北部湾东北部沉积物运移趋势分析

Sediment Transport Trend Analysis on the Northeastern Part of the Beibu Gulf

选取北部湾东北部约450个表层样品进行粒度分析,并采用矩法计算各粒度参数(平均粒径、分选系数、偏态),利用Gao-Collins粒径趋势分析模型模拟出海底表层沉积物净输运趋势,发现北部湾东部底质沉积物运移规律:总体上是由陆地向海洋输送,靠近雷州半岛一侧主要为由南向北输送,输运过程中部分沉积,部分转向东南沉积,在该调查区域大体存在8个较为明显的沉积汇聚区;同时对约230个站位利用LISST激光粒度仪进行悬浮体粒级现场测量,选取各站位底层体积总浓度作图分析,发现该海区底层悬浮体体积总浓度快速变化区与底质泥沙汇聚区具有一定的对应关系,为在该海区研究沉积物运移趋势提供了一条新的途径。

450 surface sediment samples were collected by Mussel Style Sampling Instrument in the northeastern part of the Beibu Gulf, the grain size parameters （mean diameter, sorting coefficient, and skewness） of the samples were analyzed by Mastersizer 2000.Then, the sediment transport trends were simulated by using Gao-Collins particle size trend analysis model. It is found that the sediment transportation is from land to ocean. The main direction is from south to north along the Leizhou Peninsula, some deposit in the transport path, some turn to the southeast and deposit. In the investigated area there are 8 obvious deposition zones. The suspension grain size for 230 stations was measured by the LISST, which uses the technique of laser diffraction to obtain particle volume distribution. The total volume concentration of the bottom at all stations was analyzed at the same time. It is shown that the areas of huge change of the total volume concentration are, to some extent, corresponding to those of the sediment deposition.