BS 3680-3C:1983

National foreword
Cooperating organizations
1 Scope and field of application
2 References
3 Definitions and symbols
4 Units of measurement
5 Principles of the stage-discharge relation
6 Calibration of a gauging station
7 Methods of testing stage-discharge curves
8 Uncertainty in the stage-discharge relation and in a
    continuous measurement of discharge
Annexes
A Stage-discharge curve
B Hysteresis in the stage-discharge relation
C Twin gauge station fall-discharge method
D Extrapolation of stage-discharge relation
E Correction for discharge in unsteady flow
Tables
1 Typical manual computation of the stage-discharge
    relation by the method of least squares
2 Tabulation of calculation to determine points for
    plotting stage-discharge curve and constructing
    rating table (manual)
3 Tabulated values required to calculate Se and Smr
4 Typical computation for the uncertainty in the daily
    mean discharge using hourly values of discharge
5 Student's "t" test of check gauging for bias
6 Values of Student's "t" at the 95 % confidence level
Figures
1 Computation of discharge and mean water-level for
    variations of water-level
2 Segment of stage-discharge curve
3 Determination of a - Gauge reading for zero
    discharge
4 Testing of stage-discharge curves
5 Relationship Qn = f(z0) for unit fall Hn = 0,300 m
6 Relationship between Q/Qn and H/Hn
7 Relation of stage to adjusted discharge for
    reference fall (0,300 m)
8 Normal-fall method - Simple rating-curve
9 Relation between normal fall and height
10 Measured discharge-fall relation

Specifies methods of determining the stage-discharge relation for a gauging station in both stable and unstable channels, including those subject to ice conditions. Includes an analysis of the uncertainties involved in the preparation and use of the stage-discharge relation.