Aquifer

aquifersaquitardunconfined aquiferconfined aquiferaquicludegroundwater aquifersaturationAquitardsunderground aquiferaquifer depletion
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt).wikipedia
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Water well

wellwellsbore
Groundwater can be extracted using a water well. This hole is a crude well, the wet sand represents an aquifer, and the level to which the water rises in this hole represents the water table.
The most common kind of well is a water well, to access groundwater in underground aquifers.

Groundwater

ground waterunderground waterground
Groundwater can be extracted using a water well. Along the coastlines of certain countries, such as Libya and Israel, increased water usage associated with population growth has caused a lowering of the water table and the subsequent contamination of the groundwater with saltwater from the sea.
A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water.

Hydrogeology

hydrogeologicalhydrogeologistgeohydrology
The study of water flow in aquifers and the characterization of aquifers is called 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 rocks of the Earth's crust (commonly in aquifers).

Permeability (earth sciences)

permeabilitypermeableimpermeable
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt).
The concept of permeability is of importance in determining the flow characteristics of hydrocarbons in oil and gas reservoirs, and of groundwater in aquifers.

Overexploitation

over-exploitationoverexploitedoverharvesting
Overexploitation can lead to the exceeding of the practical sustained yield; i.e., more water is taken out than can be replenished.
The term applies to natural resources such as: wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers.

Water

H 2 Oliquid wateraqueous
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt).
It also exists as groundwater in aquifers.

Water table

watertablegroundwater tableperched lake
This hole is a crude well, the wet sand represents an aquifer, and the level to which the water rises in this hole represents the water table.
Below the water table, in the phreatic zone (zone of saturation), layers of permeable rock that yield groundwater are called aquifers. In less permeable soils, such as tight bedrock formations and historic lakebed deposits, the water table may be more difficult to define.

Hydraulic head

headhydraulic gradientpressure head
Saturated means the pressure head of the water is greater than atmospheric pressure (it has a gauge pressure > 0). The definition of the water table is the surface where the pressure head is equal to atmospheric pressure (where gauge pressure = 0).
In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water well), and given information of the piezometer's elevation and screen depth.

Spring (hydrology)

springspringsspring water
Aquifers are typically saturated regions of the subsurface that produce an economically feasible quantity of water to a well or spring (e.g., sand and gravel or fractured bedrock often make good aquifer materials).
A spring is a point at which water flows from an aquifer to the Earth's surface.

Aquifer test

pumping testpump testTheis solution
If the distinction between confined and unconfined is not clear geologically (i.e., if it is not known if a clear confining layer exists, or if the geology is more complex, e.g., a fractured bedrock aquifer), the value of storativity returned from an aquifer test can be used to determine it (although aquifer tests in unconfined aquifers should be interpreted differently than confined ones). Aquifer tests and well tests can be used with Darcy's law flow equations to determine the ability of a porous aquifer to convey water.
An aquifer test (or a pumping test) is conducted to evaluate an aquifer by "stimulating" the aquifer through constant pumping, and observing the aquifer's "response" (drawdown) in observation wells.

Fresh water

freshwaterfreshlimnic
Groundwater can be found at nearly every point in the Earth's shallow subsurface to some degree, although aquifers do not necessarily contain fresh water.
Fresh water habitats are classified as either lentic systems, which are the still-waters including ponds, lakes, swamps and mires ; lotic which are running-water systems; or groundwaters which flow in rocks and aquifers.

Specific storage

storativityspecific yieldspecific storage (S s )
Confined aquifers have very low storativity values (much less than 0.01, and as little as ), which means that the aquifer is storing water using the mechanisms of aquifer matrix expansion and the compressibility of water, which typically are both quite small quantities.
In the field of hydrogeology, storage properties are physical properties that characterize the capacity of an aquifer to release groundwater.

Groundwater model

groundwater modelingComputer modelsgroundwater salinity models
Computer models can be used to test how accurately the understanding of the aquifer properties matches the actual aquifer performance.
Groundwater models are used to simulate and predict aquifer conditions.

