Many hydrometric services around the world would like to publish their streamflow records with uncertainty estimates so that end-users can make informed decisions from the data. Uncertainty analysis is also helpful to optimize the measurement processes. Most often, the discharge time series are computed by applying a stage-discharge relation (or “rating curve”) to the measured water level (or “stage”) time series. The rating curve must be established at each hydrometric station from occasional stage-discharge measurements (or “gaugings”).

For about 10 years several methods and software tools have been developed to compute the uncertainty of gaugings (Q+ and Flaure for current meters, Oursin/QRev for mobile-boat ADCP) and of rating curves and discharge time series (BaRatin and BaM!). Large-scale intercomparison experiments have been organized to provide information on uncertainty sources and levels, which proved to be invaluable for improving and validating the uncertainty propagation tools. There is still some research to be done until the whole data processing workflow from field measurements to archived data is covered with widely accepted methods.

## Uncertainty of velocity-area gaugings (Q+ and Flaure methods, surface velocity gaugings)

## Uncertainty of mobile-boat ADCP gaugings (Oursin and interlaboratory experiments)

## Uncertainty of rating curves and discharge time series (BaRatin and BaM!)

## References

### on velocity-area and surface velocity gaugings

Le Coz, J., Renard, B., Vansuyt, V., Jodeau, M., Hauet, A. (submitted) Estimating the uncertainty of video-based flow velocity and discharge measurements due to camera calibration errors, **Hydrological Processes**

Despax, A., Perret, C., Garçon, R., Hauet, A., Belleville, A., Le Coz, J., Favre, A.-C. (2016) Considering sampling strategy and cross-section complexity for estimating the uncertainty of discharge measurements using the velocity-area method, **Journal of Hydrology**, 533, 128–140

Le Coz, J., Camenen, B., Peyrard, X., Dramais G. (2015) Erratum – Uncertainty in open-channel discharges measured with the velocity-area method, **Flow Measurement and Instrumentation**, 46, 193-194.

Le Coz, J., Camenen, B., Peyrard, X., Dramais, G. (2012) – Uncertainty in open-channel discharges measured with the velocity-area method,** Flow Measurement and Instrumentation**, 26, 18-29

### on ADCP gaugings and interlaboratory experiments

Despax, A., Le Coz, J., Hauet, A., Mueller, D.S., Engel, F.L., Blanquart, B. Renard, B., Oberg, K.A. (2019) Decomposition of uncertainty sources in acoustic Doppler current profiler streamflow measurements using repeated measures experiments, **Water Resources Research**, 55

Le Coz, J., Blanquart, B., Pobanz, K., Dramais, G., Pierrefeu, G., Hauet, A., Despax, A. (2016) Estimating the uncertainty of streamgauging techniques using field interlaboratory experiments, **Journal of Hydraulic Engineering**, 142(7), 04016011

### on rating curves and streamflow series

Horner, I., Le Coz, J., Renard, B., Branger, F., Lagouy, M. (submitted) Streamflow uncertainty due to the limited sensitivity of controls at hydrometric stations, **Hydrological Processes**

Darienzo, M., Le Coz, J., Renard, B., Lang, M. (submitted) Detection of Stage-Discharge Rating Shifts Using Gaugings: A Recursive Segmentation Procedure Accounting for Observational and Model Uncertainties, **Water Resources Research**

Mansanarez, V., Le Coz, J., Renard, B., Lang, M. (submitted) Stage-gradient-discharge models: Bayesian analysis of hysteresis due to unsteady flows, **Water Resources Research**

Perret , E., Le Coz, J., Renard, B. (submitted) A rating curve model accounting for cyclic stage-discharge shifts due to seasonal aquatic vegetation, **Water Resources Research**

Mansanarez, V., Renard, B., Le Coz, J., Lang, M., Darienzo, M. (2019) Shift happens! Adjusting stage-discharge rating curves to morphological changes at known times, **Water Resources Research**, 55, 2876-2899

Kiang, J.E., Gazoorian, C., McMillan, H., Coxon, G., Le Coz, J., Westerberg, I., Belleville, A., Sevrez, D., Sikorska, A.E., Petersen-Øverleir, A., Reitan, T., Freer, J., Renard, B., Mansanarez, V., Mason, R. (2018) A comparison of methods for streamflow uncertainty estimation, **Water Resources Research**, 54, 7149-7176

Horner I., Renard B., Le Coz J., Branger F., McMillan H.K., Pierrefeu G. (2018) Impact of stage measurement errors on streamflow uncertainty, **Water Resources Research**, 54, 1952-1976

Mansanarez, V., Le Coz, J., Renard, B., Vauchel, P., Pierrefeu, G., Lang, M. (2016) Bayesian analysis of stage-fall-discharge rating curves and their uncertainties, **Water Resources Research**, 52, 7424-7443

Le Coz, J., Renard, B., Bonnifait, L., Branger, F., Le Boursicaud, R. (2014) – Combining hydraulic knowledge and uncertain gaugings in the estimation of hydrometric rating curves: a Bayesian approach, **Journal of Hydrology**, 509, 573–587.