title: The determination of longitudinal dispersion coefficients in rivers.
abstract: The dispersion coefficient of several sections of two Spanish rivers (Tagus and Ebro) is calculated using different methods. The aim of the study is to accurately know the effects of accidental leaks from two nuclear power plants that are placed upstream. Experimental data from tracer injections as well as data from hydraulic parameters were used to calculate the dispersion coefficient. Two methods based on tracer curves fit the experimental data well. One method is based on the time at which the tracer concentration is half the maximum concentration; the other method is based on the variance of the tracer curve distribution. An alternative method based on governmental data of velocity profiles and correlations of hydraulic parameters was also used. The results of this method are strongly sensitive to small variations in the stream flowrate. A new correlation is proposed to predict the dispersion coefficient with an error smaller than the one provided by other correlations in the literature.
authors.affiliation: Department of Chemical Engineering, Faculty of Chemistry, Universidad Complutense de Madrid, Spain. mcpalanc@quim.ucm.es
authors.forename: María C
authors.initials: MC
authors.lastname: Palancar
authors.forename: José M
authors.initials: JM
authors.lastname: Aragón
authors.forename: Fernando
authors.initials: F
authors.lastname: Sánchez
authors.forename: Roberto
authors.initials: R
authors.lastname: Gil
mesh_terms: D004058:Diffusion; D008962:Models, Theoretical; D011210:Power Plants; D045483:Rivers; D013030:Spain; D014878:Water Pollution, Radioactive / Q000517:prevention & control*