Mathematical models describing the water quality in rivers and groundwaters are derived from the mass balances.
For rivers, a one dimensional transport equation is derived. Different methods of parameter estimation are considered and more recent techniques are introduced.
For the application of water quality models to river management, two groups of models are considered : the simulation models and the optimization models. As a case study, the Bedford Ouse quality models are described. Practical and theoretical applications in the United Kingdom, Canada, Federal Republic of Germany, U.S.A. and Belgium are discussed.
For groundwaters, several applications of water quality transport models are discussed and the use in groundwater management is explained.