Hydro-mechanical characterisation and monitoring through conventional and satellite data: The Calita landslide case (Italy)

Landslides involving fine-grained soils, such as earth slides and earthflows, are highly sensitive to pore water pressure variations, which can reduce soil shear strength through undrained-drained mechanisms. These mechanisms may be triggered by static loading, internal stress changes, or seismic activity. Additionally, the litho-structural setting can influence subsurface water flow, causing localized pressure increases. Monitoring pore water pressure and atmospheric conditions is essential for understanding instability triggers, especially in large-scale, slow-moving earthflows. However, due to the complexity of such extensive phenomena—like the Calita landslide in the northern Italian Apennines— integrating satellite data with conventional monitoring tools is crucial for a comprehensive view of the hydraulic behaviour of the landslide. This paper presents preliminary findings from a study aimed at defining a geotechnical model of the Calita landslide and identifying its predisposing and triggering factors. While the landslide has been previously analysed from geological and geomorphological perspectives, a detailed geotechnical assessment and interpretation of monitoring data is still lacking. The study incorporates hydro-mechanical laboratory results to better understand the landslide behaviour, particularly within the framework of partially saturated soils, to support future risk mitigation strategies.