Mihael Ribičič

Computer simulation of stone falls and rockfalls

The paper gives an overview of the literature on available computer (simulation) models of stone falls and rockfalls, divided into 2D and 3D models. 2D models consider single blocks in the rock-fall mass as lumped mass or a rigid body, and are used to assess the single rockfall runout distance. Opposed to the 2D models, 3D models are composed not only of a dispositional model (depicting rockfall source areas) and friction model (determination of deposition areas and maximum runout distances), but also from a trajectory model (determination of travel areas).

Earthquake-Induced Landslides in Slovenia: Historical Evidence and Present Analyses

The paper gives a short overview of the historical earthquakes on the territory of Slovenia since AD 792, with the 1511 Idrija Earthquake (MM = 6.8 ± 0.3) as the strongest earthquake in this record. Firstly, seismotectonic characteristics of Slovenia are presented together with the seismological map of Slovenia. Secondly, a national landslide database and landslide occurrence map (cadastre) is discussed. Furthermore, different (statistical) models are presented that have been used to prepare landslide (also debris flows and rock falls) susceptibility maps of Slovenia at scale 1:250,000. The role of earthquakes as triggering factors in these models is discussed. Moreover, a field case study is discussed; the conclusions reached by the analysis of the numerous rock falls initiated during the 1998 Posocje earthquake (ML = 5.6; the strongest earthquake in the 20th century with the epicenter in the territory of Slovenia) and the 2004 Posocje earthquake (MLV = 4.9) is presented. A short final section on legislative framework in Slovenia with regard to hazard and risk mapping of slope instabilities respectively mass movements (including earthquake-induced landslides) is given.