Search Textbook

Table of Contents
Foreword
Preface
Glossary

Chapter 5: Vegetation

5.10: Distribution of Natural Vegetation in Central Manitoba

This Landsat colour composite was obtained on August 15, 1973 at which time the natural vegetation was reflecting large amounts of infrared radiation and therefore appears as red/orange in the image. Water bodies are imaged in various shades of blue: dark where there is little suspended sediment and pastel where there is a large suspended load.

In the northeast is Lake Winnipegosis 1 that drains from Long Island Bay 2 by the West Waterhen River 3 into Waterhen Lake 4 that in turn drains south via the Waterhen River 5 into the north end of Lake Manitoba 6. Dauphin Lake 7, a basin of inland drainage, is located further south. In the north are the south ends of Pelican Lake 8 and Swan Lake 9. Surrounding the large lakes in the northeast are numerous small lakes occupying structural depressions in the Interlake Region 10. In the south is the long, narrow Lake of the Prairies 11 created by a dam across the Assiniboine River at Shellmouth (off the south edge of the image).

Three highland areas—Riding Mountain 12, Duck Mountain 13, and the Porcupine Hills 14—are covered by thick moraine with numerous lake-occupied depressions. In Riding Mountain, Edwards Lake 15, Moon Lake 16, Shoal Lake 17, and Gunn Lake 18 can be identified. In Duck Mountain, Childs Lake 19, Laurie Lake 20, and Singush Lake 21 can be seen in the centre; Madge Lake 22 and Bearhead Lake 23, just west of the Manitoba/Saskatchewan border, can be seen in the west; and Wellman Lake 24 is in the north. In the Porcupine Hills, Whitefish Lake 25, South Steeprock Lake 26, North Steeprock Lake 27, Bell Lake 28, and the eastern part of Armit Lake 29 can be seen.

The red/orange tone of Riding Mountain is broken in the north by a slightly lighter toned area 30, the result of a forest fire. The same arrangement can be seen in central Duck Mountain 31—also the result of a fire. In these lighter toned areas, although the vegetation has regenerated since the fires, it is not as strong as in the surrounding regions. In the case of the Porcupine Hills there is a uniformly red/orange fringing zone 32 surrounding a less uniformly toned interior 33; the latter is a morainic lake-covered area whereas the steep fringing zone has few lakes.

Outside the three hilly areas most of the land west of Lake Winnipegosis is wooded, as is the Westlake region 34. The valleys between the hills (35 and 36) and the land southwest of Duck Mountain 37 have been cleared for agriculture, although occasional wooded areas occur, for example, along the upper Assiniboine Valley 38, in the valley of Big Boggy Creek 39, and on some Lake Agassiz strandlines 40.

A few clouds are seen on the image mainly in the southwest 41 and west 42. Over Duck Mountain small cumulus clouds cast shadows to the northwest 43, indicating that the image was obtained in the morning.

Figure 5.10: Distribution of Natural Vegetation in Central Manitoba

Figure 5.10: Distribution of Natural Vegetation in Central Manitoba

Figure 5.10

Landsat image, Colour composite: band 4-0.5 to 0.6 micrometres (green); band 5-0.6 to 0.7 micrometres (red); and band 7-0.8 to1.1 micrometres (infrared)

Date: August 15, 1973

Scale: 1:1,000,000 (approx.)