水面流速系数的分析方法

Analytical Method for Velocity coefficient at water surface

在流量测验中，有时会遇到只能测得水面流速的特殊情况，通常采用经验水面流速系数计算垂线平均流速，往往不能满足精度要求．因此，本文进行相关理论分析并得出结论：水面流速系数随水力因素变化，不为常数，而且应根据不同的河流特性，采用不同的分析方法。

In the measuring of discharge, the situation that only velocity at water surface can be measured is sometimes met. At this moment, experienced velocity coeffieient at water surface be used to calculate vertical overage velocity, however often the precision demand can not be met with. Therefore, in this paper, the author based on the relative theory analysed it and concluded that the velocity coefficient is not a constant and it varied with integrity of wind. As a result, the analysis to velocity coefficient at water surface should be based on various characteristic of rivers and different methods should be used.