Soil water

Rainfall is recorded with a rain gauge (see Figure 2.10) and is measured in millimetres of water.Thus ‘1 mm of rain’ is the amount of water covering any area to a depth of 1 mm. Therefore ‘1 mm of rain’

on 1 hectare of land is equivalent to 10 m3 or 10 000 litres of water per hectare (area 10 000 m2 depth 0.001 m).