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 Information

Computer Cartography midterm
2014-03-09 17:24:03
Computer Cartography

LSU Computer Cartography midterm
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