Stream ErosionStream Erosion

NotesNotes

WatershedWatershed

A major river or stream along with all the A major river or stream along with all the smaller streams that connect to it.smaller streams that connect to it.

TributaryTributary

A small stream that feeds a larger river.A small stream that feeds a larger river.

Streams/RiversStreams/Rivers

Streams/rivers are running channels of Streams/rivers are running channels of water that begin at high elevation (source) water that begin at high elevation (source) and run to low elevations (mouth).and run to low elevations (mouth).

Stream termsStream terms

Stream Velocity: Speed of water in a stream.Stream Velocity: Speed of water in a stream. Discharge: The volume of water in a stream.Discharge: The volume of water in a stream. Erosion: The ability of a stream to carry and Erosion: The ability of a stream to carry and

remove sediment.remove sediment. Deposition: When a stream deposits sediment Deposition: When a stream deposits sediment

because the velocity slows down.because the velocity slows down. Gradient: The steepness of the slope of the Gradient: The steepness of the slope of the

stream channel.stream channel.

Relationship of TermsRelationship of Terms

As gradient increases velocity ________.As gradient increases velocity ________.

Relationship of TermsRelationship of Terms

As gradient increases velocity increases.As gradient increases velocity increases. As gradient increases erosion ________.As gradient increases erosion ________.

Relationship of TermsRelationship of Terms

As gradient increases velocity increases.As gradient increases velocity increases. As gradient increases erosion increases.As gradient increases erosion increases. As discharge increases velocity ________.As discharge increases velocity ________.

Relationship of TermsRelationship of Terms

As gradient increases velocity increases.As gradient increases velocity increases. As gradient increases erosion increases.As gradient increases erosion increases. As discharge increases velocity increases.As discharge increases velocity increases. As discharge increases rate of erosion As discharge increases rate of erosion

_________._________.

Relationship of TermsRelationship of Terms

As gradient increases velocity increases.As gradient increases velocity increases. As gradient increases erosion increases.As gradient increases erosion increases. As discharge increases velocity increases.As discharge increases velocity increases. As discharge increases rate of erosion As discharge increases rate of erosion

increases.increases. As velocity decreases rate of deposition As velocity decreases rate of deposition

_________._________.

Relationship of TermsRelationship of Terms

As gradient increases velocity increases.As gradient increases velocity increases. As gradient increases erosion increases.As gradient increases erosion increases. As discharge increases velocity increases.As discharge increases velocity increases. As discharge increases rate of erosion As discharge increases rate of erosion

increases.increases. As velocity decreases rate of deposition As velocity decreases rate of deposition

increases.increases.

Life-stages of streamsLife-stages of streams

Youthful stream:Youthful stream: Very steep slope.Very steep slope. V-shaped channel.V-shaped channel. Steep canyon walls.Steep canyon walls. Straight channel.Straight channel. High velocity.High velocity. High rate of erosion.High rate of erosion.

Youthful StreamYouthful Stream

Youthful StreamYouthful Stream

Youthful StreamYouthful Stream

Mature streamMature stream

The v-shape channel becomes more The v-shape channel becomes more rounded.rounded.

Gradient is decreasing.Gradient is decreasing. Velocity is decreasing.Velocity is decreasing. Meanders begin to form.Meanders begin to form. A narrow flood plain begins to form.A narrow flood plain begins to form.

Mature StreamMature Stream

Old-age streamsOld-age streams

Slow velocity.Slow velocity. Very wide flood plain.Very wide flood plain. Elaborate Meandering PatternsElaborate Meandering Patterns Oxbow LakesOxbow Lakes

Old-Age StreamOld-Age Stream

Stages in a streamStages in a stream

Oxbow LakesOxbow Lakes

Oxbow LakesOxbow Lakes

Oxbow LakesOxbow Lakes

River DeltaRiver Delta

When a moving river reaches its When a moving river reaches its destination, the river’s speed will decrease destination, the river’s speed will decrease sharply.sharply.

This sharp decrease in velocity will cause This sharp decrease in velocity will cause an enormous amount of deposition to an enormous amount of deposition to occur.occur.

This depositional feature is known as a This depositional feature is known as a delta, named for the Greek letter shaped delta, named for the Greek letter shaped as a triangle.as a triangle.

Mississippi DeltaMississippi Delta