UAV-based remote sensing of the Super-Sauze landslide: Evaluation and results

Unmanned aerial vehicles (UAVs) equipped with digital compact cameras can be used to map landslides quickly and at a high ground resolution. Images taken by a radio-controlled mini quad-rotor UAV of the Super-Sauze, France landslide have been used to produce a high-resolution ortho-mosaic of the entire landslide and digital terrain models (DTMs) of several regions. The UAV capability for imaging fissures and displacements on the landslide surface has been evaluated, and the subsequent image processing approaches for suitably georectifying the data have been assessed. For Super-Sauze, horizontal displacements of 7 to 55 m between a high-resolution airborne ortho-photo of May 2007 and a UAV-based ortho-mosaic of October 2008 have been measured. Fixed areas of persistent deformation have been identified, producing fissures of different distributions and orientations comparable to glacial crevasses, and relating directly to the bedrock topography. The UAV has demonstrated its capability for producing valuable landslide data but improvements are required to reduce data processing time for the efficient generation of ortho-mosaics based on photogrammetric DTMs, in order to minimise georeferencing errors.

Research Highlights
► UAV-based landslide investigation.
► Ortho-mosaic and DTM processing of UAV-based images.
► Quality analysis and comparison between photogrammetry and TLS data sets.
► Morphometric analysis of fissure structures.