A WebGIS Application for Rendering Seismic Hazard Data in Italy

Abstract

In 2004, on behalf of the Department of Civil Protection (DPC—Dipartimento della Protezione Civile), the Istituto Nazionale di Geofisica e Vulcanologia (INGV) released a new Italian seismic hazard map. The entire scientific process was public and transparent: an international panel of experts conducted a peer review while the work was in progress, and all the input data, the final output, and the technical documentation was published. The details of the entire process are available on a dedicated Web site (http://zonesismiche.mi.ingv.it). Following the publication of the reference map, the DPC financed the S1 project to produce a set of additional elaborations that would better describe the Italian seismic hazard. This resulted in a set of maps expressed in terms of PGA and Sa (spectral accelerations), both evaluated for different probabilities of exceedance. Finally, the overall information, more than a “set of maps,” can be considered the realization of what can be defined as a complete seismic hazard model. One of the aims of the S1 project is the dissemination of the data through the Web (http://esse1.mi.ingv.it). To evaluate the state of the art in disseminating this type of data we conducted an overview of the Web sites of earthquake-prone countries,and in several cases we experienced difficulties and slowness in finding seismic hazard information for a specific area. Our goal was to provide a tool with a combined high level of interactivity and ease of use. Recognizing the need for a Web application that would enable users to intuitively and interactively locate the area of interest and show pertinent data in various formats, we decided to develop a dedicated Web interface.