1. GIS Lecture 2 Map Design

2. Outline Vector GIS Graphic Elements Colors Graphical Hierarchy
Choropleth Maps
Map Layers
Scale Thresholds
Hyperlinks

3. Vector GIS

4. Graphic Features on the World

5. Turned into a GIS Map

6. Vector GIS
Points
Point
Line
Lines
Polygon
Polygons

7. Points
Data Attached to Points

8. Points Same data displayed as two different points Burglaries
Drug Calls

9. Queries and Restrictions
Restricts the features to a specific subset

10. Lines Highways, Major Roads Street Centerlines Curbs
Attached Database Attributes
Curbs

11. Polygons
Point
Green
Spaces
Line
Buildings
Polygon
Census
Blocks

12. Graphic Elements

13. Jacques Bertin Visualization Information
“What should be printed to facilitate “communication”, that is, to tell others what we know without a loss of information”
-Jacques Bertin, Paris, February 1983
Formally educated in cartography
One of the first to explain principles of Visualization Information
Embodied in the theory of graphic representation
Principles of the semiology of graphics
Visual language.
Jacques Bertin is one of the fundamental gurus of Information Visualisation since he was the first in articulating a coherent and reasoned theory for the analysis of quantitative graphic representation.
Treating data to get information.
Communicating, when necessary, the information obtained.
Interview with Jacques Bertin

14. Bertin’s Graphic Variables
Shape
Value
Hue
Size
Texture
More Value
Saturation

15. Shape Symbols Saturation Value Hue More Value Shape Size Texture
Keep shapes simple
3-7 maximum different shapes (more than 7 make it hard to read)
Texture

16. Shape (Point) Guidelines
Use simple shapes
Use point markers that have boundary lines and solid-color fill for important points

17. Simple, Solid Points

18. Boundary Lines

19. Size Saturation Value Hue More Value Shape Size Texture Numeric Data
Low/medium/high
Must read the key to understand the magnitude
Texture

20. Size
Make the differences in size as large as possible

21. Texture
Saturation
Value
Hue
More Value
Shape
Size
Texture

22. Texture
Black and White Prints
Polygons
Large Areas

23. Value Saturation Hue More Value Value Shape Size Texture
White – less ink – smaller values
Black – lots of ink – higher values
Eye can distinguish better at the lower values – harder to distinguish at the larger values.
Texture

24. Value Increase/Decrease Contrast
The greater the difference in value between an object and its background, the greater the contrast.
In the above examples, the lighter value recedes into the light background.
The design with the greatest contrast makes the darker object more dominant.

25. Value
By creating a pattern of dark to light values, even when the objects are equal in shape and size, it leads the eye in the direction of dark to light
In the above example, the first set of all dark lines are static. The middle example leads the eye in a downward direction (dark to light). Reversing the values of the lines leads the eye upward.

26. Value

27. Value
Shape
Texture
Orientation
Size
Saturation
Value
Hue
More Value

28. More Value

29. Hue Shape Texture Orientation Size Saturation Value More Value Hue
Hue not good for showing value
Yellow in middle

30. Color Hues Each of individual color is a hue
Colors have meaning (i.e. cool colors, warm colors, political meanings)
-Cool colors calming
-Warm colors exciting
-Cool colors appear smaller than warm colors and they visually recede on the page so red can visually overpower and stand out over blue even if used in equal amounts.

31. Color Wheel
red
violet
blue
orange
yellow
green

32. Color Wheel Harmony two adjacent hues red orange violet yellow blue
The term harmonize sounds nice, pleasant. But some harmonizing colors may appear washed out (yellow/green) or too dark and similar (blue/purple) to work well together.
yellow
blue
green

33. Color Wheel Harmony two adjacent hues red orange violet yellow blue
green

34. Color Wheel Harmony two adjacent hues red orange violet yellow blue
green

35. Color Wheel Harmony two adjacent hues Contrast two hues with
one hue skipped
in between
red
orange
violet
While contrast is often needed to provide optimum readability (such as high contrast between background and text) contrasting colors on the color wheel when printed side by side can appear to vibrate and be very tiring on the eye.
yellow
blue
green

36. Color Wheel Harmony two adjacent hues Contrast two hues with
one hue skipped
in between
red
orange
violet
yellow
blue
green

37. Color Wheel Harmony two adjacent hues Contrast two hues with
one hue skipped
in between
red
orange
violet
yellow
blue
green

38. Color Wheel Harmony two adjacent hues Contrast two hues with
one hue skipped
in between
red
orange
violet
yellow
blue
green

39. Non-Contrasting vs. Contrasting

40. Saturation Shape Texture Orientation Size Value Hue More Value
Purity of color
Narrow band with
More Value
Saturation

41. Saturation

42. Saturation
Customize the Properties…of a layer

43. Double-Ended Scales Extremes Emphasized
Example: gains or loss over time
purple and orange contrast
white center is ground
purple
white
orange

