长江口及其邻近海域洪季悬沙分布特征分析

基于近几年大量的实测资料，对长江口及其邻近海域洪季期间悬沙浓度的时空分布特征进行了分析.结果表明，悬沙浓度空间上以杭州湾测点最高，其次是长江口内、长江口外，舟山海域最低；悬沙平面分布总体态势为近岸高而外海低；长江口纵向上自口内经口门向口外悬沙浓度大致呈“低-高-低”分布，沿杭州湾测点则由西向东逐渐降低；横向比较长江口外海滨四个测点发现其悬沙浓度自北向南顺次升高；悬沙浓度一般由表及底逐渐增大，但在不同水域其主要呈现的垂线结构类型则有所不同.时间上由于潮流的大小潮和潮周期变化，悬沙浓度还存在大小潮和涨落潮周期变化.另外，对长江口及其邻近海域悬沙浓度时空分布特征的原因进行了初步分析.

Analysis of temporal and spatial variation characteristics of suspended sediment concentration of the Yangtze estuary and adjacent sea areas in flood seasons

This analysis of suspended sediment concentration(SSC) was based on abundant in-situ data in recent years.The results show that:（1）the SSC in the Hangzhou Bay is the highest, in the Yangtze estuary is the second, and in the Zhoushan sea areas is the lowest; the SSC reduces gradually from the near-shore areas to the open sea, with higher in the west region and lower in the east region; the SSC shows the trend of increasing firstly from the inner estuary to the mouth, and then decreasing from the mouth to the outer estuary; at the observation stations in the Hangzhou Bay the SSC reduces from west to east.The SSC increases from north to south by transverse comparison of four stations in the outer estuary; the SSC increases generally from surface layers to bottom layers, but the main types of the vertical distributions are different in different waters. (2) The SSC has obvious and complex variations with tidal cycle, resulting from the fluctuations of the tidal currents. In addition, a preliminary analysis of reasons for the temporal and spatial variation characteristics of the SSC in the study area was also made.