Cartography Final

Card Set Information

Cartography Final
2012-05-02 20:46:12

Show Answers:

  2. Map Scale Definition
    defined as a ratio of map distance to earth distance.
  3. Map Scale Expression
    • Word Statement
    • 1 inch to 1 mile

    • Representative-Fraction
    • 1:24,000 or 1/24,000
  4. Large Scale vs Small Scale
    • Large Scale
    • 1:25,000 or larger

    • Intermediate Scale
    • 1:30,000 to 1:125,000

    • Small Scale
    • 1:250,000 to 1:7,500,000

    • Large scale maps show small area but more detailed information
    • Small scale maps show large area but limited detail
    • EX)
    • At large scale, the outline and area of a city may be shown
    • At small scale, that city may be shown as a dot
  5. Scale Conversion
    EX) 1:100,000 is equivalent to 1 centimeter to 1 kilometer

    EX) 1:24,000 is equivalent to 1 inch to 2,000 feet
  6. Scale determination
    • Use of known features
    • Use of lines of latitude and longitude
    • Use of map comparison

    • EX)
    • Assume that two features are 50 millimeters apart on a map of scale 1:125,000, and the same features are 100 millimeters apart of a map of unknown scale:

    50 X 125,000=100 X SF

    • SF = 50 X 125,000
    • ---------------------------
    • 100

    = 62,500

    Map Scale 1:62,500
  8. Physical Property of Color Production
    (What gives an object its color?)
    • the source of the light
    • (the spectral properties of the illumination source)

    • the objects that we are viewing
    • (the ability of the object to reflect light at each wavelength)

    • the eye-brain system of the viewer
    • (the sensitivity of the cones in our eyes to each wavelength)
  9. Object mode vs. Illuminant mode
    Object mode – viewing reflected light (printing)

    Illuminant mode – viewing emitted light (graphic displays on computer screen)
  10. Spectral color vs. reflected color
    • Visual spectrum
    • Pure spectral colors are not often seen except when white light is refracted through a prism

    • Reflected color
    • The color we see in nature and in all fabricated things, including maps, are made by combinations of reflected wavelengths.
    • Surfaces illuminated by white light absorb different portions of the wavelengths and reflect the remainder.
  11. Color dimensions: hue, brightness and saturation
    Hue: is the color dimension associated with different dominant wavelengths;

    • Brightness (or value): is the general term for how
    • light or dark of a color appears

    • Saturation (or chroma): is the perceived amount of
    • white in hue relative to its brightness;
  12. Additive color theory: three primary colors

    • Red+Greed = Yellow
    • Red+Blue = Magenta
    • Green+Blue = Cyan
    • Red+Green+Blue= White
  13. Subtractive color theory: three primary colors

    • Yellow+Magenta = Red
    • Yellow+Cyan = Green
    • Magenta+Cyan = Blue
    • Cyan+Yellow+Magenta = Black
  15. Balance
    All map elements need to be arranged in the map frame

    If map elements appear all on one side, they cause the map to “look heavy” on the right or left, or top, or bottom
  16. Contrast
  17. Label Placement for point, line, area features
  18. Appropriate use of color convention
    • Blue for rivers/streams; light blue for lakes/reservoir
    • Red for major roads
    • Green for forest/grass
    • Red with warm and blue with cool temperature, as in climatic and ocean representations
  19. The proper selection of color relative to map content
    • Maps showing January temperatures should not be rendered in warm hues;
    • Deserts having sparse vegetation should not be shown in green
  21. Elements of map composition
    • Title
    • Figure-Ground
    • Legend
    • North Arrow
    • Scale
    • Neatline and Border
    • Graticule
    • Inset
    • Credits
  22. Figure-ground
    • The figure is the body of the map data and is part of the map referenced in ground coordinates
    • The ground is the formless background of the figure
  23. Graticule
    A network of longitude and latitude lines on a map or chart that relates points on a map to their true locations on the earth
  24. Bertin’s visual variables
    • Shape
    • Size
    • Hue
    • Value
    • Value is the quality of lightness or darkness of achromatic and chromatic colors
    • Pattern/Texture
    • Orientation
    A thematic map is used to display the spatial pattern of a them or attribute.
  26. Choropleth map
    • Has its origins from Greek
    • Choros meaning magnitude
    • Pleth meaning place

    a map in which data collection units are shaded with an intensity proportional to the data values associated with those units.

    • prefers derived data
    • EX)
    • population is discrete data
    • area is a discrete data

    Population Density =

    • Population
    • --------------
    • Area

    • Population Density is derived data
    • Derived data meaning normalized data
  27. Proportional map
    On proportional maps, point symbols are scaled in proportion to the magnitude of point data

    • Two forms:
    • true point data- data measured at a point location
    • conceptual point data- data collected over an area, but data are conceived of as being located at a point
  28. Dot Map
    • used to portray discrete data
    • each dot represents a specified value
    • one dot = 100 people
  29. Contour Map and 3D Map
  30. Bivariate maps