UTILIZZO DEL SISTEMA GOOGLE EARTH PER LA DEFINIZIONE DI UN MODELLO DI SUSCETTIBILITÀ DA FRANA: UN TEST IN SICILIA CENTRALE

Exploiting Google EarthTM to assess a landslide susceptibility model: a test in central Sicily. A landslide susceptibility multivariate model, based on the conditional analysis approach, has been derived in the Tumarrano river basin (about 78 km2), by intersecting a GIS grid layer, expressing some selected geo-environmental conditions (outcropping lithology, steepness, plan curvature and topographic wetness index), and a landslide vector archive, produced by a Google EarthTM aided remote survey. The analysis of the Google EarthTM images dated at 2006, allowed to recognize 733 landslides (30 rotational slides and 703 flows), almost exclusively affecting clay and sandy clay rocks. Validation procedures produced largely satisfactory results, which were analyzed in the domain of the success and prediction rate curves. The research confirms the goodness of the susceptibility assessment method, as well as the powerful of Google EarthTM as a tool to manage the need of new, detailed and multi-temporal landslide archives.