群潜坝对河道糙率影响的实验研究

通过模型实验，运用能量方程反求河道糙率的方法，分析探讨了河道中修建不同间距的群潜坝后，河道糙率系数n和水深坝高比H／h（即河道中水深月与潜坝高度h之比）的相互关系。通过实验及其成果分析，可以得到，河道中修建群潜坝后，（1）河道糙率会增至原河道糙率的1．1—2．6倍甚至更大，具体大小取决于群潜坝的坝间距与水深坝高比H／h；（2）河道糙率随着河道中水深坝高比的增加先减小，后增加，而后基本趋于稳定；（3）河道糙率随着水深坝高比的变化可以分为减小区、增大区与稳定区，各区分界点处的水深坝高比与潜坝间距有关；（4）本实验条件下，减小区与增大区分界点处的水深坝高比为5．98～6．78。增大区与稳定区分界点处的水深坝高比为8．11。

The Experimental Study of the Submanine-dams' Inference on River Chainnel Roughness

Through the model experiments, this paper analyses relationship between H/h and river roughness n which is solved by the method for using the energy equation. H is river depth; h is height of submarine-dams. The conclusions, which were drown from the test results ,are： after construction of submarine-dams, （l）Roughness n is 1.1-2.6 fold or more compared with the original river, it＇s magnitude depends on the H/h and the interval of submarine-dams.（2）With increase of the H/h, the roughness first reduces then increases, and finally tends to be stable. （3）With the change of H/h, roughness n can be divided into three regions： reduce region,increase region and stable region, and the H/h at each demarcation point is related to the interval of submarine-dams.（4）In this experiment, the H/h at the demarcation point of reduce and increase region is 5.98-6.78,and the H/h at the demarcation point of increase and stable region is 8.11.