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Natural Resources Canada > Earth Sciences Sector > Priorities > Canada Centre for Remote Sensing
Tour Canada from space Whitecourt, Alberta
 Here in the foothills of the Rocky Mountains northwest of Edmonton, the natural environment is interspersed with evidence of human activity in the form of logging and oil production. The forests are comprised of a mix of coniferous and deciduous stands, the common tree types being spruce, pine and aspen. These Landsat TM scenes from August 1986 (left) and October 1986 (right) are displayed using bands 5,4, and 3 (near-infrared, red, green sensitivities) as red, green, and blue, which provides a simulation of the normal green appearance of natural vegetation. The August image has an overall green appearance since forest is the main land cover type and it has high near-infrared (TM band 4) reflectance. In October, however, deciduous trees have lost most of their leaves, resulting in relatively more reflection in bands 3 and 5, displayed as magenta tones (a mix of blue and red) on the image; the underlying geomorphology and drainage pattern (witness the hills at the bottom of the image) thus become obvious. Another predominant land cover type in this area is the bog or wetland found in depressions. The images also show an area that was burned by a forest fire. Intense logging and oil extraction activities are quite evident at both dates of imaging. Look closely and you will see several different cutover patterns, the result of changing logging practices over the past few decades. Oil extraction is evident from the many pumping stations and pipeline tracts.
Question: Why do current harvesting practices leave standing forests between the cutovers? [ Answer ]
About this Image
| Location: |
Whitecourt, Alberta |
| NTS map(s): |
83 J |
 Location Map: |
See a detailed map (1:1M) of the region |
| Image Date: |
August 28, 1986 and October 15, 1986 |
| Satellites/Sensors: |
Landsat Thematic Mapper (TM) Bands 5, 4, 3 (R, G, B) |
| Resolution: |
86 m (chip resolution 30 m) pixels |
| Image Area: |
58 x 69.5 km |
| Image Features: |
Bog, wetlands, flat land, oil, oil pumping, fire risk, fire, burnt-over, logging, harvesting, cutting, coniferous forest, mixed-wood, re-growth, deciduous forest |
| Related Tour Images: |
Port Renfrew, British Columbia |
| Related Glossary Terms: |
These terms from the CCRS Glossary may help you to understand this image and its interpretation:
colour composite, false colour composite, false colour, plant reflectance, true colour, vegetation index, leaf area index |
| Related Tutorial Sections: |
These sections of the "Fundamentals of Remote Sensing" tutorial by CCRS will help you to better understand this image and its interpretation:
2.6 2.8 5.3
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| Image Credits: |
Received, pre-processed and analyzed by the Canada Centre for Remote Sensing |
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Additional
Information: | Starting at the top left corner of this image and extending north for an estimated 154,094 hectares in total, a devastating forest fire during the spring of 1998 became one of the largest in Alberta's history. It took about three weeks to bring the fire under control. Its origin was determined to be lightning and during the fire event, the nearby town of Swan Hills was evacuated twice. |
| Question: |
Why do current harvesting practices leave standing forests between the cutovers? |
| Answer: |
There are several reasons for this strategy: it provides better protection from soil erosion along streams, it preserves some habitat for plants and animals, it is aesthetically more acceptable than a complete cutover, and it preserves some natural seeding sources for the regrowth of trees and other plants. |
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