Theory 71/Measurement & modelling/Rating curves
Rating Curves Are Stage Against Geometry
The claim
The accuracy of a streamflow rating curve is set by the ratio of stage measurement precision to channel section change, so a mobile bed invalidates a curve that a fixed bed supports.
01Mechanism
Discharge is inferred from stage through a geometry assumption that shifting beds violate.
02Prediction
Error should track the ratio.
03Refutation
Error tracking gauge precision would remove bed mobility.