| A | B |
|---|
| WATER VAPOR | The invisible, gaseous form of water. |
| GROUNDWATER | Water that fills the cracks and pores in underground soil and rock layers. |
| WATER CYCLE | The continuous process by which water moves from Earth's surface to the atmosphere and back, passing through the living and nonliving parts of the environment. |
| EVAPORATION | The process by which molecules at the surface of a liquid, such as water, absorb enough energy to change to a gaseous state, such as water vapor. |
| TRANSPIRATION | The process by which plants release water vapors through their leaves. |
| PRECIPITATION | Forms of water such as rain, snow, sleet, or hail that fall from clouds and reach Earth's surface. |
| IRRIGATION | The process of supplying water to areas of land to make them suitable for growing crops. |
| PHOTOSYNTHESIS | The process by which plants use water, plus carbon dioxide and energy from the sun, to make food. |
| HABITAT | The place where an organism lives and that provides the things it needs to survive. |
| TRIBUTARY | A stream that flows into a larger stream. |
| WATERSHED | The land area that supplies water to a river system. |
| DIVIDE | A ridge of land that separates one drainage basin or watershed from another. |
| LEVEE | A long ridge formed by deposits of sediments alongside a river channel. |
| RESERVOIR | A natural of artificial lake that stores water for human use. |
| EUTROPHICATION | The process by which nutrients in a lake build up over time, causing an increase in the growth of algae. |
| PORES | Tiny openings in and between particles of rock and soil that may contain air or water. |
| PERMEABLE | Characteristic of materials such as sand and gravel that allow water to pass easily through them. |
| IMPERMEABLE | Characteristic of materials through which water does not easily pass, such as clay and granite. |
| SATURATED ZONE | A layer of permeable rock or soil in which the cracks and pores are completely filled with water. |
| WATER TABLE | The top of the saturated zone, or depth to the groundwater in an aquifer. |
| UNSATURATED ZONE | A layer of rock and soil above the water table in which the pores contain air as well as water. |
| AQUIFER | An underground layer of rock or soil that holds water. |
| SPRING | A place where groundwater bubbles or flows out of cracks in the rocks |
| RECHARGE | New water that enters an aquifer from the surface. |
| ARTESIAN WELL | A well in which water rises because of pressure within the aquifer. |
| WETLAND | An area of land that is covered with a shallow layer of water during some or all of the year. |
