Cartographic Communication
Two Types of Maps: Reference Maps Show locations of places and geographic features Absolute locations What are reference maps used for? Thematic Maps Tell a story about the degree of an attribute, the pattern of its distribution, or its movement. Relative locations What are thematic maps used for?
Graduated Circle Maps or Proportional symbol shapes of different sizes to show where and how much Larger the circle = more phenomenon Single variable Population, median income, wheat production, or average land value Swine Flu
Dot Map A single or specified number of occurrences is represented by a dot Good for suggesting spatial pattern, distribution, and dispersion Poor at showing precise value Crime Map
Commercial wireless signals
Isometric/Isopleth/Isoline Map Features isolines that connect points registering equal values of whatever is being mapped. Isoline show where there is a uniform occurrence Poor at showing information that might be patchy
Perception of Place Where Pennsylvanian students prefer to live Where Californian students prefer to live
Choropleth Shows data in a predetermined unit. Each unit is shaded to represent how much of an item in the borders Can give a false impression of abrupt change Smaller units are better than larger (1-5) is more accurate than (1-50) Election Results
Cartogram Uses statistical data to transform a space so that the largest unit on the map is the one showing the greatest statistical value Gives a good visual representation of quantity but not good at communicating exact numbers
Most thematic maps have: Simplification- What has the cartographer chosen to keep Why are things left out? Symbolization What do the symbols add to the meaning? Does it look attractive? Classification Thematic maps use categories Equal interval or set values Induction Information is under the surface or hidden Linked to classification Centering- what is placed in the center of the map shows cultural/artistic value
Simplification
Simplification
Symbolization Super bowl Word Symbols
Symbolization
Symbolization
Symbolization
Classification
Classification
Classification
Induction
Centering
Centering
Centering
Scale
Scale
Message/Art
Message/Art