River water quality modelling: I. State of the art

River water quality models are used extensively in research as well as in t he design and assessment of water quality management measures. The applicat ion of mathematical models for that purpose dates back to the initial studi es of oxygen depletion hue to organic waste pollution. Since then, models h ave been constantly refined and updated to meet new and emerging problems o f surface water pollution, such as eutrophication, acute and chronic toxici ty, etc. In order to handle the complex interactions caused by the increase d influence of human activities in rivers it is today mandatory to couple r iver water quality models with models describing emissions from the drainag e and sewerage system (such as the IAWQ Activated Sludge model No.1). In th is paper-which is the first of a three-part series by the IAWQ Task Group o n River Water Quality Modelling-the state of the art is summarized with the above aim in mind. Special attention is given here to the modelling of con version processes but also the methods and tools to work with the models, i .e. parameter estimation, measurement campaign design, and simulation softw are, are discussed. (C) 1998 IAWQ Published by Elsevier Science Ltd. All ri ghts reserved.