Application of close-range remote sensing techniques for assessing landslide hazard in rock-carved cultural heritage sites

Rock-carved cultural heritage sites are often carved in slopes formed by weak rocks, which due to their peculiar lithological, geotechnical and morpho-structural features are often prone to weathering, deterioration and slope instability issues. In this context the use of advanced close-range remote sensing (RS) techniques, such as Infrared Thermography (IRT) and Unmanned Aerial vehicle-based Digital Photogrammetry (UAV-DP) can be profitably used for the rapid detection of conservation issues (e.g. open fractures, unstable ledges-niches, water seepage and moisture) that can lead to slope instability phenomena. These techniques when combined with traditional methods (e.g. field surveys, laboratory analysis), can provide fundamental data to implement a specific site-specific and inter-disciplinary approach for the sustainable protection and conservation strategies of Rock-carved cultural heritage sites. In this paper some examples of conservation problems in several rupestrian sites characterized by different geological contexts, from the mountainous regions of Georgia to the ancient city of Petra in Jordan, are presented, with the aim of evaluating the potential of the proposed approach integrated approach. The final aim is to provide conservators, practitioners and local authorities with a useful versatile and low-cost methodology, to be profitably used in management plans of rock carved sites.