Stage measurement uncertainty

Typical quantitative results of discharge uncertainty studies: Stage Uncertainty.

SD = standard deviation

Uncertainty Type	Estimation Method	Magnitude	Location	Reference
Stage uncertainty	Comparison with neighbouring stations	SD of 25 mm	Netherlands gauging network	Van der Made (1982)
Effect of unstable bed	Expert knowledge; uncertainty for individual measurement	±10 %	Estimate for locations with shifting sand or moving dunes	Sauer & Meyer (1992)
Instrument precision	Review of previous studies; uncertainty for individual measurement	±3-10.8 mm or ±0.1-2 %		Quoted in Harmel et al. (2006)
Instrument precision	Expert knowledge	Range ±10 mm; local oscillations of water surface can add additional uncertainty of ±20 mm	Typical example of natural rivers	Dottori et al. (2009)
Instrument precision: Float in stilling well		6 mm		Quoted in Herschy (1998): Ackers et al. (1978)
Instrument precision: Pressure transducer		1.4-40 mm		Herschy (1998)
Stage uncertainty	Expert knowledge of typical uncertainties	4 mm (high accuracy) to 15 mm (low accuracy)	Norwegian Water Resources & Energy Directorate	Petersen-Øverleir & Reitan (2005)
Stage uncertainty	Observed fluctuation	2-5 mm	Rowden Experimental Research Platform (1 ha fields), Devon, UK. 250 x 37 cm weir box, stainless steel 45° V-Notch, float (Model 6541, Unidata), stilling well, ave. annual precipitation 1055 mm.	Krueger et al. (2010)
Instrument precision	Manufacturer cited random uncertainty	2.5 mm (Trutrack, Model PLUT-HR Water level recorder)	Hillslope (172 m2), WS10 catchment, HJA Experimental Forest, Oregon, USA	Graham et al. (2010)
		0.3 mm (Model 2 Stevens Instruments Position Analog Transmitter)	WS10 catchment (10.2 ha), HJA Experimental Forest, Oregon, USA. Mediterranean climate, rainfall 2200 mm yr-1, slopes 30-45 °.
Stage uncertainty	Nominal uncertainty	3 mm		Hamilton & Moore (2012)

References

Ackers, P., 1978. Weirs and flumes for flow measurement. Wiley, Chichester.

Dottori, F., Martina, M.L.V., Todini, E., 2009. A dynamic rating curve approach to indirect discharge measurement. Hydrology and Earth System Sciences, 13(6): 847-863.

Graham, C.B., van Verseveld, W., Barnard, H.R., McDonnell, J.J., 2010. Estimating the deep seepage component of the hillslope and catchment water balance within a measurement uncertainty framework. Hydrological Processes, 24(25): 3878–3893.

Hamilton, A.S., Moore, R.D., 2012. Quantifying Uncertainty in Streamflow Records. Canadian Water Resources Journal, 37(1): 3-21.

Harmel, R.D., Cooper, R.J., Slade, R.M., Haney, R.L., Arnold, J.G., 2006. Cumulative uncertainty in measured streamflow and water quality data for small watersheds. Transactions of the ASABE, 49(3): 689-701.

Herschy, R.W., 1998. Hydrometry : Principles and practices. Wiley, Chichester.

Krueger, T., Freer, J., Quinton, J.N., Macleod, C.J.A., Bilotta, G.S., Brazier, R.E., Butler, P., Haygarth, P.M., 2010. Ensemble evaluation of hydrological model hypotheses. Water Resources Research, 46: W07516.

McMillan, H., Krueger, T., Freer, J., 2012. Benchmarking observational uncertainties for hydrology: Rainfall, river discharge and water quality. Hydrological Processes.

Petersen-Øverleir, A., Reitan, T., 2005. Uncertainty in flood discharges from urban and small rural catchments due to inaccurate head measurement. Nordic Hydrology, 36(3): 245-257.

Sauer, V.B., Meyer, R.W., 1992. Determination of error in individual discharge measurements, U.S. Geological Survey Open-File Report 92–144.

van der Made, J.E., 1982. Determination of the accuracy of water level observations, Proceedings of the Exeter Symposium. IAHS Publications 134, pp. 172-184.