Intro to Cartography -- What is cartography? -- Globes vs. Maps -- Map scales -- Map projections -- Map conventions -- Map types -- Maps through time -- Mapping today

What is cartography? Cartography is the art & science of mapmaking. Cartographers are specially-trained geographers. Maps are a geographer’s most important tool for thinking spatially (distribution and patterns). A map serves two purposes: A tool for storing reference material A tool for communicating geographic information

Globes vs. Maps The most accurate physical representation of the earth is a globe; still, even globes are inaccurate. So, why not use a globe if they are more accurate?

Map Scales Why draw at different scales? Different needs… Use: Accuracy: Scale shows the ratio of distance and area on the earth to the distance and area on the map. There is an inverse relationship between the ratio and the “size” of the scale.

Map Projections All maps are inaccurate in at least one way…they distort the earth (round to flat) There are four true measures, not all of which can be included in a single flat map. True distance (great circle) True direction (great circle) True shape True area

Map Projections Different methods of representing the round earth on a flat surface are called projections. The purpose of the map helps determine which projection to use. Examples:

Projection Method Mathematical formulas (algebraic, trigonometric) are used to plot the round earth on a piece of paper Cartographers used math to do what a flashlight and clear globe would do

Mercator Projection

Peters Projection The “controversial” map… Some believe it is reduces inflated beliefs in western (Euro & American) superiority Some believe it doesn’t deserve that much credit—it’s just another projection West Wing

Interrupted Projection

Robinson Projection This projection blends techniques to make it a more accurate in three measures Distance Area Shape

Projection Comparison Mercator (cylindrical) False distance False direction False shape False area Interrupted True (or false!) shape True area Peters False distance False direction False shape True area Robinson (compromise) Fairly accurate distance Fairly accurate shape Fairly accurate area

Map Conventions T O D A L S S All good maps have: r i e n t a o a t e u t h o r e g n d c a l e o u r c e i t l e

Map Types -- Physical -- Political -- Thematic (special purpose) Qualitative Quantitative

Physical Maps Physical maps show one or more natural features, such as mountains, lakes, rivers, and climate. Relief maps show topography Topography: different elevations on the earth’s surface (height above sea level, such as hills, valleys, mountains)

Political Maps Political maps show human-made political boundaries and features, including country borders, state or province borders, capitals, and cities.

Thematic Maps Thematic maps are special-purpose maps that show one or more specific features, or themes. There are two types of thematic maps Qualitative Quantitative

Qualitative Maps These maps show some “quality” (feature, phenomena) of the earth or humans MINNESOTA LAND USE AND COVER 1990s CENSUS OF THE LAND

Quantitative Maps These maps display “quantities” (numbers) in a visual form.

Maps Through Time The oldest known maps were made on clay tablets by the Babylonians (~2300 BC). Ancient Greeks and Romans made many advances in cartography (i.e., Ptolemy) In the Middle Ages (~1200s-1400s), maps often had religious themes; Arabs excelled in mapmaking. During the Renaissance, printing presses made maps widely available; maps often were based on exploration and used for navigation.

Modern Cartography Maps became more accurate in the 18th and 19th centuries as technologies improved. Today most all maps are made on computers that use GIS (Geographic Information Systems). Other technologies used in cartography are aerial photography, satellite imagery, and GPS.