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Geography chapter guide

Contours, height and cross-sections

Contour lines look like swirls, and you cannot turn them into slopes and side views.

Contours turn a flat map into a picture of height. This hub shows how slope, shape, cross-sections and route choice link together, and where to begin.

It is part of map and graph skills in SPM Geography. The broader companion is interpreting contours and relief.

How do the lessons connect?

Each lesson adds one idea to the last, so follow the order below.

  1. Inferring slope steepness from contour spacing: spacing gives steepness.
  2. Distinguishing a valley from a ridge: shape gives landform.
  3. Drawing a cross-section: heights and distances give a profile.
  4. Explaining a route choice: slope and landform give a reasoned choice.

The practice set mixes all four.

One small example of a full reading

This is a worked example. A map at 1:25 000 has a contour interval of 20 m. Two contours near a stream are 0.8 cm apart on the north side and 3.2 cm apart on the south side of a hill.

  • Spacing: 0.8 cm is close and 3.2 cm is wide, so the north side is steeper.
  • Ground distance: 0.8 × 25 000 = 20 000 cm = 200 m, and 3.2 × 25 000 = 80 000 cm = 800 m.
  • Gradient: the north side rises 20 m in 200 m (1 in 10), and the south side rises 20 m in 800 m (1 in 40).

A written statement: “The north side of the hill is four times steeper than the south side, because the same 20 m rise happens over 200 m instead of 800 m.” The 4 comes from 800 ÷ 200.

Who should start where?

If you… Begin with
Confuse closeness of lines with height Slope steepness lesson
Cannot tell hills from dips Valley and ridge lesson
Lose marks drawing side views Cross-section lesson
Write weak route answers Route choice lesson

The contour profile and slope reasoning trainer gives quick drills. Log each error in a mistake log.

For a teacher to go through contour maps with you, see online one-to-one Geography tuition.

Common questions

What is the first thing to check on a contour map?

The contour interval, which is the height difference between two neighbouring lines. Without it, you cannot turn the lines into heights. It is written in the key or margin of the map.

Do closer contour lines mean higher land?

No. Closer lines mean steeper land. Height is read from the numbers on the lines, and steepness from how close the lines are to each other. Mixing these up is a very common error.

Should I learn slope before cross-sections?

Yes. A cross-section needs heights from contours and distances from the scale. Being able to read a steep slope first makes the profile you draw easier to check for sense.

Where can I practise contour skills?

Use the contour practice set on this page and the contour profile and slope trainer. Both use original maps and explained answers, so you can check each step.

If contours are where your map marks disappear, one-to-one Geography lessons can work through your own maps from the first slope to a finished cross-section.

  • Online one-to-one lessons for your child with an experienced teacher.
  • Your first class is a one-hour trial, from RM50. The fee is agreed before you book.
  • Happy with the teacher? Continue with lessons of about 1.5 hours. If not, ask for another teacher.