Presentation on theme: " Type of Map (thematic* or reference)"— Presentation transcript:
1 Type of Map (thematic* or reference) Maps: Two-dimensional, scaled representations of Earth surface - show spatial data (data with locational component)Cartography (map-making) involves 5 design decisions – based on purpose of map Projection Simplification Scale Aggregation Type of Map (thematic* or reference)DISCUSSION:* Break this definition down and explain what each part means.
2 THEMATIC MAPS – depict characteristics of places Categorical type- Depict areas that are different in kind- Use several distinct colors to show different categoriesdesert forest tundraExamples: climates, religionsChoropleth type- Depict areas that are different in amount- Use shades of similar colors to show different valueshigh value medium low valueExamples: population density, literacy rates
4 Example of “choropleth map” Human Development Index (HDI) RankingsIncludes GNI/PPP, Literacy, and Life ExpectancyWhich regions have high HDI?Which regions have low HDI?Which places are exceptions?
5 Isoline type (Average Daily Solar Radiation) Lines connect points of equal valueDISCUSSION:* Do you have a preference among these two types of maps?* Do you find one of these easier to understand than the other?Dot Density type (Wisconsin Acreage in Potatoes)Each dot represents a frequency of mapped variable
6 Proportional Symbol Map (Graduated Circle type) Size of symbol varies in relation to frequency or intensity of the mapped variableDISCUSSION:* What are some of the advantages of each of the four types of thematic maps?Proportional Symbol Map (Flow Vector type)
7 Systematic methods of transferring a spherical surface to a flat map Sample Map ProjectionsSystematic methods of transferring a spherical surface to a flat mapDistortion must occur in either size, shape, distance, or direction – all projections are compromisesMercatorDISCUSSION:* How are these two map projections different?* Which do you prefer? Which one is more popular?RobinsonPolar
8 (They distort shapes to make sizes correct.) Equal-Area projections best where purpose is to compare distributions of a variable between places(They distort shapes to make sizes correct.)What impressions do you get from this map?
9 Larger-scale shows less land area in more detail. Used on local maps. The ratio of map distance to earth distance, measured in the same unitsMap Scalesmaller scaleSample Area Covered Fraction Scale Verbal ScaleWorld 1:78,000,000 1 in = 1,250 miNo. America 1:36,000,000 1 in = miCentral U.S. 1: 4,000,000 1 in = miAAA Colo map 1: 1,267,200 1 in = milarger scaleSmaller-scale shows more land area in less detail. Used to show global patterns.Larger-scale shows less land area in more detail. Used on local maps.
10 The scale at which one analyzes an issue is critical DIA – Only major U.S. airport built since 1980At the national scale, why did the location of this airport make sense?At the local scale, why was it necessary to locate the airport where it is?DISCUSSION:* Think about the nearest major airport to where you live. How close is it to the center of the city whose name it carries?* Can you think of examples around the country where the airport is not even in the city whose name it carries? Why is this?* Does this issue matter when viewing a map at the national scale? Urban scale?
11 Map AggregationThe level of detail for dividing a thematic map into geographic unitsRanges from coarse divisions (e.g., by countries) to fine divisions (e.g., by zip codes)DISCUSSION:* Is it likely that educational levels within California are the same in all parts of the state?* Are there parts of your state or province that you think probably have a higher than average percentage of Bachelor's degrees?Percent of 1990 pop age 25+ with bachelor's degreeData aggregated by State
12 Note what information is lost at higher levels of aggregation Percent of pop age 25+with bachelor's degree (1990)Note what information is lost at higher levels of aggregationAggregated by State (northeast close-up)Aggregated by County (WV, MA)DISCUSSION:* What can you learn about educational levels within West Virginia and Massachusetts on the local map that you can't see on the national map?
13 2004 Presidential Election Red = Bush; Blue = Kerry State results, by land areaCounty results, by land areaState results, by populationCounty results, by populationSource: M. Gastner, C. Shalizi, and M. Newman, University of Michigan
14 2004 Presidential Election Red = Solidly Bush (70% +)Purples = divided … redder = Bush majority; bluer = Kerry majorityBlue = Solidly Kerry (70%+)By land areaBy populationSource: M. Gastner, C. Shalizi, and M. Newman, University of Michigan
15 (Phil Gersmehl, Research in Geographic Education, 2006) Spatial Thinking(Phil Gersmehl, Research in Geographic Education, 2006)
16 Pattern Analysis: Density vs. Dispersion Which square mile has the higher density, (a) or (b)?
17 Various Pattern Arrangements What phenomena could explain the patterns shown in A, B, and C?
18 What kinds of things are symbolized by lines on this map? ConnectionsWhat kinds of things are symbolized by lines on this map?
19 Where are some patterns that illustrate this? Combination of climate, agriculture, and industry explains population density patternsWhere are some patterns that illustrate this?
20 How does this map illustrate the aura or zone of influence for Denver? Denver metro areaHow does this map illustrate the aura or zone of influence for Denver?How are hierarchies symbolized on this map?For which kinds of services does Denver’s aura extend beyond this map?
21 Where could you define a region of “Elvis-lovers”? Where are the exceptions?Where are the outliers?
22 Compare the Pacific coasts of North and South America Which places have analogous climates?
23 Spot any spatial correlations? Middle & South America Agricultural Regions (left) and Population Density (below)Spot any spatial correlations?
24 An example of the importance of spatial thinking Christian
25 TURKIC (Altaic Language Family) Diversity,exceptions,and edgescan makeforinterestingcase studiesorexamplesTURKIC (Altaic Language Family)IRANIAN (Indo-European Language Family)SEMITIC (Afro-Asiatic Language Family)
26 Iraq Ethnic Groups Turkey Knowledge of cultural regions, boundaries, and transitions is necessary for understanding conflictsSyriaIranJordanIraq Ethnic GroupsSaudi ArabiaKuwaitIraq’s population is 29 million: sixty percent are Shi’a Arab, mostly in the south.Sunni Arabs are concentrated in the center (western Iraq is sparsely populated).Over 4 million Iraqis in northern Iraq are Kurdish. Baghdad is a transition zone.