东北地区河口潮流挟沙能力的研究

Sediment-carrying capacity of tide current in Northeast China estuaries

统计分析了东北地区四个主要河口及口门外潮流的悬移质含沙量的观测结果,发现当水体相对紊动强度较弱时(相对紊动强度用水流对泥沙的有效作用力Fb与泥沙颗粒间的粘结力Fc之比Fb/Fc表示),即Fb/Fc<3时(此时含沙量小于0.8kg/m3),泥沙絮凝对泥沙的悬浮有显著的影响;而当Fb/Fc≥3时,这种影响可以忽略。本文将一日内涨、落潮阶段的平均流速、平均水深和平均含沙量作为特征参数,给出了东北地区四个主要河口及口门外涨、落潮水流的含沙量(水流挟沙力)计算公式,虽然这四个河口的潮汐特性、泥沙组成差异较大,但它们潮流的悬移质含沙量都可以被同样的水流挟沙力公式所描述,显示出本文给出的计算潮流的挟沙能力公式具有较好的普适性。

Analyses on the suspended sediment concentration of tide current in the four Northeast China estuaries show that the effect of flocculation on sediment suspending is remarkable if the relative turbulent intensity is weak, while the effect of flocculation is not obvious when the relative turbulent intensity is strong. A formula based on variables such as mean velocity, depth and sediment concentration is given to calculate sediment concentration of flood tide and ebb tide in the four Northeast China estuaries. Although the tide and sediment characters are quite different in the four estuaries, the sediment concentration can be well simulated by the formula. This indicates that the proposed formula can be generally used to other estuaries.