CGRG Bibliography of Canadian Geomorphology
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Author : Germain, D.; Hetu, B.; and Filion, L
Date : 2010.
Title : Tree-ring based reconstruction of past snow avalanche events and risk assessment in Northern Gaspe Peninsula (Quebec, Canada).
Publication : In: Tree-Rings and Natural Hazards. A State-of-the-Art. Edited by: M. Stoffel; M.Bollschweiler; D.R. Butler; and B.H, Luckman. Springer Dordrecht Heidelberg, London, New York.
Issue :
Page(s) : 51-73.
Abstract
The important points made in our long-term research program in snow avalanches in the northern Gaspe Peninsula can be stated as follows: (i) the dendrogeomorphic methods provide valuable information on the frequencies (return intervals and annual probabilities) of past snow avalanches; (ii) impact scars and tilted trees with reaction wood are the most reliable evidence of past avalanche events; (iii) the probability to extend avalanche chronologies was high with a sample size of 25-30 trees, but increased only slightly with a sample size >40; (iv) a 10% threshold value was appropriate for high-magnitude avalanche identification; and (v) the threshold value can be established using a robust statistical method rather than subjectively. However, in spite its utility in providing data on frequency-magnitude of geomorphic processes, the accuracy of this methodology has yet to be examined, particularly in regard to distinguishing the effects of other processes, i.e., snow creep, soil creep, and wind that may contribute to noticeable impacts on the tree-rings. In this respect, the use of a statistical technique to establish a threshold value should allow us to go one step further in spatiotemporal modeling. Finally, the scarcity of investigations dealing with spatial mapping (GIS) of avalanche return periods and with tree-ring sequences and icefall activity and slushflows are promising research directions, testifying that this approach is still at the developmental stage.
Bibliography of Canadian Geomorphology