Abstract:

This study aims to address the challenges associated with rockfall assessment and monitoring, focusing on the coastal cliffs of “Navagio Shipwreck beach” in Zakynthos. A complete time-series analysis was conducted using state-of-the-art methodologies including a 2020 survey using Un-manned Aerial Systems (UAS) and two subsequent surveys, incorporating Terrestrial Laser Scanning (TLS) and UAS survey techniques in 2023. Achieving high precision and accuracy in georeferencing -involving Direct Georeferencing, the utilization of Ground Control Points, and integrating Post Processing Kinematics (PPK) with Global Navigation Satellite System (GNSS) permanent stations' RINEX data are necessary for co-registering the multi-temporal models ef-fectively. For the change detection analysis, UAS surveys were utilized, employing the multiscale model-to-model cloud comparison (M3C2) algorithm, while TLS data served as a validation methodology due to its very high-resolution model. The synergy of these advanced technologies and methodologies offers a comprehensive understanding of rockfall dynamics, aiding in effective assessment and monitoring strategies for coastal cliffs prone to rockfall risk.