【摘要】 作者采用拐点法、最大曲率法和从床沙质与冲泻质的造床性质区分的方法 ,利用 2 0 0 1年 7月份长江口的采样资料 ,对长江口的床沙质和冲泻质进行了初步划分 ,并且对比了几种方法的划分结果 ,得出拐点法的临界值为 1 0 4～ 1 0 9μm ,平均值为 2 41 μm ,标准偏差为 0 76,在悬沙级配曲线中小于该粒径的百分含量为1 6 4%～ 42 6% ,平均为 2 4 8% ;最大曲率法的临界粒径范围在 1 65～ 4 3 4μm之间 ,平均值为 1 2 5 μm ,标准偏差为 0 1 9,在悬沙级配曲线中小于该粒径的百分含量为 8 6%～ 1 6 8% ,平均为 1 1 4% ;从床沙质与冲泻质的造床性质区分结果为 1 65～ 2 4μm ,在悬沙级配曲线中小于该粒径组的百分含量约为 2 0 4%。更多还原

【Abstract】 The State Key Lab. of Estuarine and Coastal Research conducted a field experiment in the summer of 2001 from Xuliujing to the outside of the mouth, to study the characteristics of hydrodynamic, sedimentary in the Changjiang Estuary. Based on these data, the analytical results show that suspended load in the Changjiang Estuary is mainly composed of clay and silt, and bed load is mainly made up of silt, but the various range of bed load is from clay to fine sand. The critical value of particle size between the bed load and the wash load was also analyzed. Three calculated methods were used to analyze the critical value of particle size between the bed load and the wash load. They are the inflexion-method, the most curvature-method and the method based on the definition of the bed load and the wash load. The critical value of particle size between the bed load and the wash load is obtained. The results show that the critical value is 1.04～1.09μm through the inflexion-method, 1.65～4.34 μm computed by the most curvature-method and 1.65～2.4μm by the method based on the definition of the bed load and the wash load.更多还原