开放通道中的液体流量测量 - 坡度面积法

[中文适用范围]： 本文件规定了一种通过观察河道表面坡度和横截面积来确定明渠流量的方法。 它适用于无法通过通常更精确的方法（例如速度面积法）直接测量流量的特殊条件下使用。 一般来说，该方法可用于确定 a) 沿河岸留下高水位标记的峰值流量的流量，b) 在一系列水位计上留下标记或记录峰值阶段的峰值流量c) 根据一系列仪表确定仪表高度时观察到的流量。 该方法通常用于将阶段-流量关系扩展到最高计量流量之上。 它不适用于确定潮汐河段的流量。 [外文原描述]： This document specifies a method of determining discharge in open channels from observations of the surface slope and cross-sectional area of the channel. It is applicable to use under special conditions when direct measurement of discharge by typically more accurate methods, such as the velocity-area method, is not possible. Generally, the method can be used to determine discharge a) for a peak flow that left high-water marks along the stream banks, b) for a peak flow that left marks on a series of water-level gauges or where peak stages were recorded by that series of gauges, and c) for flow observed at the time of determining gauge heights from a series of gauges. The method is commonly used to undertake the extension of stage?discharge relationships above the highest gauged flows. It does not apply to determining discharges in tidal reaches.