METHODOLOGY TO LOCATE GEOLOGICAL RISK FOR ASSURANCE : AN APPLICATION ON THE S. EUFEMIA AREA (CENTRAL CALABRIA, ITALY)

V. Rizzo (1), F. Fragale (2), A.Tulelli (3)

1. CNR-IRPI, via Verdi 248, Roges di Rende (Cosenza)


2. Free-lance geologist, via Grassi 31, Cosenza


3. SOGIS srl, via Sacchetti 10A, 00137 Roma

In the aims of a CEE-POP project were developed criteria to estimate geological risks along the "S.Eufemia-Catanzaro Isthmus", based on the study of historical recurrence of more common and dangerous events interesting the area, including landslides, river floods and earthquakes, and on the mapping of hazardous sites with associated vulnerability, to have a result immediately utilizable to the needs that an assurance system require. The mapped data (5 lithology classes, 6 vegetation covers, 5 landslide typology, 2 erosion intensity classes, 2 flood hazardous areas, 2 seismic amplification classes, 3 urbanisation conditions) and other related parameters (on slope morphology , hydrogeological condition, structural weakness, active fault) were collected in 1 :25.000 scale and digitized by ARCINFO, to support multiparameter cross correlation on mesh areas of 100m². Detailed data on estimated phenomena recurrence, vulnerability and esposition were furnished for each cell. A new methodology were used in the landslides classification, using five hazard typologies on the base of the tendency to reactivate themselves in the time (istantaneous, pluridecennal recurrent, secular recurrent, plurisecular recurrent, continuous)  while the relative vulnerability was based to the supposed rapidity of pre-rupture phase acceleration.