1. What is the water cycle?

2. Key Terms Water cycle Evaporation Condensation Precipitation
Transpiration
Infiltration
Runoff

3. The Water Cycle Water is always changing state.
As water evaporates from the surface, it changes from a liquid to a gas.
In the atmosphere, the water vapor condenses to a liquid and forms clouds.
Finally, the water falls back to Earth as precipitation.
This repeated movement of water between the earth and the atmosphere is called the water cycle.

4. The Water Cycle Illustrated

5. Evaporation Evaporation is the process when liquids change to gases.
Most of Earth’s surface is covered with water.
When liquid water absorbs enough heat energy from the Sun, it changes into water vapor.

6. Condensation The changing of a gas to a liquid is called condensation.
When air containing water vapor is cooled, the water vapor loses heat and changes to a liquid.
Water vapor condenses into tiny droplets of water.
These droplets join together to form clouds.
If the temperature is freezing, ice forms.
A cloud is a collection of water droplets or ice crystals.

7. Condensation

8. Precipitation
Water that falls to Earth from the atmosphere is called precipitation.
Rain and snow are the two main forms of precipitation.
As the water droplets in the clouds grow bigger, they become too heavy to stay in the air and gravity pulls them toward the Earth.

9. Precipitation

10. Transpiration
Transpiration is the process of water loss from plants

11. Soaking it Up = Infiltration
Infiltration happens when water soaks into the soil from the ground level. It moves underground and moves between the soil and rocks.

12. Surface Water
The water on the surface of the earth such as streams, lakes, and ponds.

13. Runoff
Runoff is the movement of land water to the oceans, chiefly in the form of rivers, lakes, and streams. Runoff consists of precipitation that neither evaporates nor penetrates the surface to become groundwater.

14. Water Table
The very top of the zone of saturation, or the level of underground water. Although some water can be found a few centimeters above this level due to capillary action, almost all groundwater is at or below this level. The water table can rise or fall, depending on rainfall, evaporation, or pumping action.

15. Ground Water
The water under the surface of the earth that is found within the pore spaces and cracks between particles of soil, sand, gravel, and bedrock.

16. Aquifer
The ability of a rock layer to or sediment that stores groundwater and allows groundwater to flow through it!

17. Erosion
The process that moves soil, sediments, or rocks from one location to another by wind, water, ice or gravity!

18. Watershed
This is an area of land that is drained by a water system, such as streams and creeks that feed a larger river that empties into a lake or an ocean.

19. Permeable
It is a measure of the ability for rocks or sediments to let fluids pass through its open spaces or pores!

20. Impermeable
A layer of rocks or sediments that doesn’t allow the flow of fluids to move through it.

21. Porosity
This is the percentage of the total volume of rocks or sediments that contain open spaces in between them!

22. Aquitard
This is a layer of earth material that will hold water but not let if flow at a useful rate or fast enough to be pumped from a well. Aquitards often form a confining layer through which little water moves. Clay soils, shale, and igneous or metamorphic rocks with little interconnected porosity or fractures are likely to form aquitards.

23. Checking Concepts
The process by which a gas changes to a liquid is called __________.
The main forms of precipitation are __________, and _________.
The ______________ is the repeated movement of water between Earth and the atmosphere.

24. Answers
Condensation
Rain and snow
Water cycle

25. The End