Towards water content monitoring in the vadose zone from active seismic
Résumé
V
P
/
V
S
or Poison’s ratio classically permit imaging fluids in rocks but this strategy remains underused in near-
surface applications, hence in hydrogeophysics. Yet, P-wave refraction tomography and surface-wave dispersion
inversion can be combined to produce 2D
V
P
and
V
S
sections from a single acquisition set up. This approach
recently proved to be efficient in the study of various hydrosystems and in the imaging of the Critical Zone. We
now suggest its time-lapse application in order to help the monitoring of water content in the vadose zone/aquifer
continuum. With both laboratory experiments and field data, we show how the temporal variations of P-wave travel
times and surface-wave dispersion are strongly associated to the variations of water content observed locally, thus
encouraging to exploit the full wealth of seismic signals in hydrogeophysics.