GIS Lecture 2 Map Design GIS 1 Outline

GIS Lecture 2 Map Design GIS 1

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

Vector GIS

Graphic Features on the World GIS 4

Turned into a GIS Map GIS 5

Vector GIS Points Lines Polygons GIS 6

Points Data Attached to Points GIS 7

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

Queries and Restrictions • Restricts the features to a specific subset GIS 9

Lines Highways, Major Roads Street Centerlines Curbs GIS 10

Polygons Point Green Spaces Line Buildings Polygon Census Blocks GIS 11

Graphic Elements GIS 12

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 GIS 13

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

Shape Symbols Shape Size Texture Value More Value Hue Saturation GIS 15

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

Simple, Solid Points GIS 17

Boundary Lines GIS 18

Size Shape Size Texture Value More Value Hue Saturation GIS 19

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

Texture Shape Size Texture Value More Value Hue Saturation GIS 21

Texture • Black and White Prints • Polygons • Large Areas GIS 22

Value Shape Size Texture Value More Value Hue Saturation GIS 23

Value Increase/Decrease Contrast The greater the difference in value between an object and its background, the greater the contrast. GIS 24

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 GIS 25

Value GIS 26

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

More Value GIS 28

Hue Shape Orientation Value Texture Size More Value Hue Saturation GIS 29

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. www. colormatters. com www. colorbrewer. org GIS 30

Color Wheel red orange violet yellow blue green GIS 31

Color Wheel Harmony • two adjacent hues red orange violet yellow blue green GIS 32

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

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

Color Wheel Harmony • two adjacent hues Contrast • two hues with one hue skipped in between red orange violet yellow blue green GIS 35

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

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

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

Non-Contrasting vs. Contrasting GIS 39

Saturation Shape Orientation Value Texture Size More Value Hue Saturation GIS 40

Saturation GIS 41

Saturation Customize the Properties…of a layer GIS 42

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

Change Map Example GIS 44

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

Color Spot Ramps GIS 46

Graphical Hierarchy GIS 47

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

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

Graphical Hierarchy Ground • larger areas of two contrasting GIS 50

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

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

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

Choropleth Maps GIS 54

Choropleth Maps Map using different colors or patterns to show different values GIS 55

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

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 GIS 57

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, 100 -200, 200 -300, 300 and greater Increasing interval widths -Long-tailed distributions -Example: 0 -5, 5 -15, 15 -35, 35 -75 GIS 58

Numeric Intervals (Continued) Exponential Scale -Popular method of increasing intervals -Use break values that are powers such as 2 n or 3 n -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% GIS 59

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

Custom Scales Edit the classifications and layer properties GIS 61

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

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

Other Numeric Intervals Pittsburgh, PA: Neighborhood proportion under poverty and average BMI per neighborhood BMI ! 18. 5 - 24. 9 25. 0 - 29. 9 30. 0+ Percentage in Poverty 0 - 12. 5% 12. 51% - 19. 99% 20. 0% - 39. 99% 40. 0% - 70. 10% Data Sources: BRFSS data, 2000; Reference USA, City of Pgh City Planning Dept. , U. S. Census 2000 GIS 64

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 GIS 65

Normalizing Data GIS 66

Normalizing Data GIS 67

Map Layers, Scale Thresholds, and Hyperlinks

Map Layers Organizes your layers Group logically and rename GIS 69

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

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

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 GIS 72

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

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