Search Textbook

Table of Contents
Foreword
Preface
Glossary

Chapter 1: Introduction

1.8: Air Photo Interpretation Criteria Applied to an Area South of Wawanesa

This photo illustrates the use of the air photo interpretation criteria: tone, texture, location, and shadow (shape). A field in the south-centre 1 is uniformly dark-toned and consequently has a smooth texture. It is characteristic of fallow fields in this area developed on flat, lake-bottom sediments that produce black chernozem soils. The field to the northeast 2 has supported a grain crop that has been harvested, the remaining stubble producing a light tone. However, the farmer has “cultivated” the edge of the field producing a dark-toned fringe 3. Located in the middle of two fields to the west are irregular masses 4 which, as they throw a shadow, have some vertical extent. Their locations in the centre of cropped fields suggest that they are straw piles. Another possible explanation might be that they are stone piles, but given the obvious fertility of the fields in the area, this explanation is less likely. The river in the north is the Souris 5 flowing from west to east. Some of the trees near the meander are light-toned 6 suggesting first that they are deciduous trees (in this area, probably aspen-Populus tremuloides) and second that the photo was taken in the fall when the leaves turn yellow. The direction in which the shadows—of trees 7, buildings 8, and a river cliff 9—fall is towards the top of the photo suggesting that the top of the photo is north.

Figure 1.8: Air Photo Interpretation Criteria Applied to an Area South of Wawanesa

Figure 1.8: Air Photo Interpretation Criteria Applied to an Area South of Wawanesa

Figure 1.8

Vertical air photo: A11123-224

Flight height: 12,400 feet a.s.l.; lens focal length: 8 inches

Scale: 1:15,000 (approx.)

Date: October 4, 1947

Location: Township 7, Range 17 WI

Map sheets: 1:250,000: 62G Brandon 

1:50,000: 62G/12 Wawanesa