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POTENTIAL CLIMATE CHANGE IMPACTS AND ADAPTATION FOR INFRASTRUCTURE IN NORTHERN COMMUNITIES UNDERLAIN BY PERMAFROST
ROBINSON, STEPHEN D St. Lawrence University.
Couture, Rejean Geological Survey of Canada.
Burgess, Margo M Geological Survey of Canada.
Smith, Sharon L Geological Survey fo Canada.
Regional studies in the Arctic (Maxwell, 1997) and in the Mackenzie Valley (Cohen, 1997; Dyke and Brooks, 2000) suggest that permafrost will partially or completely disappear over large areas of the Canadian north in the event of predicted climate warming. Warm (>-2oC) and thin (<50 m thick) permafrost is at greatest risk of thaw (Smith et al., 2000). There has already been significant research examining the potential impacts of climate change upon natural systems, yet the impacts upon communities and infrastructure are generally poorly known or little studied, as are possible strategies for adaptation. As much of the infrastructure in northern communities relies on the properties of frozen materials for stability, warming of the ground could degrade the performance of many existing and future structures including roads, building foundations, utilities, and embankments (Etkin, 1998; Nelson et al., 2001).
Infrastructure problems have already been experienced in the Mackenzie valley and delta regions owing to both natural and anthropogenic changes and difficulties of building on permafrost. Even under current climate conditions, the clearing of a vegetated surface imposes changes upon the thermal regime of underlying permafrost, in many instances initiating near-surface thaw and ground subsidence in ice-rich material. Over time, engineers working in northern environments have incorporated the impacts of moderate thaw into infrastructure design. However, it appears likely that these structural integrity problems will be enhanced under a warmer climate, in which near-surface thaw will become deeper, ground subsidence more pronounced, and in which the complete loss of permafrost will occur in some regions.
It appears likely that communities in the north, including both communities in this case study, will experience some negative impacts upon infrastructure owing to a warming of the ground and thaw of permafrost. There will be a need to adapt to these impacts. Some possible adaptations are reactive; that is they can be initiated after the impact has occurred, whereas others are proactive, requiring an ability to anticipate and forecast climate and impact magnitude.
This presentation discusses the potential impacts of climate change-induced permafrost thaw upon infrastructure in northern permafrost-affected communities, using case studies from the communities of Norman Wells and Tuktoyaktuk, Northwest Territories, Canada. Although this presentation focuses on the Mackenzie Valley region, in many cases the impacts and adaptation mechanisms may be applicable in other communities with similar permafrost conditions.
Cohen, S., 1997, Mackenzie Basin Impact Study (MBIS) – Final Report, Environment Canada, Ottawa, 372 pages.
Dyke, L.D., and Brooks, G.R., 2001, The physical environment of the Mackenzie valley: a baseline for the assessment of environmental change. Geological Survey of Canada Bulletin 547.
Etkin, D., 1998, Climate change impacts on permafrost engineering design. Environmental Adaptation Research Group Report, Environment Canada, Toronto, Ontario, 42 pages.
Maxwell, B., 1997, Responding to global climate change in Canada’s Arctic. Volume II of the Canada Country Study: Climate Impacts and Adaptation, Environment Canada, 82 pages.
Nelson, F.E., Anisimov, O.A., and Shiklomanov, N.I., 2001, Subsidence risk from thawing permafrost. Nature, 410, p. 889.
Smith, S.L., Burgess, M.M., and Heginbottom, J.A., 2000, Permafrost in Canada, a challenge to northern development. In: A Synthesis of Geological Hazards in Canada, G.R. Brooks (ed.), Geological Survey of Canada Bulletin 548, p. 1-24.
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