The use of geodetic tools such as time dependant gravity and inclinometry is promising to better understand the dynamics of underground soil moisture. We are currently developing an observation network on the Larzac plateau to monitor water flow at the surface and at depth in caves and potholes using several kind of instruments:

1. The absolute gravimeter FG5
2. Relative gravimeters CG5
3. Long base tiltmeters
4. Surface and underground pluviometers
5. Piezometers

This work is supported by the Montpellier observatory (OREME) by INSU (H+ network pilot sites) and by ANR grants (ANR ECCO Hydrogeodesy and ANR Hydrokarst G2)

Related publications :

Jacob, T, Chéry, J, Boudin,F, Bayer, R, Monitoring deformation from hydrologic processes in a karst aquifer using long baseline tiltmeters, Water Research, 46, W09642, 2010. PDF

Jacob, T, Bayer, R, Chery, J, Le Moigne, N, Time-lapse microgravity surveys reveal water storage heterogeneity of a karst aquifer, J. Geoph. Res., 115, B06402, 2010. PDF

Jacob, T, Chery, J, Bayer, R, Le Moigne, N, Boy, JP, Vernant, P, Boudin, F, Time-lapse surface to depth gravity measurements on a karst system reveal the dominant role of the epikarst as a water storage entity, Geoph. J. Int., 179, 751-762, 2009. PDF

Jacob, T., R. Bayer, J. Chery, H. Jourde, N. Le Moigne, J.-P. Boy, J. Hinderer, B. Luck, P. Brunet, Absolute gravity monitoring of water storage variation in a karst aquifer on the larzac plateau (Southern France), J. Hydrology, 359, 105– 117, 2008. PDF