An Identification of Environmental Disturbances from Road Developments in Subarctic Muskeg

Abstract

The location, nature, and magnitude of some environmental changes associated with the introduction of a road across a muskeg in the discontinuous permafrost zone are identified from examination of near-infrared Landsat images. Impedance of natural surface drainage by the presence of a roadbed is hypothesized to transmit upstream hydro-thermal changes through the muskeg terrain, which in turn cause change in the muskeg vegetation community. Differences among the near-infrared spectral reflectances of fen, black spruce bog, and Sphagnum bog communities are found sufficiently large for use as indices of differences in the actual biophysical natures of the muskegs. &SUMÉ. L'ktude d'images de Landsat presque infrarouges r6vvble l'emplacement, le genre et l'amplitude de certains changements dans I'environ-nement associes iI la construction d'une route B travers un marais dans une zone 21 pergklisol discontinu. L'auteur prbente une hypothk selon la-quelle l'assiette de la chaussk ferait obstacle au drainage de surface normal, causant ainsi des variations dans la vtgktation du marais. Les diffkrences en rkflectance spectrale presque infrarouge entre la terre markageuse, le markage d'kpinettes noires et le markcage de sphaigne sont d'une importance suffisante il servir d'indice dans la nature biophysique vtritable du marais.