Contour Lines
Geography: KS3, topic 1.1.4
Contour Lines
OS Maps show the relief of the land using spot heights, contour lines or layer colouring.
Sea level
- Contour lines are lines drawn on maps and they join places of the same height, a bit like dot to dot.
- Contour lines are normally orange/brown, often they have their height above sea level written.
Gradient
- Contour lines are normally drawn in 5m or 10m intervals, if they were any more frequent then there would be too many lines on the map.
- Contour lines show the gradient of the land:
- The closer together the contour lines are, the steeper the land.
- The further apart they are, the more gentle the slope.
Choropleth maps
- Some maps may use different colours to show the height of the land, these are called choropleth maps or layer colouring.
- They usually show the high land in brown and lower land in green.
Spot height
- Spot heights are the height above (or below) sea level at one particular location.
- Spot heights are often given for the highest point in an area, e.g. they will indicate mountain summits.
- Spot heights are useful to quickly find the difference in height between two points on a map, e.g. the mountain summit and the start of a walk.