Contour lines and reading the shape of the land
Geography · Key Stage 2 · The School
A line joining equal height
A CONTOUR LINE joins every point at the same height above sea level. It never crosses another contour line. Each line is usually labelled with its height in metres. Every fifth line is often drawn thicker, to make counting easier. This makes a busy map far quicker to read.
Close together means steep
Contour lines close together show steep ground. A short distance covers a big change in height. Contour lines far apart show gentle ground. The same change in height happens over a much longer distance. A cyclist checks this before planning a long ride. Nobody wants a nasty surprise halfway up a hill.
Reading a hill from lines alone
Rings of contour lines, one inside another, usually show a hill. The smallest, innermost ring is the highest point. Numbers on the lines confirm which way is up. Practice makes this quick and automatic. With enough practice, a whole valley can be read in seconds.
Hillside A has contour lines packed tightly together. Ten lines cross just one centimetre on the map. Hillside B has contour lines spread widely apart. Only two lines cross that same centimetre. Hillside A rises the same height as Hillside B. But it does so over a much shorter distance. Hillside A is the steep one. Hillside B is the gentle slope. The spacing alone told us this, without a single word of writing. A walker planning a route would pick Hillside B every time.