| A | B |
|---|
| erosion | The process by which wind, water, ice, or gravity transports soil and sediment from one location to another. |
| water cycle | The continuous movement of water from the ocean to the atmosphere to the land and back to the ocean. |
| tributary | A stream that flows into a lake or into a larger stream |
| watershed | The area of land that is drained by a water system |
| divide | The boundary between drainage areas that have streams that flow in opposite directions. |
| channel | The path that a stream follows. |
| load | The materials carried by a stream. |
| deposition | The process in which material is laid down. |
| delta | A fan-shaped mass of material deposited at the mouth of a stream. |
| alluvial fan | A fan-shaped mass of material deposited by a stream when the slope of the land decreases sharply. |
| floodplain | An area along a river that forms from sediments deposited when the river overflows its banks |
| water table | The upper surface of underground water; the upper boundary of the zone of saturation. |
| aquifer | A body of rock or sediment that stores groundwater and allows the flow of groundwater. |
| porosity | The percentage of the total volume of a rock or sediment that consists of open spaces. |
| permeability | The ability of a rock or sediment to let fluids pass through its open spaces, or pores. |
| recharge zones | An area in which water travels downward to become part of an aquifer. |
| artesian spring | A spring whose water flows from a crack in the cap rock over the aquifer. |
| point-source pollution | Pollution that comes from a specific site. |
| nonpoint-source pollution | Pollution that comes from many sources rather than a single, specific site. |
| sewage treatment plant | A facility that cleans the waste materials found in water that comes from sewers or drains. |
| septic tank | A tank that separates solid waste from liquids and that has bacteria that break down the solid waste. |
