Potentiometric surface

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A potentiometric surface is the imaginary plane where a given reservoir of fluid will "equalize out to" if allowed to flow. A potentiometric surface is based on hydraulic principles. For example, two connected storage tanks with one full and one empty will gradually fill/drain to the same level. This is because of atmospheric pressure and gravity. This idea is heavily used in city water supplies - a tall water tower containing the water supply has a great enough potentiometric surface to provide flowing water at a decent pressure to the houses it supplies.

For groundwater "potentiometric surface" is a synonym of "piezometric surface" which is an imaginary surface that defines the level to which water in a confined aquifer would rise were it completely pierced with wells. [1] If the potentiometric surface lies above the ground surface, a flowing artesian well results. Contour maps and profiles of the potentiometric surface can be prepared from the well data.

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<span class="mw-page-title-main">Water table</span> Top of a saturated aquifer, or where the water pressure head is equal to the atmospheric pressure

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<span class="mw-page-title-main">Groundwater</span> Water located beneath the ground surface

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<span class="mw-page-title-main">Hydrogeology</span> Study of the distribution and movement of groundwater

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<span class="mw-page-title-main">Artesian well</span> Confined aquifer containing groundwater under positive pressure

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<span class="mw-page-title-main">Well cluster</span>

A well cluster, also referred to as a monitoring well cluster, consists of multiple co-located monitoring wells that are constructed with intakes at different depths in the subsurface. The purpose of a well cluster is to provide groundwater samples from discrete depths at approximately the same location, and/or to measure the vertical pressure gradient to calculate the vertical component of groundwater flow. Water levels can be measured in each individual monitoring well, providing vertical profiles of groundwater pressure. The pressure difference between the groundwater table and the potentiometric surface in a submerged well can. A shallow well is used to measure the water table, and is equilibrated to atmospheric pressure. A deeper well, or piezometer, measured the potentiometric surface, determined by the water level observed when submerged and sealed. The associated change in pressure between the shallow well and piezometer, and the corresponding length, usually taken as the distance between the center of the two well screens, can be applied to Darcy's Law to calculate the vertical groundwater flow.

References

  1. Younger, Paul (2007). Groundwater in the Environment. Oxford, UK: Blackwell Publishing Ltd. ISBN   978-1-4051-2143-9.