Groundwater 11.3. Earth’s water budget From Miller’s Living in the Environment.

Groundwater

11.3

Earth’s water budget

From Miller’s Living in the Environment

Geology of an aquifer

From Miller’s Living in the Environment

Words to know…

• Water table = the top of the layer of water in the ground.

• Confining layer = layers of rock that the water can not pass through…it traps the water

• Spring = where water flows up to the surface of the ground

• Well = man made hole that goes to the water table & water is pumped to surface

Aquifer

• Layer of rock that contains groundwater.• The water sits between the grains of sand or

rock that are connected.• The water can move through the sand or rock

layer.

GW use in USA & China

From Miller’s Living in the Environment

Areas of aquifer depletion

From Miller’s Living in the Environment

Areas of ground subsidence

From Miller’s Living in the Environment

Porosity

• Percentage of open space between particles in the rock.

belmont.sd62.bc.ca

Porosity

• % of open spaces in given volume of rock• Amount of water a rock can hold• Influenced by:– Sorting • poorly sorted = lower porosity

– Packing• tightly packed = lower porosity• Loosely packed = higher porosity

Permeability

• How readily the water passes through the open spaces of the rock.

kalkaskacounty.net

Permeability

• How freely water passes through open spaces.• For a rock to be permeable, it must have

connected spaces.• Influenced by:– Size & sorting• Consistent sorting & large particles = high permeability

– Most permeable rock:• Coarse particles (sandstone, fractured limestone)

Recharge zones

• Area where water can soak into the ground and enter an aquifer.

• NC road sign example

Nicholas.duke.edu

Saltwater intrusion

From Miller’s Living in the Environment

Homework

• Read pages 320 - 325

Output

• Sketch and label a cross section an aquifer