Assessing the Vulnerability of Ministère des Transports du Québec Infrastructure in Nunavik in a Context of Thawing Permafrost and the Development of an Adaptation Strategy

The warming climate in Nunavik is affecting 9 of 13 MTQ airport infrastructure facilities in Nunavik with significant differential settlement and considerable longitudinal settling. A monitoring program along with installation of settlement plates at the most problematic locations was set up by the MTQ. Field campaigns of geophysical investigation and deep drilling were done to characterise the permafrost and to determine the depth of the active layer. The behaviour of the thawing permafrost was studied in laboratory on intact frozen samples. Over the last few years, the MTQ has been supervising research projects to predict and quantify the scale of the damage that can be expected in the wake of climate change and on adaptation techniques intended to mitigate the effects of thawing permafrost witnessed on the access road to the Salluit airport and the Tasiujaq runway. Preventive stabilization work has also been carried out on the Puvirnituq runway embankment. The work done since 2004 has allowed the MTQ to develop a specific strategy for adapting each of its infrastructure assets impacted by permafrost degradation. Adaptation solutions are chosen using a cost-benefit/effectiveness analysis and take into consideration both the safety of the engineering works and the technical and environmental constraints. These solutions entail either reducing snow accumulation and removing water from the toe of the embankment, or cooling the embankment during the winter. The vulnerability of the embankment of the Salluit airport access road prompted implementation of this strategy, and the design of embankment stabilization is currently under way.