Maps and Mapping

1
Maps and Mapping

• Never have so many poor maps
• been made so quickly
• Types of maps
• Data types and measurement
• Symbolization
• Classification
• Map scale
• Map layout

2
Maps

• A representation of the earth surface on a flat
  medium at certain scale
• A model of spatial patterns of features
• Selective
• Classified
• Generalized point, line, areas
• Graphically customized

3
Types of Maps

• General purpose maps
• Where?
• Topography
• Thematic maps
• What
• A theme

4
General Purpose Maps
5
Thematic Maps
6
Thematic Maps
7
Map Elements

• A Map
• Title what, where, when
• Scale
• Orientation
• Legend
• Others

8
Symbolization

• Symbols
• Point
• Lines
• Areas

9
Symbolization

• Qualitative difference
• Different things
• Landuse, residential, commential
• Highways, Railways
• Quantitative difference
• Essentially same thing, but different in degree
• Population density
• Temperature
• Crime rate
• Population

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Qualitative Differences

• Different shapes
• Different patterns
• Different colors

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Quantitative Difference

• Size of symbol
• Value of color

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Symbolization
Qualitative Quantitative Shape
Color (Hue) Pattern Size
Value
Points Lines Areas
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Choropleth Map
14
Area Map
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Isopleth Map
16
Bad Choice of Colors
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Map Scale

• Representation
• Representation fraction (RF) 12,500
• Graphic scale
• Verbal scale one cm on the map represents 25
  meters on the ground

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Large scale vs. small scale
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Orientation North Arrow

• North arrow appropriate

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Orientation

• North arrow not appropriate

21
Grid
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Classification

• Equal Interval
• The range of possible values is divided into
  equal-sized intervals
• Natural breaks
• Finding the biggest gap
• Quartiles
• Same number of observations in a class
• Standard deviations
• Mean and standard deviation
• Equal area

23
Natural Break
Percentages of Asian Pacific Islanders, 1999
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Equal Interval
25
Quantile