Groundwater and Aquifers

The saturated zone is the region below the water table where all the pores and cracks in the ground are filled with water.

An aquifer is a layer of rock or soil that contains groundwater and can yield a significant amount of water.

The water table is the upper boundary of the saturated zone, where the pressure of the water is equal to the atmospheric pressure.

The unsaturated zone is the region above the water table where the soil or rock contains some water, but not enough to saturate all the pores and cracks.

The capillary zone is the zone immediately above the water table where water is held by capillary action, which is the ability of water to move upward against gravity through small pores and cracks.

Infiltration is the process by which water moves from the unsaturated zone to the saturated zone.

Percolation is the process by which water moves from the saturated zone to the unsaturated zone.

Transpiration is the process by which water moves from plants to the atmosphere.

Recharge is the process by which water is added to an aquifer.

Discharge is the process by which water is removed from an aquifer.

Aquifer yield is the term used to describe the amount of water that an aquifer can yield.

Aquifer transmissivity is the term used to describe the ability of an aquifer to transmit water.

Aquifer storage coefficient is the term used to describe the ability of an aquifer to store water.

Aquifer flow rate is the term used to describe the rate at which water moves through an aquifer.

Aquifer gradient is the term used to describe the difference in elevation between two points in an aquifer.