"Improvements necessary for a river pollutant transport model to obtain a better performance "

A wealth of field facts, including the high human pressure on rivers, the eutrophication danger and the complexity of in-river phenomena (causing difficulties in water quality modelling) revealed the need to offer reliable tools for the pollutant transport modelling and for the understanding and estimation of the complex in-river pollutant behaviour. This paper presents an application of ADModel (a detailed advection dispersion pollutant transport model) for the case of River Swale (UK), in order to show why an improved representation (a) of the hydrodynamic river characteristics and (b) of the pollutant transformations; is very important for the advection-dispersion models, as it generates a major gain in the modelling skills (e.g. prediction improvement) and on the understanding of in-river phenomena. ADModel obtained good results during calibration against field measurements of concentration, showing that an improved version (using detailed representation of the river stretch and pollutant transformations) facilitates a better model performance and a wider applicability, including the identification of additional phenomena along the river stretch, of importance in ordinary situations and also during un-controlled pollution situations. Keywords: ADModel, in-river pollutant transport model, river water quality, phosphorus prediction, rating equations.