Types of Maps and GIS Components for Geography

General Purpose Maps

Used as reference maps.

Thematic Maps

Formal data (population, soil type, climate etc.). Can be quantitative or qualitative.

Topographic Maps

Show elevation and relief. Physical and built cultural features (reference map).

Quantitative Thematic Maps

Characteristics of numeric data (population, farms, votes etc.).

Qualitative Thematic Maps

Spatial distribution of a phenomenon.

Point Symbols

Use points to represent the presence of a feature.

Dot Density Maps

Use dots to show the distribution of a phenomenon.

Graduated Symbol Maps

Use symbols of different sizes to represent numeric values.

Polygon / Area Symbols

Use shaded or colored areas to represent data.

Choropleth Maps

Use varying colors or shading to represent data values within defined areas.

Line Symbols

Represent linear features such as roads or rivers.

Isoline

A line on a map that connects points of equal value.

Flow Line Maps

Show movement between locations. Qualitative (storm direction) or quantitative (migration flow - numeric data).

Legend

Explains symbols used on a map.

North Arrow

Shows orientation.

Scale

Shows relationship between map distance and real-world distance.

Topography

Shape and physical characteristics of Earth's surface features.

Elevation

Vertical distance of a surface in relation to sea level.

Relief

Difference in elevation between two or more points on Earth's surface.

Contour Lines

Lines of equal elevation (in relation to sea level).

Contour Interval

Increment between contour lines. Measured in meters.

Interactive Maps (GIS)

Maps that allow users to interact with layered spatial data.

Google Earth

Satellite imagery; interactive globe. GIS-based program used during the semester.

Geographic Information System (GIS)

A digital record of geographic information. Information 'layered' together via coordinate system.

Geographic Database

Collection of spatial data stored digitally.

Basemap

The reference map layer beneath other data layers.

ArcGIS

A GIS platform used to create, analyze, and display geographic data.