CONTOURS

Created by tbonnar.

CONTOURS

Three Dimensions

In real life we see in 3D, but maps are only two dimensional. It is therefore difficult for maps to show three dimensions.

Three Dimensions

It is possible, but very difficult, to create a form of 3D map such as those shown here.

Profile (Side View)

There are two ways maps try to show 3D:

1. Profile (Side View)

Profile (Side View)

Contour Map (Top View)

There are two ways maps try to show 3D:

2. Contour Map (Top View)

Contour Map (Top View)

Contour Lines

A Contour Map Takes a

3D representation and turns it into a 2D map.

Contour Lines

Contour lines are a map’s way of showing you how high the land is.

They join together places of the same height and form patterns that help us to imagine what the land actually looks like.

Contour Lines

Contour lines are drawn in intervals that never change and never cross each other.

Contour Lines – Shapes Revealed Contour maps are used in atlases, because they

can provide more detailed information about a location.

For example, in the two boxes below we can predict the shape of the land based on the contour line.

Contour Lines – Shapes Revealed

Contour Lines – Shapes Revealed

Contour Lines – Shapes Revealed

Contour Lines - Steepness

We can also learn about the steepness of the slope(in math class this would be called the gradient). In the box below we can see that the distance between the lines indicates the slope.

gentle/not steep

cliff – lines are touching

steep

Contour Lines - Steepness

The closer together the contour lines are, the steeper the land. Contour lines that are wide apart show us that the land is flatter.

 

Exercises

Stop here to do Contour Pages 1 & 2.

How are contour lines made?

Contour lines are created by first finding spot heights (heights at particular places) for a whole region and then connecting the locations that have identical spot heights.

How are contour lines made?

Below, you can see two examples of “connecting the dots” in order to create contour lines.

How are contour lines made?

Note that the contour lines have different contour intervals. Maps usually specify the contour interval.

Usually the contour interval is a round number. Ex. 10 metres or 100 metres

Try connecting the dots in the example below.

How are contour lines made?

Note that the contour lines have different contour intervals. Maps usually specify the contour interval.

Usually the contour interval is a round number. Ex. 10 metres or 100 metres

Try connecting the dots in the example below.

How are contour lines made?