Defining Kinematic and Evolutive Features of Earth Flows Using Integrated Monitoring and Low-Cost Sensors Paola Revellino, Luigi Guerriero, Giuseppe Ruzza, and Francesco M. Guadagno Abstract Mid to long-term monitoring of earth flow displacements is essential for the understanding of their kinematic features, process dynamic and evolution, and designing of mitigation measures. This paper summarizes methods, results, and interpretations of monitoring activities carried out between 2006 and 2020 at three earth flow sites in southern Italy characterised by structurally and litholog- ically complex slopes: (1) the Montaguto, (2) the Mount Pizzuto, and (3) the Pietrafitta landslides. By integrating traditional monitoring techniques and specifically devel- oped low-cost sensors, kinematic and evolutive features of the three earth flows were analyses allowing detailed reconstruction of the relationship among basal-slip sur- face geometry, deformation styles and pattern, geomor- phic structures, movement velocity and sediment discharge during ordinary and extraordinary movements. Final results highlight that earth flows are composed of distinct kinematic zones with characteristic longitudinal velocity profiles. Velocity variation along a kinematic zone, which is controlled by the basal and lateral geometry of the slip surface, is consistent with the distribution of structures on the ground surface of the flows, reflecting stretching and shortening of material during movement. Seasonal movements characterized by alternation between relatively slow persistent movement and acceleration are induced by material recharge passing through each kinematic zone and depends from this amount. Finally, it is empathised the use of low-cost sensors for displacement monitoring associated with traditional instrumentations, which give the advantage to obtain multiple stations distributed over large areas and reduce the cost of expensive monitoring campaigns. Keywords Earth flow Á Kinematic Á Displacement Á Evolution Á Monitoring Á Low-cost sensors Introduction Earth flows are among the most common mass movement in nature, and are pervasive in many rapidly eroding landscapes (Mackey et al. 2009; Revellino et al. 2010). Their architec- ture derives from a complex evolution regulated by climatic aspects and the availability of material for sediment-pulse formation (Guerriero et al. 2014, 2015a, b). Earth flow activity alternates between long periods of slow and/or localized movements and surging events (e.g. Guerriero et al. 2015a). Persistent-slow movement of earth flows creates defor- mational structures at their surface (i.e. faults and folds; Guerriero et al. 2013a, b). Observation of mesoscopic structures forming their surface (e.g. Guerriero et al. 2014) shows that earth flow material is affected by both longitu- dinal extension and shortening, controlled by the geometry of the basal slip surface (Guerriero et al. 2014). In struc- turally and lithologically controlled earth flows (e.g. Pinto et al. 2016), the basal slip surface can be a series of alter- nating steeply and gently sloping surfaces (e.g. Guerriero et al. 2014) along the earth flow profile, which confine distinct kinematic zones operating in unison to transmit P. Revellino (&) Á G. Ruzza Á F. M. Guadagno Department of Sciences and Technologies, University of Sannio, via de’ Sanctis, 82100 Benevento, Italy e-mail: paola.revellino@unisannio.it G. Ruzza e-mail: gruzza@unisannio.it F. M. Guadagno e-mail: guadagno@unisannio.it L. Guerriero Department of Earth, Environment and Resources Sciences, Federico II University of Naples, Naples, Italy e-mail: luigi.guerriero2@unina.it © Springer Nature Switzerland AG 2021 N. Casagli et al. (eds.), Understanding and Reducing Landslide Disaster Risk, ICL Contribution to Landslide Disaster Risk Reduction, https://doi.org/10.1007/978-3-030-60311-3_2 25