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www.usgs.gov/faqs/what-difference-between-a-confined-and...

A water-table--or unconfined--aquifer is an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall. Water-table aquifers are usually closer to the Earth's surface than confined aquifers are, and as such are impacted by drought conditions sooner than confined aquifers.

sciencing.com/differences-confined-aquifer-unconfined...

Aquifers are bodies of water located underground. They may be enclosed within surrounding rock, which is called a confined aquifer, or exist within a layer of water-saturated gravel or sand, which is called an unconfined aquifer. Both kinds of aquifers are used for irrigation, industrial applications and consumption.

www.quora.com/What-is-the-difference-between-confined-and...

An unconfined aquifer would be an aquifer where there is no aquaclude (impervious layer) between the aquifer and the surface. A confined aquifer exists between two aquacludes. If there is a break in the aquaclude that separates the aquifer from the surface, water can flow out toward the surface.

dpipwe.tas.gov.au/.../aquifers/confined-unconfined-aquifers

Confined Aquifers Confined aquifers are permeable rock units that are usually deeper under the ground than unconfined aquifers. They are overlain by relatively impermeable rock or clay that limits groundwater movement into, or out of, the confined aquifer. Groundwater in a confined aquifer is under pressure and will rise up inside a borehole ...

answers.yahoo.com/question/index?qid=20090204203307AAcc0TE

Best Answer: See link below. In general, an unconfined aquifer has a surface pressure equal to the atmosphere and has the water table as its upper boundary. Confined aquifers are trapped by an overlying layer of lesser permeable rock or clay, and can build up additional pressure.

en.wikipedia.org/wiki/Aquifer

Confined versus unconfined. There are two end members in the spectrum of types of aquifers; confined and unconfined (with semi-confined being in between).Unconfined aquifers are sometimes also called water table or phreatic aquifers, because their upper boundary is the water table or phreatic surface. (See Biscayne Aquifer.)Typically (but not always) the shallowest aquifer at a given location ...

sciencing.com/difference-between-aquifer-water-table...

Aquifers can be considered unconfined or confined. An unconfined aquifer's bottom is a layer of nonporous rock, which restricts water flow, creating a barrier to the aquifer. The water table is the top layer of the unconfined aquifer. A confined aquifer sits below a unconfined aquifer and layer of nonporous rock.

quizlet.com/15847419/chapter-9-flash-cards

confined: surrounded by a layer of impermeable rock or clay which doesn't permit water to flow to or from the aquifer unconfined: porous rock covered by soil, so water can easily flow in and out of it unconfined aquifers can be recharged from precipitation water percolating through the soil

www.usbr.gov/lc/yuma/programs/YAWMS/GROUNDWATER_aquifer.html

The aquifer in the Yuma area is an unconfined aquifer, composed primarily of sand, gravel, clay and silt sediments deposited by the Colorado and Gila rivers. Confining bed A confining bed is a body of distinctly less permeable material that is located above or below one or more aquifers. Confined aquifer A confined aquifer is an aquifer that is ...