Application of ground-based radar interferometry to monitor an active rockslide and implications for emergency management

A rockslide of about 10(6) m(3) was reactivated in April 2002 on Monte Beni near the town of Firenzuola in Northern Tuscany (Italy). The rockslide caused the evacuation of 3 private houses and the interruption of the Regional Road n.65 "della Futa", one of the main transportation routes connecting Firenze and Bologna. During the emergency, in order to rapidly acquire data on the state, distribution and style of activity of the moving rockslide, a monitoring campaign was carried out, using an innovative radar device capable of a remote sensing assessment of ground displacement fields with a high resolution and accuracy. The system is a ground-based radar interferometer, known as LISA (Linear Synthetic Aperture radar), which has been successfully tested in past experiences for landslide monitoring. The production of multi-temporal maps of ground displacements, over a time span of 5 days, has provided a clear picture of the rockslide mechanism and activity. These data were utilised by public authorities and decision makers to define temporary measures for risk reduction and risk management.