洪水测验,通常用浮标测水面流速,也用缆道或缆车以流速仪测水面流速,然后乘水面流速系数,再借用断面计算流量。水面流速系数是根据大量的五点法垂线测速资料计算而得。采用流速系数的关键问题是它的代表性问题,即流速系数的误差问题。本文试根据汉江武候镇站五点法测速资料,进行水面流速系数及误差分析。分析之目的在于回答三方面的问题 Flood test, usually using the buoy to measure the surface flow rate, but also with the cable or cable car to measure the surface velocity meter, and then by the surface flow coefficient, then borrow the section to calculate the flow. Surface velocity coefficient is based on a large number of five-point method of vertical velocimetry calculated. The key problem of using the flow coefficient is its representative problem, that is, the error of the flow coefficient. Based on the five-point velocity data of Wuhou Town Station in Hanjiang River, this paper analyzes the coefficient of surface water velocity and error analysis. The purpose of analysis is to answer three questions