Areas that were recently logged in 1984 appear in pink, while areas logged between 1984 and 1991 are portrayed in bright blue. The Landsat TM data used in the colour composite seen here, has a ground resolution of 30 metres and covers an area of about 30km x 30km over temperate rain forest on the southwest coast of Vancouver Island. Three bands of imagery, one from 1991 and two from 1984 have been displayed as red, green and blue to create this colour composite image. This combination of data clearly indicates changes which have occurred in the forest over seven years. Landsat TM is used by forestry companies, Provincial and Federal Government Agencies and Environmental Organizations to monitor forest activities such as cutting, road building and reforestation.
Satellite imagery is a valuable tool in assessing the environmental impact of forest activities.
It can also assist in responsible forest management. Both the medium and the adjacent dark green areas represent similar forest of similar condition. The differing tone represents different illumination by the sun, since these areas are on opposite-facing slopes. This phenomenon is one of the many challenges facing visual interpretation of imagery.