Université de Fribourg

Tree-ring reconstruction of past debris flows based on a small number of samples—possibilities and limitations

Stoffel, Markus ; Bollschweiler, Michelle

In: Landslides, 2009, vol. 6, no. 3, p. 225-230

Tree-ring analyses have often been used in the past for the reconstruction of spatiotemporal patterns of previous debris-flow activity, often yielding very precise and extensive data for torrents where information on former activity was largely missing. Unless dendrogeomorphology is slated for multimillion Euro developments, the large sets of tree-ring series that are usually used in these...

Université de Fribourg

Debris flows on forested cones – reconstruction and comparison of frequencies in two catchments in Val Ferret, Switzerland

Bollschweiler, Michelle ; Stoffel, Markus

In: Natural Hazards and Earth System Sciences, 2007, vol. 7, no. 2, p. 207-218

Debris flows represent a major threat to infrastructure in many regions of the Alps. Since systematic acquisition of data on debris-flow events in Switzerland only started after the events of 1987, there is a lack of historical knowledge on earlier debris-flow events for most torrents. It is therefore the aim of this study to reconstruct the debris- flow activity for the Reuse de Saleinaz and...

Université de Fribourg

Differentiating past events on a cone influenced by debris-flow and snow avalanche activity - a dendrogeomorphological approach

Stoffel, Markus ; Bollschweiler, Michelle ; Hassler, Gion-Reto

In: Earth Surface Processes and Landforms, 2006, vol. 31, no. 11, p. 1424 - 1437

Dendrogeomorphology was used to investigate past events on a cone affected by both debris flows and snow avalanches. We report on results of 520 cores from 251 injured Larix decidua Mill. and Picea abies (L.) Karst. trees sampled on the Birchbach cone (Swiss Alps). Detailed analysis of tree-ring sequences allowed dating of 561 growth disturbances in individual trees for a 252 yr...