Monitoring Rock Slope Dynamics and Rockfall Patterns from 3D Point Cloud Data at a Site in Western Colorado

ABSTRACT: Rockfall is a common geological hazard in mountainous regions, posing a significant risk to infrastructure and communities. Effective management of rockfall hazards relies on a thorough understanding and monitoring of changes in rock slopes to characterize slope stability and identify zones of instability. Point-cloud-based monitoring techniques such as photogrammetry and terrestrial laser scanning (TLS) have been increasingly used in recent years to track slope dynamics and measure surface changes. In this study, we present the results of a multi-year lidar monitoring campaign at a rock slope in Western Colorado. To track slope changes over time, the Multi-scale Model to Model Cloud Comparison (M3C2) was applied in CloudCompare. Detected areas of change were clustered, manually evaluated to separate rockfalls from erroneous change and then volumes of rockfall clusters were estimated. This process resulted in a detailed rockfall database documenting the size, frequency and spatial distribution of rockfall events. The results highlight seasonal patterns in rockfall activity.