MAP PROJECTIONS
& TYPES OF MAPS
AP HUMAN GEOGRAPHY
MAP PROJECTIONS
MAP PROJECTIONS
• Cartographers have to deal with the problem of
making maps of a spherical earth onto a flat
surface  this leads to distortions
• Shape can be distorted
• Distance between two points can increase or decrease
• Relative size may be altered, areas can appear much
larger than they really are
• Direction can be distorted
ROBINSON PROJECTION
ROBINSON PROJECTION
• More accurately shows the area near the poles
• Used to show proportions of land to water
• Distorts cardinal directions and distance
MERCATOR PROJECTION
• Used primarily for
navigation since it
is easiest to plot
direction
• Increased
distortion the
further away from
the equator
• Makes the North
look much larger
GALL-PETERS PROJECTION
GALL-PETERS PROJECTION
• Focuses more on land area accuracy
• Released in 1974, based off a 1800 design
• More accurately shows southern hemisphere as
larger than northern hemisphere
• Areas near the poles are stretched horizontally
GOODE HOMOLOSINE PROJECTION
DYMAXION PROJECTION
TYPES OF MAPS
MAPS AS A TOOL TO UNDERSTAND
SPATIAL PATTERNS
• Maps can give insight to how a phenomenon is
occurring and provide the starting point for
understanding the why
Example: A doctor figures out why a group of specific
people are getting cholera by using a map to see
they were all living in the same general area and
using the same water pumps, which were causing
the cholera outbreak
CHOROPLETH MAPS
• A map showing quantity by area. It uses shades of
colors to show intervals
ISOLINE MAPS
• A map that is used to display distributions. It consists
of lines that connect to show equal value
PROPORTIONAL (GRADUATED)
CIRCLE MAPS
DOT MAPS
CAUTION: MAPS CAN BE DECEIVING!
• Every map is flawed in some way
• Cartographers can be wrong, include inaccurate
data, or make you perceive something differently
that they want you to see by distorting the map
• Glancing at that
map, we’d think
California, Texas,
Florida, and New
York were
horribly
dangerous
places to live
• The problem is
that we’re
basically looking
at a map of
population. Of
course the more
people live in a
place, the more
crimes (all else
being equal) will
be committed
there
• These maps, from
ads for Verizon
Wireless, show 3G
network coverage
by Verizon and
AT&T. The impression
they give is that
most of the US isn’t
covered by AT&T at
all
• BUT if you look at
the map of
population density,
you will see that
areas with the most
people are covered