Water cycle

continuous movement of water on, above and below the surface of the Earth

The water cycle (or hydrological cycle) is the cycle that water goes through on Earth.

The water cycle

Water is essential for life as we know it. It is present throughout the Solar System, and was part of the Earth from its formation. The source of the water was the same as the source of the Earth's rock : the cloud particles which condensed in the origin of the solar system.[1]

ProcessesEdit

This is the process that water starts and ends in the water cycle.

  • The cycle starts when water on the surface of the Earth evaporates. Evaporation means the sun heats the water which turns into gas.
  • Then, water collects as water vapor in the sky. This makes clouds.
  • Next, the water in the clouds gets cold. This makes it become liquid again. This process is called condensation.
  • Then, the water falls from the sky as rain, snow, sleet or hail. This is called precipitation.
  • The water sinks into the surface and also collects into lakes, oceans, or aquifers. It evaporates again and continues the cycle.

Humans activities that affect the water cycleEdit

Human activities that change the water cycle include:

Related pagesEdit

ReferencesEdit

  1. Van Andel, Tjeerd H. 1994. New views on an old planet: a history of global change Chapter 14. 2nd ed, Cambridge. ISBN 0-521-44755-0