a lesson on how water moves underground

1. Water
Underground

2. How Water Moves Underground
• Water underground trickles down between
particles of soil and through cracks and
spaces in layers of rock

3. Effects of Different Materials
• Permeable materials have large and
connected pores; materials such as sand and
gravel allow water to pass through or
permeate.
• Impermeable materials have few or no
pores or cracks; therefore the water cannot
pass through easily
• Examples: clay and granite

5. Water Zones
• **The area of permeable rock or soil that is
totally filled or saturated, with water is
called the saturated zone**
• **The top of the saturated zone is called
the water table**
• The area above the water table is called the
unsaturated zone

7. Bringing up Groundwater
• In some areas, the water table meets the
surface
• Aquifers:
– Any underground layer of rock or sediment that
holds water is known as an aquifer**
– Size: small underground patch to the size of
several states

8. Aquifers continued
• Functions: drinking water, water for
crops, and water for livestock
• Rate of Movement: depends on the slope
of the aquifer and permeability of rocks

9. Wells
• **People can obtain groundwater from an aquifer
by drilling a well below the water table**
• If the level of the aquifer drops, a well can run
dry
• The water table can rise after heavy rain or snow
melts

11. Using Pumps
• Mechanical pumps bring up groundwater
• If water is pumped out too fast, a well will
run dry
• New water that enters the aquifer from the
surface is called recharge

12. Relying on Pressure
• **In an artesian well, water rises because
of pressure in an aquifer**
• If groundwater becomes trapped between
two layers of impermeable rock or
sediment, the pressure sends water spurting
up through the punctured hole
• No pump is necessary