Search Textbook

Table of Contents
Foreword
Preface
Glossary

Chapter 1: Introduction

1.2: Sequential Air Photos of the Assiniboine River Near the Junction with Birdtail Creek

Figure 1.2a: 1946 Photo

The photo shows a stretch of the south flowing Assiniboine River 1 just above (0.75 miles: 1.2 km) its junction with Birdtail Creek. The river meanders freely across the floor of the Assiniboine Spillway, a flat-floored valley that used to carry water from glacial lakes in Saskatchewan to glacial Lake Agassiz in southern Manitoba. Several abandoned channel sections 2 can be seen, all of which were abandoned before the first map of the area was made in 1882. Note two narrow meander necks 3 and 4 in the southern half of the photo.

Note also: 1) the relatively light tone of the sediment-laden Assiniboine River 5, compared with the dark sediment-free water 6 in abandoned channels; and 2) the mottled texture 7 in the area of deciduous woodland west of the river where trees are changing colour at the beginning of fall resulting in various tones.

Figure 1.2b: 1981 Photo

In this 1981 photo the narrow neck 1 (3 in figure 1.2a) has broken resulting in an abandoned channel 2. The meander neck in the centre 3, although narrower than on the older photo, is still extant but looks as if it will break any time.

Note also: 1) the uniform dark tone of the deciduous trees west of the Assiniboine 4 in this summer photo when all the leaves were green; and 2) a small recently abandoned channel 5 in the south.

Figure 1.2.a: 1946 Photo

Figure 1.2.a: 1946 Photo

Figure 1.2a

Vertical air photo: A10707-57

Flight height: 9,800 feet a.s.l.; lens focal length: 152.4 mm

Scale: 1:17,000 (approx.)

Date: October 4, 1946

Location: Township 15, Range 27/28 WI

Map sheets: 1:250,000 62K Riding Mountain

1:50,000 62K/6 Birtle




Figure 1.2.b: 1981 Photo

Figure 1.2.b: 1981 Photo

Figure 1.2b

Vertical air photo: 8126-00-037

Flight height?: lens focal length: 152.034 mm

Scale: 1:15,800 (approx.)

Date: August 16, 1981

Location: Township 15, Range 27/28 WI

Map sheets: 1:250,000 62K Riding Mountain

1:50,000 62K/6 Birtle