Integration of Permanent Scatterers Analysis and High Resolution Optical Images within Landslide Risk Analysis

In the framework of the on-going SLAM project (Service for Landslide Monitoring), funded by the European Space Agency (ESA) the Permanent Scatterers processing and the analysis of high resolution images (e.g. SPOT5) have been performed at a basin scale, on the whole territory of the Arno River basin (Central Italy). The project aims at the development of a service based on the integration of EO-data within the current practices used for landslide risk management. The studied area, with a spatial extension of about 9,000 km, has been chosen for the presence of a high number of mass movements (up today about 20,000 landslides have been mapped and 300 of them have been classified as at high risk from the institutional authorities) and for its significance, in terms of landslide typology and environmental conditions, with respect to the Italian Apennine territory. By considering the technical requirements imposed by the Italian legislation for the documents related to landslide risk management, three products based on EOdata have been defined related to landslide inventory mapping, landslide hazard mapping and landslide monitoring. To this aim, about 350 SAR images have been interferometrically processed by means of the PS technique, detecting about 600,000 PS. The processing of SPOT5 images and aerial-photos, still in progress, have been performed for the extraction of features related to the landslide presence, useful for the geomorphological analysis and, as a consequence in order to give a spatial meaning to the punctual information provided by the PS. This procedure has been coupled with a intense geological interpretation phase characterized by the analysis of traditional in situ monitoring data, ancillary data and the performing of field surveys. The results of the above described methodologies will impact on the current documents used by the Arno Basin Authority for the landslide risk management (e.g. P.A.I., Piano di Assetto Idrogeologico) creating a case history of major importance in Europe.