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high to very high, characterized by height differences of more than 700 m. 
The relief features of these broad landscapes units express the 
regional character of their geomorphic origin. Unit P, for example, has a 
typical character of a glaciated plain, while the pronounced relief of the 
hilly and mountainous landscapes (Units H and M) indicates a varying degree of 
bedrock control. 
Local Relief Features 
Local relief is a component of the general relief pattern that 
expresses a particular surface configuration by a type and degree of slopes. 
A slope may be classified as simple or complex . A simple slope defines a 
relatively uniform incline, while a complex slope consists of an aggregate of 
slope patterns. The quantitative slope values and the rate of change may be 
measured on a stereoscopic model and expressed numerically, or estimated and 
described as slope-steepness classes. Actual grouping of slope-steepness 
classes may be arranged arbitrarily to suit the requirements of a particular 
project or study. In the biophysical land classification, for example, the 
simple and complex slopes may be expressed as broad steepness classes: 
inclines up to 10% - gentle slopes, 11 to 30% - moderate, 31 to 60% - steep, 
and inclines over 60% as very steep slopes (Gimbarzevsky 1973). 
In practical application of air photo interpretation techniques the 
stereoscopic analysis of local relief pattern provides a reliable base for 
stratification of the land surface into relatively homogeneous land units 
having similar physical characteristics. The entire area, for example, 
portrayed in Figure 2, is an extensive plain landscape, characterized by a 
relatively low relief. Further analysis of local relief features, their size, 
shape and spatial arrangement allows a recognition of some specific components 
of this low relief landscape, such as land unit "AE", which is composed of 
directionally oriented narrow, low ridges, some 5 to 10 m high, a typical 
diagnostic relief pattern of sand dunes, that may be easily separated from the 
ground moraine (T), or lacustrine plain (L). 
In a medium-scale mapping (e.g. 1:25,000 or 1:50,000) the landscape 
components may be delineated on the basis of local relief and classified as 
individual map units, (e.g. flat, slope, hills), or as a complex of slopes, 
hills and depressions (e.g. rolling plain, dissected plateau, etc.). In 
air-photo analysis of landscapes with a high relief, such as a portion of a 
mountainous landscape illustrated in Figure 3, the recognition of main 
landscape components is relatively simple: the massive bedrock ridges (R), 
bedrock-controlled long slopes (T), or glaciated valleys (F) are easily 
recognized from their distinctive relief pattern alone. An additional 
evaluation of the surface configuration of these landscape components reveals 
the geomorphic origin of landforms and their physical characteristics. Within 
the glaciated valley (F, Fig. 3), for example, the lower section of the 
Kicking Horse River flood plain with sharply defined boundaries, may be 
classified as a braided type (b, Fig. 3), where the surface material is coarse 
gravel subjected to periodic flooding, while the upper section is a