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Le ravin Le Moyne à Château-Richer. Une avalanche alimentée par la neige soufflée en provenance du champ ouvert au sommet du versant (dénivelée 40 m, inclinaison 40°–45°) a fait une victime le 14 février 2000. Photo B. Hétu.

Le ravin Le Moyne à Château-Richer. Une avalanche alimentée par la neige soufflée en provenance du champ ouvert au sommet du versant (dénivelée 40 m, inclinaison 40°–45°) a fait une victime le 14 février 2000. Photo B. Hétu.

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L’analyse croisée des enquêtes des coroners, des articles de journaux et des compilations déjà publiées a permis de retracer 43 avalanches de neige mortelles au Québec depuis 1825. Le bilan provisoire s’élève à 73 morts et à plus de 50 blessés. Soixante pour cent des victimes avaient moins de 20 ans. Plus de la moitié des victimes (38 morts en 12 a...

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... autre surprise de cette enquête concerne la nature des versants propices au déclenchement des avalanches dans le contexte québécois. (Figure 6), en passant par les talus des terrasses marines ou fluviales, les falaises mortes ou vives (Fig- ure 7), les flancs d'un ravin (Figure 8), d'une minè a ciel ouvert, etc. L'inclinaison des pentes avalancheuses est généralement comprise entre 30 • et 50 • , mais elle peut descendrè a 25 • (cas de Blanc-Sablon). Plusieurs versants avalancheux de Lévis, qui correspondent en faitàfaità une an- cienne falaise, ont une pente qui approche-et même, dépasse dans certains cas-les 50 • . ...

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... Such databases also enable a quick access to data that can be analysed using the most recent advances in geostatistical and modelling techniques providing avenues for risk mitigation. Historical documents have been increasingly employed in natural hazard research (Pfister et al., 2006;Raška et al., 2014;Pereira et al., 2016) and several research studies have stressed the potential use of documentary data sources to reinforce the knowledge on snow avalanche events, illustrating the strong interaction between economic and social development and snow avalanche activity (Irwin and Owens, 2004;Hétu et al., 2011;Podolskiy et al., 2014;Hétu et al., 2015). Since the beginning of the 21st century, policies for disaster risk reduction have shifted from structural mitigation measures to a more comprehensive and integrated approach in which mapping is an essential tool for better understanding natural disaster dynamics (EEA, 2010). ...
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... Since the mid-1800s, historical records indicate that more than 700 fatalities have been related to snow avalanches (Campbell et al. 2007). Although most snow avalanche fatalities occur in western Canada, many such incidents have also been reported on the short slopes of eastern Canada (Liverman et al. 2001;Hétu et al. 2011Hétu et al. , 2015. Archival research, coroner's investigations and newspaper searches indicate that snow avalanches are the second most deadly major natural hazard after landslides in the province of Quebec (Landry et al. 2013), with over 73 victims reported between 1825 and 2009 . ...
... The recent survey by Hétu et al. (2011) on mortality resulting from snow avalanches also revealed that the typical victim of a deadly avalanche in Quebec is a young boy killed in his home or while playing on a short but steep slope near his home, during or immediately following a snowstorm (80 % of cases occurred during a snowstorm or in the 48 h following the storm event). As previously mentioned, snow avalanches are not restricted to mountain ranges. ...
... For accidents occurring after 1950, and reported in previously published compilations or in newspapers Schaerer 1979, 1980;Schaerer 1987;Jamieson and Geldsetzer 1997;Jamieson and Brooks 1998;Hétu and Bergeron 2004;Campbell et al. 2007; Sécurité publique Canada 2007;Hétu et al. 2011), it appears that Quebec is experiencing an increase in deaths associated with recreational outdoor activities, a trend also observed in most industrial countries (Atkins and Williams 2000;Jamieson and Stethem 2002). Winter sports are currently booming in Quebec, especially activities in the backcountry (skiing, alpine touring, snowshoing, ice climbing, etc.). ...
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... Les pentes avalancheuses du nord de la Gaspésie ont été cartographiées à différentes échelles (Transports Québec 2005;Hétu 2007). La fréquence à long terme des avalanches a été déterminée par dendrochronologie dans permis de dresser un premier bilan de la mortalité attribuable aux avalanches de neige pour l'ensemble du Québec, d'établir une typologie des accidents en fonction du type d'activité pratiquée et de tracer le portrait 'sociologique' des victimes (Boucher et Hétu 2009;Hétu et al. 2011). L'une des surprises de cette enquête réside dans la répartition géographique des victimes. ...
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Cette étude réalisée à partir de l’analyse croisée des archives, des registres d’accidents, des données météorologiques d’Environnement Canada et de cartes et photographies anciennes illustrant l’évolution des déboisements et de l’urbanisation à Québec et à Lévis depuis le début du XIXe siècle, a permis de mieux cerner les conditions météorologiques et les facteurs de terrain propices au déclenchement des avalanches sur les courtes pentes du Québec. Nos résultats démontrent que les chutes de neige abondantes couplées à de forts vents sont la principale cause des avalanches sur les courtes pentes du Québec méridional. Les avalanches se produisent sur des pentes fortement inclinées dont le dénivelé est le plus souvent compris entre 30 et 80 m. Les zones de départ des avalanches sont généralement situées à moins de 100 m d’altitude. Les pentes avalancheuses sont dotées au sommet d’une surface plane, déboisée, qui permet le transfert de la neige par le vent et la surcharge rapide des hauts de versant, ce qui favorise un régime d’avalanches calqué sur les tempêtes. Dans la région de Québec et de Lévis, les avalanches, beaucoup plus fréquentes à la fin du XIXe siècle que par la suite, sont une création humaine qui fait suite au déboisement. La forte activité avalancheuse de la fin du XIXe siècle s’explique par des chutes de neige plus abondantes, par des tempêtes de neige plus fréquentes, par le déboisement des pentes et par une utilisation du sol (agriculture) propice au transport nivéo-éolien. Le reboisement des versants et l’urbanisation croissante du replat au sommet des versants tout au long du XXe siècle a réduit les transports éoliens et fortement diminué les risques d’avalanche.
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