## 3 GHM Characterization of the Landslide Classes: A Preliminary Attempt
According to the inclinometric monitoring data, the earthflow body moves through the transversal sections at a constant, very low to extremely low mass rate. The river erosion of the landslide toe contributes to the activity of the landslide [114; 119]; in addition, recent 3D modelling of the seepage regime in the slope [128], validated by piezometric monitoring, showed that the seasonal rainfall infiltration also influences the landslide activity. The Masseria Marino and Brindisi di Montagna landslides (Table 6; Figure 16) are representative of many other earthflows occurring in the Basento Valley [110]. The interpretation of the Masseria Marino earthflow mechanism was based on both phenomenological (stage I) and numerical (stage III) analyses, supported by accurate monitoring of the displacements, both at ground level and at depth, and of the piezometric levels [113; 127; 108]. This earthflow involves, again, intensely fissured clays, which result largely from the runout of a wide landslide in the upslope area; the latter is also characterized by an intermittent retrogressive activity. The runout material moving downslope influences the kinematics of the channel body, whose displacement rates vary from a few mm/year to 12 cm/day [110; 113; 116]. Moreover, the channel movements appear also to be connected to the increase in the pore water pressures related to the seasonal rainfall infiltration. According to [PERSON] et al. [145], the activity of the earthflow is controlled by a combination of processes, both drained and undrained, i.e., the impact of the runout material coming from the upslope area and rainfall infiltration. The interpretation of the Brindisi di Montagna earthflow mechanism (Table 6; Figure 16) is derived from the stage I, II and III analyses performed by various authors [123; 125; 146]. Again, the earthflow materials derive from the runout of an ancient and wide rotational landslide upslope in a source area location of important tectonic displacements due to the activity of a fault. Therefore, the clayey soils in the source are fissured and have a very chaotic structure, and the earthflow body is largely made of scalp clays, including disarranged rock blocks. As a whole, the earthflow activity is intermittent, characterized by variable displacement rates, from a few mm/year to 1 m per day. The activity relates to both the piezometric level fluctuations, resulting from the rainfall infiltration, and the undrained loading determined by the runout material moving from the source area, where the top landslide reactivation occurs [125]. The evolution of the Montaguto earthflow [121; 147; 122] was inferred from analyses conducted according to all the three stages of the diagnostic methodology in Figure 5, including extensive topographic (LIDAR, robotic total stations, GBInSAR), inclinometric and piezometric monitoring,The earthflow body is made of remolded clay with rock fragments, coming from the Faeto Flysch Formation which outcrops in the source area. The substrate, on which the earthflow moves (channel and accumulation area), consists of clayey marls and fine sands belonging to the Villamaina Synthem. In 1954, the source area of the earthflow was affected by multiple landslide events, the toe of which was at midslope. Recently (2005-2006; 2010), according to [PERSON] et al. (2012, 147), on the basis of monitoring data and numerical modelling, the reactivation of movements was shown to be due to consolidation processes following the undrained loading caused by the runout masses from the source area. In summary, all the earthflow case studies discussed above provide evidence of similarities in the values of the main landslide factors and in the landslide mechanism. The disturbed and heterogeneous features of the soils involved in the earthflowing, generally disturbed and fissured clays of low shear strength, including floating rock blocks, represent a factor predisposing the slope to landslides.