Water Science School
Water Cycle Components
Earth's water is always in motion, and the natural water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Water is always changing states between liquid, vapor, and ice, with these processes happening in the blink of an eye and over millions of years.
The Water Cycle for Schools and Kids

Use our Water Cycle for Schools area to introduce water-cycle science to elementary and middle-school students.
ExploreThe Water Cycle for Adults and Advanced Students

We offer extensive analyses about all of the parts of the water cycle; this area is recommended for high-school students to adult ages.
ExploreThe Water Cycle
The U.S. Geological Survey (USGS) offers you the most comprehensive information about the natural water cycle anywhere. We've developed Web pages aimed at both younger students and kids and at ...