68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

PERMAFROST DEGRADATION ADJACENT TO SNOW FENCES ALONG THE DEMPSTER HIGHWAY, PEEL PLATEAU, NWT

Session: Permafrost Degradation I / Dégradation du pergélisol I

Brendan O'Neill, Carleton University (Canada)
Chris Burn, Carleton University (Canada)

The long-term ground thermal effects of a snow fence in continuous permafrost (Fence 1) were examined on Peel Plateau, west of Fort McPherson, NWT. Active-layer thicknesses and vegetation changes were also described at three additional fences (Fences 2-4). The fences were erected in the early 1980s, so present environmental conditions represent the effects of over 30 years of modification to snow conditions. We observed increased snow cover, active-layer thickness (ALT), and moisture content at Fence 1, which have combined to prevent winter freezeback, so that a talik now exists at the site. ALTs were statistically related to distance from the fence at flat sites, but not at sites of slope =5° with good drainage.