Class 1b: Introduction to maps

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Class 1bIntroduction to maps
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What is a map?

• A two-dimensional representation of the spatial
  distribution of selected phenomena

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Why make maps?
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Latitude and longitude

• Latitude how far north or south

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Latitude and longitude

• Longitude how far east or west

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How do we read maps?
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Map scale

• Ratio of the distance on the map to the distance
  on the ground

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Map scale

• Graphic

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Map scale

• Verbal
• 1 inch equals 10 miles

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Map scale

• Representative fraction or ratio
• 124,000

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Map symbolization
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Point symbols

• Every symbol counts as one occurrence

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Line symbols

• One-dimensional

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Area symbols

• Each territory or region has one value

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Topographic maps
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Topographic maps
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Topographic maps
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Map projections

• Project a round globe onto a flat surface

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Map projections

• Three properties to consider

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Cylindrical projections

• Shapes are preserved, but not area

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Conic projections
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Planar projections
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Other projections