Management of historical seismic data using GIS: The Island of Ischia (Southern Italy)

This paper presents the results of the use of Geographic Information Systems (GIS) in managing information on the effects of earthquakes in historical times on the island of Ischia. The unpublished sources on the Casamicciola earthquake of 28 July 1883 and the extensive bibliography documenting the island's seismicity from 1228 showed the need to proceed towards a type of data storage that would also allow management of the same data. Application of GIS techniques allowed us to insert, extract, handle, manage and analyse the data for the zoning of seismic damage on the island of Ischia. The end-product consists of information layers, such as maps of isoseismals, the damage, and hazard involved, as well as numerical tables associated to maps. The study was developed using GIS Arc-View 3.2 software (ESRI) and is structured in thematic vectorial levels and rasters. The overlapping themes constitute a cartographic data base of the island. The damaged sites are located on a map at a scale of 1:10,000, with all the information on the 1883 earthquake (total number of houses, number of collapsed houses, collapsed or damaged rooms, photographs, plans of buildings, etc.) being associated to each site. The GIS is structured in such a way as to be able to be integrated with further georeferenced data and with other databases. It is thus able to provide support both for in-depth analyses of the dynamic processes on the island and extend the assessment to other natural risks (volcanic, landslides, flooding, etc.). © 2004 Kluwer Academic Publishers.