Transcript Why do Geographers use Maps and What do Maps tell us?

Why do Geographers
use Maps?
AP Human Geography
Why do Geographers use Maps?
• All maps simplify the world
• Cartographers generalize information they
present on maps
Maps VS. Globes
Maps
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Maps are flat representations of the
curved surface of the earth.
Can be shown in a book.
Can be folded up and used for planning
trips.
Can show large areas or small areas.
They are flexible tools that can provide
large amounts of information very
efficiently.
Not as accurate as globes.
Flat representation of the curved surface
of the earth, something has to be
distorted
Globes
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Most accurate
Scale model of the earth, shows actual
shapes, relative sizes, and locations of
landmasses and bodies of water.
Accurate information about distances
and directions between two points.
Very small representations of the
earth.
Not much detail.
Difficult to carry around
You can look at only one half of a
globe at any one time.
Map Projections
• Used to portray all or part of the round earth on a flat surface
– Cannot be done without some distortion
• Every projection has its own advantages and disadvantages
• Cartographers select the projection best suited to their needs
• Maps or parts of the map show one or more of the following, but
never all:
– True directions
– True distances
– True areas
– True sizes (shape)
Parts of a Map
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Title-What? Where? When?
– Explains what map potrays
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Map Key-AKA Legend
– What the symbols/colors mean
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Orientation
– At least North arrow
– Cardinal Directions (N,S,E,W)
– Intermediate Directions (NE, NW, SE, SW)
• Scale
– Distance on the map (1in=1mi)/ a ratio
– Large scale =small area. Very Detailed (Neighborhood)
– Small scale = Large area. Less Detail (Earth)
• Grid
– Location Tool
– Coordinate system
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Latitude- runs east to west (Equator)
Longitude-runs north to south meets at poles (Prime Meridian)
Complete List of Map
Parts
D-ate
O-rientation
G-rid
S-cale
T-itle
A-uthor
I-ndex
L-egend
S-ources
Map Parts by Importance
T-itle
O-rientation
D-ate
A-uthor
L-egend
S-cale
I-ndex
G-rid
S-ources
A Few Types
of Maps
General Purpose/ Reference Maps
• Show basic information.
• Such as location of:
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– landforms
– political boundaries
– water
– cities
Absolute Location
– Use of coordinate system that allows you
to plot where on Earth something is
• Do not change
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Relative Location
– Describes a place in relation to other
human and physical features
• Constantly change over time
• Examples
• Political Maps
• Physical Maps
• Road Maps
Political Maps
• No topographic features
• Focuses on boundaries of a place.
• They also include the locations of cities
– large and small, depending on the detail of the
map.
• Example
– 50 U.S. states and their borders along with
the United States' north and south
international borders
Physical Maps
• Shows the physical landscape features of a
place.
• Focus on mountains, rivers and lakes
– water is always shown with blue
– Mountains and elevation changes are usually shown
with different colors and shades to show relief
• Example:
– Hawaii
Mental Maps
• Maps in our minds of places we have been
and places we have just heard of
• Activity spaces
– Places we travel to routinely in our rounds of
daily activity
• Geographers study mental map formation
of all types of people, and all show
differences in their formation of mental
maps
Mental Map
of the
Americas
Example Mental Map
Thematic Maps
• Shows particular themes connected with
geographic area
• Show different, very specific topics
• Examples:
– average rainfall distribution for an area
– distribution of a certain disease throughout a county.
What is a Choropleth Map?
• A type of thematic map
• Areas are colored or shaded to reflect the value of the mapped
phenomena or to display classes of value
Examples of Choropleth Maps
Choropleth Maps
Cartograms
• Thematic mapping variables are
substituted for land area or distance
• The space of the map is distorted in order
to convey the information
http://www.worldmapper.org/index.html
Single Dot/Graduated Dot Maps
• Dot maps employ dots to convey
information about a distribution.
– A single dot may represent one occurence of something
(an earthquake) or more than one (a dot might
represent 100,000 people, for example).
– Graduated circle maps also use a point symbol, but the
symbols have different sizes in proportion to some
qualtity that occurs at that point. The populations of
different cities are frequently depicted on graduated
circle maps.
Remote Sensing
• How geographers monitor the Earth using
technology that is a distance away from the
place being studied
– Data is collected using satellites and aircraft
– Google Earth
GIS
• Geographic Information Systems; used to organize,
translate, disaggregate geographic data
Satellite Image converted to contour or elevation map
GPS
• Global Positioning System; mobile device used to provide exact
coordinates
http://www.cnn.com/video/data/2.0/video/tech/2009/08/12/eod.gps.maps.c
nn.html
Geocaching
• New hobby!
• People are using their GPS units to play a
treasure hunt game all over the world
http://www.geocaching.com/