Technical Note: How image processing facilitates the rising bubble technique for discharge measurement

Technical Note: How image processing facilitates the rising bubble technique for discharge measurement

Hilgersom, K.P.
Luxemburg, W.M.J.

Civil Engineering and Geosciences

Water Management

2012-02-06

In this article, we rehabilitate the integrating rising bubble technique as an effective means of obtaining discharge measurements. Since Sargent (1981, 1982a), the technique has not been applied widely, mainly as a result of practical difficulties. We hypothesize that modern image processing techniques can greatly improve the rising bubble technique. We applied the technique in both a laboratory setup and a field study, after determining the bubble rising velocity for our nozzles in the specific case. During our measurements, we captured digital photographs of the bubble envelope at the water surface, each picture being a single measurement of the discharge. The photographs were corrected for lens distortion and reprojected so that accurate distances on water surface level could be obtained. This easy digital procedure resulted in accurate discharge measurements, even when turbulence was involved and the averages of multiple image analyses yielded good results. The study shows that the rising bubble technique can be a preferable discharge gauging technique in some situations. Recent developments in image processing facilitate the method substantially.

rising bubble technique
discharge measurement
hydrological measurements
river discharge

http://resolver.tudelft.nl/uuid:f5b2780f-7755-41c5-b600-30ae15c0a3c5

European Geoscience Union

2016-01-20

1027-5606

https://doi.org/10.5194/hess-16-345-2012

Hydrology and Earth System Sciences, 16, 2012

Institutional Repository

journal article

© 2012 The Author(s)
CC Attribution 3.0 License