Guillaume FORTIN, Département d'histoire et de géographie, Université de Moncton, Canada
Daniel GERMAIN, Département de géographie, Université du Québec à Montréal, Canada
In Canada, extreme weather events have increased significantly in number and cost since the 1980s. November 2021 was punctuated by several extreme and destructive hydroclimatic events that occurred almost simultaneously in Western (British Columbia) and Eastern (Nova Scotia and Newfoundland) Canada. Although the causes of these events are not interrelated, they remain a concern for the health and safety of vulnerable populations. The heavy rains recorded have broken several historical records and seriously disrupted the transportation of goods and services.
In this presentation, we analyze the causes and consequences of this major crisis that brought up to 211 mm of rain in 24 hours (Ingonish Beach station, pulverizing the previous record dating back to 1970) in the study area. Particular attention will be paid to the "atmospheric river" phenomenon that hit the study area and was the main source of moisture that caused the extreme rainfall recorded by several weather stations in the region. The atmospheric river phenomenon is common in Western Canada but relatively rare in Eastern Canada, which is partly explained by the geographic configuration of the affected areas. In addition, destructive winds reaching up to 120 km/h accompanied this exceptional storm, which increased the amplitude of the waves and their destructive force on the road infrastructure in coastal areas. The closure and destruction of several sections of the Trans-Canada Highway (the only link connecting several isolated communities) and the interruption of the ferry service linking Nova Scotia to Newfoundland (road transport) are examples of the impacts of this extreme weather event.
Mots clés : extreme rainfall|atmospheric river|major impacts|Eastern Canada
A103220GF