LECTURE TWO: MAPS
Map definition:
“A map is any concrete or abstract representation of the features that occur on or near
the surface of the earth or other celestial bodies”
Characteristics of maps:
Plan or near-plan views
Use of symbols
Can show physical and cultural features
Show location and attribute information
Mental, virtual and real maps:
Mental maps
o
Images of environment stored in our minds
o
Used for navigation, visualization
Virtual (computer) maps
o
Temporary maps displayed on computer monitor
o
Database used to generate graphic display
Real, or “cartographic” maps
o
Paper maps
o
Now generally produced by computers – i.e real map is a printout of a virtual
map
Mental maps:
Represent knowledge of the spatial organization of our environment, characteristics of
different locations or regions
How do they acquire information:
o
Direct experience
o
Indirect experience (e.g. tv)
o
Extra-perception, i.e. thinking, or inference
Differ from reality
o
Incomplete
o
Selective retention of information
o
More accurate for familiar areas
Neighborhood mental maps:
Three maps of the same neighborhood drawn by children, common elements found in
each, but differences in scale, use of symbols, and details
Images of urban environments:
Image of the city: kevin lynch – urban theorist
5 things in the urban environment:
o
Paths – routes linking places together
o
Landmarks – office towers, historical buildings
o
Nodes – main centres of activity
o
Districts – homogenous areas
o
Edges – boundaires between districts
Maps based on collected data:
Charts/plans – hydographic, aeronautical
General – reference, topographic, photomaps
Thematic – univariate, special purpose
Virtual maps:
Computer maps
o
Temporary screen displays
o
Spatial databases used to generate maps
Interactive
o
Based on selective query of data base – user can design custom map
GIS locater – region of waterloo
Google earth, google sky
o
Animation
Growth of boston, weather maps
Charts and plans:
Variable scale
To be worked on rather than looked at
General reference maps:
spatial association of features
Accuracy standards
E.g. topographic maps
Thematic maps:
Focus on particular theme, e.g. soils, population
Univariate, multivariate, derived
Cadastral map:
Defines land ownership
Functions of maps:
Navigation
o
Road maps
o
Buse route maps
o
Hydrographic charts
Visualization
o
Scale reduction – see spatial relationships or patterns
Measurement
o
Geometric properties
o
Monitor change over time
o
Not all maps suitable for all types of measurement
Characteristics of maps:
Graphical representation of data and their spatial relationships
Plan or near plan views
Relate features in terms of distances and angles
o
May only be approximately correct due to distortion
Use of symbols
o
Able to represent any characteristic which varies over space, not just physical
features
Maps should stand on their own
o
Include scale, legend, north arrow, title
Advantages of maps:
