Water quality modelling involves the prediction of water pollution using mathematical simulation techniques. A typical water quality model consists of a collection of formulations representing physical mechanisms that determine position and momentum of pollutants in a water body. Models are available for individual components of the hydrological system such as surface runoff; there also exist basinwide models addressing hydrologic transport and for ocean and estuarine applications. Often finite difference methods are used to analyse these phenomena, and, almost always, large complex computer models are required.

Formulations and associated Constants

Water quality is modelled by one or more of the following formulations:

• Advective Transport formulation
• Dispersive Transport formulation
• Surface Heat Budget formulation
• Dissolved Oxygen Saturation formulation
• Reaeration formulation
• Carbonaceous Deoxygenation formulation
• Nitrogenous Biochemical Oxygen Demand formulation
• Sediment oxygen demand formulation (SOD)
• Photosynthesis and Respiration formulation
• pH and Alkalinity formulation
• Nutrients formulation (fertilizers)
• Algae formulation
• Zooplankton formulation
• Coliform bacteria formulation (e.g. Escherichia coli)

See also

• Hydrological transport models
• Volumes of water on earth
• Water resources
• Water quality
• Wastewater quality indicators

External links

• USGS
• U.S. Environmental Protection Agency
• Rates, Constants, and Kinetics Formulations in Surface Water Quality Modeling
• Washington State Department of Ecology (QUAL2Kw and other models)
• Catchment Modelling Toolkit