Earth's Resources

aquifer

An underground layer of rock where ground water collects. The water in a well usually comes from an aquifer

surface water

Fresh water in lakes, streams, and rivers

Lotic

Moving water such as creeks, rivers, and streams

Lentic

Standing water such as ponds, lakes, and swamps

reservoir

The body of water that is stored behind a dam. A reservoir stores fresh water for a town or city

precipitation

The liquid or solid forms of water that fall to Earth. (Rain, sleet, hail, and snow are different kinds of precipitation.)

water cycle

The path that water follows as it evaporates into the air, condenses into clouds, and returns to Earth as rain, snow, sleet, or hail. In the water cycle, water evaporates from lakes and oceans into the air and then condenses and falls back to Earth as rain or snow

ground water

The water found beneath Earth's surface. In some areas, ground water fills the small spaces that are between underground rocks, soil, and sand.

condensation

To change form from a gas to a liquid. When water vapor in the air cools, it condenses into tiny droplets of liquid water.

evaporation

To change form from a liquid to a gas. On a warm dry day, puddles on the sidewalk evaporate quickly.

water vapor

Water that is in the form of a gas. Steam, which is invisible is water vapor.

watershed

the area that drains into a lake, stream, or river via streams or ditches, directly over the ground surface or through the ground

Water Treatment Plant

the process of making water more useful

transpiration

the process where plants absorb water through the roots and then give off water vapor through pores in their leaves