Groundwater

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Groundwater

• Objectives
• 1.)Distinguish between porosity and Permeability
• 2.) Identify the two moisture zones below the
  Earths surface
• 3.) Relate the contour of the water table to the
  contour of the land
• 4.) Describe how groundwater can be polluted
• 5.) Describe artesian formations
• 6.) Describe 2 land features produced when
  groundwater is heated beneath the surface.

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Groundwater stats

• 90 of earths liquid freshwater is stored
  beneath the ground
• 20 of freshwater needs in the united states is
  fulfilled by groundwater
• Groundwater is stored in aquifers (layers of
  sediment with the ability to store water)

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How do sediments store water?

• Porosity- the percentage of open space in a given
  volume of rock or sediment- the more porous, the
  more water the rock can hold.
• If rock beds are very well sorted- meaning each
  consist of the same grain sizes, they have a
  higher chance of storing water

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How do rocks store water cont..

• Its not good enough for a rock to just be porous,
  it must also be permeable to store water
• Permeability depends upon how the open spaces
  between grains are connected
• Some rocks are impermeable (water cannot pass
  through) because there is little or no space
  between grains.

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Parts of an Aquifer
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Zones of groundwater

• Beginning from the bottom
• - an impermeable layer of rock- this way water
  can be trapped
• - zone of saturation- water is saturated into
  pore spaces of rock
• - water table borders the zone of saturation
  and zone of aeration
• - zone of aeration zone where water may
  migrate towards the surface
• - capillary fringe where water is drawn up
  by soil due to capillary action

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Lets define capillary action

• the movement of water within the spaces of a
  porous material due to the forces of adhesion,
  cohesion, and surface tension.

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A good place to drill a well

• Make sure you drill below the water table, so
  that it can be replenished for a sufficient
  amount of time
• Pick an area where there is a depression in
  topography chances are that beneath the surface
  there is a depression too, this way more water is
  likely to be stored there
• Remember water moves to low

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Maybe a good place to drill..
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Where you would find a spring

• A region where the ground surface drops below the
  water table
• This can occur due to rugged topography or by
  faulting
• Oftentimes where theres a spring, theres a fault

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Artesian Wells and Springs

• Artesian wells are found far from water sources,
  yet so much water is stores underground, it
  naturally flows to the surface without pumping
• Having a cap rock may assist in forming an
  artesian well because it increases water pressure
  enabling water to naturally flow to the surface
• Artesian springs typically make up the desert
  oasis

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Hot springs and geysers

• Water that rises to the surface before cooling
  due to contact with a magma chamber
• Geysers are hot springs that erupt periodically

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Pollution