上海市南汇南滩近期演变特征分析

作者利用经验正交函数(EOF)方法分析了上海市南汇南滩近期冲淤特征，表现为随着时间的推移在空间上纵向与横向的两种波动.纵向上,南汇南滩的冲淤波动以类似行进波的形式向西传播,速率约为820m/a,波动幅度沿程递减,横向上,以水下斜波和海床的衔拉部位为节点,整个剖面以类似驻波的形式上下振动,节点上下出现相反的冲淤趋势,即上冲下淤或上淤下冲.水下斜波带冲淤幅度最大,滩地和海床相对要小.

The Charateristics of Topography Change on Nanhui Nan Shoal,Shanghai

Using empirical orthogonal function (EOF) method,this paper discusses the charateristics of topography change on Nanhui Nan Shoal.It is concluded as follows:First, erosion or deposition occurs sequentially from east to west alongshore.Second, there is an equilibrium node at the transitional part between submarine slope and seabed.Shoal profile change to the upside of the node is oppsite to the downside,i.e. the upside eroded while the downside deposited, and vice versa. The elevation change is very large on submarine slope, but it is relatively small on tidal flat and on seabed.