UAV-based reconnaissance and analysis of a large seismic-induced landslide in central Italy

Three large earthquakes (Mw 6.0, 5.9, and 6.5) impacted regions of Central Italy August 24, October 26, and October 30 in 2016. Following the Mw6.5 event on October 30, a large wedge-type landslide occurred above the Nera River, approximately 1 kilometer west of Visso. The landslide initiated above the highway Strade Provinciale 209, producing a significant amount of talus that dammed the river and flooded the highway. Because of the challenging site conditions, traditional forms of remote sensing including terrestrial laser scanning were not feasible to perform. This paper presents in innovative solution that was applied for documenting and modeling this landslide. The solution involved the use of an unmanned aerial vehicle (UAV) mounted with a small video camera, and structure from motion (SfM) computer vision image processing for three dimensional point cloud and digital terrain model development. The equipment, methods, and workflow applied in the reconnaissance and modeling of the landslide are described. Results of geostructural and failure mechanism analyses performed on the UAV-based point cloud model are presented. The study ultimately demonstrates the potential usefulness and robustness of UAV-based remote sensing methods.