Discharge uncertainty (ADCP, ADV, LSPIV)
Typical quantitative results of discharge uncertainty studies: New Measurement Techniques.
This table originated from McMillan et al. (2012) but is now open to the community to add to and use as a resource.
ADV = acoustic Doppler velocimetry; ADCP = acoustic Doppler current profiling; LSPIV = Large Scale Particle Image Velocimetry; SD = standard deviation
| Uncertainty Type | Estimation Method | Magnitude | Location | Reference |
| ADCP discharge measurement uncertainty | Relative error of discharge calculated using ADCP vs. current meter and/or rating curve | Mean relative error from multiple transects was -3 to 5 % (from meter) or -7 to 5 % (from rating) dependent on site | USA (5 sites on Illinois, Kankakee, Mississippi and Missouri rivers). Depths 1.1-3.8 m, widths 33-527 m, velocities 0.4-1.3 m s-1. | Mueller (2003) |
| Relative error of discharge calculated using ADCP vs. multiple concurrent current meters | SD of relative error 5.8 %; distributions given from large set of test cases, plus results for alternative measurement set-ups | Multi-location field sites (including USA, Canada, Sweden, Netherlands) plus laboratory testing | Oberg & Mueller (2007) | |
| ADV velocity measurement uncertainty, with & without calibration | Relative error of discharge calculated using ADV velocity (20 min average) vs. impellor velocity (60 s period per sample) | Flow estimates were within 20 % of the current-metered flow for 93 % of samples after calibration (68 % before calibration) | Pontbren, Wales, UK, 5 concrete-lined sections. 3 circular: diameter 0.6-1.6 m, depth 0-0.71 m, velocity 0-3.0 m s-1. 2 rectangular: width 3.17, 4.17 m; depth 0-0.67 m, velocity 0-3.9 m s-1. | McIntyre & Marshall (2008) |
| Mobile LSPIV instantaneous velocity & discharge measurement uncertainty | Relative error from theoretical velocity field based on 27 error sources; case study comparison with rating curve & ADCP methods | Theoretical errors in velocity from 10-35 % at 95 % confidence level; case study gave discharge error at 2 % compared to rating curve & 5.5 % compared to ADCP | Analysis of typical conditions. Case study at Clear Creek near Coralville, Iowa, USA. 20 m wide, 0.7 m deep, stage 1.2 and velocity 5.2 m s-1 during study. | Kim et al. (2008) |
| Simulated LSPIV measurements against theoretical true values | Error variance obtained via linear regression of simulated vs. true values | 5 % under normal conditions, increasing to 17 % with a high tilt angle (70º) | Numerical simulation | Hauet et al. (2008) |
| LSPIV instantaneous discharge measurements during high flows compared with rating curve & current meter reference values | Relative error at a number of observation times | 47 % at low flows, 13-23 % on rising limb, 2 % during stable high flow period | River Arc, France, during dam release operation. Discharge range 10-150 m3 s-1, width 60-70 m, gravel-bed river. | Jodeau et al. (2008) |
| Microwave & UHF Doppler Radars uncertainty in instantaneous discharge measurement | Correlation coefficients between radar measurements & conventional rating curve methods over 16-week period | 0.883, 0.969, 0.992 dependent on Doppler radar system | Cowlitz River, Washington, USA(5800 km2). Width 92 m, depth 2-7 m. | Costa et al. (2006) |
References
Costa, J.E., Cheng, R.T., Haeni, F.P., Melcher, N., Spicer, K.R., Hayes, E., Plant, W., Hayes, K., Teague, C., Barrick, D., 2006. Use of radars to monitor stream discharge by noncontact methods. Water Resources Research, 42(7): W07422.
Hauet, A., Creutin, J.D., Belleudy, P., 2008. Sensitivity study of large-scale particle image velocimetry measurement of river discharge using numerical simulation. Journal of Hydrology, 349(1-2): 178-190.
Jodeau, M., Hauet, A., Paquier, A., Le Coz, J., Dramais, G., 2008. Application and evaluation of LS-PIV technique for the monitoring of river surface velocities in high flow conditions. Flow Measurement and Instrumentation, 19(2): 117-127.
Kim, Y., Muste, M., Hauet, A., Krajewski, W.F., Kruger, A., Bradley, A., 2008. Stream discharge using mobile large-scale particle image velocimetry: A proof of concept. Water Resources Research, 44(9): W09502.
McIntyre, N., Marshall, M., 2008. Field verification of bed-mounted ADV meters. Proceedings of the Institution of Civil Engineers-Water Management, 161(4): 199-206.
McMillan, H., Krueger, T., Freer, J., 2012. Benchmarking observational uncertainties for hydrology: Rainfall, river discharge and water quality. Hydrological Processes 26(26): 4078–4111
Mueller, D.S., 2003. Field evaluation of boat-mounted acoustic Doppler instruments used to measure streamflow. Proceedings of the IEEE/OES Seventh Working Conference on Current Measurement Technology. IEEE, New York, 30-34 pp.
Oberg, K., Mueller, D.S., 2007. Validation of streamflow measurements made with acoustic Doppler current profilers. Journal of Hydraulic Engineering-ASCE, 133(12): 1421-1432.