GIS-based terrain analysis of linear infrastructure corridors in the Mackenzie River Valley, NWT

The impact of global warming on permafrost terrain was discussed with particular reference to the structural stability and performance reliability of the proposed pipelines and roads in the Mackenzie River Valley in the Northwest Territories. Engineers, regulators and decision makers responsible for the development of these networks must have access to information about current and future terrain conditions, both local and regional. The Geological Survey of Canada is developing an ArcGIS resident, multi-component terrain analysis methodology for evaluating permafrost terrain in terms of the probable geothermal and geomorphological responses to climate warming. A GIS-integrated finite-element transient ground thermal model (T-ONE) can predict local-regional permafrost conditions and future responses of permafrost to climate warming. The influences of surface and channel hydrology on local erosion potentials can be determined by analyzing the topographic and topologic characteristics of the terrain. A weights of evidence-based landscape-process model, currently under development, will consider multiple terrain factors for mapping terrain that is susceptible to slope failure, subsidence or erosion. This terrain analysis methodology is currently being applied to a 2 km buffer spanning the proposed Mackenzie Gas Pipeline right-of-way, and along winter and all-weather road networks in the Mackenzie River Valley. Initial ground thermal modeling has identified thermally sensitive terrain for which permafrost will either completely disappear or warm significantly to near isothermal conditions within the next 25 to 55 years