Water erosion

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Water erosion

• Water wears a path as
• it travels down a slope

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Kind of water erosion
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Rill erosion

• Have you ever seen a scar or small channel on the
  side of a slope that was
• left behind by running water? That is
  evidence of rill erosion
• An erosion process in which many small
  channels a few centimetres deep are formed it
  occurs mainly on recently cultivated soils. See
  also rill.

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• Rill erosion is the most common form of erosion.
• Its effects can be easily removed by tillage, it
  is the most often overlooked. It occurs when soil
  is removed by water from little streamlets that
  run through land with poor surface draining.
• Rills can often be found in between crop rows.

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Rill Erosion picture
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Gully picture
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Gully erosion

• It is a rill erosion channel becomes broader and
  deeper
• Gullies are larger than rills and cannot be fixed
  by tillage. Gully erosion is an advanced stage of
  rill erosion, just as rills are often the result
  of sheet erosion

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Question-1

• What is Tillage?
• Tillage practices are used for wind erosion
  control by producing a rough, cloddy surface that
  maintains surface residue and conserves soil
  moisture. When used along with crop residues,
  also known as stubble mulch tillage, reduced
  tillage, or conservation tillage, it reduces wind
  velocity and traps eroding soil.
• Tillage is also very effective in controlling
  rill and sheet erosion. The rough surface along
  with crop residues prevents rain water from
  carrying of soil particles and other organic
  matter.

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Stream Erosion

• Some times water continues to flow along a
  depression it has created. It becomes a stream
  like the one shown

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Picture Steam erosion

• It constantly picks up sediments from the bottom
  and sides of its channel. Water picks  up and
  carries some of the lightweight sediments, while
  large, heavy particles just roll along the bottom
  of the stream channel. All of these
  difference-sized materials scrape against the
  bottom and sides of the cannel, where they
  continue to knock loose more sediments. Because
  of this a stream continually cuts a deeper and
  wider channel   

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Stream picture
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Sheet Erosion

• Sheet erosion is defined as the uniform removal
  of soil in thin layers from sloping land.
• This, of course, is nearly impossible in reality
  the loose soil merely runs off with the rain.
• It is happens when rainwater flows into lower
  elevations, carrying sediments with it
• The water loses some of its energy of motion and
  it drains into the soil or slowly evaporates

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Sheet Erosion picture
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Deposition

• Think about...
• As water moves throughout a river system,What do
  you suppose happens as it loses some of its
  energy of motion? 

The water can no longer carry some of its
sediments, and they are deposited.
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Deposition

• Some stream sediments arent carried very far at
  all before they are deposited.
• -Many sediments are deposited within the stream
  channel it self-Other stream sediments travel
  great distances before hey are deposited 

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Type of Deposition

• There is two types of Deposition

Delta A triangular deposit of sediment that
forms when a stream or a river slows as it
empties into an ocean, gulf, or lake.
Alluvial fan A triangular deposit of sediment
that forms when water rushing down a slope loses
its energy and abruptly slows at the bottom,
depositing its sediment load.