Accueil > Recherche > Equipes > HyDRIMZ : Eau, sol, sédiment, qualité > Thématiques scientifiques de l’équipe HyDRIMZ > Identification des sources et évaluation des flux de matières dans la zone critique > Passive acoustic monitoring of bedload discharge in large gravel bed rivers
Développement de la méthode hydrophone de mesure du transport de fond dans les rivières
par- 7 mars 2017
Geay, T., P. Belleudy, C. Gervaise, H. Habersack, J. Aigner, A. Kreisler, H. Seitz, and J. B. Laronne (2017), Passive acoustic monitoring of bed load discharge in a large gravel bed river, J. Geophys. Res. Earth Surf., 122, doi:10.1002/2016JF004112.
résumé illustré :
Hydrophones are used for passive monitoring of bed material movement. Experiments were performed in small and large gravel bed rivers ; signal properties are compared with other measurements.
Four questions are addressed in using this surrogate method concerning its capability for the monitoring of bedload discharge :
Rhine River at Leimersheim (Germany)-in low flow conditions
The DfG sampler is dipped into the river from a bedload measuring boat.
It is equipped with a video camera recording the image of the bed at the entrance to the sampler. -A hydrophone records ambient noise.
➔ seems to be integrative of a large surface of bed (see point 4)
Arc River (Savoie, France) during flushing operations
The Helley-Smith sampler is dipped into the river from a crane.
The surface velocity is measured with a radar (SVR Gun).
At the same X-section, -two hydrophones are immerged with a hydraulic bomb.
Arc River (Savoie, France)
but complex sound propagation alters the signal
Drau River (Dellach, Austria) in spring and summer
The hydrophone is fixed onto the river bed. It records sound from bedload during spring and summer.
The station is equipped with a series of 40 geophones and the correlation is made between the sound pressure level (hydrophone signal) and the energy recorded at each of individual geophone plates.
Period A : active bedload transport all across the section ; period B : active bedload transport in the left & center of the X-section. Correlations show that hydrophone integrates bedload signal at a distance of approx. 10m.
Philippe Belleudy, IGE
Dans la même rubrique :