hydrogeology Hydrogeology (''hydro-'' meaning water, and ''-geology'' meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rock (geology), rocks of the Earth's crust (ge ...

, groundwater flow is defined as the "part of streamflow that has infiltrated the ground, entered the

phreatic zone The phreatic zone, saturated zone, or zone of saturation, is the part of an aquifer, below the water table The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractur ...

, and has been (or is at a particular time) discharged into a stream channel or springs; and seepage water."Chorley, R.J., 1978. Glossary of Terms. In: M.J. Kirkby (Ed), Hillslope Hydrology, John Wiley and Sons, Chichester, U.K.: 1-42 It is governed by the groundwater flow equation. Groundwater is water that is found underground in cracks and spaces in the soil, sand and rocks. Where water has filled these spaces is the phreatic (also called) saturated zone. Groundwater is stored in and moves slowly (compared to

surface runoff Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to ''channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other ...

in temperate conditions and watercourses) through layers or zones of soil, sand and rocks:

aquifer An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

s. The rate of groundwater flow depends on the permeability (the size of the spaces in the soil or rocks and how well the spaces are connected) and the

hydraulic head Hydraulic head or piezometric head is a measurement related to liquid pressure (normalized by specific weight) and the liquid elevation above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22, eq.3.2a. It is usually meas ...

(water pressure). In polar regions groundwater flow may be obstructed by

permafrost Permafrost () is soil or underwater sediment which continuously remains below for two years or more; the oldest permafrost has been continuously frozen for around 700,000 years. Whilst the shallowest permafrost has a vertical extent of below ...

References

{{Authority control Hydrology Limnology Aquifers Water streams

See also

References