GVII-80 
PHOTOGRAMMETRIC ENGINEERING 
of Human Geography (7). In this study he 
described Peru as having two broad nat 
ural regions: the Maritime Andes and the 
Eastern Andes. Within these regions he 
described the dominant “topographic 
types” 1 and their relationship to agricul 
ture, settlement, pastoral life, and com 
munications between groups. These topo 
graphic types represented such recurring 
features as high plateaus, basins, canyons, 
snow-covered mountains, etc. He used 
three basic principles. The first is one of the 
fundamental tenets of the science of geog 
raphy, and may be called the principal of 
relationships. The physical elements of the 
earth are related to each other and to social 
forces which affect the land, permitting cor 
relations to he made between the land and 
human activity. For example, in appraising 
the damage done by a forest fire the relief, 
soil, vegetation cover and the climate are 
all related, and they in turn are related to 
Fig. 1.—Regional diagram representing the deep 
canyoned country of southern Peru (4). The dark hatchures 
represent the canyon type, where settlements are located 
on the only agricultural land, the open diagonal crosshatch 
represents the plateau type, used for pasture, and the close 
diagonal crosshatch represents the mountain type. (From 
Bowman’s “The Andes of Southern Peru.”) 
several techniques to illustrate these 
relationships, the most effective of which 
was the “regional diagram,” as shown in 
Figure 1, a composite sketch map repre 
senting a typical situation, showing the 
topographic types and how they combined 
with other factors to affect man’s use of the 
land from place to place in the region. 
Bowman’s classifications were based on 
1 The term “topographic type,” “natural 
land type,” “landscape type” and “terrain 
type” are used synonymously in this paper. 
the economic value of the timber and the 
watershed. These relationships permit a 
classification of terrain 2 according to its 
physical and economic values. 
The second principle was first expressed 
by Bowman himself (6). A given composi 
tion of the physical elements of the earth is 
repeated essentially from place to place over a 
region, with the result that types of natural 
2 The term “terrain” is used in its broadest 
sense in this paper to include the entirety of the 
physical and cultural landscape.