Map Reading, Spatial Analysis, and Geographic Skills
Map-reading and spatial analysis questions test scale, grid references, contours, cross-sections, and thematic maps. You must show the calculation, not just guess.
Core skills
Scale converts map distance to ground distance. A 1:50,000 map means 1 cm = 500 m. Grid references are read eastings first, then northings. Contour interval is the vertical distance between lines; close contours mean steep slopes. A V-shaped contour pointing upstream marks a valley. Gradient = vertical rise ÷ horizontal run. Aspect is the direction a slope faces. Thematic maps include choropleth, isoline, dot, and flow maps; GIS overlays layers.
Worked example
Two points are 4 cm apart on a 1:50,000 map. Ground distance = 4 × 500 m = 2,000 m. Their elevations are 200 m and 400 m, so rise = 200 m. Gradient = 200 ÷ 2,000 = 0.10 = 10%. If the map shows a valley between them, the straight-line gradient is not the same as the path gradient.
Traps
Do not confuse grid north with true north; do not read a grid reference as latitude and longitude; do not use map distance as ground distance; check the contour interval before calculating; and remember that a choropleth shows rates, not totals.