A New Tree-Ring-Based, Semi-Quantitative Approach for the Determination of Snow Avalanche Events: use of Classification Trees for Validation

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Schläppy, Romain, Jomelli, Vincent, Grancher, Delphine, Stoffel, Markus, Corona, Christophe, Brunstein, Daniel, Eckert, Nicolas, Deschâtres, Michaël
• Other Authors: Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Dendrolab.ch Bern, Institute of Geological Sciences Bern, University of Bern-University of Bern, Climatic Change and Climate Impacts Research Group, Institute for Environmental Sciences Geneva (ISE), Université de Genève = University of Geneva (UNIGE)-Université de Genève = University of Geneva (UNIGE), Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), ANR-09-RISK-0007,MOPERA,MOdélisation Probabiliste pour l'Evaluation du Risque Avalanche(2009)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: ANALYSE STATISTIQUE; EPA; CHAMONIX; AVALANCHE; DENDROMETRIE; GEOMORPHOLOGIE; [SDE]Environmental Sciences; [SDE.ES]Environmental Sciences/Environmental and Society; [SDE.MCG]Environmental Sciences/Global Changes; Briand; Sion; Antarctic and Alpine Research; Arctic
• Online Access: https://hal-cnrs.archives-ouvertes.fr/hal-03036941; https://hal-cnrs.archives-ouvertes.fr/hal-03036941/document; https://hal-cnrs.archives-ouvertes.fr/hal-03036941/file/Schl%C3%A4ppy%20et%20al.%20%282013%29.pdf; https://doi.org/10.1657/1938-4246-45.3.383

International audience On forested paths, dendrogeomorphology has been demonstrated to represent a powerful Vincent Jomelli* tool to reconstruct past activity of avalanches, an indispensable step in avalanche hazard Delphine Grancher* assessment. Several quantitative and qualitative approaches have been shown to yield Markus Stoffel † ‡ reasonable event chronologies but the question of the completeness of tree-ring records remains debatable. Here, we present an alternative semi-quantitative approach for the Christophe Corona † determination of past snow avalanche events. The approach relies on the assessment of Daniel Brunstein* the number and position of disturbed trees within avalanche paths as well as on the Nicolas Eckert § and intensity of reactions in trees. In order to demonstrate that no bias was induced by the dendrogeomorphic expert, we carry out a statistical evaluation (Classification and Regres-Michael Deschatres § sion Trees, or CART) of the approach. Results point to the consistency and replicability *Laboratoire de Géographie Physique, of the procedure and to the fact that the approach is not restricted to the identification of Université Panthéon-Sorbonne, UMR high-magnitude avalanches. Evaluation of the semi-quantitative approach is illustrated on 8591 CNRS, 1 place Aristide Briand, Fa well-documented path in Chamonix, French Alps. For the period 1905-2010, comparison 92195 Meudon cedex, France †Dendrolab.ch, Institute of Geological between the avalanche years recorded in a substantial database (Enquête Permanente sur Sciences, University of Berne, les Avalanches, or EPA) and those defined with dendrogeomorphic techniques shows that Baltzerstrasse 1 ‫ם‬ 3, CH-3012 Berne, the avalanche record reconstructed from tree-ring series contains 38% of the observed Switzerland events.