Three Years of Progress in Digital Applications and Monitoring Utilizing 3D Reality Capture Technologies for Landslide Hazard Mitigation: Insights from Multiple Sites in Greece

Landslide and rockfall hazards pose persistent risks to infrastructure, cultural heritage, and public safety in regions characterized by complex geological conditions and intense geomorphological processes. Over a three-year research program, substantial progress was achieved in the development and field application of photogrammetry-based monitoring methodologies for landslide and rockfall hazard assessment across multiple sites in Greece. The proposed framework was implemented and tested under real field conditions in a wide range of geological, geomorphological, and engineering environments.
Extensive and repeated field campaigns were conducted at pilot sites with diverse geological and geotechnical characteristics. In mountainous road environments, photogrammetric monitoring methodologies were applied to steep road cuts in Evritania (Agia Vlacherna, Fidakia, Gavros, Prousos, and Valavora), where slope instabilities affect critical transportation corridors of increased geotechnical and socio-economic importance. These sites are characterized by structurally controlled rock slopes and complex landslide mechanisms requiring systematic monitoring.
In coastal and insular environments, the research included applications on Nisyros, in the area of the Monastery of Panagia Spiliani, on Kos, along the coastal zone of Empros Therma beach, and on Zakynthos. The latter represents a characteristic case study related to the protection of the world-famous Navagio (Shipwreck) beach, where rockfall hazards threaten both visitors and cultural–touristic assets. Additional applications were carried out on natural, artificial, and engineered slopes in Ilia and northern Evia, further expanding the spectrum of engineering geological conditions examined.
The methodological approach integrates UAV-based photogrammetry and terrestrial laser scanning with detailed engineering geological investigations and targeted ground-based monitoring. Multi-temporal 3D datasets enabled quantitative surface change detection and volumetric analysis of rockfall events, while complementary subsurface measurements supported the interpretation of deformation patterns in rotational and translational landslides. The geographical dispersion of the investigated sites allowed a comparative evaluation of slope behavior under different failure mechanisms, strengthening the validation and general applicability of the proposed methodologies.
Overall, the findings underline the importance of combining multi-temporal 3D reality capture with field-based geotechnical observations, providing a transferable monitoring and analysis framework applicable to landslide- and rockfall-prone slopes under diverse geological and engineering geological conditions.