Assessing the effect of lithological setting, block characteristics and slope topography on the runout length of rockfalls in the Alps and on the island of La Réunion

Abstract. In four study areas within different lithological settings and rockfall activity, lidar data were applied for a morphometric analysis of block sizes, shapes talus cone characteristics. This information was used to investigate the dependencies between size, shape lithology on one hand runout distances other hand. our study, we able show that seems have an influence size gravitational sorting did not occur all studied debris cones but parameters apparently control length boulders. Such parameter be shape, as it plays role moderating in two sites, while could confirm this sites. We also investigated terrain such slope inclination, profile curvature roughness. The derived roughness values clear difference sites seem good proxy distribution thus further studies analyse larger sample with lithologies.