GeographyReading the map like a geographer30 min★★ difficulty

Ordnance Survey maps: grid references, scale and relief

An OS map answers questions no photograph can: how steep is that slope, how far is the walk, is the village above the flood line? This lesson teaches the skills that come up in every geography exam and every real walk.

Part of your national curriculum

Geographical skills and fieldwork: Interpret Ordnance Survey maps, including using grid references, scale, topographical and other thematic mapping, and aerial and satellite photographs

Lesson overview

What you'll learn in this lesson

Interpret Ordnance Survey maps, including using grid references, scale, topographical and other thematic mapping, and aerial and satellite photographs

Key learning points

• Grid references
• Scale and distance
• Contours and relief
• Maps, photographs and settlement

This lesson at a glance

30 minutes
18 parts to scroll through
4 quick checks
Marked quiz at the end
Gentle pace: short sittings with pauses

Words to know

interpretordnancesurveyreferencestopographical

Scroll down — the lesson carries on below

Part 1 of 18 · Discover6%

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Ordnance Survey maps: grid references, scale and relief

An English teaching video on this topic from Learn Bright. Watch it, then scroll down for the lesson.

In a nutshell

Interpret Ordnance Survey maps, including using grid references, scale, topographical and other thematic mapping, and aerial and satellite photographs

What you already know

Part 2 of 18

Before we start

What you already know

You should be able to use a ruler and read a simple map key.

Key words

Part 3 of 18

Key words

Words you'll need today

Four-figure reference: Locates a whole grid square, eastings before northings.
Six-figure reference: Locates a point to 100 m within a square.
Scale: The ratio between map distance and real distance, e.g. 1:25,000.
Contour: A line joining points of equal height above sea level.
Cross-section: A side-on drawing of the land surface along a line.

Learning cycle

Part 4 of 18

Learning cycle 1 of 2

Finding places and distances

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 5 of 18

Learn

Grid references

Always read eastings first, then northings — along the corridor, then up the stairs. A four-figure reference such as 3421 names the square whose bottom-left corner is easting 34, northing 21. For a six-figure reference, divide each square mentally into tenths and add the extra digit: 345213 sits five tenths across and three tenths up within square 3421, locating a point to about 100 metres.

Explore the idea

Part 6 of 18

Learn

Scale and distance

On a 1:25,000 map, 4 cm on the paper is 1 km on the ground; on a 1:50,000 map, 2 cm is 1 km. Measure straight-line distance with a ruler, and curved routes with string or the edge of a piece of paper marked off in steps. Always state units and convert carefully — losing a factor of ten is the single most common error in map questions.

Quick check

Part 7 of 18

Quick check

In a grid reference you read…

Reset break

Part 8 of 18

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now

Quick check

Part 9 of 18

Quick check

On a 1:25,000 map, 1 km on the ground is…

Learning cycle

Part 10 of 18

Learning cycle 2 of 2

Reading the shape of the land

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 11 of 18

Learn

Contours and relief

Contours join points of equal height, usually every 5 or 10 metres. Lines close together mean a steep slope; widely spaced lines mean gentle ground. Concentric rings show a hill, with the spot height at the summit; contours bending upstream in a V mark a valley. Practise describing relief in sentences with figures: 'the land rises from 60 m in the valley to 210 m at the summit, steeply on the western side'.

Explore the idea

Part 12 of 18

Learn

Maps, photographs and settlement

Aerial and satellite photographs show what is there now — crops, new buildings, flooding — while the map gives height, names and boundaries. Used together they let you explain patterns: a nucleated village at a river crossing, a linear settlement along a road, farms spread out across gentle lowland. Answer settlement questions with map evidence: give a grid reference, a height, or a distance to justify each point.

Quick check

Part 13 of 18

Quick check

Contour lines very close together show…

Quick check

Part 14 of 18

Quick check

Which is the best map evidence for describing a settlement?

Common mix-ups

Part 15 of 18

Common mix-ups

Things people often get wrong

Northings come first — eastings always come first, along the bottom before up the side.
Contours show slope steepness directly — spacing shows steepness; the numbers show height.
A six-figure reference names a square — it names a point to about 100 m.

Challenge round

Part 16 of 18

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

Mastery quiz

Part 17 of 18

Marked quiz

End of lesson quiz: Ordnance Survey maps: grid references, scale and relief

6 questions, marked with the reasoning shown. No timer.

1. A four-figure reference locates…
2. On a 1:50,000 map, 2 cm represents…
3. Contours bending in a V that points upstream indicate…
4. Concentric closed contour rings show…
5. A satellite photograph adds which information the map lacks?
6. A settlement strung out along a single road is described as…

Lesson round-up

Part 18 of 18

Lesson round-up

Ready when you are

Quiz score

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Points this lesson

Best run

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Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

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Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Flooding on the River Calder

The town of Harbrook sits where a steep valley opens onto a flat floodplain. In December 2015, 120 mm of rain fell in 36 hours onto ground that was already saturated. The river rose 2.4 m in five hours, and 380 homes and 54 businesses flooded. Two roads and the railway closed for eleven days.

Geographers pointed to physical causes — steep slopes, impermeable rock, heavy rainfall — and human causes: moorland drained upstream, new housing built on the floodplain, and drains designed for smaller storms.

Since then the town has planted 40 hectares of woodland upstream, built leaky dams in small streams, and raised flood walls to 1.8 m. In the storm of 2020 the peak river level was 0.3 m lower and 40 homes flooded, not 380.

Written for Good Learning Co.

Reading questions

List two physical and two human causes of the 2015 flood.
Explain how planting woodland upstream lowers the river's peak level.
Using the figures, judge how successful the scheme has been. Quote data in your answer.

Case study notes
Writing
Write the place, the facts and the figures from this lesson so you can revise them later.
Half a page
Explain answer
Writing
Answer in full sentences, giving causes and effects. Use one figure or place name as evidence.
8–10 sentences
Map or sketch
Diagram
Draw the map, cross-section or field sketch with a key, title and labels, then photograph it.
1 map with a key
Data work
Working out
Plot your figures as a graph on paper and write one sentence about the pattern.
1 graph + 1 sentence

Write your answer, notes or working here

Saved as you type.

Photos of paper work, diagrams or working outHow many minutes did the written work take?

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Interpret Ordnance Survey maps, including using grid references, scale, topographical and other thematic mapping, and aerial and satellite photographs