); inforesgeo.it (G.V)  
[PERSON] Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Genova 26, 16132 Genova, Italy; [EMAIL_ADDRESS] (A.V. ); [EMAIL_ADDRESS] (A.G.); [EMAIL_ADDRESS] (A.G.)  
EgsGeo Consultant, Via [PERSON] 32/1, 16039 Sestri Levante, Genoa, Italy; [EMAIL_ADDRESS] (B.M. ); [EMAIL_ADDRESS] (G.R. ); inforesgeo.it (G.V)  
Egidio Armadillo  
1 Department of Earth, Environment and Life Sciences (DISTAV), University of Genova, Genova 26, 16132 Genova, Italy; [EMAIL_ADDRESS] (A.V. ); [EMAIL_ADDRESS] (A.G.); [EMAIL_ADDRESS] (E.A. ); [EMAIL_ADDRESS] (A.C.)  
EgsGeo Consultant, Via Rico Erlado 32/1, 16039 Sestri Levante, Genoa, Italy; b.  
the source of serious social and economic impacts due to their effects in terms of damage to the built environment [14; 15]. The mobility of reactivated and slow-moving landslides can be controlled by pre-disposing (i.e., time-invariant conditions), preparatory (i.e., time-dependent processes exhibiting cyclical changes or trends), and triggering (i.e., transitory processes developing over very short time periods) factors [1; 16; 17]. As known from both the theoretical and experimental mechanical behaviour of soils and rocks, rainfall-induced pore water pressure changes play a key role in conditioning normal effective stresses along existing sliding surfaces, consequently preparing for the onset of slope instability mechanisms [18; 19]. The kinematics response of reactivated slow-moving landslides to precipitations can be time-delayed; namely, acceleration phases are most observed after several days and even months [9; 20]. Both the timing and magnitude of hydrologically driven pore water pressure variations at depth depend on the extent of rain or snowmelt water infiltration from the ground surface [21; 22; 23; 24]. In large landslides, typically showing complex hydrogeological settings, other conditions can modify pore water pressure regimes, such as groundwater circulation through different aquifers or the origination of local excess pore pressures due to the spatial variability of hydraulic conductivity across the landslide-forming materials [25; 26; 27; 28; 29; 30; 31; 32]. More rapid groundwater recharges can be related to preferential flow circuits developing through highly fissured moving landslide masses [33; 34]. Despite the close connections between pore water pressure changes and the development of movements in slow landslides, several studies revealed the inherent complex nature of both the mechanical and hydrological processes governing their kinematics [1; 5; 9; 10; 35; 36; 37]. In some cases, non-linear relationships between the piezometric surface oscillation and the movement rate were documented [33; 38], while in others, different motion rates were observed depending on whether pore water pressure increases or decreases, revealing a hysteretic behaviour [10; 23; 25; 36]. In this regard, several geomechanical models describing the stress-strain-time relationships in geomaterials (e.g., viscous-plastic, rate strengthening, and softening behaviours) have been used to interpret the spectrum of motion characteristics observed in the field [39; 40; 41]. The displacement trends in slow landslides that are driven by pore water pressure changes can be investigated using different approaches, such as numerical modelling [39; 41], laboratory experiments [37; 42; 43], geotechnical field monitoring [7; 10; 33; 36; 44], and remotely sensed data analysis [9; 45; 46]. In the framework of field-based measurements, surface displacement data [10; 36; 47] or techniques that do not always imply a direct connection between measured displacements and landslide movements, such as wire extensometers [48; 49; 50], are often used. In contrast, the employment of displacements directly and continuously measured at localized sliding zones can be relatively challenging, often due to technical or economic constraints.