Abstract. The volcanic archipelago of the Aeolian Islands (Sicily, Italy) is included on the UNESCO World Heritage list and is visited by more than 200 000 tourists per year. Due to its geological characteristics, the risk related to volcanic and seismic activity is particularly high. Since 1916 the archipelago has been hit by eight local tsunamis. The most recent and intense of these events happened on 30 December 2002. It was triggered by two successive landslides along the north-western side of the Stromboli volcano (Sciara del Fuoco), which poured approximately 2-3×10 7 m 3 of rocks and debris into the Tyrrhenian Sea. The waves impacted across the whole archipelago, but most of the damage to buildings and infrastructures occurred on the islands of Stromboli (maximum run-up 11 m) and Panarea.The aim of this study is to assess the vulnerability of buildings to damage from tsunamis located within the same area inundated by the 2002 event. The assessment is carried out by using the PTVA-3 Model (Papathoma Tsunami Vulnerability Assessment, version 3). The PTVA-3 Model calculates a Relative Vulnerability Index (RVI) for every building, based on a set of selected physical and structural attributes. Run-up values within the area inundated by the 2002 tsunami were measured and mapped by the Istituto Italiano di Geofisica e Vulcanologia (INGV) and the University of Bologna during field surveys in January 2003. Results of the assessment show that if the same tsunami were to occur today, 54 buildings would be affected in Stromboli, and 5 in Panarea. The overall vulnerability level obtained in this analysis for Stromboli and Panarea are "average"/"low" and "very low", respectively. Nonetheless, 14 buildings in StromCorrespondence to: F. Dall'Osso (filippodallosso@gmail.com) boli are classified as having a "high" or "average" vulnerability. For some buildings, we were able to validate the RVI scores calculated by the PTVA-3 Model through a qualitative comparison with photographs taken by INGV and the University of Bologna during the post-tsunami survey. With the exception of a single structure, which is partially covered by a coastal dune on the seaward side, we found a good degree of accuracy between the PTVA-3 Model forecast assessments and the actual degree of damage experienced by buildings. This validation of the model increases our confidence in its predictive capability. Given the high tsunami risk for the archipelago, our results provide a framework for prioritising investments in prevention measures and addressing the most relevant vulnerability issues of the built environment, particularly on the island of Stromboli.

We present here a novel method to assess coastal vulnerability to tsunami based on GIS (Geographical Information System), ASTER imagery (Advanced Spaceborn Thermal Emission and Reflection Radiometer) and SRTM-3 elevation model (Shuttle Radar Topography Mission-3). We developed this method within the CRATER project (Coastal Risk Analysis for Tsunamis and Environmental Remediation) and applied it on the whole western coast of Thailand. As result, we generated a set of vectorial vulnerability maps with a geometrical resolution of 90m (scale 1:450 000). This approach provides a low-cost and quick tool to analyse extended coastal tracts, and prioritize investments for prevention measures or for further high-resolution analysis. Un nuovo approccio (metodo CRATER) per la stima a scala regionale della vulnerabilità a tsunami mediante immagini ASTER Riassunto Il lavoro presentato introduce un nuovo metodo per la stima della vulnerabilità costiera a tsunami, basato sul GIS (Geographical Information System), sull'impiego di immagini ASTER (Advanced Spaceborn Thermal Emission and Reflection Radiometer) e modelli di elevazione SRTM-3 (Shuttle Radar Topography Mission-3). Il metodo è stato sviluppato nell'ambito del progetto CRATER (Coastal Risk Analysis for Tsunamis and EnvironmentalRemediation) ed applicato all'intera costa occidentale della Tailandia. I risultati consistono in un set di mappe vettoriali della vulnerabilità con risoluzione di 90m (scala 1:450 000). Tale approccio costituisce un mezzo relativamente economico e veloce per l'analisi di estesi tratti costieri e per la gestione di investimenti in misure di prevenzione o in ulteriori analisi ad alta risoluzione. Tsunami, Vulnerabilità costiera, ASTER, GIS, Uso Suolo. Dall'Osso et al. Tsunami vulnerability at the regional scale: the CRATER method Parole chiave:

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This paper concerns the nonlinear, higher-harmonic, wave-forces acting on a vertical surface-piercing cylinder. New laboratory data is presented which confirms that in the case a vertical cylinder, the diameter of which is large but not sufficiently large that the body lies within the linear diffraction regime, the second- and third-harmonic forces are not well described by existing models. This is particularly apparent when the incident waves are steep and have a relatively small wave period. Indeed, under these conditions the second-, third- and fourth-harmonic forces are shown to be comparable in size. This is clearly at odds with the results of a traditional perturbation expansion. An explanation for this lies in the nature of the scattered wave field, particularly the high-frequency waves identified by Sheikh & Swan [1]. The phasing of these scattered waves are, at least in part, dependent upon the motion of the fluid around the circumference of the cylinder and will not therefore be captured by a series solution based solely on the harmonics of the incident wave motion. The paper considers several test cases, fully exploring the correlation between the nonlinear forcing and the high-frequency scattering. The practical implications of these results are also addressed.