Time-lapse resistivity and seismic profiles (Vp, Vs) for Subsurface Characterization: A Case Study in a Well-Documented Agricultural Field

Geophysical prospection offers non-invasive tools to investigate subsurface properties, that can be particularly useful in agricultural contexts. This study focuses on an agricultural field managed by INRAE (French National Research Institute for Agriculture, Food and Environment), under a Mediterranean climate (Avignon, FR). The site benefits from characterization of lithological profiles, soil physico-chemical analyses, and continuous monitoring of groundwater table depth as well as soil water content at a few depths.

We employed Electrical Resistivity Tomography (ERT) and seismic methods to develop 1D and 2D profiles of resistivity and seismic wave velocities (Vp and Vs, for the compressional and shear waves, respectively). Apparent resistivity data from ERT were inverted using pyGIMLi to generate 2D resistivity models, while first-arrival travel times from seismic data were similarly inverted with pyGIMLi to produce Vp profiles. Surface wave were analysed by Multichannel Analysis of Surface Waves (MASW) to derive Vs through dispersion curve inversion following the SWIP workflow developed by Pasquet and Bodet (2017). These profiles provide insights into subsurface structure and heterogeneity, reflecting variations in soil and lithological properties, as well as water content variation.

While this study focuses on presenting resistivity, Vp, and Vs profiles, the integration and joint inversion of these seimic and resistivity datasets for detailed hydrological and geomechanical characterization is planned as part of future work in this doctoral research. This approach aims to enhance our understanding of water distribution and soil mechanical properties in agricultural environments.