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91 Water Quality

Part 8. Water Quality and Biogeochemistry

  1. Michel Meybeck1,
  2. Norman E Peters2,
  3. Deborah V Chapman3

Published Online: 15 APR 2006

DOI: 10.1002/0470848944.hsa093

Encyclopedia of Hydrological Sciences

Encyclopedia of Hydrological Sciences

How to Cite

Meybeck, M., Peters, N. E. and Chapman, D. V. 2006. Water Quality. Encyclopedia of Hydrological Sciences. 8:91.

Author Information

  1. 1

    Sisyphe/CNRS, University of Paris, Paris, France

  2. 2

    United States Geological Survey, Georgia Water Science Center, Atlanta, GA, US

  3. 3

    University College Cork, Environmental Research Institute and Department of Zoology, Ecology and Plant Science, Cork, Ireland

Publication History

  1. Published Online: 15 APR 2006


Water quality is the term used to describe the chemical, physical, and biological characteristics of water. Furthermore, the physical, chemical, and biological characteristics of a water body, “its water quality”, determine the suitability of that water for a particular value, for example, potability, ecosystem status, agriculture, industry, recreation. Water-quality issues have become a rapidly evolving component of the environmental sciences primarily due to the increasing demand on water resources and amenity value and the intricate linkage between water-quality use and ecosystem health. Water quality varies markedly in time and space. Episodic temporal water-quality variations can occur in minutes whereas, periodic variations can occur on short timescales from diurnal, associated with variations in light and temperature, to seasonal and longer associated with climatic variations. Spatial variations also vary markedly from millimeters and centimeters in soil profiles to very large-scale variations (>1000 km), for example, associated with water residence times, lithology, landscape position, land use, and bioclimatic zone. In the absence of the effects of human activities, water quality is primarily controlled by climate (precipitation and temperature) and geology (lithology, geomorphology, soil). The water quality of a given volume of water is derived from the sum of effects of mixing and interactions from all upstream sources including atmospheric deposition (precipitation and dry deposition), soil water (matrix and macropore), groundwater, springs, wetlands, irrigation ditches and canals, streams, ponds, lakes, reservoirs, rivers, and estuaries. In most parts of the world, human activities have now caused multiple and complex changes in background water quality.


  • water quality variables;
  • origins of solutes;
  • space variability;
  • time variability