Abstract:

Kalymnos Island features extensive vertical limestone cliffs that span throughout the entire onshore area, establishing it as one of the world's premier locations for sports climbing. Drawing thousands of tourists and climbers annually, Kalymnos captivates with its unparalleled natural beauty and unique geomorphological relief. The absence of vegetation and the prevalence of large limestone vertical cliffs contribute to a distinctive geological setting, showcasing detached boulders throughout the island and positioning it as an ideal site for studying rockfall events worldwide. To investigate this peculiar geological landscape, contemporary close-range remote sensing techniques such as UAS images photogrammetric processing, terrestrial LiDAR point clouds, and high-resolution satellite imagery within a GIS platform are employed. This integrated approach facilitates the creation of detailed terrain models and enables the identification of spatial boulder distribution on the downslope areas of steep carbonate cliffs. Moreover, the diachronic study of the detected high-risk locations delineated the surface changes at the foot of the steep slopes where several back analyses were performed. Utilizing these quantitative techniques provides valuable information for designing protective measures for the stability of the slopes, highlighting the safe climbing routes for the athletes and the infrastructure at the cliff bases. Strategies involve anchoring individual rock blocks, removing unsafe rock masses, and implementing restraining nets or dynamic rockfall barriers at strategic locations along the route trail to mitigate risks effectively.