This paper summarises the geological and geomorphologic studies and the main results of the monitoring survey carried out on some landslides in some areas in Basilicata region (southern Italy). The landslide monitoring was done using an integrated approach: traditional survey systems and applications based on the GPS technique. The adoption of a ″mixed″ approach, with the contemporary use of classical techniques and GPS, has been introduced since the space geodesy tools become very effective for the monitoring of landslide movements.
The success of GPS for landslide monitoring is due to its characteristics such as a relative easiness in the acquisition of data and a very high precision and accuracy in the measurements. In addition, the GPS allows an easy reconstruction of the velocity field of a landslide, which adds a really helpful information for the modelling of the phenomena. However the surface velocity obtained by GPS could be not representative of the deep movements of gravitational phenomena. This means that in the monitoring of landslides GPS can not be used in stand-alone mode: the use of classical methods is necessary to really understand the evolution of a landslide.
One test site was at Lauria locality, an urbanised area interested by large and active landslides; the lasts are subject to frequent reactivation causing severe damage to the urban structures. Results of GPS survey, in good agreement with the information′s coming from geomorphologic studies, show that large part of the investigated area are affected by slow but continue deformations.
Other results came from the survey (in progress) about slope instability processes observed in two areas of the Parco Archeologico Storico Naturale delle Chiese Rupestri del Materano. In the investigated areas, the lithological defects and intense fracturing state of carbonate rocks cause it′s the cause of mass movements of blocks (rock falls, topples and rockslides) that could seriously damage some fine rupestrian heritages present in the area. The potentially unstable carbonate blocks have been defined by geological and geomorphologic studies and actually this sites are under monitoring with a survey system, made up by a traditional topographic survey, GPS measures and a deformation measurement system. |
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