Influence of Terrain Model Resolution on Rockfall Dispersion

This study used site-specific LiDAR as the input slope geometry for RocFall3, a 3D rockfall simulation tool. A total of 20,000 rigid body simulations were performed using two block shapes, four block sizes, and five terrain resolutions to investigate how terrain model resolution, block shape, and block size influence rockfall dispersion. Dispersion area is defined as the minimum area required to fully encapsulate the seeder location and final resting locations of all simulated blocks. Results showed that higher-resolution terrain models led to larger dispersion areas. Block shape had a strong influence: hexagonal blocks produced a rounded cone pattern, while spherical blocks formed an elongated end cone. For spherical blocks, dispersion decreased with increasing mass, a trend not observed in hexagonal blocks. A localized terrain feature altered dispersion for spheres but not for hexagons. Final resting locations also differed: spheres settled primarily in the lowest-angle slope zone, while hexagons dispersed across the two lowest zones.