1 mm of rain equals how much water?
With a rainfall of 1 mm, every square metre receives 1 litre of rain water. A rainfall of 1 mm supplies 0.001 m3, or 1 litre of water to each square metre of the field. Thus 1 ha receives 10 000 litres. What is the total amount of water received by a field of 5 ha under a rainfall of 15 mm?