Reconstruction of Surficial Rock Blocks by Means of Rock Structure Modelling of 3D TLS Point Clouds: The 2013 Long-Chang Rockfall

Terrestrial laser scanning (TLS) enables the digital representation of rock outcrops with unprecedented resolution and accuracy. Currently, extracting full-scale block structures from raw TLS data (e.g. for assessing rockfall source areas) requires special techniques. This contribution describes processing methods for reconstructing three-dimensional representations of blocky rock masses from raw point cloud data. The developed workflow involves extracting structural and topographical details, fitting location-dependent discontinuities bounding the rock blocks, and reconstructing the block array embedded in three-dimensional geomorphology. The method is applied to a case study of the 2013 Long-Chang rockfall located in the Guizhou Province of China. Based on these initial results, the workflow will be applied to rockfall source evaluations throughout the karstified Kaili region within Guizhou.