Recognizing the need to ensure year-round availability of the Dempster Highway in the context of increasing traffic and a changing climate, Yukon Government Department of Highways and Public Works (HPW) has initiated a project to create a functional plan that specifically considers contributions of climate change to geohazards along the highway. Research and analysis required to assess climate and geohazard vulnerability have been carried out by the Northern Climate ExChange, part of the Yukon Research Centre at Yukon University, feeding into the functional planning process carried out by an engineering consultant. This project included various activities. The first step consisted of a preliminary assessment and literature review, where data and reports from previous surveys and studies pertaining to the study area and its surroundings were reviewed. Additional information such as articles, air photos, satellite imagery, geological and surficial geological maps were reviewed to gain insight about the geomorphologic and surficial geologic conditions of the area. The preliminary assessment was followed by field assessments which took place during the summer and fall, 2017. Field work included a combination of drilling, electrical resistivity tomography (ERT), and installation of ground temperature monitoring instruments. Core samples collected during drilling were kept frozen and returned to the Northern Climate ExChange (NCE) lab in Whitehorse for further analyses including soil grain-size analysis, cryostructure, volumetric excess ice content and gravimetric ice content. Ground temperature data were downloaded in the fall from monitoring instruments installed earlier in the summer, and from those installed in previous years.
In 2013, a team made up of representatives from the government of Northwest Territories Highways, government of Yukon Highways, EBA Engineering and Carleton University began the first phase of a project aimed to assess the vulnerability of the Dempster Highway to the impacts of climate change. Surveys for the road began in 1958 and it was opened in 1979. It is a very remote, gravel road that provides the only year-round highway connection between Inuvik and the rest of Canada’s highway network, and was built on continuous permafrost for 90% of its 736 km. The road structure is an embankment, designed to maintain permafrost and prevent thaw subsidence. Over the past decade there has been an increase in the frequency and severity of issues related to drainage, erosion, and permafrost degradation. As the climate continues to warm, rising streams and increasing numbers of extreme weather events will put additional strain on the aging drainage system. With much of the highway located in the continuous permafrost zones, the warming climate also has a direct impact on the performance of the road, and can result in settlement, sinkhole formation, embankment failure, and other geohazards. Although there are no communities along the Yukon section of the highway, it is a critically important route to the Beaufort Delta Region in the Northwest Territories, serving as a long-haul transport route for food, fuel, supplies, and other goods. The remote location and length of the highway, coupled with the challenging terrain and ground conditions result in relatively high maintenance costs, considering the low traffic volumes (63 vehicles per day).