High-Resolution Geoelectrical Characterization of Steep Pyroclastic Slopes by a New 3D Data Acquisition Technique

Debris-flows are among the most dangerous types of landslide often induced by intense rainfall events and favored by the presence of unconsolidated soils on steep slopes. In this framework, the knowledge of the electrical resistivity distribution of the cover materials is useful to define their lithological and physical characteristics, as they provide information about the saturation level of the cover and the areas more prone to slide. Nevertheless, the use of conventional electrode layouts for 3D-resistivity imaging is limited by the difficulty to operate in contexts with complex topography. In this work, a non-conventional 3D electrode configuration is proposed for a high-resolution characterization of Mt. Faito pyroclastic covers (Campania Region, southern Italy). The adopted scheme has been able to provide a very detailed image of the investigated slope allowing to discriminate the different horizons within the pyroclastic cover as well as the different degree of fracturing of the carbonate bedrock. The obtained resolution has been found higher than that provided by a conventional 2.5D ERT survey performed in the same survey area.