As water evaporates, it travels into the air and becomes part of a cloud. The cloud stores this moisture until it falls down to earth as rain, hail or snow (precipitation).

The rain evaporates and the cycle starts all over again - never ending. Water keeps moving and changing from a solid to a liquid to a gas, over and over again.

We can see the hydrological cycle at work every day in some part of the world. After rain, runoff is created and travels over the earth's surface, filling lakes and rivers. It also percolates into the earth, where it is stored in underground reservoirs, known as aquifer.

In areas of high precipitation, there are usually large bodies of water, such as lakes and oceans. These areas allow more water to evaporate, forming clouds.

In mountainous regions, the clouds move up and the water vapor condenses to form precipitation and freezes. Snow falls on the peaks and runoff occurs, starting the cycle over again.

Word Search with these terms:

• Hydrologic - relating to water
• Evaporation - liquid water becoming a gas
• Water vapor - water as a gas in the air
• Condensation - water vapor becoming a liquid
• Surface runoff - water that runs along the soil and goes into lakes and rivers
• Precipitation - rain, snow, sleet or hail
• Groundwater - water under the ground, as in a spring or well
• Aquifer - a large water source under the ground
• Percolation - water moving downward through openings in the soil
• Clouds
• Rain