Geographical skills · GCSE Geography
OS map skills
GCSE Geography OS map skills: four- and six-figure grid references, scale, contours and spot heights, and measuring distance — the paper-ready toolkit for locating landforms and settlements without guessing.
Along the corridor, up the stairs — eastings then northings. Contours that hug are steep; contours that chat are gentle. Scale turns paper into metres.
The important bits
What you need to know
- 1
Grid references: eastings (the numbers along the bottom, read first) then northings (up the side). Four-figure locates a 1 km square; six-figure locates a 100 m box inside it. “Along the corridor, up the stairs” is the memory hook that stops inverted references.
- 2
A six-figure reference needs you to estimate tenths within the square. Practise until a church symbol’s third digits are automatic. Wrong order (northings first) is an instant miss on a 1-mark question that everyone else banks.
- 3
Scale: on many GCSE extracts, 1:25 000 (4 cm = 1 km) or 1:50 000 (2 cm = 1 km). A scale line is safer than memory when the map is reduced on the exam paper. Check the printed scale bar every time.
- 4
Distance: paper distance × scale. Straight-line (as the crow flies) versus winding road or river (use string or the edge of a paper, then the scale bar). Units in km, with a sensible degree of precision — not eight decimal places.
- 5
Contours join equal height. Close contours = steep slope; wide contours = gentle. In a valley, contour Vs point upstream towards higher ground, with the river in the hinge. On a spur, the V-shaped tongue of high land points downhill. Spot heights and triangulation pillars give exact elevations; trig points are the triangulation stations.
- 6
Height and landforms: contour patterns show valleys (V pointing upstream), spits need the coast and a river mouth, interlocking spurs in uplands, floodplains as flat wide contour spacing beside a river. The map question is often “use the map to evidence a landform you named”.
- 7
Direction: compass from grid north. Relief: cross-sections if asked — plot distance against height, join dots, do not invent cliffs between two contours unless the spacing says so.
- 8
Symbols: churches with towers versus spires, cuttings, embankments, blue tourist layers on some 1:25 000 sheets. A key is on the paper — use it. Guessing a blue triangle is how people throw marks.
Quotations worth analysing
Short evidence. Real method.
“Eastings then northings: along the corridor, up the stairs.”
Write the six digits without a space in the middle if the paper wants 345678 not 345 678 — follow the question. Order is the mark.
“Contours that sit on each other’s laps are a steep slope; contours that gossip far apart are gentle.”
Then name the landform. Steep plus a coast might be a cliff; steep plus a river in a V is a valley side.
“Always believe the scale bar on the extract, not the scale you memorised from Year 7.”
Photocopy reduction wrecks “4 cm = 1 km” if you ignore the bar. Measure, then convert.
Go deeper
Six figures without the panic
Find the 1 km square: two-digit easting of the left line, two-digit northing of the bottom line. Then split that square into tenths. If the church is three-tenths of the way east and seven-tenths north, the six-figure is those extra digits slotted in: e.g. 123 457 becomes 123457 depending on the square. Practise on a real 1:25 000 sheet until you stop using a ruler for tenths — in the hall you may only have your eye. A common fail is reading the northing first because the number is printed sideways. Another is confusing 1:25 000 tourist blue with a grid line. If two symbols sit in the same 100 m box, the question usually wants the named feature’s location, not the car park next door. One mark, no method marks: it is right or it is not. Drill it.
Go deeper
Contours are a 3D sentence
A contour interval (often 5 m or 10 m on UK exam extracts) is the vertical jump between lines. Count the lines, multiply, add the starting height. Spot heights beat guesses on a summit. Valley: contour Vs point upstream, a river in the middle, perhaps a narrow floodplain where lines suddenly open. Spur: the opposite tongue of high land. Cliff: contours merge or sit extremely tight; on some maps a cliff symbol appears. For a cross-section, mark the two end grid references, transfer contour crossings to graph paper, plot height, join with a smooth line that respects spacing — do not draw a knife-edge unless contours demand it. Examiners award the shape more than artistic shading. If the question says “steepest slope”, look for the tightest pack, then give a compass direction.
Go deeper
Distance, scale, and the winding A-road
Straight-line distance is a ruler on two points, then the scale bar. Route distance follows the road or path: tick along with a paper edge, then lay that length on the bar. At 1:25 000, 4 cm on the map is 1 km on the ground — unless the extract is reduced, so always use the printed bar. Convert 6.2 cm to 1.55 km, then round as the question asks (nearest 0.1 km is typical). Mixed units look professional: metres for a footpath, kilometres for a valley. Combine with grid references: “the meander from 345678 to 350680 is 1.2 km along the channel”. That sentence is map evidence in a 6-marker. The skills question is often the easiest on the paper if you have drilled scale and contours; it is free marks left on the table if you have not.
See the idea in action
Question: give a six-figure grid reference for the church, state the distance along the B-road from the church to the junction, and describe the relief west of the river. Reference: eastings first, tenths estimated (e.g. 204 517). Distance: paper-edge along the road, scale bar → 1.4 km. Relief: west of the river, contours 10 m apart and tightly packed, steep valley side; east, wide spacing, floodplain. Direction: steepest slope faces east towards the channel. That is a full map-use paragraph, not a guess.
Exam technique
Turn knowledge into marks
Say eastings then northings out loud. Check the scale bar every time. For contours, tight = steep, V pointing upstream = valley. Use the key. These are the cheapest marks in Geography if you practise on real OS extracts.
Common mistakes
Do not give these marks away
- 01
Putting northings before eastings, or offering a four-figure when six were asked.
- 02
Ignoring the printed scale bar and using the wrong cm-to-km conversion.
- 03
Reading valley and spur contour patterns the wrong way round, or calling a gentle slope steep because it is shaded green.
What is the correct order for a UK OS grid reference?
ANorthings first, then eastings (“up the stairs, then along the corridor”)
BEastings first, then northings (“along the corridor, then up the stairs”)
CLatitude first as in an atlas index only
DThe two numbers in whichever order is printed largest on the map
Show the answer
Eastings first, then northings (“along the corridor, then up the stairs”). Bottom numbers then side numbers. Four-figure for the 1 km square, six-figure to tenths within it. Reverse the order and you land in the wrong square.
Quick questions
If this is the bit you searched
What is a six-figure grid reference?
A location to 100 m: two-digit easting, extra tenth, two-digit northing, extra tenth. Eastings first. It sits inside a four-figure 1 km square.
How do contours show steep land?
Lines close together mean a steep slope; lines far apart mean gentle land. The contour interval tells you the height jump between lines.
How do I measure distance on an OS map?
Measure on the paper (straight ruler or paper-edge along a road), then convert with the scale bar. Do not trust a memorised scale if the extract is reduced.
Which way do contour Vs point in a valley?
Upstream, towards higher ground, with the river in the hinge of the V. Spurs do the opposite: tongues of high land pointing down-valley.