Multi-Scale Hydrogeophysical Integration: From Lab Calibration to Field Mapping of Unsaturated Soil Moisture in Peri-urban Slope Instabilities

The increasing frequency of extreme climatic events, from protracted droughts to high-intensity precipitation, necessitates robust frameworks for monitoring soil hydrological dynamics and associated geological risks. Hydrogeophysical methods, particularly when integrated with multi-sensory environmental arrays, offer a powerful means of capturing the spatiotemporal evolution of pore pressure, a key driver of slope instability. This study presents a multi-parametric, multi-scale monitoring strategy deployed at an open-air laboratory situated on a slow-moving peri-urban landslide in the southern Apennines (Basilicata, Italy) developed as part of the ITINERIS project (PNRR M4C2 Inv.3.1 IR EU’s Next Generation program).

We combine time-lapse Electrical Resistivity Tomography (tl-ERT) with a diverse hydrological sensor suite, including tensiometers, piezometers, soil temperature probes, and a non-invasive Cosmic Ray Neutron Sensing (CRNS) station for area-wide moisture estimation. To address the complexities of hydrogeological scaling, e.g., the dynamic nature of soil moisture patterns and their scale-dependent manifestations, we developed a customized laboratory framework designed to replicate field-scale coupled ERT and hydrological measurements. This dual-scale approach enables the derivation of site-specific petrophysical relations and facilitates the calibration of 2D/3D dynamic thermo-hydro-geophysical model.

This work focuses on the development of a robust data mining and processing workflow designed to harmonize heterogeneous geophysical, hydrological, and meteorological datasets. In this study, we present the validation of laboratory protocols alongside the preliminary setup of multi-scale field monitoring and field acquisition systems. By proposing inversion strategies and automated quality control, we aim to minimize interpretative ambiguity and move towards a more geologically consistent representation of vadose zone mechanisms. This integrated approach is establishing a preliminary foundation for future predictive modelling while offering a scalable solution for monitoring hydrogeological hazards in complex environments.