Lauren Gavillet: Dynamique d’érosion et étude de stabilité d’un petit bassin versant alpin: le cas du Courset (VD, Switzerland)

Lauren Gavillet
Supervisor: Prof. Michel Jayboyedoff
Internal Experts: MSc. Pierrick Nicolet, MSc. Benjamin Rudaz
External Expert: Marcel Burri

The landslide triggered on August 26, 2005 by a heavy rain event, in the watershed of the Courset is the origin of this master thesis. To determine if this event was exceptional or if we can expect an intensification of erosion processes, the activity of the watershed is analyzed through its dynamic erosion and through analysis of the stability of slopes.

To collect interesting and useful informations on the watershed, a history of developments and events that have affected the watershed of the Courset is established. Geotechnical analyzes are performed to characterize the soils of the watershed. These results are then used to model the stability of slopes. Rainfalls in the region are also analyzed to be used in this modeling.

After a description of the watershed dynamics, longitudinal profiles and their knickpoints are identified in order to locate areas of the profiles that will be affected by erosion. The erosion potential of the entire watershed is also estimated. Past erosion is studied in light of the observed current activity.

A synthesis of the controversial quaternary filling hypothesis of the Lavey-Le Châtel glacial trough is established, and a new reconstitution is proposed.