Methods of Geographic Inquiry
Scale
TYPES OF MAPS
• All maps can be classified under three headings:
general purpose, thematic, and topographic
• General Purpose Maps - provide many types of
information on one map. Most atlas maps, wall maps,
and road maps fall under this category.
• Thematic Maps - provide very specific information
about a place. These maps are designed to show
information on one particular topic.
• Topographic Maps - use international symbols to show
a variety of features. These maps show a small area in
great detail.
TYPES OF MAPS
General Purpose Map
Thematic Map
Topographic Map
Scale
• Scale is a measure of the relationship between
the size of a model and its size in real life.
Scale
• A map is a model of the Earth’s surface
• Maps come in many different sizes and show
different areas
• Map scales are widely varied because of this
Large Scale vs. Small Scale
• A large scale
map shows
a small area
of the Earth
is great
detail
• Example: a
map of the
Village of
Newcastle
Large Scale vs. Small Scale
• A small
scale map
shows a
large area
of the
Earth with
little detail
• Example:
globe
Types of Scale
Visual or Graphic, Verbal or Statement and Representative Fraction
SCALES all indicate the same thing. They are equivalent and
interchangeable.
• The three main types of scale are:
• Verbal or Statement Scale - this scale uses two different
measurements to describe the relationship. (i.e. 1cm to 15km or
1cm:4km)
• Representative Fraction Scale - This scale is written either as a
fraction 1/50 000 or more commonly as a ratio 1:50 000. Both
numbers represent the same units of measurement.
• Graphic or Visual Scale - This is a visual scale, a bar subdivided
into smaller segments, each of which has a specific distance
associated with it.
Types of Scale
Representative Fraction Scale
Graphic or Visual Scale
Verbal or Statement Scale
Calculating Scale
• There are two things to remember when
calculating scale
• First, map scales always start with the number
1
i.e. 1:50 000 or 1cm=10km
• Second, one kilometer has 100 000 cm
Calculating Scale
• When calculating distance using scale you simply
measure the distance on the map and multiply by
the scale number.
• i.e. map measurement = 6cm
Scale is 1cm=32km
Actual distance is: 6x32=192km
OR
• i.e. map measurement = 5cm
Scale is 1:50 000
Actual distance is: 5x50 000 = 250 000cm
250 000 / 100 000 = 2.5km