Map Projections

Map Projections Definition: The representation of the globe on a two dimensional flat map. No map projection is perfect and all maps distort a certain property. All maps have four features that can be distorted that include: Shape, Size (area), distance, and direction. The reason for this being that there is no perfect way to represent a 3-D object on a 2-D plane. Each different type of map sacrifices one or more of these properties to make a flat map.

Map Name Map Uses Distortion Way to identify Robinson Just a compromise. Distorts a little bit of everything. Round sides and flat top and bottom.

Map Name Map Uses Distortion Way to identify Mercator Used by ships for navigation. Size and shape especially at the poles. Greenland looks about the same size as Africa.

Map Name Map Uses Distortion Way to identify Goode Homolosine

Map Name Map Uses Distortion Way to identify Polar Used for airline companies to discover cheapest route across oceans. Distorts the bottom half of the globe. It’s completely round and the image is from above looking down.

Map Name Map Uses Distortion Way to identify Peter Preserves area to accurately display the actual land mass especially to “third world” countries, that were mapped biasedly earlier. Shape of countries especially near the equator. Africa and South America are longer and Europe is more compact.

Map Name Map Uses Distortion Way to identify Azimuthal

Types of Maps Reference Maps- show features related to location which can be natural or man-made. For example: road maps, political maps, and topographical maps. Thematic Maps- are based on a particular characteristic or theme. Different types of thematic maps are better suited to represent some data than others, depending on the data and the objective

Types of thematic maps Choropleth mapping shows statistical data aggregated over predefined regions, such as counties or states, by coloring or shading these regions. Choropleth map of water use.

Thematic map A Cartogram- distorts land area based on some variable . Population 2050

Thematic map A dot distribution map (also known as dot density map) is a map type that uses a dot symbol to show the presence of a feature or phenomenon. Dot maps rely on a visual scatter to show spatial pattern. Acres of Harvested Wheat in Illinois in 2012

You better know your Map Projections and Types of Maps!