Computer Cartography midterm

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  1. Dasymetric mapping
    • first referenced in 1936 by J. K. Wright
    • show densities of anything
  2. intangible maps
    • mental maps
    • maps that you carry in your mind
    • it can be drawn and converted to a tangible map
  3. qualitative maps
    • what is shown at a particular location
    • they don’t display the quantity of item that can be found, just what is found
    • can display names of areas
  4. cartogram
    • symbols are used but the size varies based on quantities
    • distortion displays different types of data
  5. enumeration unit rules
    • block is considered to be the basic unit for the census, for privacy reasons
    • there are larger units above it, like county and state
    • 3 rules of thumb as to how many categories should be defined on a map breakdown
    • 7±2 = 7-9
    • Image Upload
    • 2x < n < 2x+1, where 2x = the largest value below the total
    • Ex.: if total is 100 then 2x = 26 = 64
  6. Choropleth map
    • always use derived/standardized values
    • Do NOT use absolute values or actual numbers
    • Use derived values that only show rates, densities, or percentages
  7. linear features
    • Italic
    • Blue
    • Label should be on top of the feature, not bellow
    • If it’s too long put the name multiple times
    • On rivers use regular kerning
    • If river is a polygon, apply polygon rules
  8. Map titles
    • in ALL CAPS
    • Include area covered
    • Time frame of the map
  9. Class interval methods
    • Equal steps
    • Quantiles
    • Arithmetic progression
    • Geometric progression
    • Optimal
    • Natural breaks
    • Standard deviation
  10. Quantiles
    • create classes with the same number of values in each class
    • generic name for any number
  11. Optimal
    • Prefered method
    • put values into a class that are very similar and each class is very different
    • internal homogenous
    • external heterogeneous
    • default method used in ArcGIS
    • good choice
    • Chenks wrote an article in the 70s and defined the Chenks method
  12. Natural breaks
    • Prefered method
    • Look for valleys, natural breaks (low points), in the frequency distribution
    • Graphic array
    • sort values by size and organize from smallest to largest
    • apply the breaks where there is a difference
  13. Proportional symbol mapping
    • next to choropleth mapping it’s the 2nd most popular type of maps
    • can map absolute and standardized values
    • a symbol type is selected, usually a circle
    • can map both aerial and point information
    • centroid of the enumeration unit
    • flexibility is higher
    • can be collected for polygons or point locations
    • different techniques used for proportional symbol mapping
  14. proportional symbol mapping techniques
    • absolute scaling (not used much any more)
    • -   sizes of the symbols are mapped proportional to the quantities they represent
    • -  need to know how to calculate the exact symbol type
    • Apparent (magnitude) scaling
    • -  lots of comparison between 2 different sizes
    • -  developed based on the study of people’s interpretation of the sizes
    • -  discussed in the article
    • Range grading is used today
    • -  Distinguish ability is very important
    • -  usually the smallest circle is on top and larges is at the bottom
    • -  can use numbers easily remembered, not easily remembered and ranges
    • -  do not put more than 2-3 attributes on a map at the same time
  15. Isarithmic map
    • divided into 2 categories: isometric and isoplethic
    • made by connecting points of the same value
    • usually included in many GIS packages
    • 3D representation of a surface
    • Fishnet option
    • can be rotated and angles can be changed
    • Shaded relief presentation
    • east slopes are typically light, the west are dark
  16. Isometric map
    data is collected at points
  17. Isoplethic map
    data for areas
  18. triangulation
    • use of triangles to identify areas
    • isolines need to be smoothed out
  19. interpolation
    • if there are different values they can be displayed in several ways
    • foreground information should be displayed more prominently
    • if the isaline is longer than label it more than once
  20. Cartogram
    • uses size and shape distortions
    • no symbols
    • no fill
    • contiguous cartogram:  boundaries stay together as in reality just deformed
    • non-contiguous cartogram:  boundaries are separated
  21. 3 two-dimensional symbols used for proportional symbol maps
    • circle
    • triangle
    • square
  22. Image Upload
    • proportional symbol map shows spatial numerousness
    • dots should coalesce in densest parts of the map
  23. Image Upload
    • Classed and unclassed choropleth maps
    • top is the 4 class conventional
    • bottom unclassed
  24. Image Upload
    value-by-area cartogram
  25. Image Upload
    voluminous and bounded by continuous surface
  26. Image Upload
    Isarithmic map
  27. Image Upload
    Planimetric map: shows the model's surface
  28. Image Upload
    Thematic map with enumeration unit being a county
  29. Image Upload
    radial type of line map
  30. Image Upload
    network type of line map
  31. Image Upload
    distributive type of line map
Card Set:
Computer Cartography midterm
2014-03-09 17:24:03
Computer Cartography

LSU Computer Cartography midterm
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