Methodology for landslide risk analysis in the Province of Forlì-Cesena (Italy)
Topic of the practice
Landslide Risk Analysis
Good Practice Information
Forli-Cesena uses a methodology for the analysis of the hydro geological hazard and for the assessment of the risk concerning geological instability suitable for homogeneous territories. The methodology is based on known reference parameters, which allow homogeneous maps for landslide risk to be produced. The methodology for landslide risk analysis divides the activities carried out by the different bodies and authorities into two phases: 1) Identification of the hazard and analytical risk evaluation; 2) Analysis of risk maps and determination of possible scenarios (forecast and prevention programs). The first phase was carried out by the regional Geological and Seismic Service for the Soil, the Basin Technical Service and the Basin Authority. The second phase was carried out by the Regional Agency of Civil protection and the Province of Forlì-Cesena.
However, this approach leaves out all the landslide features determining hazard except for morphology and dimensions. It does not consider the kind of landslide (falls, slides, flows) or their activity state (dormant, active), nor does it assess the likelihood of the event to occur again (and the time-span). In this risk analysis methodology, also the estimate of the vulnerability of the exposed elements (built-up areas, transfer and service infrastructures) was considered based only on the U.I.E. and therefore the percentage of the likely damage based on the specific dangerousness of the landslide was not calculated.
Evidence of success
This practice allows the identification of elements with high risk landslides in the whole territory of Province of Forlì-Cesena (30 municipalities). Knowing the risk exposed elements, municipalities can elaborate evacuation plans and procedures. The Municipalities of Santa Sofia, Meldola, Tredozio and Modigliana made evacuation procedures on the basis of this practice.
Contact details to obtain further information on the practice
Annex completed on: 09-25-2012