Three Features of a River

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Three Features of a River

• By Wilby,
• Gazza
• And
• The Cravenator

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Three Features of a River

• Meanders By Luke Wilby
• Ox-Bow Lakes By Gareth Cotton
• Waterfalls By Robert Craven

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Meanders
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What is a Meander?

• A meander is a well developed bend in a river.
  They are formed by the river eroding the outside
  of the bend and depositing sediment on the
  inside. As time goes on the bend becomes more and
  more defined.

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How Meanders are Formed

• http//www.cleo.net.uk/resources/displayframe.php?
  src309/consultants_resources2F_files2Fmeander4.
  swf
• Step-By-Step

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Contents
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Oxbow Lakes
An ox-bow lake is a type of lake which is formed
when a wide meander from a stream or a river is
cut off to form a lake. They are called oxbow
lakes due to the distinctive curved shape that
results from this process.
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• Complete Animation (external link)
• Step-By-Step Analysis

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• When a river reaches the floodplains, which are
  common in the lower course of a river, the
  channel begins to meander widely. This results in
  deposition occurring on the convex bank (river
  beach) due to the low velocity of the water at
  this point. In contrast, lateral erosion and
  undercutting occurs on the concave bank (river
  cliff) where the river water is traveling at high
  speed.

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• Continued erosion and deposition occurring at
  meander

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• Continuous erosion on the concave bank (river
  cliff) and continued deposition of the convex
  bank (river beach) of a meandering river, causes
  the formation of a pronounced meander with two
  concave banks getting closer.

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The narrow neck of land between the two
neighbouring concave banks is finally cut
through, either by lateral erosion of the two
concave banks or by the strong currents of a
flood.
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• Following the collapse of the river cliffs, thus
  adjoining the two previous segregated parts of
  the river, a new straighter river channel is
  created and an abandoned meander loop, called a
  cut-off, is formed. Deposition continues until an
  ox-bow loop is formed which is disconnected from
  the main channel.

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• Usually deposition, plant matter and the gradual
  collapse of the banks will fill up the ox-bow
  which may only be seen in times of flooding.

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Quiz

• What is the feature called, which is the concave
  bank, where the water flows at the highest
  velocity?
• River Beach
• River Cliff
• Cut-Off
• Meander

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Correct
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Quiz

• 2. When an oxbow lake is formed, is the main
  channel more curved or more straighter than what
  it was before the ox-bow lakes formation?
• Straighter
• Curved

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Quiz

• 3. In what course do ox-bow lakes occur?
• Upper
• Middle
• Lower

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Correct
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The End

• This quiz was designed with people of average
  intelligence in mind.

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Waterfalls

• By Robert Craven

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What are waterfalls?

• A waterfall is a steep descent of the water of a
  river. Famous waterfalls include Angel Falls
  (right) and Victoria Falls (above).

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How are waterfalls formed?

• Click on the picture

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Its quiz time!!!

• Your first question
• Which of the following is a famous waterfall
• Elizabeth Falls answer
• Victoria Falls answer
• Henry Falls answer
• Water Falls answer

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Incredibly and extremely

• CORRECT!!!

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Incredibly and extremely

• WRONG!!!

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Ok clever clogs, question 2

• What does a waterfall create as it continues to
  wear away softer rock
• Rapids answer
• Another waterfall answer
• A plunge pool answer
• An oxbow lake answer

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Incredibly and extremely

• CORRECT!!!

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Incredibly and extremely

• WRONG!!!

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You made it this far, time for the final question

• What is left when a waterfall retreats up a
  stream
• A lake answer
• A gorge answer
• An oxbow lake answer
• A big gaping hole answer

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Incredibly and extremely

• CORRECT!!!

Well done! Back to the menu for you
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Incredibly and extremely

• WRONG!!!