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Perched Groundwater

Ground Water Hydrology

  1. Leo S. Leonhart

Published Online: 15 APR 2005

DOI: 10.1002/047147844X.gw811

Water Encyclopedia

Water Encyclopedia

How to Cite

Leonhart, L. S. 2005. Perched Groundwater. Water Encyclopedia. 5:352–355.

Author Information

  1. Hargis Associates, Inc., Tucson, Arizona

Publication History

  1. Published Online: 15 APR 2005

Abstract

Perched ground water is subsurface water that forms a saturated horizon within porous media at an elevation higher than the local or regional groundwater table. This condition may result from various field conditions, but the requisite condition is a soil or rock horizon of significantly lower vertical hydraulic conductivity (Kv) (perching unit) amid contrastingly higher Kv strata. Downward movement of infiltrating water through the higher Kv materials is retarded and accumulates above and/or within the perching unit. This typically “mounds” saturated water above the perching unit, leaving an unsaturated (vadose) horizon below the perching unit. The upper limit of saturation in a perched zone is referred to as a perched water table, whereas the lower limit has been defined as an inverted water table.

Keywords:

  • perched groundwater;
  • perching unit;
  • perched water table;
  • inverted water table;
  • vertical hydraulic conductivity;
  • groundwater mound;
  • flood basalts;
  • high volcanic islands;
  • semiperched groundwater;
  • tension-saturated zone;
  • temporary saturated zone;
  • NAPL