Understanding the Hydrologic Cycle and Groundwater Concepts

hydrologic cycle

The continuous movement of water through Earth's systems (evaporation, precipitation, etc.).

groundwater

Water stored underground in the pores and cracks of soil and rock.

aquifer

A rock layer that stores and transmits groundwater.

aquitard

A layer that slows or prevents groundwater movement.

porosity

The percentage of open space in a rock or sediment.

permeability

The ability of a material to transmit fluids.

discharge in groundwater

Water leaving an aquifer (e.g., into a spring or well).

recharge in groundwater

Water entering an aquifer, usually from precipitation.

unconfined aquifer

An aquifer directly open to the surface, with a water table on top.

confined aquifer

An aquifer trapped between aquitards and under pressure.