Northwest Territories Geological Survey

Knowledge of ground ice conditions and landscape thaw susceptibility provide the foundation to support resilient infrastructure in the north. Ground ice distribution, combined with terrain and climate factors, dictates landscape sensitivity of permafrost regions. Terrain, ground ice, and climate conditions across the 875 km Dempster and Inuvik-Tuktoyaktuk highway corridor vary to produce a natural laboratory where the factors that influence thaw sensitivity can be assessed. The Geological Surveys of Canada and the Northwest Territories are working together to develop robust methodology to identify, classify, and map permafrost, mass-wasting, and thermokarst features to provide baseline spatial information to support terrain studies and risk assessment along the corridor. Using a 3-D mapping approach that combines high-resolution satellite imagery and elevation data, geomorphological features related to periglacial, hydrological, and mass movement processes are identified and mapped within a 10 km-swath centred along the highway corridor. To ensure reproducibility and reliability of the results among mappers, the methods are tested by a number of technicians and include quality control/quality assurance measures. In addition to generating critical geoscience data for this region, the methods have been transferred to a stand-alone protocol, which can be applied in other fine-scale permafrost terrain or hazard mapping projects. Our overarching goal is to use the map data in conjunction with available geoscience data to develop better landscape system models. However, the maps also support other research projects such as the interpretation of local surface deformation patterns using satellite radar methods (DInSAR), provision of fine-scale data used to upscale terrain mapping efforts, and risk assessment along northern highways.