Composition of the driftwood of the floods from August 19 to 23, 2005 in Switzerland
Introduction
During the floods in August 2005 in Switzerland, many villages encounter problems not only because of a high water flow, but also because of large amounts of driftwood. Therefore the question of the origin and the formation of the driftwood arised.
Project aims
The project aims at gathering information about the origin of the driftwood and the processes that were involved in its formation. Therefore, the driftwood was examined in respect of
- volume
- species composition
- freshness/degree of decomposition
- degradation in the water
- etc.
Methods
After consultation of the cantons, the survey started after the end of the heavy rains. The survey was done in the following reagions: Berner Oberland, Entlebuch, Emmental, Obwalden, Prättigau.
Results
The first results show that the majority of the drift wood was of natural origin. The proportion of construction- or fire-wood was less than 20% at most sites. A large variation was found in the partition of fresh wood. At some sites, only 10% of the natural wood was fresh at others more than 90%.
Project details
Project duration
2005 - 2020
Project lead
- Christian Hug
- Flurin Sutter
- Dr. Tilo Usbeck