MAPPING OF DISCONTINUOUS PERMAFROST USING THE GEOGRAPHIC INFORMATION-SYSTEM - MANITOUNUK STRAIT, NORDIC QUEBEC (CANADA)

Two variables (surficial deposits, vegetation assemblages) were entere d numerically into a GIS which allowed the production of a permafrost regional map. A second permafrost map produced by air photo interpreta tion and precise field work were compared with the GIS-produced map. T he two maps are similar at 92%. In the test region, surficial deposits stand out as the most significant control factor of permafrost distri bution: permafrost areas appear almost exclusively in the clayey silts of the Tyrrell Sea and in the fine matrix till under several bare dru mlin ridges. Vegetation cover, which controls snow depth, comes out as the second variable that allows detailed mapping of permafrost within the fine sediment areas. (C) 1997 by John Wiley & Sons, Ltd.