Detection and Classification of Muskox Habitat on Banks Island, Northwest Territories, Canada, Using Landsat Thematic Mapper Data

• Published in: Arctic 1991-01, Vol.44 (5), p.66-74
• Main Author: Ferguson, Robert S.
• Format: Article
• Language: English
• Subjects: Highlands; Landsat; Musk oxen; Pixels; Remote sensing; Remote sensing satellites; Sedges; Subshrubs; Territories; Tundras; Vegetation; Wildlife habitats
• ISSN: 0004-0843; 1923-1245
• DOI: 10.14430/arctic1572

The feasibility of using Landsat Thematic Mapper data for mapping muskox summer habitat was tested on northern Banks Island, Northwest Territories. Digital image enhancement and classification techniques were examined to determine if summer foraging habitats could be detected and mapped using Thematic Mapper imagery. Interpretations of the satellite data were verified in the field during the summers of 1988 and 1989. The most important summer foraging habitats for muskoxen included the wet sedge meadow, graminoid tundra and graminoid/dwarf shrub tundra cover types. These lowland habitats were generally distinguishable on enhanced colour images and were easily differentiated from upland areas. The most suitable colour composite for differentiating muskox summer habitats was the near-infrared (band 4), shortwave infrared (band 5) and red (band 3) spectral bands displayed in red, green and blue respectively. Upland cover types, including dwarf shrub tundra, hummocky tundra and dwarf shrub/lichen barrens, were more difficult to differentiate because of spectral variability resulting from differences in plant cover and site characteristics. The classified image had an overall accuracy of 88%. The summer habitats of particular importance to muskoxen had classification accuracies of 84-89%. Detection of important foraging habitats on Thematic Mapper imagery is attributable to the spectral distinctiveness of wet graminoid communities and the high spectral sensitivity and spatial resolution of the infrared sensors, which allow detection of differences in surface moisture and vegetation physiognomy. /// L'île Banks située dans les Territoires du Nord-Ouest a servi de site pour l'étude de faisabilité concernant l'utilisation des données obtenues avec l'appareil de cartographie thématique Landsat pour circonscrire l'habitat estival du boeuf musqué. On a utilisé l'accentuation de l'image numérique ainsi que des techniques de classification pour déterminer si les aires de pâturage pouvaient être détectées et cartographiées à l'aide des images de cartographie thématique. Au cours des étés de 1988 et de 1989, on a procédé sur le terrain à des vérifications de l'interprétation des données obtenues par satellite. Les aires de pâturage du boeuf musqué les plus importantes comprenaient la prairie à laîches humide, la toundra de graminées et les types de couvert de toundra de graminées/buissons nains. On pouvait généralement distinguer ces habitats de terres basses sur les ima