Maps, Cartography, and Map Features (Vocabulary)

Module 1

Defining a map

• Map: A two-dimensional (flat) representation of a geographic area or place.

  • Expressed in the notes as a 2D depiction of a real place.

• Cartographer: A person who makes maps.

• Four key points to remember about maps:

  • 1) Maps present information about the world in a simple, visual way.

  • 2) Cartographers gather and use a large amount of data to draw maps.

  • 3) Maps use a spatial perspective to show spatial patterns.

  • 4) Maps reveal spatial patterns that result from a specific process.

• Review prompt (from slides): What are TWO of the four key points to remember about maps?

  • Possible answers include any two of the four points listed above.

How maps aggregate data and illustrate spatial patterns

• Learning goals:

  • Explain how maps aggregate data and illustrate spatial patterns.

  • Explain how time-distance decay can be illustrated on a graph or map.

• Data aggregation: The process of collecting and organizing large amounts of information.

• Spatial patterns: The placement or arrangement of objects on Earth’s surface; also includes the space between those objects.

• Time-distance decay: Also known as the "first law of geography"; the idea that near things are more related than distant things, and interaction between two places decreases the farther apart they are.

  • Expressed conceptually: near things are more related, and interaction fades with distance.

  • Mathematical/diagrammatic representation (conceptual): interactions decay as a function of distance, often illustrated on graphs or maps.

• Review question (from slides): What is data aggregation?

  • Answer: The process of collecting and organizing large amounts of information.

The different parts of a map

• Map symbols

  • Question prompt: What symbols does this map use? What does each symbol represent?

• Compass rose

  • Definition: A drawing, usually found on the edge of a map, showing the four cardinal directions (north, south, east, and west) and the map's orientation.

• Absolute direction

  • Definition: Corresponds to the direction on a compass: north, south, east, west, and combinations such as northeast and southwest.

• Map scale

  • Definition: The distance on a map in relation to distance in actual space.

  • Note: Scale can be described as the territorial extent of an idea or object.

• Absolute distance

  • Definition: The distance that can be measured with a standard unit of length, such as a foot, yard, mile, or kilometer.

• Relative distance

  • Definition: A measurement of the level of social, cultural, or economic similarity between places despite their absolute distance from each other.

• Relative direction

  • Definition: A direction that can be described as position, such as in front of or behind, to the left or to the right.

• Elevation

  • Definition: Distance above sea level.

• Isoline

  • Definition: On a map, a line that connects or links different places that share a common or equal value, such as elevation.

• Topographic map

  • Definition: A graphic representation of the three-dimensional configuration of Earth's surface.

Elevation, isolines, and topography in maps

• Elevation: Distance above sea level.

• Isoline: A line connecting places that share a common value (e.g., elevation) on a map.

• Topographic map: A graphic representation of the three-dimensional configuration of Earth’s surface.

Reflect: value of maps as information carriers

• Reflection question from the slides:

  • "They say a picture is worth a thousand words. How many words do you think a typical map is worth, and why?"

  • Answer summarized: A typical map conveys far more than a thousand words; maps visually display a great deal of data in a compact format (e.g., elevation, locations, symbols, movement, trends, etc.).

Main types of maps

• Identify the two main types of maps.

• Describe different types of thematic maps.

Main types of maps: Reference vs. Thematic

• Reference map

  • Definition: A map that shows geographic locations on Earth’s surface, such as the locations of cities or oceans.

  • Purpose:

  • Allows you to see where things are.

  • Emphasizes location.

  • Focuses on accuracy and exact positions of mapped features.

• Thematic map

  • Definition: A map that emphasizes the spatial patterns of geographic statistics or attributes, and sometimes the relationships between them.

Connections to broader geography and real-world relevance

• Maps present data spatially, enabling quick visual interpretation of complex information.

• Data aggregation supports larger-scale analyses by combining many data sources into coherent patterns.

• Time-distance decay reminds us that proximity matters for interactions, influencing fields like economics, epidemiology, transportation, and urban planning.

• Understanding map parts (symbols, compass, scale, distance, direction, elevation, isolines) is essential for reading any map accurately.

• Elevation and isolines help in understanding terrain and landscape features critical for navigation, planning, and environmental studies.

• Topographic maps provide a three-dimensional sense of the terrain on a two-dimensional medium.

• Reference versus thematic maps: one locates and contextualizes, the other explains patterns and relationships, guiding analysis and decision-making.

Quick references and definitions (glossary-style)

• Map: A 2D representation of a geographic area.

• Cartographer: A mapmaker.

• Data aggregation: Collecting and organizing large amounts of information.

• Spatial patterns: Arrangement and spacing of features on the Earth's surface.

