Landslide monitoring with integrated techniques

In the last years, the GPS technique has become a very useful tool for the monitoring of landslide movements. The success of this application is, of course, due to the characteristics of GPS techniques that combine a relative easiness in the acquisition of data with very high precision and accuracy in the measurement. Moreover, the GPS allows an easy reconstruction of the velocity field of a landslide which adds a really helpful information for the modelling of this kind of phenomena. The surface velocity obtained by GPS, however, could be not really representative of the deep movements of gravitational phenomena. This means that in the monitoring of landslides it’s not possible to leave out of consideration the information coming from other techniques of investigation. In the paper are summarised the geological and geomorphological studies and the main results of the monitoring survey carried out on some areas located in Basilicata region (southern Italy). The landslide monitoring system is made up by traditional survey system and new technologies. One test site was at Lauria locality, an urbanized area interested by large and active landslides; the lasts are subject to frequent reactivations causing severe damage to the urban structures. The results of GPS survey, in good agreement with the results of the geomorphologic study, show that some of the analysed landslides are subject to a slow, continue deformations. Other results come from the survey (in progress) about slope instability processes observed in two different areas of the "Parco Archeologico Storico Naturale delle Chiese Rupestri del Materano" where fine rupestrian heritages are present. In these areas, the considerable acclivity of the slopes and the lithological defects and intense fracturing state of carbonate rocks cause rapid mass movements of the blocks (rock falls, topples and rockslides). On the basis of geological and geomorphological studies, the potentially unstable carbonate blocks that need survey have been defined. The design of the survey system is made up by a traditional topographic survey, GPS measures and a deformation measurement system.