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Sectors of the Campania region (southern Italy), where pyroclastic airfall deposits cover carbonate slopes, have frequently experienced debris avalanches and debris flows. These landslides are triggered by heavy rainfall and in the last century caused severe destruction and hundreds of deaths. Their occurrence is controlled by the interaction of several factors, both natural and human induced. The initial failure is linked with the presence of morphological discontinuities such as rocky scarps and road cuts, which interrupt the stratigraphical continuity of an “infinite slope”. Here the main criteria for susceptibility analysis are defined trying to develop a procedure for identify highly-susceptible sources, runout and invasion areas.

Coastal cliff erosion is a significant hazard for the safety of people, buildings, utilities and infrastructure, given the sudden and episodic nature of the retreat process in time and space. Thus, understanding past retreat trends and a regular diagnosis of the cliff face condition is fundamental for risk management. In this study we show preliminary results of a project aimed at the definition of the coastal erosion (in terms of temporal and spatial scales) of a small portion of cliff located along the Maronti beach in Ischia, Italy. Drone-based and terrestrial acquisition approaches offered the opportunity to exploit photogrammetric techniques to estimate the spatial and temporal rate of change of the investigated portion of cliff. In this study, cliff face topographical evolution is evaluated out by comparing the results obtained from three photographic datasets (variable approach either boat and UAV-based) obtained in 2011, 2021 and 2023. Spatial distribution of two main instability events dated back to 2020 and 2022 were well represented in the maps of change generated with the M3C2 algorithm. The comparison of point clouds for the period 2011-2021 and 2021-2023 produced max retreat rate of the cliff face of approximately 12 and 25 m, respectively. Results highlighted the need for robust co-registration methods to accurately estimate erosion rates. Critical issues are discussed to highlight potentials and limitations encountered with the abovementioned multi-temporal cliff evolution assessment techniques. [ABSTRACT FROM AUTHOR]

The Benevento Province (southern Italy) has been historically affected by soil erosion and ground deformation (i.e. landslides; Revellino et alii, 2019), as testified by documents and reports which describe damage scenario, social effects, surveys and measures carried out. Revellino et alii (2010) highlighted as the landslide index, defined as the ratio of areas affected by landslides over total areas, reaches up to 90%. Earth flows make up about 46% of these landslides, involving structurally complex geologic formations and often responsible for damaging human infrastructures (e.g. roads and service lines; Guerriero et alii, 2016; Maresca et alii, 2022). As a result, the province has widespread problems in management of the landslide hazard, due to the activation (and reactivation) of phenomena connected to both rainfall and seismic events. In order to reconstruct state of activity maps for the Benevento Province, a multitemporal analysis of multiplatform satellite data was carried out, with a resolution of cells of 20×20 m. In particular, PSInSAR (ERS 1&2 for the time-span 1992-2000, ENVISAT for 2002-2010, and RADARSAT for 2003-2007) and ISBAS data (Sentinel-1 for 2017-2020), were first treated by a grid-based approach to uniform the PS data and subsequently, by a multiplatform approach defining weighted average velocity (VWA) maps on the base of the extent of the area with data availability. Finally, a multiplatform activity-matrix approach allowed the definition of landslide activity maps based on a velocity threshold of ± 3 mm/y, derived by VWA maps. Specifically, velocity threshold allowed to discriminate for each cell of the analyzed area i) stable cells (velocities between ± 3 mm/y), ii) unstable cells (velocities greater than ± 3 mm/y), iii) cells with no data (unclassified). The multiplatform activity-matrix approach at provincial scale was used to identify and analyze unstable area (hotspots), currently involved in active deformation processes. Among them, the Paupisi municipality (Benevento Province) was identified as critical for the involvement of built-up areas and infrastructures in landslide deformation processes. For that reason, Paupisi area was selected as study case and a detailed analysis of the PS distribution as well as reconstruction and evaluation of deformation trend were carried out. Finally, a relation between land deformation and rainfall events was also investigated. [ABSTRACT FROM AUTHOR]