Dynamics of Moving Water

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Dynamics of Moving Water
CGF3M
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Dynamics of Moving Water

• The Hydrosphere
• Hydrologic Cycle
• Infiltration
• Runoff
• Stream Flow
• Velocity
• Discharge
• Flow

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Hydrologic Cycle
Condensation Precipitation Infiltration Runoff Eva
poration
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Hydrologic Cycle

• Infiltration precipitation that seeps into the
  ground.
• Factors affecting infiltration
• Interparticle size the size and connectedness
  of the particles in the ground, eg., sand vs clay
• Vegetation (associated organisms) loosen the
  soil.
• Rainfall intensity
• Seasonal factors, eg., freezing of the ground
• Permafrost is there any, its depth
• Urban landscape - paving, buildings, etc.

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Hydrologic Cycle

• Infiltration cont
• When rain falls, the first type of erosion is
  splash erosion.
• Raindrop impacts reduce infiltration rate because
  the soil particles become more compacted

movement of material downhill.
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Hydrologic Cycle

• Runoff flow of water from the land as both
  surface and subsurface discharge.
• Occurs when rate of precipitation is greater than
  rate of infiltration.
• Usefulness recreational, sewage disposal,
  domestic, irrigation, food source, hydroelectric
  power, etc.

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Hydrologic Cycle

• Runoff Categories
• Surface Runoff/Overland flow
• excessive overland flow can lead to sheet erosion
  forming small rills or tiny rivers.
• can include Channel Flow (water traveling in a
  river or stream).
• Subsurface Runoff/Ground Water
• travels beneath the surface towards a body of
  water.

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Stream Flow

• The velocity (speed) of flow in a river is
  controlled by
• Gradient
• Friction due to resistance of water on the bed of
  the channel.
• Volume

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Stream Flow

• Discharge volume of water that flows past a
  given point can be determined by the following
  factors
• Q A x V
• Q is discharge
• A is cross-sectional area of stream
• V is mean velocity (in m3/sec usually)

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Stream Flow

• Load ability of a stream to carry load of solid
  material varies with discharge, velocity and
  particle size.

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The End!