Development and validation of an equation to estimate longitudinal dispersion coefficient in medium-sized rivers

In this paper, an equation has been developed to estimate the longitudinal dispersion coefficient (D-L) in medium-sized rivers, with flow between 16.20 and 98 m(3)s(-1), from experimental tests using fluorescent tracers. The equation was deduced by dimensional analysis and adjusted to the field data by the multiple linear regression technique. Thereafter, the validation of the equation was performed by testing it in another database, which is different from the one it had been developed for, with flow between 19.57 and 48.54 m(3)s(-1). Additionally, the performance of four other empirical equations was compared for D-L prediction using three comparative methods. The developed equation showed appropriate statistical adjustment and good result, with better overall performance when compared with other equations proposed in literature.