The Geological Survey of Canada initiated an assessment of infrastructure needs in the north, by examining its sensitivity to impacts of permafrost degradation under climate warming, using a community case study approach on a transect through the Mackenzie Region. Such evaluations at a scale useful for anticipating and adapting to the impacts of climate change in northern population centres did not exist.

The Mackenzie Region has undergone the most warming (1.7oC) over the last century in Canada (Environment Canada, 1995). General circulation models predict that for climate warming resulting from a doubling of CO2 the region will experience increases in mean annual air temperature of up to 4 or 5oC. Regional studies such as Environment Canada's Mackenzie Basin Impact Study (Cohen, 1997) and the Canada Country Study - Arctic Region (Maxwell, 1997), and Natural Resources Canada's Physical Environment of the Mackenzie Valley (Dyke and Brooks, 2000) show that the permafrost will partially or completely disappear over large areas of the north in the event of predicted climate change. The design of much of the infrastructure in northern communities relies on the properties of frozen materials for stability, and warming of the ground could degrade the performance of existing structures (Bush et al, 1998). Problems have been experienced, in roads, foundations, utilities, and embankments, due to both natural and anthropogenic changes. Future climate warming could enhance or generate problems affecting the integrity of both existing and new infrastructure.

Permafrost coverage

Two communities, Norman Wells and Tuktoyaktuk, were selected, each with different characteristics in terms of population, resources, development, infrastructure, and permafrost conditions. Norman Wells is located in the northern part of the discontinuous permafrost zone and has higher ground temperatures than Tuktoyaktuk which lies within the continuous permafrost zone. With the recent trend in devolution of local power and costs from territorial governments, northern communities are increasingly more responsible for their own infrastructure. The community-level approach allowed, in collaboration with stakeholders, an examination of the need for adaptative measures and strategies for existing infrastructure and the planning of future development upon permafrost terrain. This project provided a critical tool for setting the priorities for the development and implementation of a more comprehensive northern community infrastructure adaptation strategy.

1. Outlining infrastructure, surficial geology, and permafrost for two northern case study communities

This project compiled a summary of infrastructure and existing geotechnical and permafrost data for the selected northern communities, Norman Wells and Tuktoyaktuk. Infrastructure data includes foundation and construction type, maintenance history and performance. Surficial geology, geotechnical and permafrost conditions in each community are assessed through a survey of surficial deposits, borehole stratigraphy, geotechnical studies, ground ice and ground temperatures, primarily from existing data. A generic review of foundation problems related to permafrost was initiated in order to help identify and implement the most appropriate response strategies related to climate change impacts. This has resulted in the compilation of a summary report for each community outlining present infrastructure, surficial geology, and permafrost conditions.

The entire digital database and borehole viewers are published as GSC Open File 3912.

2. Assessment of the sensitivity of northern infrastructure to climate change impacts

This phase of the project attempted in a rational way to assess the sensitivity of permafrost-affected infrastructure to current climate trends and to future climate change scenarios. This utilized thermal modeling in combination with an evaluation of geotechnical data to assess the potential impact of thawing in both the continuous and discontinuous permafrost zones. The combination of permafrost modelling and geotechnical evaluation provided a methodological framework for assessing foundation performance and the potential for problematic ground conditions at the community level. This framework, building upon the screening process of Bush et al, (1998), provided the opportunity to expand research on infrastructure, permafrost and climate change scenarios to other northern communities.

Permafrost-affected infrastructure

Permafrost-affected infrastructure

3. Assess the need for the development of adaptation strategies and initiate a planning process

These results assisted communities and authorities responsible for design, construction, and maintenance of infrastructure, such as town public works departments, in developing adaptation plans for incorporating climate change into these duties. This community-level approach will set the stage for a broader northern priority setting exercise and action plan.

4. Communication and outreach

Our understanding of the science and the potential climate change impacts upon infrastructure in permafrost terrain has been communicated to community and other stakeholders (industry, engineers etc.) through written reports and consultation as an aid to developing adaptation strategies according to their needs. Non-technical documentation (e.g. posters, pamphlets (Front [PDF, 5.0 Mb, viewer], Back [PDF, 1.9 Mb, viewer]), exhibits, or a guidebook) on climate change and its impacts related to permafrost, infrastructure and northern communities' safety and their environment and economy were provided to institutions such as museums, schools, and Town Councils for educational awareness.

Cohen S.J. (1997). Mackenzie Basin Impact Study (MBIS). Final report, Environment Canada, Environmental Adaptation Research Group, 372 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.

Dyke L.D. & Brooks G.R. (Editors) (2000). The physical environment of the Mackenzie Valley: a baseline for the assessment of environmental change. Geological Survey of Canada Bulletin 547, p. 189 pages.

Bush, E., D.A. Etkin D. Hayley, E. Hivon, B. Ladanyi, B. Lavender, G. Paoli, D. Riseborough, J. Smith and M. Smith, 1998. Climate Change Impacts on Permafrost Engineering Design (Downsview: Environment Canada, Environmental Adaptation Research Group)