Water Cycle

Water is always moving through our environment. It moves through the air, through plants and through the earth. This continuous movement is called the water cycle.

It starts when the sun warms water from lakes, ponds, or the ocean and turns it into water vapor. This process is called evaporation.

Water vapor is invisible. It rises into the air. When it gets high enough, it cools and changes back into water droplets. We call this process condensation. When water changes into little drops by “condensing” in the air, we get clouds.

http://www.epa.gov/safewater/kids/flash/flash_watercycle.html

 

As more water vapor cools into the clouds, the water droplets that form the clouds become larger and larger. When they get big enough, they fall to the ground as rain. Some of the rain runs off the land and drains into rivers, lakes and streams (runoff).

Some of the rainwater soaks into the ground (infiltration) and becomes groundwater. Groundwater is under the ground and in the soil. It is the water that plants use. People sometimes drill wells to get to the groundwater. They may use groundwater for drinking water or to water their crops.

As water falls to earth in various forms of precipitation, plants intercept or catch some of the water before it falls to the ground. This is called interception.

Plants also put water back into the air through a process we call transpiration. When the sun shines on plants, tiny drops of water are released into the air. Transpiration is how plants lose water out of their leaves.

The cycle repeats over and over again.