Quantification of Methane Bubbles Ebullition in Freshwater Reservoirs of Temperate Zone using Sonar Working with 120 kHz Frequency

0442226 - ÚCHP 2015 eng C - Conference Paper (international conference)
Frouzová, Jaroslava - Tušer, Michal - Stanovský, Petr
Quantification of Methane Bubbles Ebullition in Freshwater Reservoirs of Temperate Zone using Sonar Working with 120 kHz Frequency.
Geophysical Research Abstracts. Vol. 16. -: -, 2014, s. 11398. ISBN N.
[European Geosciences Union. Vienna (AT), 27.04.2014-02.05.2014]
R&D Projects: GA ČR GAP504/12/1186
Institutional support: RVO:67985858 ; RVO:60077344
Keywords : ebullition * freshwater * methane
Subject RIV: EH - Ecology, Behaviour
http://meetingorganizer.copernicus.org/EGU2014/EGU2014-11398.pdf

During hydroacoustic vertical surveys of fish, an indispensable amount of gas bubbles have been observed rising from the bottom towards the water surface. Unfortunately, the gas ebullition essentially interferes with acoustic detection of fish, thereby biasing an estimate of fish quantity. First, to distinguish between fish and bubble echo, comparing acoustic properties of the echoes (e.g. echo shape, echo width, or phase deviation) seemed to be inapplicable. Nevertheless, the difference in the movement ‘behavior’ (i.e. direction and speed), looks more promising, but it is necessary to obtain the exact position of a sound beam. Second, when gas bubbles are recognized, a functional regression model of acoustic response to the bubble size can be used to estimate size and volume distribution of bubbles. The experiment with man-made methane bubbles was performed to learn the dependence of acoustic response to the bubble size, and a regression model was created.
Permanent Link: http://hdl.handle.net/11104/0245118