• Time-distance decay: Interaction decreases as distance increases; near places relate more closely.

• Map symbols: Visual icons used to represent real-world features on a map.

• Compass rose: Indicates cardinal directions and map orientation.

• Absolute direction: Direct compass-based directions (N, S, E, W, NE, NW, SE, SW).

• Relative direction: Described in relation to objects (in front of, behind, left of, right of).

• Map scale: Ratio of map distance to real-world distance.

• Absolute distance: Measured distance using standard units (e.g., kilometers).

• Relative distance: How similar places are in social, cultural, or economic terms, regardless of physical distance.

• Elevation: Height above sea level.

• Isoline: Line joining places with equal value (e.g., elevation).

• Topographic map: 3D-like representation of terrain on a 2D surface.

• Reference map: Focuses on precise locations and accurate placement of features.

• Thematic map: Emphasizes patterns of statistics or attributes and possible relationships between them.

Note on study approach

• When studying, focus on how data aggregation leads to observable spatial patterns.

• Practice identifying map parts on real-world maps: symbols, compass, scale, directions, elevation cues, and isolines.

• Compare reference and thematic maps to understand how different map goals guide design and interpretation.

  Main types of maps

  • Choropleth map: A thematic map that shows data aggregated for a specific geographic area, often using different colors to represent different values.

  • Cartogram: A map that distorts the geographic shape of an area in order to show the size of a specific variable; the larger the area on a cartogram, the larger the value of the underlying variable.

  • Proportional or graduated circle map: A map that uses symbols (such as circles or dots) of different sizes to represent numerical values.

  • Dot density or dot distribution map: map that uses dots to represent objects or counts; the dot can represent one object (a one-to-one dot density map) or it can represent a number of objects (a one-to-many dot density map).

  Reflect: Why are there so many different types of maps?

  • The variety exists because each map type is designed to communicate different aspects of data and to suit different tasks or audiences.

  • Some map types emphasize area accuracy, others emphasize rate or quantity, and others emphasize spatial distribution or density.

  • The choice depends on what you want the viewer to notice and the potential for data distortion or misinterpretation.

  Benefits and drawbacks of map projections

  • For this learning goal, you will learn to:

    • Explain the benefits and drawbacks of map projections.

    • Identify several different examples of specific map projections.

    • Contrast differences between specific map projections.

  • Map projection: A method for representing the surface of Earth or a celestial sphere on a plane (two-dimensional) surface; all map projections distort some aspect of Earth's surface.

  • Mercator projection: A map projection that is useful for navigation because the lines connecting points on the map represent the true compass direction; however, landmasses become increasingly distorted the farther away they are from the equator.

  • Peters projection: A map projection that shows all landmasses with their true areas but distorts their shapes.

  • Goode homolosine projection: A map projection that avoids shape distortion and the restrictions of a rectangular map by creating “interruptions” in the map's continuity; in each section, map projection regions are shown "equally," like an orange peel being laid out in a flat surface.

  • Polar projection: A map projection that looks down at Earth from the perspective of one of the poles (North Pole or South Pole).

  • Robinson projection: A map projection that attempts to create the most visually appealing representation of Earth by keeping all types of distortion relatively low over most of the map.

  Connections to foundational principles and real-world relevance

  • Map projections involve trade-offs between preserving area, shape, distance, and direction.

  • Choice of projection affects interpretation of geographic data and can influence decisions in areas such as policy, urban planning, and resource allocation.

  • Understanding these trade-offs helps in selecting the appropriate visualization for a given dataset and audience.

  Practical implications and ethical considerations

  • Misleading visuals can arise if a projection or map type exaggerates or downplays certain regions or data values.

  • Visual accuracy matters for international comparisons, resource planning, and informing public policy.

  • When presenting data, accompany the map with notes about the projection and any distortions to aid correct interpretation.

  Summary of key definitions and concepts

  • Map projection: A method for representing the surface of Earth or a celestial sphere on a plane; all projections distort some aspect of Earth's surface.

  • Choropleth map: Visualizes aggregated values by geographic area using color shading.

  • Cartogram: Scales geographic units by a variable's magnitude, distorting area to reflect data values.

  • Proportional/graduated circle map: Uses symbol size to represent numerical values.

  • Dot density map: Uses dots to represent counts or objects; one-to-one or one-to-many representations are possible.

  • Mercator projection: Great for navigation, preserves direction but distorts area away from the equator.

  • Peters projection: Preserves area but distorts shapes.

  • Goode homolosine projection: Breaks continuity to reduce shape distortion; described as “like an orange peel laid out in a flat surface.”

  • Polar projection: Views Earth from a pole, focuses on polar regions.

  • Robinson projection: Strives for visually pleasing balance by reducing overall distortion.