伶仃洋出海航道浮泥形成机制与分布特征

Formation mechanism and distribution characteristics of the fluid mud in the seaward channel of the Lingding Sea

伶仃洋出海航道前后5次大规模的浮泥观测表明,航道中曾普遍发现浮泥层,但近期分布范围有所缩小;浮泥层厚一般在0.1～0.6 m之间,层厚较大的分布区主要集中在航道北段深槽区。根据浮泥分布的多年变化与洪、枯季变化分析,浮泥主要分布在航道深槽内且洪季浮泥层厚度与范围明显比枯季大,表明水动力条件相对较弱和较为丰富的细颗粒泥沙来源是浮泥形成的重要条件;浮泥层由于具有易流动性和可塑性,其形成位置、厚度与长度受潮汐作用影响明显而具有周期性变化。

According to the observation results in the seaward channel of the Lingding Sea in 1990,1991 and 2001 and 2006,fluid mud was widely found in the channel,but the distribution area decreased recently.The thickness of the fluid mud was 0.1～3.3m in general,and the thicker was mainly found in the north reach of the channel.The distribution changes of fluid mud between years and seasons prove that fluid mud is mainly formed in the channel and the observed depth and area of fluid mud in flood seasons is obviously bigger than that in dry seasons,which shows that the weaker hydrodynamic environment and the abundant fine particle are the two important conditions of fluid mud formation.Owing to the high fluidity and plasticity of the fluid mud itself,its formation location, thickness and length have periodic changes affected by the tidal action.