44. Change Map Example

45. Color Spot
White background allows yellow color spot to be visualized

46. Color Spot Ramps

47. Graphical Hierarchy

48. Graphical Hierarchy Goal
direct attention toward or away from available Information

49. Graphical Hierarchy Goal Figure-Ground
direct attention toward or away from available Information
Figure-Ground
visual separation of a scene into recognizable figures and inconspicuous background (ground)

50. Graphical Hierarchy
Ground
larger of two contrasting areas

51. Graphical Hierarchy Ground larger of two contrasting areas
grays, light browns, heavily saturated hues

52. Graphical Hierarchy Ground Figure larger of two contrasting areas
grays, light browns, heavily saturated hues
Figure
long wavelength hues
coarse texture

53. Graphical Hierarchy Ground Figure larger of two contrasting areas
grays, light browns, heavily saturated hues
Figure
long wavelength hues
coarse texture
strong edge

54. Choropleth Maps
A map with areas colored or shaded such that the darkness or lightness of an area symbol is proportional to the density of the mapped phenomena or is symbolic of the class. classification Process of assigning individual observations of features into groups, categories, or classes.

55. Choropleth Maps
Map using different colors or patterns to show different values
Knowing what type of data you have and what you want to show will help you determine what quantitative value to map. In general, you can follow these guidelines:
Map counts or amounts if you want to see actual measured values as well as relative magnitude. Use care when mapping counts as the values may be influenced by other factors and could yield a misleading map. For example, when making a map showing the total sales figures of a product by state, the total sales figure is likely to reflect the differences in population among the states.
Map ratios if you want to minimize differences based on the size of areas or number of features in each area. Ratios are created by dividing two data values. Using ratios is also referred to as normalizing the data. For example, dividing the 18- to 30-year-old population by the total population yields the percentage of people aged 18–30. Similarly, dividing a value by the area of the feature yields a value per unit area, or density.
Map ranks if you are interested in relative measures and actual values are not important. For example, you may know a feature with a rank of 3 is higher than one ranked 2 and lower than one ranked 4, but you can't tell how much higher or lower.

56. Classifying Data
Process of placing data into groups that have a similar characteristic or value

57. Numeric Intervals
Non-overlapping and exhaustive intervals covering the range of values for an attribute
Keep the number of intervals as small as possible to help simplify the user’s ability to absorb information
Cut points (break points) are points at which we choose to break the total attribute range up into these intervals
Use a mathematical progression or formula instead of picking arbitrary values – less likely to be accused of manipulating data

58. Numeric Intervals (Continued)
Numeric interval options:
Equal intervals
Consistent widths
Easy to understand
Use equal width intervals in multiples of 2,5, or 10.
Example: 0-100, , , 300 and greater
Increasing interval widths
Long-tailed distributions
Example: 0-5, 5-15, 15-35, 35-75

59. Numeric Intervals (Continued)
Exponential Scale
Popular method of increasing intervals
Use break values that are powers such as 2n or 3n
Generally start out with zero as an additional class if that value appears in your data
Example: 0, 1–2, 3–4, 5–8, 9–16, and so forth
Quantiles
Separating a distribution into equal sizes of feature attribute records per interval
Example: 0-25%, 25%-50%, 50%-75%,75%-100%

60. Numeric Intervals (Continued)
Use quantile numeric scales for analytical maps, but use equal interval scales for general public maps

61. Custom Scales
Edit the classifications and layer properties

62. Original Map (Natural Breaks)
Uninsured U.S. Population, 2005

63. Custom Map (Equal Intervals)
Uninsured U.S. Population, 2005

64. Other Numeric Intervals
Pittsburgh, PA: Neighborhood proportion under poverty and average BMI per neighborhood
BMI !
30.0+
Percentage in Poverty %
12.51% %
20.0% %
40.0% %
Data Sources: BRFSS data, 2000; Reference USA,City of Pgh City Planning Dept., U.S. Census 2000

65. Normalizing Data
Divides one numeric attribute by another in order to minimize differences in values based on the size of areas or number of features in each area
Examples:
Dividing the 5 to 17 year-old population by the total population yields the percentage of people aged 5-17
Dividing a value by the area of the feature yields a value per unit area, or density
For example, dividing the 18- to 30-year-old population by the total population yields the percentage of people aged 18–30. Similarly, dividing a value by the area of the feature yields a value per unit area, or density.

66. Normalizing Data

67. Normalizing Data

68. Map Layers, Scale Thresholds, and Hyperlinks

69. Map Layers
Organizes your layers
Group logically and rename

70. Scale Thresholds Minimum Scale Range
If you zoom out beyond this scale, the layer will not be visible

71. Scale Thresholds
When you zoom in, the layers are visible

72. Scale Thresholds Maximum Scale Range
If you zoom in beyond this scale, the layer will not be visible
State Capitals not visible at this scale

73. Hyperlinks
Links images, documents, WEB pages, etc. via features on a map

74. Summary Vector GIS Graphic Elements Colors Graphical Hierarchy
Choropleth Maps
Map Layers
Scale Thresholds
Hyperlinks