Rockfall susceptibility zoning and evaluation of rockfall hazard at the foot hill of mountain Orliagas, Greece

Rockfalls are frequently generated in mountainous areas and threatened manmade environment. Therefore, the detachment of large size boulders and their fall track are issues that should be evaluated for urban planning and the construction of lifelines and road networks. In order to achieve this, several methodologies had been proposed and applied, regarding the evaluation of the landslide hazard. The most known methods concern the application of GIS software for the evaluation of the run-out distances of boulders and the simulation of the fall tracks. In this article, a delineation of areas susceptible to rockfalling at the foothills of mountain Orliagas, Greece, is provided using the minimum shadow angle method and, in addition, selected case studies of rockfalls were studied. These cases were simulated and analyzed using the Rockfall software while the employed parameters were tested and calibrated using silent witnesses. The outcome provided by this study, is that the simulated fall track and the rockfall run-out distance were in agreement with the spatial distribution of the reported boulders while the total kinetic energy and the bounce height during the fall track have been evaluated, thus can be used for the construction of remedial measures. In addition, as it is shown in the resulting by this study maps, the area between the villages of Ziakas and Spileo can be separated into two zones, A and B, regarding the landslide hazard for the road network which is evaluated as low and very high, respectively.