Le tecniche radarinterferometriche nella pianificazione territoriale

The paper describes the experiences made in the Interreg Alcotra IIIa RiskNat project by three Italian regions, Liguria, Piemonte and Valle d’Aosta, in the field of landslide assessment by means of persistent scatterers radarinterferometry. If a sufficient series of radar images is available, the technique allows, with accuracies in the order of mm a-1, to evaluate the displacement of ground radar targets represented by rocks, buildings and other structures. In a regional scale analysis the density of these points (named PS or DS) may reach several thousands per km2 , thus permitting a very good cinematic characterization of slow-moving landslides. The technique is about twelve years old and, in many Italian regions, is now an ordinary working tool. Within the project, several software tools were developed in order to perform both pre- and post-processing analyses. The technique has numerous advantages, the most important being the possibility of surveying wide areas at minimal cost, thus providing information about a large number of landslides. The drawbacks are basically related to geometric aspects, for the technique detects only one component of the total displacements, the one along the line connecting the radarsatellite and the ground target (named LOS, line of sight). In the three regions the technique was positively used both for landslides assessment and for land use planning.