1. GIS Lecture: Maps

2. Summary Thematic Maps (Choropleth) Use of Color Categorical Maps
Graphical Hierarchy

3. Thematic vs. Categorical
Thematic maps – Quantity different amounts
Categorical maps – Quality different types

4. Thematic Maps

5. Classification Intervals
Edit the classifications and layer properties

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

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

8. 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;City of Pgh City Planning Dept., U.S. Census 2000

9. Use of Color

10. Color Overview Colors have meaning
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
Colors have political and cultural meanings

11. Color Overview Hue is the basic color
Value is the amount of white or black in the color
Saturation refers to a color scale that ranges from a pure hue to gray or black

12. Color Overview
Monochromatic color scale is a series of colors of the same hue with color value varied from low to high

13. Customized ramps
Customize the Properties of a layer

14. Color Wheel Guidelines
Use opposite colors - those directly across from one another to differentiate graphic features
3 or 4 colors equally spaced - good for differentiating graphic features
Use adjacent colors for harmony - such as blue, blue green, and green or red, red-orange, and orange

15. Contrasting and Non-contrasting Colors

16. Dichromatic Color Scale
Two monochromatic scales joined together with a low color in the center, color increasing toward both ends
Natural middle-point, such as 0 for some quantities (profits and losses, increases and decreases)

17. Change Map Example

18. Color Spots
White background allows color spot to be visualized

19. Color Spot Ramp

20. Categorical Maps

21. Categorical Map Example
- Light Pole Owner

22. Categorical Map Example
- Zoning

23. Categorical Map Example
- Street sweeping days

24. Graphic Hierarchy

25. Graphic Hierarchy
Assign bright colors to the most important graphic elements
Such graphic elements are called “figure”

26. Graphic Hierarchy
Assign drab colors to the graphic elements that provide orientation or context, especially shades of gray
Such graphic elements are called “ground”

27. Graphic Hierarchy
Place a strong boundary, such as a heavy black line, around polygons that are important to increase figure
Use a coarse, heavy cross-hatch or pattern to make some polygons important, placing them in figure

28. Graphic Hierarchy

29. Summary Thematic Maps (Choropleth) Use of Color Categorical Maps
Graphical Hierarchy