Ryan Kromer is PhD graduate of Queen’s University and a post doctoral researcher at the Colorado School of Mines. He was a visiting PhD student at the University of Lausanne during 2015 and 2016 and is now visiting the Risk group from April to June 2019. During his visit, he will be conducting research on automated monitoring of landslides using terrestrial LiDAR and photogrammetry. The research visit is supported by the Herbette Foundation. Ryan is looking forward to another fruitfull visit with the group.
In collaboration with the Fondazione Montagna Sicura, Michel Jaboyedoff, Antoine Guerin and Li Fei went to Entrèves (Aosta Valley, Italy) on 23 October 2018 to investigate the 1997 Brenva rockslide scar (3’870 m, Mont-Blanc massif), which reactivated in September 2016. A helicopter flight of about 25 minutes allowed acquiring hundreds of pictures (digital and thermal) of the rock mass in exceptional conditions, as the high mountain was dry in late autumn 2018. A high-resolution Structure-from-Motion model was then generated using these pictures, allowing us to analyze in detail the structural features and rockfall activity of the Sperone della Brenva.
Directors: Prof. Michel Jaboyedoff and Dr. Marc-Henri Derron
Jury: Dr. François J. Baillifard, Prof. Lars H. Blikra, Prof. Jacques Locat, Dean François Bussy
Landslide processes can have direct and indirect consequences affecting human lives and activities. In order to improve landslide risk management procedures, this PhD thesis aims to investigate capabilities of active LiDAR and RaDAR sensors for landslides detection and characterization at regional scales, spatial risk assessment over large areas and slope instabilities monitoring and modelling at site-specific scales.
At regional scales, we first demonstrated recent boat-based mobile LiDAR capabilities to model topography of the Normand coastal cliffs. By comparing annual acquisitions, we validated as well our approach to detect surface changes and thus map rock collapses, landslides and toe erosions affecting the shoreline at a county scale. Then, we applied a spaceborne InSAR approach to detect large slope instabilities in Argentina. Based on both phase and amplitude RaDAR signals, we extracted decisive information to detect, characterize and monitor two unknown extremely slow landslides, and to quantify water level variations of an involved close dam reservoir. Finally, advanced investigations on fragmental rockfall risk assessment were conducted along roads of the Val de Bagnes, by improving approaches of the Slope Angle Distribution and the FlowR software. Therefore, both rock-mass-failure susceptibilities and relative frequencies of block propagations were assessed and rockfall hazard and risk maps could be established at the valley scale.
At slope-specific scales, in the Swiss Alps, we first integrated ground-based InSAR and terrestrial LiDAR acquisitions to map, monitor and model the Perraire rock slope deformation. By interpreting both methods individually and originally integrated as well, we therefore delimited the rockslide borders, computed volumes and highlighted non-uniform translational displacements along a wedge failure surface. Finally, we studied specific requirements and practical issues experimented on early warning systems of some of the most studied landslides worldwide. As a result, we highlighted valuable key recommendations to design new reliable systems; in addition, we also underlined conceptual issues that must be solved to improve current procedures.
To sum up, the diversity of experimented situations brought an extensive experience that revealed the potential and limitations of both methods and highlighted as well the necessity of their complementary and integrated uses.
Hello to everyone,
We will be presenting a Short Course at the European Geosciences Union General Assembly. The course is entitled “Use of 3D point clouds in Geosciences: Acquisition, Processing and Applications” and the pdf of the Powerpoint presentations can be downloaded here.
DATE AND PLACE: Monday 13th of April, from 17:30 to 19:30 in room B7. If you are a PhD student or an Early Stage Researcher, you are welcome to assist.
CONTENTS OF THE COURSE
|Introduction to course + speakers (AA+MJ)||5’|
|1. Short introduction to LiDAR sensors + photogrammetry (MHD)||15’ (20’)|
|2. Point cloud acquisition, pre-processing and available software (AA)||15’ (35’)|
|3. 3D geological mapping (FH)||15’ (50’)|
|——10 min. Pause ——||10’ (1h)|
|4. Rock structural characterisation (AG)||15’ (1h 15)|
|5. Monitoring: Change detection + Deformation (DC)||15’ (1h 30)|
|6. Perspectives and discussion (AA)||15’ (1h 45)|
The PowerPoints of the course and some RAW 3D point clouds will be uploaded here some days before the beginning of the course. Some other information can be found here: http://meetingorganizer.copernicus.org/EGU2015/session/19506
Also, we want to account with your vision, in case you’ll be interested in contributing for the last part of our course (“6. Perspectives and discussion”), you can contact us and send us your contribution.
Good news! The number of citations that we are receiving concerning Natural Hazards related journals is considerably increasing… For the past five years we have had the 2nd most cited paper in Natural Hazards journal (Springer) …
We also obtained not bad results concerning Natural Hazards and Earth System Sciences journal (Copernicus): have a look at the 4th and 5th most cited papers in the last five years
NATURAL HAZARDS & EARTH SYSTEM SCIENCE: http://scholar.google.ch/citations?hl=fr&view_op=list_hcore&venue=EKUCyVlF5DoJ.2014
Abellán, A., Oppikofer, T., Jaboyedoff, M., Rosser, N. J., Lim, M. and Lato, M. J. (2014), Terrestrial laser scanning of rock slope instabilities. Earth Surf. Process. Landforms. DOI: 10.1002/esp.3493
This manuscript presents a review on the application of a remote sensing technique (terrestrial laser scanning, TLS) to a rock slope characterization and monitoring. Key insights into the use of TLS in rock slope investigations include: (a) the capability of remotely obtaining the orientation of slope discontinuities, which constitutes a great step forward in rock mechanics; (b) the possibility to monitor rock slopes which allows not only the accurate quantification of rockfall rates across wide areas but also the spatio-temporal modelling of rock slope deformation with an unprecedented level of detail.
Further investigation on the development of new algorithms for point cloud filtering, segmentation, feature extraction, deformation tracking and change detection will significantly improve our understanding on how rock slopes behave and evolve.
Perspectives include the use of new 3D sensing devices and the adaptation of techniques and methods recently developed in other disciplines as robotics and 3D computer-vision to rock slope instabilities research.
More information and full paper on the ESPL website.
SafeLand was a Large-scale integrating Collaborative research project funded by the The Seventh Framework Programme for research and technological development (FP7) of the European Commission. The project team, composed of 27 institutions from 13 European countries, was coordinated by Norwegian Geotechnical Institute (NGI).
SafeLand aimed at developing generic quantitative risk assessment and management tools and strategies for landslides at local, regional, European scales. It also established the baseline for the risk associated with landslides in Europe, and improved our ability to forecast landslide and detect hazard and risk zones.
During this 3-years project, our group mainly contributed to the following deliverables:
- D 1.6: Analysis of landslides triggered by anthropogenic factors in Europe
- D 2.10: Identification of landslide hazard and risk “hotspots” in Europe
- D 4.1: Review of Techniques for Landslide Detection, Fast Characterization, Rapid Mapping and Long-Term Monitoring (as Editor)
- D 4.4: Guidelines for the selection of appropriate remote sensing technologies for monitoring different types of landslides
- D 4.8: Guidelines for landslide monitoring and early warning systems in Europe – Design and required technology
- D 5.1: Compendium of tested and innovative structural, non-structural and risk-transfer mitigation measures for different landslide types
All deliverables and more information about the SafeLand project can be found on www.safeland-fp7.eu.
Featured image: Landslide in Namsos, Norway (copyright SafeLand)