Geography 3080 INTRO TO CARTOGRAPHY AND COMPUTER MAPPING Spring 2008

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Geography 3080 INTRO TO CARTOGRAPHY AND COMPUTER
MAPPING Spring 2008

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INTRO TO CARTOGRAPHY AND COMPUTER MAPPING
What is a map anyway
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What is a map

• A map is a graphic representation of the whole or
  a part of an area.
  
• A map uses points lines and polygons to
  graphically represent an area.
  
• A map visually represents spatial relationships
  that exist in the real world.

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Real vs. Virtual Maps

• Real Map any tangible map product that has a
  permanent form and that can be directly viewed
  (aka hard copy).
  
• Virtual Maps a map image that can be directly
  viewed but is not permanent
  
• 3 types
• A map image projected on a computer monitor
• Mental images that are conceptual equivalent of a
  conventional printed map (mental map).
  
• Information gathered by field researchers or
  remote sensing methods (i.e.. elevation soil
  type ethnicity names and locations of
  geographic features).

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Maps Are

• Concerned with 2 elements of reality location
  and attributes.
  
• Representations of a larger reality.
• Scale
• Involve transformation of space.
• Projection and coordinate systems
• Abstractions of reality.
• Generalizations
• A collection of signs and symbols.
• Maps can lie.

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Location and Attributes
Maps are concerned with location.
 Position in 2-dimensional space (i.e. xy
coordinates latitude/longitude)
Maps are concerned with attributes.
Qualities or quantities such as income or
population Many relationships can be formed from
location and attributes.
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Location and Attributes Relationships
Relationships among locations where no attributes
exist (Distance) Relationships among various at
tributes at one location (population ethnicity
income) Relationships between locations and attr
ibutes (variation in income from place to place)
Relationships between location of combined attri
butes (relation of income to education as it
varies from place to place)
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Representations of a larger reality
A map is always smaller than the reality which
it represents. A map of the world the size of the
world would be ridiculous and it would defeat
the purpose of a map. Scale is the relationship
between reality and the map. It serves to set a
limit on the information that can be included in
a map. A 110000 scale means that 1 inch on the
map represents 10000 inches in the Earths
surface
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The Transformation of Space
The only true representation of the world is a
globe.   Distortion occurs during transformation
from 3-dimensional to 2-dimensional.   Map
projections are used to minimize the distortion
of certain features. The mapmaker uses a certain
projection based on the purpose of the map.
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Abstractions of Reality
The real world is complex so mapmakers
generalize simplify and edit the type and
amount of information presented on a map.
  Therefore maps portray only the information
deemed necessary by the mapmaker to illustrate
the purpose of a map.
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Symbols Represent Reality

• Symbols are used to depict certain elements of
  reality on a map. The legend explains what each
  symbol represents.
  
• For example on a weather map a sun represents
  sunny skies while snow represents snowy
  conditions.

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Maps Lie
Mapmaking is an art form as well as a science so
it is subjective. Maps are merely simplification
s or models of the real world. Often what is
not shown is more important than what is shown on
a map. Therefore all maps lie to some degree.
When one is using maps it must be known that
biases can exist and interpretations must be
tread carefully upon.
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Map Elements
Typographical information Title legend labels
(names) author source Neatline Scale Orien
tation
Insets
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Typographical Information

• Title Purpose of the map
• Subject of map
• Time period in which it applies
• Other aspects
• Legend Map symbols w/explanation
• Symbols may include lines geometric
  shapes
  
  
  proportion circles or even graphs. Colors may
  vary.
• Labels Names of political or physical features
  and other elements requiring
  identification
  
• Author Source who made the map where the data
  to make the map came from
  

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Neatline
A narrow line that frames the mapped area.
  A box.
Not crucial to the function of a map.
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Scale

• The ratio between the size of features on a map
  and the size of the same features on the ground.
  
  
• Helpful to the map user in most cases.
• Scale may take the form of a representative
  fraction a word statement or a graphic scale.
  

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Orientation
Orientation of a map consists of the way that it
is aligned relative to the earths surface.
North is usually at the top but this is not
always true. Orientation must be shown to map us
er. Can be done using a north arrow.
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Insets

• Small map included within a main map.
• 4 general forms
• An enlargement of a portion of the mapped area.
• Locator map which shows where a mapped region
  lies in relation to larger better known region.
  
  
• Areas related to the main map such as islands
  that fall under control of the main map are
  shown.
  
• Additional information is provided such as
  climatic or soil maps of the main map/ area.

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Title
Neatline
Labels
Legend
North Arrow
Author Source
Scale