CARTOGRAPHIC BASICS

1
MAP SCALE

• Scale varies across all maps
• Pattern of scale distortion depends on map
  projection
• Scale along line/point of SF 1 (reference
  globe vs flat
• map) displayed in several ways
• Representative fraction, or simple scale
• 1100,000 or 1/100,000
• Verbal statement One inch to 16 miles
• Bar Scale
• Area Scale

2
REFERENCE SYSTEMS

• Some common, familiar reference systems
• Dewey Decimal system for libraries
• Street addresses used by postal service
• Road map grids used by Rand McNally, etc. on
  travel maps
• Zip Codes for area reference
• Area Codes used by phone company for area
  reference

3
COORDINATE SYSTEMS

• Geographical coordinate system
• Older of two systems now in general use
• Uses latitude and longitude to locate positions
  on the
• uniformly curved surface of the earth
• Primary system used for navigation and
  surveying
• Rectangular/plane coordinate systems
• Used for locating positions on a flat map
• Evolved from cartesian coordinates applied to
  maps for
• for military purposes

4
COORDINATE SYSTEMS

• Cartesian Coordinates
• Originally devised by armies for easier
  computation of
• artillery trajectories
• Defined by origin and unit of distance
  basically a graph
• Depend on Euclidean geometry

5
COORDINATE SYSTEMS

• Rectangular Coordinates
• Based on Cartesian coordinate system
• Large scale maps typically use a conformal
  projection
• to maintain distance and direction
  calculations using
• rectangular coordinates
• False easting and northings are typically added
  to
• coordinate values to keep coordinates in the
  upper right
• hand quadrant of the graph positive
  values
• Most plane coordinate systems based on only
  these three
• conformal map projections transverse
  Mercator, polar
• stereographic, Lamberts conformal conic
• Not used for small scale maps too much
  distortion

6
COORDINATE SYSTEMS

• United States coordinate systems in common use
• Universal Transverse Mercator Grid System
• Topographic maps, satellite imagery, natural
  resource
• databases, applications requiring precise
  positioning
• Uses meter as basic unit of measure
• Contains 60 narrow zones running N/S
• SF constant only along NS meridian of each zone
• Accurate overall to 1 part in 2500

7
COORDINATE SYSTEMS

• United States coordinate systems in common use
• Universal Polar Stereographic Grid System
• Used to represent two circular polar zones not
  covered
• by UTM system
• SF is constant along parallels, which are
  circles in
• this projection
• Accurate overall to one part in 2500

8
COORDINATE SYSTEMS

• United States coordinate systems in common use
• State Plane Coordinate System
• Devised in the 1930s plane rectangular
  coordinate
• system for each individual state
• Based on transverse Mercator or Lamberts
  conformal
• conic projections line of constant SF depends
  on
• which projection used
• Unit of measure is feet
• Overall accuracy to one part in 10,000

9
COORDINATE SYSTEMS

• United States coordinate systems in common use
• Public Land Survey System
• Basic unit is areal, not linear acre
• System is defined on the ground, not on a map
  grid
• Currently covers ¾ of land in the 50 states
• Baseline and meridian are defined on the ground
  and
• serve as origins
• System defines township, range, section
• Commonly used for legal descriptions of property

10
CARTOGRAPHIC DESIGN

• Most design choices are compromises
• Design as a process
• Stage one imagination, creativity, graphic
  ideation
• gt decide on type of map, size and shape, basic
  layout,
• data to be represented, mapping technique,
  etc.
• Stage two specific graphic plan, most
  decisions made
• gt kinds of symbolism, number of classes and
  class limits
• of data, color use, typographical
  relationships, line
• weights, etc. (often done on the fly using
  computers)
• Stage three detailed specifications
• gt define all symbols and line weights, colors,
  lettering
• size, etc.

11
CARTOGRAPHIC DESIGN

• Design as a product
• Does the map look right?
• Should be clear, simple, uncomplicated, and
  elegant
• Map should not look contrived
• Map should be aesthetically pleasing, while at
  the same
• time being thought provoking
• Does the map accurately and effectively
  communicate
• your message the results of your data
  analysis?
• WHO IS YOUR AUDIENCE?

12
CARTOGRAPHIC DESIGN

• Basic Graphic Elements
• Point position
• Line direction and position
• Area extent, direction, position
• Primary Visual Variables
• Shape regular/geometric or irregular/pictograph
  ic
• Size length/height/area/volume larger more
  important
• Orientation lines/elongated shapes need
  reference
• Color (hue) actual color (red, green, blue,
  etc.)
• Color (value) tone or relative
  lightness/darkness
• light high value, dark low value
• Color (chroma) saturation/intensity/richness/pu
  rity
• measured by how much gray is present

13
CARTOGRAPHIC DESIGN
From Robinson, Sixth Edition, page 320
The Primary Visual Variables With some Examples
of their Simple application To the classes of
symbols
14
CARTOGRAPHIC DESIGN
Types and symbols useful in quantitative mapping
and their visual dimensions.
Courtesy JP Publications. From Dent, Fifth
Edition, page 78.
15
CARTOGRAPHIC DESIGN

• Secondary Visual Variables (pattern)
• Arrangement random or systematic shape and
• configuration of component marks that make
  up a pattern
• Texture size and spacing of component marks
  that make
• up a pattern
• Orientation direction arrangement of parallel
  rows of
• marks or parallel lines that make up a
  pattern

16
CARTOGRAPHIC DESIGN
The Secondary Visual Variables with some examples
of their simple application to the basic graphic
elements.
From Robinson, Sixth Edition, page 321
17
CARTOGRAPHIC DESIGN

• Symbol Classes
• Symbols should focus attention on what the symbol
  
• represents, not what the symbol looks like
• Point emphasizing symbols
• Dots, triangles, pictographs
• Denote position, location of feature, intensity
  at a
• place, representative location for spatial
  summary
• Examples geographic coordinate location, radio
• tower, spot height, centroid of area
  distribution,
• conceptual volume (city population)
• Does not take up any geographical space

18
CARTOGRAPHIC DESIGN

• Line Emphasizing Symbols
• Individual linear signs
• Depict rivers, roads, political boundaries
• Can also represent non-linear data such as
• elevation/depth/volume contour lines
• May or may not indicate actual geographical size
  of
• features

19
CARTOGRAPHIC DESIGN

• Area Emphasizing Symbols
• Indicate that region has some common attribute
• Examples include water, administrative
  jurisdiction,
• soil type, other homogeneous measurable
• characteristic
• Homogeneous nature depicted by even color or
• uniform repetition of point or line symbols
  (pattern)

20
CARTOGRAPHIC DESIGN

• Volume Emphasizing Symbols
• Represent vertical or intensity dimension of
  spatial
• phenomenon through space
• Examples include terrain surfaces
• May be symbolized by color value (lightness)
• variations, spot height data, profile or
  contour lines