| A | B |
|---|
| water vapor | The invisible, gaseour 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 vapor through their leaves |
| precipitation | forms of water such as rain, sleet, snow, or hail that fall from coulds 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 that it needs to survive |
| tributary | a stream that flows into larger streams |
| 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 or 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 growth of algae |
| pore | 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 | characteristics 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 rockss and soil above the water table in which the pores contain ari as well as water |
| aquifer | An undergound 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 |
