长江口北支沉积物粒径趋势及泥沙来源研究

本文以长江口北支沉积物的粒度分析资料为根据, 运用Gao-Collins粒径趋势分析模型对该区域进行分析处理, 获得采样区沉积物粒径趋势矢量分布. 结果表明: 长江口北支青龙港以上河段的沉积物有向下游搬运的趋势; 而青龙港以下的河段, 沉积物的搬运方向是从下游指向上游; 长江口北支口外海域的沉积物有向长江口北支运移的趋势. 在此基础上, 本文还探讨了导致长江口北支不断淤积的物质来源: 北支以口外海域来沙为主, 上游也有少量泥沙直接进入北支; 北支口外海域来沙以长江口南支入海泥沙扩散倒灌为主, 苏北沿岸泥沙供给很少.

Analysis on sediment transport patterns and sediment sources of north branch of Changjiang estuary

in terms of the grain size analysis of the sediment in north branch of Changjiang estuary, the article analyzed the study area by means of Cao-Collins's grain size trends analysis model and attained the distribution pattern of sediment grain size trends vector in the area. The result of the analysis shows that the sediment in the upper reaches of Qinglong river section moves towards down stream; whereas, the sediment in the lower reaches of Qinglong river section trends to move to upper stream. The sediment in the adjoining sea area is transported towards the north branch of Changjiang estuary. On this basis the sediment sources which lead to the gradually silt up of north branch is investigated. It is concluded that most of the sediment of north branch comes from the adjoining sea area, of which the major part is comes from the diffused sediment of the south branch and transported to the adjoining sea area.