【摘要】 南汇东滩位于长江口与杭州湾的交汇处,是长江口与杭州湾水沙交换的重要通道,文章结合水动力特征指出南汇东滩是长江口外一个特殊的潮流动能减弱区,潮滩南北两侧潮流动能相对较强,涨落潮时过境泥沙易于落淤。根据长江口外的盐淡水混合类型分布及实测泥沙粒径组成指出风浪天气下南汇东滩是南槽淤积泥沙的主要物质来源,部分泥沙经南槽出海后随涨潮流进入杭州湾,大风天气下南汇东滩与杭州湾北岸地形演变成相反趋势,进一步证明南汇东滩是长江口与杭州湾泥沙交换的中转站。文章最后结合Lagrange质点运动轨迹分析了边滩不同区域质点的运动趋势,发现潮滩南北两侧质点运动趋势相反,提出边滩泥沙运动分界点的位置。研究表明南汇东滩特殊的动力机制对长江口与杭州湾北岸的岸滩演变具有重要的影响。更多还原

【Abstract】 Nanhui tidal flat located in the joint area between the Yangtze Estuary and Hangzhou Bay is an important way for water and sediment exchange between the Yangtze Estuary and Hangzhou Bay.In this paper,based on hydrodynamic characteristics,the view is pointed that the tidal current force is relatively lower on Nanhui tidal flat compared to the north and south.So sediment is easy to silt when pass the place in ebb or flood.Based on the distribution of mixing type of salt and fresh water and the measured grain size,the fact that Nanhui flat is an important sediment resource to south channel is confirmed.Meanwhile part of the sediment in south channel will be transported to Hangzhou Bay which leads to the trend that the shoal in such mentioned two places will change in different ways especially in high wind speed weather.Further more the sediment transportation passage on the Nanhui tidal flat is discussed either.Different transport trends have been found on the north and south of flat and the division position has been pointed.All the results show that the special dynamic mechanism on flat is playing an important role in the beach profile evaluation of the Yangtze Estuary and Hangzhou Bay.更多还原