中文摘要：

2003年2月17～24目，在长江口南槽最大浑浊带地区进行了大、小潮水文泥沙定点连续观测。用OBS-5观测水深、盐度和浊度，用直读式海流计（SLC9—2）观测不同水层流速，同时获取了不同潮时不同水层悬沙水样。通过对水深、盐度、浊度、悬沙浓度和流速等数据进行大、小潮周期对比与分析。得出如下主要结果：（1）盐度和水流流速变化范围分别为13．5～22．3和0．30～2．13m／s；（2）表层与底层悬沙浓度变化范围分别为180～222mg／L和1019～1300mg／L；（3）一个潮周期内，可出现4次悬沙浓度峰值；（4）通常情况下，悬沙浓度值涨潮大于落潮，大潮大于小潮，但强风或风暴潮会改变大、小潮的悬沙浓度变化格局。研究表明，研究区悬沙浓度变化具有一定的周期性和规律性，但也存在一些不确定性。长江口南槽最大浑浊带的发育主要是由于“潮泵效应”和盐水异重流引起的对床底侵蚀和泥沙再悬浮造成的。另外，动水絮凝和滩槽之间泥沙交换，也对最大浑浊带的形成与发育有重要影响。

英文摘要：

Observations were made of turbidity, water depth and salinity using Optical Backscatter Sensor（OBS- 5,made in USA）and the current velocities using current meter（SLC9-2, made in Qingdao, China）and water samples were taken in the water column over different individual tidal cycles in the Turbidity Maximum（TM） Zone in the south passage of the Changjiang River Estuary in February 17 to 24（dry season）,2003. Comparison and analysis of the data of SSC,current velocity and salinity in the spring and neap tide give the following results; （1）The range of current velocities was 0.3 to 2.13 m/s. The phenomenon of asymmetry（both time and current velocity）for the flood tide and ebb tide was found during the observations. The time of ebb tide of spring tide and neap tide was 2 hours and 0.5 hour longer than that of the flood tides respectively. The average current velocity in spring tide was 1.74 times that of neap tide. The curves of flood tide were much steeper than that of ebb tide,especially during the spring tide. （2）The variation range of salinity was 13.5 to 22.3 during the observations（dry season from November to April in the study area）. The salinity value in spring tide was higher than in neap tide and increased from the surface to the bottom. In spring tide, the salinity of the middle layer and the bottom layer was well mixed because of the strong dynamics. The salt-wedge occurred near the bed during the neap tide. （3）There were four different peak values of SSC at flood peak,ebb peak,flood slack and ebb slack. The maximum value during the whole observations occurred at the flood peak of the spring tide. The peak values between the flood slack and ebb slack were resulted from the rapid upward diffusion of the high concentration suspended silt under the action of overlying turbulent flow. The most part of the high concentration suspended silt layer in the middle of the water column came from the suspended sediment and turbid water near the bed. This was the process of sedime