Multi-scale analysis for environmental dispersion in wetland flow

Presented in this work is a multi-scale analysis for longitudinal evolution of contaminant concentration in a fully developed flow through a shallow wetland channel. An environmental dispersion model for the mean concentration is devised as an extension of Taylor’s classical formulation by a multi-scale analysis. Corresponding environmental dispersivity is found identical to that determined by the method of concentration moments. For typical contaminant constituents of chemical oxygen demand, biochemical oxygen demand, total phosphorus, total nitrogen and heavy metal, the evolution of contaminant cloud is illustrated with the critical length and duration of the contaminant cloud with constituent concentration beyond some given environmental standard level.