Statistical analysis of three-years time-lapse electrical resistivity imaging for the study of the petacciato landslide

In the last ten years, time-lapse electrical resistivity tomography technique has been applied to monitor the temporal and spatial changes of resistivity values in different environmental and natural processes like saline intrusion, aquifer recharge, water content change, etc. The growing use of this technique is mainly due to the significant technological improvements occurred in recent years. Indeed, the introduction of new static multi-channel systems has allowed the reduction of acquisition time, the remote control of system and the monitoring of temporal variation of resistivity also in areas where the accessibility can be complicated. This paper reports the results of a statistical analysis of time-lapse ERT data acquired in a landslide area located in Molise region (Italy). A prototype geoelectrical system was installed in the area with the aim to indirectly estimate the water content change in the subsoil by continuously measuring the resistivity. The analysis was performed on apparent resistivity values without applying any inversion software. In this way no artefacts or errors due to the inversion process were introduced.