长江口外海滨悬浮体的粒度特征及其与锋面的关系

The Grain Size Characteristics of the Suspended Matters in the Offshore Region of the Changjiang Estuary and the Relation with the Front Information

本文根据１９８８～１９９１年河口锋区现场调查资料分析的基础上，论述长江口外海滨悬浮体的粒度组成、分布及其与锋面的关系。长江口悬浮体的粒度较细。在平面分布上，北粗南细，西粗东细，季节变化上冬季较夏季粗。悬浮体粒度在河口锋面两侧差异很大，内侧粗，外侧细。悬浮体的粒度组成主要受制于物质来源、河口表层沉积物的结构及水动力条件等。

This paper intends to describe the composition, distribution of the suspended matters in the offshore region of the Changjiang Estuary and the relation with the front. The suspeneded matters in the offshore region of the Changjiang Estuary are finer in grain-size, among them the volume of the fine silt is dominated. In the plane distribution, the suspended matters are coarser in the north and finer in the south, and are coarser in the west and finer in the east. In vertical from the surface to the bottom, they are gradually coarser and coarser. In one tidal period, they are coarser in the ebb strength and finer in the flood slack. The suspended maters have seasonal changes, coarser in the winter and finer in the summer. In both sides of the estuarine front, the suspended matters are obviously different, coarser in the inner side and finer in the outer side of the front. The composition of the suspended matters in grain-size and its variations are affected by the material resources, the structures of the surface sediments in the Estuary, and the hydro-dynamic conditions with runoff, tidal currents and waves.