High-resolution characterization of shallow aquifer by 2D viscoelastic full-waveform inversion of shallow seismic wavefield acquired at the Krauthausen test site

Full-waveform inversion (FWI) method has been proved as an effective tool for high-resolution imaging of the subsurface. We have investigated the potential of shallow seismic-wave 2D viscoelastic FWI as a method in high-resolution hydrogeological near-surface characterization. FWI is applied to two orthogonal profiles acquired at the Krauthausen natural laboratory (Germany). The multiparameter models of viscoelastic FWI (P-and S-wave velocities, attenuation of P- and S-waves, density) show pronounced lateral variations below the profiles. The groundwater table is located at around 2 m, where a sudden P-wave velocity increase occurs. An S-wave low velocity layer exists at the depth of 4-6 m with a high Poisson’s ratio value close to 0.5, which corresponds to a saturated sand layer know from previous studies.
A $K$-mean cluster analysis is used to correlate and integrate information contained in the inverted results. By considering the derived Poisson’s ratio, P-wave, and S-wave velocities by FWI, we can convert the complex relationship between the multivariate data into a lithological meaningful zonation of the survey region. By comparing the lithological units in the alluvial aquifer with the cone penetration tests clusters, the face maps provide valuable information about the subsurface heterogeneity and connectivity. ... mehrThis experiment indicates that the multiparameter models derived by viscoelastic FWI contain usefull information for high resolution near-surface aquifer characterization.