Seismically-induced landslide susceptibility evaluation: Application of a new procedure to the island of Ischia, Campania Region, Southern Italy

Review article "Remarks on factors influencing shear wave velocities and their role in evaluating susceptibilities to earthquake-triggered slope instability: case study for the Campania area (Italy)"

“…Rapolla et al (2010Rapolla et al ( , 2012 proposed a quick procedure to assess the seismic slope stability at different scales/levels that accounts for (A) the seismicrelevant property of the rocks/soils that crop out -expressed as transversal seismic velocity (Vs), (B) the incline angle of slopes -obtained from high-resolution digital elevation models of the topography of the investigated areas, (C) the seismic intensity that most likely will affect the study area -expressed in terms of European Macroseismic Scale (EMS-98), which is based on the the Mercalli-Cancani-Sieberg (MCS) and Medvedev-Sponheuer-Karnik (MSK-64) scales. The seismically-induced landslide susceptibility level of an area can be obtained from the average of factors A and B, considered as predisposing factor, multiplied by the triggering factor C. Referring to the above cited literature for details about the procedure, we would like to note here that a crucial point of the procedure is a correct evaluation of the A parameter, the lithology index.…”

“…7a Rapolla et al (2010Rapolla et al ( , 2012 (Fig. 7a), landslides occur mainly in the areas characterized by flysch lithologies, represented by the 2nd, the 3rd and the 4th litho-seismic units in Table 4.…”

“…The procedure was applied at different scales in two areas of southern Italy: the Campania region and the Island of Ischia (Fig. 6) (Rapolla et al, 2010(Rapolla et al, , 2012.…”

“…It employs a two-phase model consisting of fluid and a solid matrix made of sand and clay particles homogeneously Table 3. Rock and soil classification based on geo-lithological, geomechanical and geophysical features (modified after Rapolla et al, 2010 mixed to form composite granules. In order to use this model for clay-rich rocks, the authors assumed that the bulk and shear moduli of the grain material, and the dependence of the compliance on porosity, are function of the clay content.…”

“…In fact, land use planning needs information about seismic hazard at a sustainable cost, whereas more complete, detailed and expensive studies should be focused only on areas where a detailed zoning is necessary. Rapolla et al (2010Rapolla et al ( , 2012 proposed a quick strategy for land planning targets which employs the shear wave velocity values (Vs) as crucial factor for zoning on seismicinduced landslide susceptibility. The method, whose approach is shared by other procedures (e.g.…”