Phreatic

phreasphreatic zonephreatomagmatic
The Earth's crust can be divided into two regions: the saturated zone or phreatic zone (e.g., aquifers, aquitards, etc.), where all available spaces are filled with water, and the unsaturated zone (also called the vadose zone), where there are still pockets of air that contain some water, but can be filled with more water.
The term phreatic is used in hydrology and the earth sciences to refer to matters relating to ground water (an aquifer) below the water table (the word originates from the Greek phrear, phreat- meaning "well" or "spring").

Sandstone

sandstonesred sandstoneGodulian sandstone
Porous aquifers typically occur in sand and sandstone.
Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs.

Libya

🇱🇾LibyanLY
Along the coastlines of certain countries, such as Libya and Israel, increased water usage associated with population growth has caused a lowering of the water table and the subsequent contamination of the groundwater with saltwater from the sea.
With the discovery of oil in the 1950s also came the discovery of a massive aquifer underneath much of Libya.

Overdrafting

groundwater depletionwater exploitationgroundwater extraction
Analyzing this type of information over an area gives an indication how much water can be pumped without overdrafting and how contamination will travel.
Overdrafting is the process of extracting groundwater beyond the equilibrium yield of the aquifer.

Losing stream

sinking riverinfluent streamdisappearing streams
Characterization of karst aquifers requires field exploration to locate sinkholes, swallets, sinking streams, and springs in addition to studying geologic maps.
This is the opposite of a more common gaining stream (or effluent stream) which increases in water volume farther down stream as it gains water from the local aquifer.

Hydraulic conductivity

Transmissivitypermeabilitypermeable
Aquitards are composed of layers of either clay or non-porous rock with low hydraulic conductivity.
An aquifer may consist of n soil layers.

Darcy's law

Darcy’s LawDarcyDarcy flow
Aquifer tests and well tests can be used with Darcy's law flow equations to determine the ability of a porous aquifer to convey water.
One application of Darcy's law is to analyze water flow through an aquifer; Darcy's law along with the equation of conservation of mass are equivalent to the groundwater flow equation, one of the basic relationships of hydrogeology.

Biscayne Aquifer

(See Biscayne Aquifer.) Typically (but not always) the shallowest aquifer at a given location is unconfined, meaning it does not have a confining layer (an aquitard or aquiclude) between it and the surface.
Because the top part of the Biscayne aquifer is the water table, this aquifer is known as an unconfined aquifer.

Well test

specific capacitywater well testwell tests
Aquifer tests and well tests can be used with Darcy's law flow equations to determine the ability of a porous aquifer to convey water.
Well testing differs from aquifer testing in that the behaviour of the well is primarily of concern in the former, while the characteristics of the aquifer (the geological formation or unit that supplies water to the well) are quantified in the latter.

Well drainage

drainage by wellsGroundwater drainage by wellsflow to wells
When calculating flow to drains or flow to wells in an aquifer, the anisotropy is to be taken into account lest the resulting design of the drainage system may be faulty.
2) The depth is selected in accordance to aquifer properties. The well filter must be placed in a permeable soil layer.

Fossil water

water miningfossil aquiferfossil aquifers
Occasionally, sedimentary or "fossil" aquifers are used to provide irrigation and drinking water to urban areas.
Fossil water or paleowater is an ancient body of water that has been contained in some undisturbed space, typically groundwater in an aquifer, for millennia.

Vadose zone

vadoseunsaturated zonesaturated
The Earth's crust can be divided into two regions: the saturated zone or phreatic zone (e.g., aquifers, aquitards, etc.), where all available spaces are filled with water, and the unsaturated zone (also called the vadose zone), where there are still pockets of air that contain some water, but can be filled with more water. The water table and unsaturated zone are also illustrated.
Unlike the aquifers of the underlying water-saturated phreatic zone, the vadose zone is not a source of readily available water for human consumption.