Snow avalanches, debris flows and floods at Torrent du Lourtier and Dranse de Bagnes

Debris flows and snow avalanches regularly occur in the channel of the Torrent du Lourtier (Val de Bagnes, Valais Alps). At the confluence with the Dranse de Bagnes river, debris-flow material and avalanche snow may cause (log) jams. In addition, several precipitation-induced flood events have been reported for the Dranse de Bagnes river in the recent past. Based on the results of geomorphic mapping, 390 increment cores from European larch (Larix decidua Mill.) and Norway spruce (Picea abies (L.) Karst.) have been sampled at the confluence of the Torrent de Lourtier and the Dranse de Bagnes in order to differentiate the areas of influence of the three different processes. It is the first time that three geomorphic processes are investigated at once and first results can be expected for 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