Epiphreatic zone

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Cross section showing the water table varying with surface topography as well as a perched water table Water table.svg
Cross section showing the water table varying with surface topography as well as a perched water table
Cross-section of a hillslope depicting the vadose zone, capillary fringe, water table, and the phreatic or saturated zone. (Source: United States Geological Survey.) Vadose zone.gif
Cross-section of a hillslope depicting the vadose zone, capillary fringe, water table, and the phreatic or saturated zone. (Source: United States Geological Survey.)

In a cave system, the epiphreatic zone or floodwater zone is the zone between the vadose (unsaturated) zone above and phreatic (saturated) zone below. It is regularly flooded and has a significant porosity. It has a great potential for cave formation. [1]

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<span class="mw-page-title-main">Vadose zone</span> Unsaturated aquifer above the water table

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Water content or moisture content is the quantity of water contained in a material, such as soil, rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 to the value of the materials' porosity at saturation. It can be given on a volumetric or mass (gravimetric) basis.

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<span class="mw-page-title-main">Infiltration (hydrology)</span> Process by which water on the ground surface enters the soil

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<span class="mw-page-title-main">Underground lake</span> Lake under the Earths surface

An underground lake is a lake underneath the surface of the Earth. Most naturally occurring underground lakes are found in areas of karst topography, where limestone or other soluble rock has been weathered away, leaving a cave where water can flow and accumulate.

Groundwater remediation is the process that is used to treat polluted groundwater by removing the pollutants or converting them into harmless products. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. Globally, between 25 per cent and 40 per cent of the world's drinking water is drawn from boreholes and dug wells. Groundwater is also used by farmers to irrigate crops and by industries to produce everyday goods. Most groundwater is clean, but groundwater can become polluted, or contaminated as a result of human activities or as a result of natural conditions.

<span class="mw-page-title-main">Agricultural hydrology</span>

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<span class="mw-page-title-main">Non-aqueous phase liquid</span> Liquid solution contaminants that do not dissolve in or easily mix with water

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<span class="mw-page-title-main">Finite water-content vadose zone flow method</span>

The finite water-content vadose zone flux method represents a one-dimensional alternative to the numerical solution of Richards' equation for simulating the movement of water in unsaturated soils. The finite water-content method solves the advection-like term of the Soil Moisture Velocity Equation, which is an ordinary differential equation alternative to the Richards partial differential equation. The Richards equation is difficult to approximate in general because it does not have a closed-form analytical solution except in a few cases. The finite water-content method, is perhaps the first generic replacement for the numerical solution of the Richards' equation. The finite water-content solution has several advantages over the Richards equation solution. First, as an ordinary differential equation it is explicit, guaranteed to converge and computationally inexpensive to solve. Second, using a finite volume solution methodology it is guaranteed to conserve mass. The finite water content method readily simulates sharp wetting fronts, something that the Richards solution struggles with. The main limiting assumption required to use the finite water-content method is that the soil be homogeneous in layers.

References

  1. Prelovšek, Mitja (2009). Present-Day Speleogenetic Processes, Factors and Features in the Epiphreatic Zone: Dissertation (PDF). University of Nova Gorica. p. 5.
  2. "Aquifer Anatomy | EARTH 111: Water: Science and Society". www.e-education.psu.edu. Retrieved 2024-06-08.
  3. "Infiltration | hydrologic cycle | Britannica". www.britannica.com. Retrieved 2024-06-08.
  4. "saturated zone". Oxford Reference. Retrieved 2024-06-08.
  5. "USGS Unsaturated Zone Flow Project". wwwrcamnl.wr.usgs.gov. Retrieved 2024-06-08.