Flow

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Flow
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What is flow?

• Flow is materials that move as a fluid.
• The debris is a mixture of rock, soil, and water
  moving as a thick liquid.
• They can be very devastating.
• Examples mudslides, landslides, and floods,
  avalanches

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Mudflow

• What is a mudflow?
• A mudflow is a flow of water that contains a
  LARGE amount of suspended particles and silt
  (being carried in the water).
• Speeds can reach up to 60 mph.
• It can take everything in its path.
• Boulders as large as houses have been moved by a
  mudflow.

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Mudslide

• How is a mudslide different form a mudflow?
• A mudslide is a mudflow that occurs on a slope.
• They are most common on steep slopes where there
  is not enough vegetation to prevent rapid
  erosion.

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Mudslide Pictures
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Landslide

• Landslides are very similar to mudflows/slides
  EXCEPT that they do not involve water.
• It is a dislodging of matter from a hillside that
  causes a mass of earth and rock to fall.
• Landslides often occur on steep hills.

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Weakened Slopes

• What causes hills and mountains to become
  weakened?
• Erosion by rivers, glaciers, or ocean waves
• Fires that leave slopes bare and vulnerable to
  rain
• Heavy rain or snow that saturate the ground

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Weakened Slopes Cont

• Structure of the slope weakened by earthquakes
• Loose ash and debris slopes formed by the ash
  from volcanic eruptions
• Traffic, blasting operations, machinery, and
  thunder can cause vibrations in weak slopes
• Weight of snow, stockpiling of ores, waste piles,
  and buildings add stress to weak hillsides.

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Where?

• Landslides happen in every U.S. state and
  territory.
• Some areas are more vulnerable Rocky Mountains,
  Appalachian Mountains, and the Pacific Coastal
  ranges and parts of Alaska and Hawaii.
• Most of these regions have areas of very weak or
  stressed material resting on steep slopes.

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Landslide Pictures
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Floods

• What is a flood?
• Flooding occurs when a river, creek, or stream
  overflows its banks and spreads to cover its
  flood plain.
• Long and heavy rainfall causes flooding.
• Flooding can also occur when a river is blocked
  by an accumulation of soil, ice, fallen trees, or
  anything else that diverts water to surrounding
  areas.

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Floods Cont

• Severe flooding can affect millions of acres of
  land and force thousands of people to evacuate
  their homes.
• Several weeks or months may pass before flood
  waters recede or are absorbed into the ground.

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Affect on Soil

• The displacement of soil by flood water not only
  removes fertile soil from farms, but deposits it
  in and around homes and businesses, making
  cleanup an even greater chore.

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Flood Pictures
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Guiding Question

• What can be done to reduce the impact caused by
  mudslides, landslides, and floods?