中文摘要：

2007年9月27日至10月5日长江口洪季中水期间,在徐六泾2号水文平台处,结合OBS3A、LISST100（B）和ADCP对该地区的悬浮泥沙在大中小三种不同潮型下进行观测。详细分析了洪季中水期该处悬浮絮凝体沉降特性,结果表明不同潮差会对絮凝体的特性产生较大的影响,在相同絮凝体粒径下,大潮差时絮凝体有效密度和沉降速度都是小潮差时絮凝体的1.5倍,整个测量期间沉降速度约为0.5～3.0mm/s。针对目前利用分形学研究泥沙沉降特性的成果结合本文结果可知徐六泾处絮凝体质量分形维数约为2.5,并且由于泥沙形状及分布不均的影响泥沙沉降特性的系数约为0.43～0.5。

英文摘要：

From Sept. 27 to Oct. 5,2007 ,an OBS3A,a LISST100 （Type B） and an ADCP were used together to measure the settling velocity of fine sediment at Xuliujing Station. The results show the fine sediment had different settling properties in the spring tide and neap tide. When the floe size was equal, the effecitive floe density and settling velocity during the spring tide was 1.5 times of those during the neap tide. The range of settling velocity was from 0.5 to 3.0mm/s during the study period. Based on the theory of fractal geometry, the mass fraetal dimension was about 2. 5 and the combined coefficient which affected the settling properties from the non-spherical shape of floe and non-uniform primary particles was about between 0. 43 and 0. 5.