Groundwater

6th

Groundwater

• What if you dump a bucket of water on the ground what will happen?

Depends on the Ground

Permeability

• If you dump water in a parking lot it will puddle up and eventually evaporate

• If you dump the water in your front yard the water will seep into the ground through the cracks between soil particles

Impermeable vs. Permeable

• The hard asphalt of the parking lot is Impermeable meaning that water can not flow through it

• The Ground in the front yard is softer and is Permeable, meaning the water can flow into the ground.

More examples

• Impermeable: Clay and Granite

• Permeable: Sand, Soil, and Gravel.

Permeability

• Materials are permeable if they have pores that allow water to pass through, or “permeate.”

• Materials are impermeable if they have few or no cracks --> water cannot pass through easily

Water Zones• Once the water

flowing through a permeable material reaches an impermeable material the area begins to fill with water (think of filling a glass of water)

Impermeable

Wat

er b

egin

s to

rise

Looking back at our glass of water

Unsaturated zone

Water table

Saturated zone

Water zones

• Once a permeable area is full this area is known as a saturated zone

• The top of a saturated zone is called the water table

• The permeable area above the water table is called the unsaturated zone

Looking back at our glass of water

Unsaturated zone

Water table

Saturated zone

Bringing up Groundwater

• Aquifer- the layer of permeable rock that holds water (in our glass of water example, the glass itself would be the aquifer)

• The water table moves up and down with in the aquifer depending on how much water is present.

Wells

• Well- a hole dug into the ground that penetrates the water table and then pumps water to the surface.

• Dry well- when a well no longer penetrates the water table no more water can be pumped from the ground.

Normal Well

Which one is a Dry well?

Artesian well

• When water is trapped between two impermeable materials and you puncture the top layer of rock the pressure of the rocks above will force the water to the surface with out the need for a pump

Artesian Well

• http://www.youtube.com/watch?v=KMtEQqbi4CI

• http://www.youtube.com/watch?v=iDSfB66qkYY

Geysers –natural eruptions of groundwater to the surface

• When groundwater begins to heat up under ground it builds up pressure and erupts to the surface.

• http://www.youtube.com/watch?v=_gyhvqbIaOE

• Where in the world are there lots of geysers?

• http://www.youtube.com/watch?v=wE8NDuzt8eg