Assessing seismic site effects at regional scale: the SERENA research project

The complexity of the geological setting of the Italian peninsula implies variable site conditions affecting seismic hazard. Their extensive mapping is needed for a reliable assessment of the induced risk on residential areas, industrial agglomerations, infrastructures, strategic sites, cultural heritage spread on the entire national territory. The research meets the need for a national reference map providing co-seismic ground deformation at the scale of interest of land use planning and bridging the information gap now existing among the urbanized areas covered by seismic microzonation studies. The project aims at defining a multidisciplinary procedure for a multiscale mapping of the local seismic hazard of Italy, exploiting the potentialities of having spatially extensive information for combining site-specific to regional estimates of site effects. The key elements are: i) full exploitation of geological/geomorphological data, ii) extensive numerical modelling, and iii) empirical testing of local hazard estimates. The study deals with the regional scale analysis and classification of the landscape and the geological-technical properties of the near-surface stratigraphic configurations (GeoMorpho-Stratigraphic Units, GMSUs), which affect seismic hazard. The GMSUs are obtained by combining geomorphological analysis and automated landscape classification procedures, field-based lithostratigraphic constraints, instrumental signatures from geophysical investigations, and geotechnical parameters. Distinct parameterizations will be assessed for each GMSUs to feed simplified numerical models to quantify synthetic hazard indicators suitable for risk evaluations and land use planning. Outcomes will be managed through a coherent probabilistic approach to bound relevant uncertainty as a function of locally available data. Outcomes will be tested by considering site-specific analyses.