MAPS
Chapter 2
MAPS
• The only accurate way to depict the
earth’s surface is by using a globe, but
globes have drawbacks.
Globes
• Difficult to carry (compared to a map)
• Can only views on side at a time
• Scale too small to be accurate
MAP PROJECTIONS:
• A map projection is a method used to
transfer features of a globe onto the flat
surface of a map.
TYPES OF MAP PROJECTIONS
Mercator projection:
• Positives: Compass bearings are correct
(not distorted)—useful for marine charts.
• Negatives: Distortion of distances, areas
and shapes of landmasses and oceans
(e.g.: Greenland looks huge)
Mercator projection
Winkel Tripel Projection (Equal
Area Projection):
• Positives: Best balance between size and
shapes. Adopted by the National
Geographic Society (in USA) as standard
world reference map (1998)
• Negatives: Still minor distortion
Winkel Tripel Projection (Equal
Area Projection):
MAPS
• A map is a representation of part of the
Earth’s features drawn on a flat surface
using a variety of symbols, colours and
scales.
Large and Small Scale Maps
• Scale shows the relationship between the
size of an object in real life and the size of
that object on a map
Large and Small Scale Maps
• Small scale maps show a small amount of
detail in a large area (e.g.: a world map)
• Large scale maps show a lot of detail in a
small area (a map of a small area, like a
school yard or a neighbourhood).
Types of map scale
Written or verbal scale
• E.g.: 1 cm = 1 km
• Or
• One centimetre on the map equals one
kilometre on the ground
Line or Graphic Scale
• Uses a ruler that is divided into units of
distance
• You would compare the distances on a
map to the distances shown on the ruler
Representative Fraction (Rf) or
Ratio Scale
• Uses a fraction or ratio to show the
relationship between the units on the map
and the units on the earth’s surface.
• 1:50 000 or 1/50 000
• 1 km = 1 000 m = 100 000 cm
• A map with a scale of 1:50 000 has a
scale equivalent of 2 cm = 1 km (1 cm =
0.5 km
Rule of five
• 1:50 000 = (count back 5 decimal places)
= 1 cm = 0.5 km
How to find distance on a map
• What is the distance in kilometres between
Pearson Airport and the CN Tower?
Using Line/Graphic Scale
• Step 1
Step 2
Step 3
Step 4
• Answer: 6 km is the distance between
Pearson Airport and the CN Tower
Using the Verbal or Rf Scale
• Verbal: 1 cm = 1 km or 1 cm:1 km
• Rf: 1:100 000 or 1/100 000
• Using the rule of five we can deduce that
1:100 000 equals 1cm = 1km
• Knowing that 1 cm = 1km, then 6 cm = 6
km
TYPES OF MAPS
• General Purpose: contain many different
types of information such as bodies of
water, cities and highways (e.g.: road
maps)
TYPES OF MAPS
• Thematic: Contains
information on only
one topic (e.g.:
Geological maps
show different rock
types)
TYPES OF MAPS
• Topographic: Large scale map showing
both natural and human features, plus
contour elevations (e.g.: Municipal maps)