Analysis of Ordinary Buildings on the Island of Ischia (Italy) for a Seismic Impact Assessment

Abstract

Ischia is a quiescent volcanic complex, characterized by several periods of activity, also of explosive typology. Each year, seismic stations detect few low-energy events, although in the past severe earthquakes occurred, causing extensive damage. The last significant seismic event, with a magnitude of 3.91, occurred on 21st August 2017, again in the municipality of Casamicciola. The hazard constituted by seismic phenomena is compounded by a high exposed value, in terms of population and buildings. From 1861 to today, the resident population has increased considerably, from 23,511 to 62,831 units, to which are added 4 million tourists a year. The high risk of the Ischia territory highlights the need to bring the sustainable planning at the centre of the debate, considering the vulnerability of the area. In this perspective, an application aimed at assessing the seismic impact scenario induced by a single seismic event is illustrated below. The aim is to show a methodological approach able to quantify the resources necessary for emergency planning and organization of operational intervention.