Map reading

Traps in Map reading

• Converts units with the wrong factor
  1 km = 100 000 cm. Convert map distance × scale denominator to cm first, then ÷ 100 000 for km.
• Divides the quantities the wrong way round
  Write the unit you need (people per km², km per cm) and let it tell you which quantity goes on top.
• Map reading errors
  Close contours = steep slope; wide = gentle. Gradient = vertical interval ÷ horizontal equivalent (same units). Four-figure grid ref: eastings first, then northings.
• Reverses the process or effect
  Trace the cause and effect step by step and check the direction at each step.
• Uses the wrong operation
  Picture the situation (higher = colder; back bearing = ± 180°) before choosing the operation.
• Gives only part of the answer
  Recall the full definition or list of factors and check the option covers it.
• Picks a closely related feature or term
  Learn related features as contrasting pairs: how each forms and what it looks like.
• Confuses weather instruments
  Baro- = pressure; hygro- = humidity; anemo- = wind speed; wind vane = direction; rain gauge = rainfall; Six's thermometer = max/min temperature.
• Confuses types of rainfall
  Convectional: intense surface heating (equatorial afternoons). Relief/orographic: air forced over highlands (windward wet, leeward rain shadow). Frontal/cyclonic: warm air rises over cold air (temperate).
• Gives a figure from the question as the answer
  If your answer is a number already in the question, check again: convert, reverse or scale it as the question demands.
• Grid reference and bearing errors
  Grid reference: eastings (along the bottom, left to right) first, then northings ('along the corridor, then up the stairs'). Bearings are measured clockwise from north at the starting point; back bearing = bearing ± 180°.