Spatio-temporal reconstruction of debris-flow activity at Torrent de la Greffe (Vionnaz)

The village of Vionnaz is located on the cone of the Torrent de la Greffe. Over the centuries, the torrent has repeatedly menaced or even partly damaged the settlement; this is why a first massive protection dam has already been built in the 17th century. In the aftermath of the most recent debris-flow event in 2005, the existing dam is currently being prolonged. In order to better comprehend past as well as potential future events in the Torrent de la Greffe, abandoned channels and deposits have been mapped on the cone and 313 increment cores, wedges and cross-sections sampled from broadleaved and conifer trees (incl.. Acer pseudoplatanus L., Alnus sp., Fagus sylvatica L., Fraxinus excelsior L., Picea abies (L.) Karst., Robinia pseudoacacia L., Salix ssp.). First results are expected to be available by mid 2008.


Mandators: Swiss Federal Office for the Environment (FOEN), Cantonal Department for Traffic, Construction and Environment (Canton of Valais)

Project duration: August 2007 – September 2008

Contact: Markus Stoffel


Bollschweiler, M., Stoffel, M., Schlaeppy, R. (2011): Debris-flood reconstruction in a pre-alpine catchment in Switzerland based on tree-ring analysis of conifers and broadleaved trees. Geografiska Annaler 93:1-15 [PDF]