Abstract
The rapid growth of population in cities places great pressure on urban ecosystem health and management, especially on urban water supply and disposal of wastewater. To cope with urban water degradation, indicators are needed for predicting and evaluating anthropogenic impacts on wetlands. Presented in this paper is a analytical study of the environmental dispersion in a three-layer wetland in terms of the longitudinal evolution of the lateral mean concentration. An environmental dispersion model for the mean concentration in the three-layer wetland is devised as an extension of Taylor's classical formulation. The analytical results illustrate the effect of dimensionless parameters on the environmental dispersivity. Other related indicators for urban water quality assessment in three-layer wetlands, i.e., the critical length and duration of the contaminant cloud of typical contaminant constituents are illustrated and characterized. (C) 2014 Elsevier Ltd. All rights reserved.