Earth Science Stream Vocabulary

Runoff

Water that flows downslope on earths surface and may enter a stream, river, or lake; its rate is influenced by angle of the slope, vegetation, rate of precipitation, and soil composition

Mouth

Where a stream empties into another body of water

point bar

inside bend of a meander

cut bank

outside bend of a meander

Tributaries

Any body of water that flows into another, larger system (willamette-springbrook)

Solution

Load is dissolved

levee

Natural or artificial bank confining a stream or a river. Natural levees form during flooding when the stream deposits materials adjacent to banks

Oxbow lake

Pinched off meanders, forms as a river straightens its channels

Suspension

Sediment is heavier than water but because water is stirred up and moving they remain suspended until water fully settles (sand, silt, clay)

Laminar flow

Smooth, parallel to channel, usually slow moving water (loss of gradient)

base level

The level of the body of water in which a stream flows. The ultimate base level is the ocean, local base levels could be lakes or another river. A stream cannot cut its bed or valley any lower than its final case level (water cannot flow uphill)

Headwaters

Where a stream begins (its source area)

Alluvial fan

Where a stream enters another body of water at its base level, deposition of the rivers load takes place forming a fan shaped deposit of sediment

floodplain

Wide, level area that borders a stream and is covered by its water during flooding events

Delta

a triangular tract of sediment deposited at the mouth of a river, typically where it diverges into several outlets.

Turbulent flow

confused, swirling, erratic, typically in fast moving water (steep gradient needed)

meander

curves or bends in the stream

discharge

volume of water passing a certain point at a given time area(velocity)=discharge

Drainage basin/water shed

Area of Earths surface that collects water and flows to one particular point

Bed load

Sediments rolling and sliding along the stream bed or bottom of the stream (sand, gravel, boulders)