Streams and Rivers

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Streams and Rivers
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Streams and RiversDefinitions

• Tributary A stream that runs into another stream
  or river
• River System A river and all of its tributaries
• Watershed includes all of the land that drains
  into the river

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• Floodplain a nearly flat area along a stream or
  river that is naturally subject to flooding.

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Streams and Rivers Continued

• Oxbow Lake a C-shaped lake formed when a meander
  is cut off from the main channel due to a lack of
  energy and sedimentation

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Rivers with Many Meanders
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Formation of a Cutoff and Oxbow Lake
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Deltas

• Delta a nearly flat plain of alluvial deposit
  between diverging branches of the mouth of a
  river, often triangular
• Alluvial Deposit clay, silt or gravel deposited
  where the stream slows down 

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Characteristics of Streams and Rivers

• Meander to take a winding or indirect course-gt
  the bends in a river
• Velocity The distance that water travels in a
  given amount of time.
• Gradient The slope of a stream
• (vertical distance/horizontal distance)

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Characteristics Continued

• Discharge the volume of water that passes a
  certain point in a given amount of time
• Channel The path through which the water flows.
  The size and shape effects the velocity

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Diagram- will complete in class
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Water Velocity

• Streams flow fastest in the middle, just below
  the surface
• The surface is slower because air provides a
  little friction
• The bottom is slower because the ground provides
  friction
• The sides are slower because the edge/shore
  provides friction

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From Above From WithinX marks the area
of highest velocity
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ESRT (pg 6)
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V-Shaped Valleys

• Most youthful river valleys are V-shaped
• V-shaped valleys are found in regions where there
  is enough rain to erode the sides of the valley

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The Yellowstone River Is an Example of a
V-Shaped Valley
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Visualizations

• How Sediment is Transported
• Meanderings

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• Erosion occurs on the outside of the bends where
  the water is moving the fastest
• Deposition occurs on the inside of the bends
  where the water is moving the slowest

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Video

• Watch Ms. Whittaker embarrass herself
• https//www.youtube.com/watch?vEwsxXs8vfhAindex
  93listUUWC9pBDUrv8isgrWjCRs5Gg

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Erosion by Wind

• When small, loose sediments like sand are
  available, erosion by wind is possible
• Arid regions are the most common places for wind
  erosion to take place

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• Ventifacts wedge-shaped rocks formed by wind
  erosion, often pitted. The weaker, less resistant
  materials are worn away the fastest

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• Sand dunes are hills of sand deposited by wind
• Found wherever there are strong winds and loose
  sand
• Have long, gentle slope on windward side
• Have shorter, steep slope on leeward side

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