3D numerical modelling of rockfalls in the Lecco urban area (Lombardia Region, Italy)

Reliable prediction of rockfalls is a major need in mountain areas, both for hazard assessment and countermeasure design. In this paper, a 3D kinematic modelling approach is presented, which is able to solve site-specific rockfall problems using an original simulation code with high resolution input data. The code allows detailed rockfall simulations on a 3D topography computed from a Digital Elevation Model. The case study of the Mt. S.Martino – Mt. Coltignone cliffs, impending on the Lecco urban area (Lombardia Region, Northern Italy) is discussed. The example is particularly interesting, due to the occurrence of frequent rockfall events, valuable elements at risk (urban areas, corridors) and countermeasures (barriers and retaining walls). Model calibration issues are discussed by comparing model results to available experimental data. The scale dependency of model results is also discussed.