Groundwater

Where is groundwater located and how do humans

Recap of the Water Cycle

Groundwater• Groundwater is water

below the earth’s surface

• Groundwater is the biggest supplier of fresh water used for drinking, agriculture, and industry but it only makes up less than 1% of the hydrosphere

Groundwater• Groundwater is recharged

when precipitation (rain, snow, sleet, hale) infiltrate into the ground

• Groundwater is stored in the ground in materials like gravel or sand.

• Water can also move through rock formations like sandstone or through cracks in rocks.

Porosity and Permeability• The amount of pore spaces

(holes) within a rock/soil that can hold water is referred to as a material’s porosity

• Substances are defined due to the connectedness of the pore spaces– well connected pores it is

referred to as a permeable surface

– Poorly connected pores it is referred to as impermeable

Groundwater Zones• There are two zones

– The zone of aeration has water and air filling pore spaces between rock and soil particle.

– The zone of saturation has only water filling pore spaces between rock and soil particles.

• The top of the zone of saturation is called the water table.

• An aquifer is an underground layer of rock or soil that contains water

Groundwater Storage• There are two types of aquifers,

which store groundwater– A confined aquifer has an

impermeable layer above it– An unconfined aquifer has an

impermeable layer below it• An aquitard layer that prevents

water from escaping; impenetrable

• Artesian Aquifer groundwater rises on its own due to pressure

Groundwater Movement

• Groundwater moves from areas of high pressure to areas of low pressure

• Groundwater can flow into– Oceans– Rivers (gaining

streams)– Wetlands– Lakes

Removing Groundwater• Companies/homes draw

groundwater from the ground using wells

• There are unsuccessful wells and successful wells (the Goldie Locks complex)

• Successful wells – Infiltrate the water table– Are found in the middle of

the water table so they do not pull pollutants or dirt

Removing Groundwater

• When many wells are pulling water from an aquifer they can create a cone of depression

• In coastal zones this can cause salt water intrusion, where salt water invades the freshwater aquifer