| A | B |
|---|
| stream | Flowing water that follows a distinct course over the land. |
| elevation profile | Description of how a stream changes elevation from its beginning to its end. |
| source | Origin and the highest elevation of a stream. |
| stream gradient | The change of elevation of a stream's channel with horizontal distance. |
| mouth | The point at which a stream empties into another body of water; located at base level for that stream. |
| base level | Lowest elevation to which a stream can flow. |
| cross section | A view of an object in which it is sliced in half to show its shape or arrangement. |
| tributary | Smaller stream that feeds into a larger one. |
| stream system | A stream and all of its tributaries. |
| drainage basin | Land area that a stream drains, bounded by the basin divide. |
| divide | A ridge or mountains, hills, or even just higher land that separates one drainage basin from another. |
| meander | A wide, looping bend in a low gradient stream. |
| floodplain | A broad, level area surrounding a low gradient river, created by regular flooding of the river. |
| perennial stream | A continuous stream; flows year round. |
| intermittent stream | A stream that does not flow year round; flows only after heavy rainstorms, from snowmelt, or during wet seasons. |
| lake | Any isolated body of water that doesn't freely share water with the ocean. |
| eutrophication | Natural or artificial increase of nutrients in a lake or stream. |
| limnology | Science of all forms of surface and underground fresh water, including lakes and rivers. |
| thermal turnover | Seasonal process by which lakes exchange surface and bottom water as they cool and warm with the seasons. |
| seiche | Small oscillations in water level similar to sloshing in a bathtub caused by changes in air pressure as weather systems move across a body of water. |
