Author(s): K. O. Baek; I. W. Seo
Linked Author(s): Il Won Seo
Keywords: No Keywords
Abstract: Methodologies for determining the transverse dispersion coefficient in river mixing can be roughly classified into two categories: an observing method, and an estimating method. The former evaluates the dispersion coefficient from the concentration data which can be obtained by tracer tests or field measurements. The latter estimates the dispersion coefficient based on the hydraulic and geometric parameters when there is no concentration data. For observing methods, what have been widely used are moment-based methods which, however, have a restriction that it can be applied to a steady concentration situation neglecting the longitudinal dispersion, and so, only transverse dispersion coefficient can be obtained. An alternative methodology for observed dispersion coefficient is a routing procedure. For estimating methods, theoretical equations have been derived from the concept of shear flow which has dominant effects on the transverse mixing. Empirical equations have been developed using regression techniques based on the dimensional analysis and experimental data. These two equations are interdependent to each other. The complicated theoretical equation can be simplified by empirical approaches and the functional relationships of the empirical equation can be derived from theoretical bases. In this study, the methodologies for determining the transverse dispersion coefficient were reviewed and assessed.
Year: 2009