1. WARM UP: /13/14
As a stream curves, or ______________, the water moves faster on the outside of the curve causing _____________. On the inside the water moves slower and _________________ occurs.
What is a watershed?

2. Groundwater

3. Groundwater Groundwater is water stored below Earth’s surface
When water soaks through the ground it becomes groundwater
Infiltration

4. Porosity Porosity is the amount of space in between soil particles
High Porosity = Lots of space between the soil
Low Porosity = Little space between the soil

5. Permeability
Permeability is the materials ability to allow fluids to pass
High Permeability = Water can travel through soil easily
Low Permeability = Water can’t travel through soil easily

6. Impermeable layers
Water can not flow through very easily; soil has very small pore spaces; ex: clay

7. Groundwater
Zone of Saturation-Area where groundwater fills up all pores in the soil
The zone of aeration is above the Zone of saturation
The water table is the boundary between these 2 zones

8. Wells A well is a hole drilled into the zone of saturation
An aquifer is the area where groundwater can be extracted
Can cause the water table to drop

9. Aquifers
An unconfined aquifer has no barrier between its top layer and the surface of the ground.
Confined aquifers are sandwiched between two largely impenetrable layers like clay or shale

11. Why is groundwater sometimes considered nonrenewable?
In arid, dry regions it took hundreds of thousands of years to accumulate groundwater.
As population increases, more groundwater is being pumped out than is being replenished.

12. Groundwater Depletion
Ground subsidence (sinking) can occur if water is used faster than it is replenished
Karst Topography
Sink Holes

13. Groundwater Depletion
San Joaquin Valley, California
Land subsided due to excessive groundwater withdrawl in the 1920’s.
Sank 8 meters by 1970