A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, crick, gill (occasionally ghyll), kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or runnel.

Streams are important as conduits in the water cycle, instruments in groundwater recharge, and corridors for fish and wildlife migration. The biological habitat in the immediate vicinity of a stream is called a riparian zone. Given the status of the ongoing Holocene extinction, streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity. The study of streams and waterways in general is known as surface hydrology and is a core element of environmental geography.^[1]

Types

River

A large natural stream, which may be a waterway.

Creek

• In North America, Australia and New Zealand, a small to medium sized natural stream. Sometimes navigable by motor craft and may be intermittent.
• In parts of New England,^[2] the UK and India, a tidal inlet, typically in a salt marsh or mangrove swamp, or between enclosed and drained former salt marshes or swamps (e.g. Port Creek separating Portsea Island from the mainland). In these cases, the stream is the tidal stream, the course of the seawater through the creek channel at low and high tide.

Tributary

A contributory stream, or a stream which does not reach the sea but joins another river (a parent river). Sometimes also called a branch or fork.

Brook

A stream smaller than a creek, especially one that is fed by a spring or seep. It is usually small and easily forded. A brook is characterized by its shallowness and its bed being composed primarily of rocks.

Other names

In the United Kingdom, there are several regional names for a stream:

• Beck is used in Yorkshire, Lancashire , Dumfriesshire and Cumbria.
• Bourne is used in the chalk downland of southern England (although strictly a bourne is wet in summer and dry in winter).
• Brook is used in the Midlands, Lancashire and Cheshire.
• Burn is used in Scotland and North East England.
• Nant is used in Wales.
• Stream is used in Southern England.
• Syke is used in lowland Scotland and Cumbria.
• Allt is used in Highland Scotland.

In North America:

• Kill in southern New York, Pennsylvania, Delaware, and New Jersey comes from a Dutch language word meaning “riverbed” or “water channel”, and can also be used for the UK meaning of ‘creek’.
• Run in Ohio, Pennsylvania, Maryland, or Virginia can be the name of a stream.
• Branch, fork, or prong can refer to tributaries or distributaries that share the same name as the main stream, generally with the addition of a cardinal direction.
• Branch is also used to name streams in Maryland and Virginia.
• Falls is also used to name streams in Maryland. Little Gunpowder Falls and The Jones Falls are actually rivers named in this manner, unique to Maryland.
• Stream and brook are used in Midwestern states, Mid-Atlantic states and New England.
• Crick is used in some parts of the United States.

Parts of a stream

Bar

A shoal that develops at the mouth of a river as sediment carried by the river is deposited as the current slows or is impedded by wave action. The Temperance River on Lake Superior’s north shore is so named because it is one of the few rivers flowing into the lake that does not have a bar at its mouth.

Spring

The point at which a stream emerges from an underground course through unconsolidated sediments or through caves. A stream can, especially with caves, flow aboveground for part of its course, and underground for part of its course.

Source

The spring from which the stream originates, or other point of origin of a stream.

Headwaters

The part of a stream or river proximate to its source. The word is most commonly used in the plural where there is no single point source.

Confluence

The point at which the two streams merge. If the two tributaries are of approximately equal size, the confluence may be called a fork.

Run

A somewhat smoothly flowing segment of the stream.

Pool

A segment where the water is deeper and slower moving.

Riffle

A segment where the flow is shallower and more turbulent.

Channel

A depression created by constant erosion that carries the stream’s flow.

Floodplain

Lands adjacent to the stream that are subject to flooding when a stream overflows its banks.

Stream bed

The bottom of a stream.

Gauging station

A point of demarkation along the route of a stream or river, used for reference marking or water monitoring.

Thalweg

The river’s longitudinal section, or the line joining the deepest point in the channel at each stage from source to mouth.

Wetted perimeter

The line on which the stream’s surface meets the channel walls.

Nickpoint

The point on a stream’s profile where a sudden change in stream gradient occurs.

Waterfall or cascade

The fall of water where the stream goes over a sudden drop called a nickpoint; some nickpoints are formed by erosion when water flows over an especially resistant stratum, followed by one less so. The stream expends kinetic energy in “trying” to eliminate the nickpoint.

Mouth

The point at which the stream discharges, possibly via an estuary or delta, into a static body of water such as a lake or ocean.

Source: http://en.wikipedia.org/wiki/Stream