@prefix qx8: <http://data.loterre.fr/ark:/67375/QX8> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

qx8: a skos:ConceptScheme .
qx8:-96KDHZG8-1
  skos:prefLabel "groundwater"@en, "eau souterraine"@fr ;
  a skos:Concept ;
  skos:narrower qx8:-HJG2Q6WP-S .

qx8:-HJG2Q6WP-S
  skos:exactMatch <https://fr.wikipedia.org/wiki/Niveau_pi%C3%A9zom%C3%A9trique#:~:text=Le%20niveau%2C%20la%20cote%20ou,'aide%20d'un%20pi%C3%A9zom%C3%A8tre>, <https://en.wikipedia.org/wiki/Water_table> ;
  skos:definition "Le niveau, la cote ou la surface piézométrique est l'altitude ou la profondeur (par rapport à la surface du sol) de la limite entre la nappe phréatique et la zone vadose dans une formation aquifère. Ce niveau est mesuré à l'aide d'un piézomètre. La cote piézométrique au point i s'écrit : Cp(i) en mètres (m). Le niveau piézométrique théorique normal moyen en un lieu et à une date donnée dans l'année est le niveau de référence par rapport auquel on dira que la rivière est en situation de crue ou d'étiage, ou que la nappe est rechargée ou en manque d'eau. Là où la nappe affleure, c'est le plafond de la nappe, qui peut être le niveau d'une rivière, d'un fleuve, d'un étang naturel, etc. (Adapté de : <a href=\"https://fr.wikipedia.org/wiki/Niveau_pi%C3%A9zom%C3%A9trique#:~:text=Le%20niveau%2C%20la%20cote%20ou,'aide%20d'un%20pi%C3%A9zom%C3%A8tre\">https://fr.wikipedia.org/wiki/Niveau_pi%C3%A9zom%C3%A9trique#:~:text=Le%20niveau%2C%20la%20cote%20ou,'aide%20d'un%20pi%C3%A9zom%C3%A8tre</a>.)"@fr, "The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the locality. It can also be simply explained as the depth below which the ground is saturated. The water table is the surface where the water pressure head is equal to the atmospheric pressure (where gauge pressure = 0). It may be visualized as the \"surface\" of the subsurface materials that are saturated with groundwater in a given vicinity. The groundwater may be from precipitation or from groundwater flowing into the aquifer. In areas with sufficient precipitation, water infiltrates through pore spaces in the soil, passing through the unsaturated zone. At increasing depths, water fills in more of the pore spaces in the soils, until a zone of saturation is reached. 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. “Water table” and “water level” are not synonymous. If a deeper aquifer has a lower permeable unit that confines the upward flow, then the water level in this aquifer may rise to a level that is greater or less than the elevation of the actual water table. The elevation of the water in this deeper well is dependent upon the pressure in the deeper aquifer and is referred to as the potentiometric surface, not the water table. (Adapted from: <a href=\"https://en.wikipedia.org/wiki/Water_table\">https://en.wikipedia.org/wiki/Water_table</a>)"@en ;
  skos:altLabel "niveau piézométrique"@fr, "piezometric surface"@en, "niveau hydrostatique"@fr ;
  skos:prefLabel "surface piézométrique"@fr, "groundwater table"@en ;
  skos:broader qx8:-96KDHZG8-1 ;
  a skos:Concept ;
  skos:inScheme qx8: .