Comprehensive Notes on Maps and Spatial Patterns Unit 1 (1)

Introduction to Maps

Types of Maps

  • Reference Maps: Provide general information about places.
    • Used to refer to where you are.
    • Examples:
      • Political Maps: Show human-created boundaries like countries, states, cities, and capitals.
      • Physical Maps: Display natural features such as mountains, rivers, and deserts.
      • Road Maps: Indicate highways and streets.
      • Plat Maps: Label property lines and show land ownership; e.g., property lines drawn from a survey.
  • Thematic Maps: Show spatial aspects of data or a phenomenon.
    • The theme can be found by looking at the map title or legend.
    • Examples:
      • Choropleth Maps: Use various colors, shades of one color, or patterns to show the location and distribution of data. They are confined to political boundaries (regions, countries, states, counties, etc.). For example, the percentage of people who live in urban areas across the world, physical data (climate, temperature), political issues (voting data).
        • Limitation: Data averaged for an entire country could be misleading due to local variations.
      • Dot-Density/Distribution Maps: Show the specific location and distribution of something.
        • More dots indicate more data.
        • Each dot represents a specified quantity, though any kind of symbol can be used instead of dots.
        • Limitation: Can skew perception of population density in particular areas.
      • Graduated/Proportional Symbol Maps: Use symbols of different sizes to indicate different amounts of something.
        • Larger symbols represent more, and smaller symbols represent less.
        • The dot size is proportional to the amount of data.
        • Useful for visuals and showing hot spots of data; e.g., COVID-19 maps.
      • Isoline & Topographic Maps:
        • Isoline/Isometric Maps: Use wavy lines connecting points of equal value to show variations in natural phenomena across space.
          • Not confined to political boundaries.
          • Examples: weather maps, barometric pressure, temperature, and precipitation across space.
        • Topographic Maps: Show changes in elevation (2D or 3D textured).
      • Cartogram Maps: The size of countries (or states, counties, etc.) are shown according to some specific statistic, which changes the political boundaries.
        • Examples: based on population, GDP, election data.

Map Scale

  • Scale indicates what you are actually looking at.
    • Global Scale: Shows the entire world.
    • Regional Scale: Multiple countries (supranational region) or a region within a country (subnational).
      • Examples: Latin America (supranational), Pacific Northwest (subnational).
    • National Scale: One country.
    • Local Scale: Anything smaller than a country; large-scale maps.
      • Examples: Texas in the US or a city like Paris, France.

Small-Scale vs. Large-Scale

  • Large-Scale Maps:
    • Show a smaller amount of area.
    • Provide large amounts of detail.
    • Zoomed-in maps.
  • Small-Scale Maps:
    • Show a larger amount of area.
    • Provide small amounts of detail.
    • Zoomed-out maps.

Types of Spatial Patterns on Maps

  • Spatial patterns refer to the general arrangement of data.
  • Absolute Direction:
    • Exact, precise, constant.
    • Cardinal directions: North, South, East, West.
    • Helps orient where we are (N, S, E, W never changes).
  • Relative Direction:
    • Described as a position dependent on where you are currently (in front, to the left).
    • Related to relationships.
    • Example: "Turn left at the Target, then right at the second stop-sign."

Absolute Distance vs. Relative Distance

  • Absolute Distance:
    • Exact, precise, measured in miles/kilometers/feet.
    • Example: "Oak Hills is 21.3 miles away from my house."
    • Map Scale.
    • Example: The distance from Coppell, TX, to New York, NY, is 1,550 miles.
  • Relative Distance:
    • Measured in time, often dependent on the mode of transport, and a description of where something is in relation to other things.
    • Based on connectivity/flow.
    • Examples: 23 hours to drive to New York, 21 days and 19 hours to walk to New York, and 6 days and 12 hours to bike to New York.
    • Example: Amazon has drastically decreased the relative distance between consumers and products.
      • Prime- buy anything and have it delivered in 2 days!

Pattern Distribution

  • Clustered/Agglomerated:
    • Data is arranged in a group or concentrated area.
    • Example: Highest $$% clustered along the Mexican-American border (SW US) because it is closer and culturally similar.
      • Impact: Need more bilingual services and Catholic churches.
  • Linear:
    • Arranged in a straight line.
    • Usually along a river, road, or railroad.
  • Dispersed:
    • Spread out over a large area.
    • Example: Malls spread out so they aren’t in competition with each other.

Map Projections & Distortions

  • All maps are selective in information; map projections inevitably distort spatial relationships in shape, area, distance, and direction (SADD).
  • The grid on the globe is not perfect squares like maps we typically see, causing distortion in different types of map projections.
  • There are four distortions using the acronym SADD – Shape, Area, Distance, Direction
  • Every projection has distortion, but at least one part of SADD must be preserved.
Map Projection Types:
  • Mercator:
    • Strengths/Preservation: Directions because lines represent true compass direction; lines of Latitude and longitude meet at right angles.
    • Weaknesses/Distortion: Distance between lines of longitude appears constant; area-land masses near the poles appear large.
    • Fact/Purpose: Used originally for navigation.
  • Peters:
    • Strengths/Preservation: Area-Sizes of land masses are accurate.
    • Weaknesses/Distortion: Shapes are inaccurate, especially near the poles; direction because locations change.
    • Fact/Purpose: Used for spatial distribution related to area.
  • Polar:
    • Strengths/Preservation: Distance-Used to show the closeness of all the continents on Earth.
    • Weaknesses/Distortion: Area-Landmasses that are closer to the poles seem much bigger than they actually are; shape-the closer you get to the equator, the more squished the landmasses get.
    • Fact/Purpose: Historically used to determine the distance between US and Russia to know how long it might take a nuclear warhead to reach us (During the Cold War).
  • Goode-Homolosine:
    • Strengths/Preservation: Area and Shape preserved.
    • Weaknesses/Distortion: Distance and Direction; interrupts the oceans.
    • Fact/Purpose: Spatial distribution.
  • Robinson:
    • Strengths/Preservation: No major distortion; Oval shape appears more like a globe than it does a rectangle.
    • Weaknesses/Distortion: Shape, Area, Distance, and Direction are all SLIGHTLY distorted.
    • Fact/Purpose: Used for general purposes-compromise between Mercator & Peters projection.