Geographic Information Systems GIS Output

1. Color Theory Additive primaries blue, green, and red Subtractive primaries yellow, cyan, and magenta

1. (1) Additive Primaries Superimposing blue, green, and red light blue + green + red = white

Yellow, cyan, and magenta are complements to blue, red, and green, respectively Various combinations of the three primaries produce different colors 1. (1) Additive Primaries

1. (2) Subtractive Primaries Superimposing yellow, magenta, and cyan dye: yellow + magenta + cyan = black yellow + magenta = red yellow + cyan = green magenta + cyan = blue

1. (2) Subtractive Primaries Yellow, cyan, and magenta Cyan = white – red Magenta = white – green Yellow = white - blue

2. Cartographic Symbols Point symbols Line symbols Area symbols

2. (1) Point Symbols Points e.g. cities, lakes, stores, trees Lines e.g. rivers, streets and roads, pipelines, airline routes Areas e.g. field crops, depth to water table, demographic statistics, marketing regions

Strategies of Symbolization USGS Map Symbols The use of point, line, and area symbols depends on - spatial scale of a project - purpose of a project - convention

Strategies of Symbolization M. Dolce

Strategies of Symbolization

Identification and Awareness of Hazardous Waste Sites

Strategies of Symbolization Chesapeake Bay nitrogen levels Chesapeake Bay nitrogen levels

3. Primary Graphic Elements Hue Value Size Shape Spacing Orientation Location

3. Primary Graphic Elements Hue - Color Value - Lightness or darkness of a mark, tone Size - size of a mark Shape - shape of a mark Spacing - distance between component marks Orientation - directional arrangement of marks Location - location of map components, titles, legends, etc.

3. (7) Location Location of map components, titles, legends, etc Title Legend Data source

Shape/ Pattern Color Point Data Nominal Numerical Line Data Area Data Nominal Numerical Graphic Element X X X X X X Size X X X Value X X X X -- Graphic Element is not suitable.

4. Components of Map Design Clarity and legibility Visual contrast Visual balance Figure vs. ground Hierarchical organization

4. (1) Clarity and Legibility Size Length vs. width Contrasting color and shape of symbols Map components

4. (2) Visual Contrast Sufficient difference among symbols

Jim Besley & Kurt Snider, US Fish & Wildlife Service 4. (3) Visual Balance Relative position and visual importance of map components The two centers of an image space Optical Center Geometric center The designer should arrange the map’s elements around the optical center, rather than the geometric center

4. (4) Figure vs. Ground Differentiation, closed, small or continuous forms, brightness, detail of features and ground Figures – important objects Grounds – things less important

4. (4) Figure vs. Ground Figures – important objects Grounds – things less important

4. (5) Hierarchical Organization Extensional - network of lines of varying significance Subdivisional - internal relationship of a hierarchy

Hierarchy Contrast, shading, color, and text masking are all techniques used to create hierarchy.

Hierarchy

Readings Chapter 7