黄河下游“河道糙率比玻璃水槽还小”之我见

My Opinion on "Channel Roughness is Smaller Than that of the Glass Flume" of the Lower Yellow River

分析了黄河下游“河道糙率比玻璃水槽还小”的原因,认为:①出现这一现象与高含沙水流的“减阻效应”无关;②资料整编没有考虑水深在横断面分布的极不均匀性,是引起糙率计算结果偏小的主要原因;③测验误差也是影响糙率计算结果的原因;④没有考虑断面的水力不均匀性使得糙率的计算值总是系统偏小,这一现象必须予以纠正。同时,提出了用水力不均匀系数来纠正这一现象,得到了合理的结果。

The paper analyzes the reasons of 'channel roughness is smaller than that of the glass flume' of the lower Yellow River and concludes that ① it has no connection with 'resistance reduction effect' of high sediment concentration flows; ② it has not considered that the depth is extremely uneven in cross-section in data compiling, which is the main reason of resulting in smaller roughness; ③ observation error also effected the calculation results of roughness and; ④ it has not considered the hydraulic inhomogeneity of cross-section, which must be corrected. In the meanwhile, it puts forward to correct the calculation by hydraulic coefficient of non-uniformity and achieves reasonable results.