动特征，应用数学模型进一步认定了南汇附近近岸水域存在一个近南北向的泥沙通道，泥沙出南槽后往南向杭州湾口输移的特征。 同时本文根据边滩上水质点运动轨迹，提出了南汇边滩沿岸泥沙运动存在分界的观点，分析南汇边滩与南槽，边滩与杭州湾北岸的关系，对于南汇东滩附近长江口、杭州湾的主要水沙交换通道，杭州湾北岸的涨、落潮输沙带特征也进行了讨论。 最后本文将建立的水沙数学模型应用于南汇嘴控制工程及没冒沙生态水库工程，分析了工程实施后对长江口、杭州湾水沙交换的影响，得出实施工程后通过长江口进入杭州湾的泥沙有所减少，杭州湾北岸将发生冲刷等结论。更多还原

【Abstract】 Due to the existence of compact flow and sediment flux exchange between Changjiang estuary and Hangzhou bay, the 2D numerical sediment model in orthogonal curvilinear coordinate system is built in this paper. Based on the model, the characteristics and mechanism of flow and sediment flux exchange are analyzed and discussed.In the numerical model, DSI and Euler-Lagrange methods have been introduced in the numeration of flow module and sediment module respectively. Based on the least square method, a new method called enumeration method has been used firstly in this paper. The method is different from the normal method, which makes a regression analysis after logarithm. The error analysis and result comparison show the coefficients determined by the enumeration method are more reasonability and that the results of formula are more accurate in calculating the natural sediment -carrying capacity of flow.The different effluent factors on flux exchange between Changjiang estuary and Hangzhou bay have been discussed in this paper. Based on the analysis on tidal current energy and wave action, the characteristics that the sediment on Nanhui shoal will silt in flood season and be eroded in dry season have been explored preliminary. Through the comparison between Euler residue and Lagrange residue around Nanhui shoal, the phenomena that sediment from Changjiang river will be sent to Hangzhou bay and the existence of north-south direction sediment transportation pathway near Nanhui shoal has been verified.Through the analysis on Lagrange residue on Nanhui shoal, the existence of dividing line on which has been advanced. The relationship between Nanhui shoal and Nan-slot and that between Nanhui shoal and the north part of Hangzhou bay have been discussed. The main flow and sediment exchange pathway near Nanhui shoal and the predominant range of sediment transportation in the north of Hangzhou bay have been researched.Finally the model has been used in Nanhui control engineering and Meimaosha ecological reservoir engineering , the effluences of engineering on Changjiang estuary and Hanghzhou bay have been analyzed ,the conclusion is made that the sediment flux from Changjiang estuary to Hangzhou bay will be reduced and the erosion will occur in the north part of Hanghzou bay .更多还原