Class Introduction to maps

What is a map? A generalized view of an area, usually some portion of Earth’s surface, as seen from above at a greatly reduced size Any geographical image of the environment A two-dimensional representation of the spatial distribution of selected phenomena

Why make maps? To represent a larger area than we can see To show a phenomenon or process we can’t see with our eyes To present information concisely To show spatial relationships

Represent a larger area

Show what we can’t see

Present info concisely

Show spatial relationships

How do we read maps? Maps are selective views of reality Size of the map relative to reality (scale) What’s on the map (symbolization) Shape of the map (projection)

Map scale What is it? Scale is the relationship between the two points on the map and the actual distance between the same two points on the ground Scale Indicates how much distance on the ground has been reduced to fit on a map Scale is also how much bigger or smaller something is compared to the real thing

Map scale Why use it? Helps us calculate distances between places without actually having to go out to the place Helps calculate the size/area and density of a place How is it shown? In words – 1 cm represents 1 km (1 cm on the map shows 1 km on the ground) In numbers, as a ratio or representative fraction (RF) – 1:100,000 or 1/100,000 (1 cm on the map represents or shows 100,000 cm or 1 km, on the ground) As a line scale or linear scale

Different types of scale maps Large scale –Shows lots of detail in a small area –The smaller the numbers in the ratio, the more detail is shown over a small area Small scale –Shows less detail in a large area –The larger the numbers in the ratio, the less detail is shown over a large area What is the point of looking at the scale of a map? Help us decide which map to use for different activities

How does it work Example 1:5,000,000 – would be used for planning a big trip (Small scale map) 1: 1,000,000 – would be used for planning a tour by car (larger scale map) 1:25,000 – would be used for finding directions, or planning a walking tour (Large scale map) How do we do it? First measure the distance on the map with a piece of paper (choose two points on the map) Then use the line scale of the map to convert the distance from cm (on the map) to km/m (on the ground)

Large-scale Small-scale

Map symbolization Symbols are a code instead of text Three kinds: point, line, area Consider shape, size, orientation, pattern, color, value

Indicate location Describe location

Show a distribution

Indicate a value

Line symbols One-dimensional Mostly taken for granted (borders, roads) Isolines connect same values Flow-line maps indicate value by width of line

Isolines (Contour lines)

Flow-line maps

Differences in kind