View source for 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

{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Uncertainty Type'''
| align="center" style="background:#f0f0f0;"|'''Estimation Method'''
| align="center" style="background:#f0f0f0;"|'''Magnitude'''
| align="center" style="background:#f0f0f0;"|'''Location'''
| align="center" style="background:#f0f0f0;"|'''Reference'''
|- valign="top"
| 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)
|- valign="top"
| ||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)
|- valign="top"
| 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)
|- valign="top"
| 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)
|- valign="top"
| 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)
|- valign="top"
| 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)
|- valign="top"
| 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.

[[Category:Uncertainty]]