Geography Reference
In-Depth Information
A
APPENDIX
Maps
The geographer's greatest ally is the map. Maps can
present enormous amounts of information very effectively,
and can be used to establish theories and solve problems.
Furthermore, maps often are fascinating, revealing things
no other medium can. It has been said that if a picture is
worth a thousand words, then a map is worth a million.
Maps can be fascinating, but they often do not get the
attention they deserve. You may spend 20 minutes care-
fully reading a page of text, but how often have you spent
20 minutes with a page-size map, studying what it reveals?
It is diffi cult to summarize every pattern a map shows in a
caption or paragraph of text. Readers should actively read
maps by looking for patterns and themes. For example, in
chapter 2 on population we study several maps that depict
the human condition by country, including birth and death
rates, infant mortality, hunger index, and life expectancy.
In the text, we can refer only to highlights (and low points)
on those maps. But make a point of looking beyond the
main issue to get a sense of the global distributions these
maps represent. It is part of an intangible but important
process: to enhance your mental map of the world.
While on the topic of maps, we should remind our-
selves that a map—any map—is an incomplete representa-
tion of reality. In the fi rst place, a map is smaller than the
real world it represents. Second, it must depict the curved
surface of our world on a fl at plane, for example, a page of
this topic. And third, it contains symbols to convey the in-
formation that must be transmitted to the reader. These are
the three fundamental properties of all maps: scale, projec-
tion, and symbols.
Understanding these basics helps us interpret maps
while avoiding their pitfalls. Some maps look so convinc-
ing that we may not question them as we would a para-
graph of text. Yet maps, as representatives of the world all,
to some extent, distort reality. Most of the time, such dis-
tortion is necessary and does not invalidate the map's mes-
sage. But some maps are drawn deliberately to mislead.
Propaganda maps, for example, may exaggerate or distort
reality to promote political aims. We should be alert to
cartographic mistakes when we read maps. The proper
use of scale, projection, and symbolization ensures that a
map is as accurate as it can be made.
MAP SCALE
The scale of a map reveals how much the real world
has been reduced to fi t on the page or screen on which it
appears. It is the ratio between an actual distance on the
ground and the length given to that distance on the map,
using the same units of measurement. This ratio is often
represented as a fraction (e.g., 1:10,000 or 1/10,000). This
means that one unit on the map represents 10,000 such
units in the real world. If the unit is 1 inch, then an inch
on the map represents 10,000 inches on the ground, or
slightly more than 833 feet. The metric system certainly
makes things easier. One centimeter on the map would
actually represent 10,000 cm or 100 meters. Such a scale
would be useful when mapping a city's downtown area, but
it would be much too large for the map of an entire state.
As the real-world area we want to map gets larger, we
must make our map scale smaller. As small as the fraction
1/10,000 seems, it still is 10 times as large as 1/100,000,
and 100 times as large as 1/1,000,000. If the world maps in
this topic had fractional scales, they would be even smaller.
A large-scale map can contain much more detail and be far
more representative of the real world than a small-scale
map. Look at it this way: when we devote a half page of
this topic to a map of a major city (Fig. A.1), we are able to
represent the layout of that city in considerable detail. But
if the entire country in which that city is located must be
represented on a single page, the city becomes just a large
dot on that small-scale map, and the detail is lost in favor
of larger-area coverage (Fig. A.2). So the selection of scale
depends on the objective of the map.
A-1
