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Rainfall can trigger flow-like mass movements characterised by different percentages of solid and water (debris flows, hyperconcentrated flows, and flash floods). They exhibit different magnitude (volume), run-out distance and consequence, due to both distinct triggering mechanisms and kinematic features. Indeed, discriminating among these phenomena for appropriate risk analysis and zoning is a relevant issue also considering that the volume of the flow may sudden increase along the propagation path. The paper deals with September 2010 combined types of flows occurred at Atrani village (Amalfi coast, southern Italy), and originated by heavy rainstorm in the catchment located upslope to the urban centre. The events were reconstructed by using multi-source information. Field surveys, geological analysis, elaboration of videos recorded during the events and numerical modelling were combined. A 40 minutes lasting water flood abruptly combined to a relatively small-sized high-discharge hyperconcentrated flow, with the consequence of an abnormal flow that invaded the narrow main street of the urban area in few minutes. The peak discharge at the catchment outlet was increased by erosion and/or other rainfall-induced slope instabilities occurred in the whole catchment. As main conclusion, the multidisciplinary analysis has resulted effective to enhance the understanding of the complex flow-like mass movements. [ABSTRACT FROM AUTHOR]

In this paper, we present a GIS-based method for regional zoning of seismic-induced landslide susceptibility and show its application to the territory of the Campania region, Southern Italy. The method employs only three factors that we believe are most significant in the susceptibility assessment: the type of outcropping rock/soil, the slope angle, and the MCS intensity. Each of the three parameters is quantified in terms of relative weight expressed as indices, and the resulting Seismic Landslide Susceptibility index of an area is given by the average of the indices of the first two factors multiplied by the index of the third factor. The result of this susceptibility zonation applied to Campania shows a good agreement between the distribution of the historical earthquake-triggered landslides and the highly susceptible zones. [ABSTRACT FROM AUTHOR]

Abstract: We apply the Permanent Scatterers Synthetic Aperture Radar Interferometry (PS-InSAR) technique to the Campania Region (Southern Italy), which includes the Southern Apennines chain and Plio-Quaternary structural depressions, with the aim to detect ground displacements at a regional scale. The study area, which extends for 13,600 km2, is characterized by intense urbanization, active volcanoes (Phlegraean Fields, Vesuvius and Ischia), seismogenic structures, landslides, hydrogeological instability. PS-InSAR technique allows us to identify a set of radar benchmarks (PS) where accurate displacement measurements can be carried out. About 1.7·106 PS are identified by processing Synthetic Aperture Radar (SAR) images acquired in ascending and descending orbits from 1992 to 2001 by the European Remote Sensing satellites (ERS). The PS-InSAR application at regional scale detected ground deformations ranging from +28 to −39 mm/yr. The calculated velocity values are consistent with the available GPS and levelling data from selected areas. We identify volcanic areas in which the deformation is mainly related to the depressurization of the local hydrothermal systems, and recognize deformations along seismogenic and aseismic NNW–SSE and NW–SE faults. The deformations localized along the Southern Apennines chain are mainly related to landslides while those occurring in the plains are due to subsidence processes induced by intensive drainage from wells, i.e. anthropic activity. The review of 9 years of SAR data shows that tectonic, volcanic/hydrothermal, gravity, and anthropic processes are responsible for the ground deformation of Campania. The proposed joint interpretation of deformation fields related to natural and anthopogenic factors provides a comprehensive view of the dynamics of the Earth’s surface. [Copyright &y& Elsevier]