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CH. 2.13 - Essential Map Elements Explained

Oct 2, 2024

Lecture: Key Elements of Maps

Essential Elements of a Map

  1. Title

    • Every map needs a title to indicate what it represents.
    • Examples:
      • "The World"
      • "The United States of America"
      • "Geologic Map of California" (indicates different rock types/geology).

  2. Date

    • Importance:
      • Natural features change slowly (e.g., volcanic eruptions, flood-induced river course changes).
      • Human and cultural changes occur frequently.
    • Example:
      • Long Beach map dated 1964, over 50 years old, may not reflect current features.

  3. Legend

    • Explains symbols and colors used on the map.
    • Provides information on features such as vegetation, rivers, creeks, etc.
    • Example:
      • Legend for Geologic Map of California explains rock types by color.
      • For US Geological Survey maps, a separate legend page is used, available as Appendix B in textbooks.

  4. Scale

    • Definition: A scale is a ratio representing the relationship between distances on a map and actual distances.
    • Types of Scales:
      • Fractional Scale: Uses a fraction to depict scale (e.g., 1/4 scale means 1 foot on model = 4 feet in reality).
      • Ratio Scale: Similar to fractional scale (1:4 ratio, no units needed).
      • Verbal Scale: Units are expressed in words (e.g., 1 inch = 25 feet).
    • Examples:
      • Model car: 1/4 scale or 1:4 ratio.
      • Home plan: 1:30 ratio (1 inch represents 30 feet).
      • Building floor plan: 1:300 ratio (1 inch represents 25 feet).
      • Long Beach map: 1:24,000 ratio (1 inch represents 24,000 inches or 2000 feet, approximately 1/3 mile).

Additional Concepts

  • Quadrangle Maps

    • Defined by lines of latitude and longitude.
    • Example: Long Beach Quadrangle.

  • Understanding the Legend

    • Examples of questions answered by the legend:
      • How is vegetation represented?
      • What do township and section lines look like?
      • Example provided for location of sections and township lines near Recreation Park.

Practical Applications

  • Floor plans and building layouts (e.g., D building at Long Beach City College) use scales to show changes and navigate spaces.
  • Understanding conversions in scales for practical use, e.g., from inches to feet or miles.

By understanding these key elements, one can accurately interpret and utilize maps for various purposes.

Full transcript