Map Reading, Interpretation and Geographic Skills
The Map Reading, Interpretation and Geographic Skills domain tests practical map use: scale, grid references, contours, bearings, cross-sections and the interpretation of thematic maps and graphs. Marks depend on precise, ordered method.
Scale and distance
A representative fraction of 1:50,000 means 1 cm on the map represents 50,000 cm, or 0.5 km, on the ground. Convert measured centimetres to kilometres by multiplying by 0.5. For curved routes, measure in short straight segments or with a thread, then convert.
Grid references and direction
Give the easting before the northing. A four-figure reference locates a grid square; a six-figure reference locates a point to 100 m. In 456789, the easting is 45.6 and the northing is 78.9. Bearings are measured clockwise from north, 000°–360°; use grid north on the map and note magnetic variation if asked.
Contours, gradient and cross-sections
Contour interval is the height between successive lines. Close contours mean steep slope; a V-shaped contour points upstream in a valley. Gradient = vertical interval ÷ horizontal distance, expressed as a ratio, fraction or percentage. A cross-section plots height against distance; vertical exaggeration = horizontal scale ÷ vertical scale.
Worked example
A point lies 5.4 cm from another on a 1:50,000 map, and the height difference is 150 m. Distance = 5.4 × 0.5 km = 2.7 km. Gradient = 150 m ÷ 2,700 m = 1 in 18, or about 5.6%. A grid reference for a point six-tenths across square 45 and nine-tenths up square 78 is 456789.
Traps
Reading northing before easting is the most common error. Forgetting to convert centimetres to kilometres, using magnetic north without instruction, and reversing the contour V (it points upstream, not downstream) all lose marks. On thematic maps, check the legend and units before describing a choropleth or dot pattern.