Map Work, Geographical Data Interpretation and Field Study
This section covers Map Work, Geographical Data Interpretation and Field Study. It tests scale, contour reading, conventional signs, graph interpretation and the design of a small field investigation.
Core rules
- Scale may be statement (1 cm = 1 km), representative fraction (1:50,000) or graphical. RF is unitless.
- On contours, close spacing means steep slope; wide spacing means gentle slope. A V pointing upstream indicates a valley; a U pointing downstream indicates a spur.
- Contour interval is the vertical difference between successive contours. Spot heights and benchmarks give exact elevations.
- Pie-chart angle = (value ÷ total) × 360°. Bar graphs compare categories; line graphs show trends.
- Field study needs an aim, a sampling method (random, systematic or stratified), a questionnaire or measurement schedule, ethical consent, and a report that separates data from interpretation.
Worked example
A map has RF 1:50,000. Two villages are 6.4 cm apart. Ground distance = 6.4 × 50,000 cm = 320,000 cm = 3.2 km. On a 1:25,000 map, the same ground distance would measure 12.8 cm, because halving the denominator doubles the map length for the same ground distance.
Traps
- Reading a contour V as pointing downstream.
- Forgetting to convert centimetres to kilometres.
- Treating RF as having units.
- Using degrees and percentages interchangeably in a pie chart.
- Choosing a biased sample and calling it random.