A Study of Pollutant Mixing and Evaluating of Dispersion Coefficients in Laboratory Meandering Channel

General behaviors based on hydraulic characteristics of natural streams and channels have been recently analyzed and developed via various numerical models. However in the states of natural hydraulics, an experimental research should be performed simultaneously with the mathematical analysis due to effects of hydraulic properties such as meander, sediment, and so on. In this study, to find effects of hydraulic characteristics and evaluate longitudinal and transverse coefficients using 2-dimensional advection-dispersion equation in meandering channels, a laboratory experimental channel has been set up with 2 S-curved sections. In addition, results of the experiments have been compared with velocity fields of same hydraulic conditions. From the analysis of the pollutant clouds illustrated from the results of tracer tests, separation, stagnation, and superposition of several pollutant clouds have been occurred from asymmetric velocity fields and effects of the secondary flow which can be estimated with using SCI (secondary current intensity). Specific relationships between hydraulic properties such as ratio of width to depth, Froude number and flow patterns with dispersion coefficients which can be well-expressed could be elucidated with 2-D routing procedure.