Geography 222 The Power of Maps and GIS

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Geog 222 Lecture Outline: Cartographic Maps
Update: 9/24/14

Recap: the way we envision or visualize the environment takes two general forms


PsychoSensory Mapping: valuable because...


1. Basic Components of Cartographic Maps

Many types of cartographic maps

Some basic elements of cartographic maps:


1a. Map Scale

Scale: Google Earth Zoom


Map Scale:

Maps are always smaller than the portion of the Earth's surface they portray


Map Scale Types

Graphic scale: line or bar on map represents some set distance

Word scales: describes the scale of the map in words

Fractional scales: representative fraction: a proportion between map distance and Earth distance


Large and Small Scale Maps

Large scale / Small scale distinction is based on the representative fraction



1b. Map Graticule

In order to locate phenomena on the earth we need some way to locate that phenomena: a system of location. A grid of lines that intersect at right angles is the simplest way to do this: The geographic grid or graticule:


There are many such grids/graticules: Map Locational Reference Systems

Most common grid: latitude (east/west lines) and longitude (north/south lines)

Latitude/Longitude is based on the rotation of the earth


1c. Map Projections: flattening out the spherical earth

ex) globe

ex) different map projections (Interactive Album of Map Projections)

All flat maps distort shape or size or direction: can hold one constant, but not all three

What is vital to remember at this point is that all flat maps are projected and the projection process always involves some kind of major map distortion


1d. Map Generalization: using judgement in the elimination of detail and reduction of the number of features out in the "real" world:


1e. Map Content: reference vs. thematic

Reference maps: general use (for many purposes): primary aim is to portray human or environmental details accurately

ex) Google Maps or Map Quest.


Thematic maps: particular use: primary aim is to portray a general spatial pattern of one or several human or environmental phenomenon

ex) US Surnames
ex) US Languages
ex) Fourteen ways to die in Shanghai
ex) Pop vs. Soda


1f. Map Symbolization

Symbol: A thing representing something else because of relationship, association, convention, or resemblance.

Map symbolization: guidelines and rules for symbolizing data on maps: the realm of map making


2. The Cartographic Process: Map Making and Map Use

A broad, general way to look at cartographic maps in terms of the cartographic process



3. Map Making: factors which influence how and why a map is created

3a. Map Purpose

There are a multitude of purposes for which a map can be designed


3b. Geographical Reality

Some aspects of reality are easier to map than others:


The reality you are mapping varies:


3c. Data Availability and Quality

Availability of data to map varies:


Quality of data to map varies


3d. Technical Limitations

What a map looks like can be the result of the equipment used to create the map, the cartographer's skills, and the time, budget, and labor restrictions imposed on the map making process


3e. Conditions of Use

Maps are shaped for the conditions of use


4. Map Use: Map Reading, Map Analysis, Map Interpretation

Map use (reading) can be broken down into several steps: often happen simultaneously


Example) College Basketball: % from each county in the US (darker = more)


Example) Languages in the US


Example) Military Recruits: % from each county in the US (tan = low, green = high)



Next: a bit of cartographic history



E-mail: jbkrygier@owu.edu

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