Background to rivers
Background information for the study of rivers.
The hydrological cycle is also known as the water cycle.
Seas and oceans contain 97 per cent of the world's water, and ice holds 2 per cent. That leaves just 1 per cent of the world's water as fresh water on land or in the air. This water is recycled again and again through the process of evaporationevaporation: The process in which a liquid turns into a gas, condensationcondensation: Condensation is a change of state in which gas becomes liquid by cooling. and water transfers such as surface run-off.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.