Intro to CartographyIntro to Cartography

---- What is What is cartography?cartography?

-- Globes vs. Maps -- Globes vs. Maps

---- Map scalesMap scales

---- Map projectionsMap projections

---- Map conventionsMap conventions

---- Map typesMap types

---- Maps through timeMaps through time

---- Mapping todayMapping today

What is cartography?What is cartography?

Cartography is the Cartography is the artart & & sciencescience of mapmaking. of mapmaking.

Cartographers are specially-trained Cartographers are specially-trained geographers.geographers.

Maps are a geographer’s most important tool Maps are a geographer’s most important tool for thinking spatially (distribution and patterns).for thinking spatially (distribution and patterns).

A map serves two purposes:A map serves two purposes:1.1. A tool for storing reference materialA tool for storing reference material

2.2. A tool for communicating geographic informationA tool for communicating geographic information

Globes vs. MapsGlobes vs. Maps

The most accurate The most accurate physical representation physical representation of the earth is a globe; of the earth is a globe; still, even globes are still, even globes are inaccurate.inaccurate.

So, why not use a globe So, why not use a globe if they are more if they are more accurate?accurate?

Map ScalesMap ScalesWhy draw at different scales? Why draw at different scales? Different needs…Different needs…

1.1. Use:Use:2.2. Accuracy:Accuracy:

Scale shows the ratio of Scale shows the ratio of distance and area on the earth distance and area on the earth to the distance and area on the to the distance and area on the map.map.

There is an inverse relationship There is an inverse relationship between the ratio and the “size” between the ratio and the “size” of the scale.of the scale.

Map ProjectionsMap Projections

All maps are inaccurate in at least one All maps are inaccurate in at least one way…they distort the earth way…they distort the earth (round to flat)

There are four true measures, not all of There are four true measures, not all of which can be included in a single flat map.which can be included in a single flat map.

1.1. True distance (great circle)True distance (great circle)2.2. True direction (great circle)True direction (great circle)3.3. True shapeTrue shape4.4. True areaTrue area

Map ProjectionsMap Projections

Different methods of representing the round Different methods of representing the round earth on a flat surface are called earth on a flat surface are called projectionsprojections..

The purpose of the map helps determine The purpose of the map helps determine which projection to use.which projection to use.

Examples:Examples:

Projection MethodProjection Method Mathematical formulas Mathematical formulas

(algebraic, trigonometric) (algebraic, trigonometric) are used to plot the round are used to plot the round earth on a piece of paperearth on a piece of paper

Cartographers used math Cartographers used math to do what a flashlight to do what a flashlight and clear globe would doand clear globe would do

Projection ComparisonProjection Comparison

Mercator (cylindrical)Mercator (cylindrical)False distanceFalse distanceFalse directionFalse directionFalse shapeFalse shapeFalse areaFalse area

InterruptedInterruptedFalse distanceFalse distanceFalse directionFalse directionTrue (or false!) shapeTrue (or false!) shapeTrue areaTrue area

PetersPetersFalse distanceFalse distanceFalse directionFalse directionFalse shapeFalse shapeTrue areaTrue area

Robinson (compromise)Robinson (compromise)Fairly accurate distanceFairly accurate distanceFalse directionFalse directionFairly accurate shapeFairly accurate shapeFairly accurate areaFairly accurate area

Mercator ProjectionMercator Projection

Peters ProjectionPeters Projection

The “controversial” The “controversial” map…map…

Some believe it is Some believe it is reduces inflated reduces inflated beliefs in western beliefs in western (Euro & American) (Euro & American) superioritysuperiority

Some believe it Some believe it doesn’t deserve that doesn’t deserve that much credit—it’s just much credit—it’s just another projectionanother projection

Interrupted ProjectionInterrupted Projection

Robinson ProjectionRobinson Projection

This projection blends This projection blends techniques to make it techniques to make it a more accurate in a more accurate in three measuresthree measures DistanceDistance AreaArea ShapeShape

Map ConventionsMap ConventionsAll All goodgood maps have: maps have:

T O D A L S S T O D A L S S itle

rientation

ate

uthor

egend

cale

ource

Map TypesMap Types

---- PhysicalPhysical

---- PoliticalPolitical

---- Thematic (special purpose)Thematic (special purpose)1.1. QualitativeQualitative

2.2. QuantitativeQuantitative

Physical MapsPhysical Maps

Physical maps show one or more show one or more natural natural features, such as mountains, lakes, rivers, and features, such as mountains, lakes, rivers, and climate.climate.

Relief maps show Relief maps show topographytopographyTopography: different elevations on the earth’s Topography: different elevations on the earth’s surface (height above sea level, such as hills, surface (height above sea level, such as hills, valleys, mountains)valleys, mountains)

Political MapsPolitical Maps

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

Thematic MapsThematic MapsThematic maps are special-purpose maps Thematic maps are special-purpose maps that show one or more specific features, or that show one or more specific features, or themes.themes.

There are two types of thematic mapsThere are two types of thematic maps1. Qualitative

2. Quantitative

Qualitative MapsQualitative Maps

These maps show some “quality” (feature, These maps show some “quality” (feature, phenomena) of the earth or humansphenomena) of the earth or humans

MINNESOTA LAND USE AND COVER1990s CENSUS OF THE LAND

Quantitative MapsQuantitative Maps

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

Maps Through TimeMaps Through Time

The oldest known maps were made The oldest known maps were made on clay tablets by the Babylonians on clay tablets by the Babylonians (~2300 BC).(~2300 BC).

Ancient Greeks and Romans made Ancient Greeks and Romans made many advances in cartography (i.e., many advances in cartography (i.e., Ptolemy)Ptolemy)

In the Middle Ages (~1200s-1400s), In the Middle Ages (~1200s-1400s), maps often had religious themes; maps often had religious themes; Arabs excelled in mapmaking.Arabs excelled in mapmaking.

During the Renaissance, printing During the Renaissance, printing presses made maps widely available; presses made maps widely available; maps often were based on maps often were based on exploration and used for navigation.exploration and used for navigation.

Modern CartographyModern Cartography

Maps became more Maps became more accurate in the 18accurate in the 18thth and 19 and 19thth centuries as technologies centuries as technologies improved.improved.

Today most all maps are Today most all maps are made on computers that made on computers that use GIS (Geographic use GIS (Geographic Information Systems).Information Systems).

Other technologies used in Other technologies used in cartography are aerial cartography are aerial photography, satellite photography, satellite imagery, and GPS.imagery, and GPS.