BS 3680-5:1992

Committees responsible
National foreword
1 Scope
2 Normative references
3 Definitions
4 Principle of the method of measurement
5 Selection and demarcation of site
6 Devices for measurement of slope
7 Procedure for installing gauges and making observations
8 Computation of surface slope
9 Cross-sections of the stream
10 Computation of discharge for non-uniform and composite
   cross-sections
11 Computation of discharge for uniform cross-sections
12 Uncertainties in flow measurement
 Annex A (informative) Approximate values of coefficients n and
        c for open channels
Annex B (informative) Bibliography
Table A1 - Coefficients for channels with relatively coarse bed
           material and not characterized by bed formation
Table A2 - Coefficients for channels other than those with
           coarse bed material
Figure 1 - Composite cross-section of a channel
Figure 2 - Cross-section of a channel
Figure 3 - Longitudinal section of a reach

Method of determining liquid flow from observations of surface slope and cross-sectional area of channel. It is suitable for use under somewhat special conditions when direct measurement of discharge by more accurate methods, such as the velocity-area method, is not possible.