Characterization of environmental dispersion in two-layer wetland flow under the effect of wind and ecological degradation

Abstract

Flow and environmental dispersion are crucial to control biodiversity and to manage ecosystem and water resources. Present study presents a dispersion model for a pollutant transport in two-layer wetland flow under the surface-wind along with second-degree degradation effect using multi-scale homogenization technique. The novelty of this paper is to characterize action of the mean concentration subject to wind and second-degree degradation effect. An increase in positive wind direction results in a larger involvement of conveyance capacity in wetland flows, leading to an enlargement of the depth-averaged mean velocity. An analytical solution for the mean concentration along the vertical direction and the maximal area of the region influenced by pollutant transport requires considering hydraulic dispersion and ecological degradation. As a results, it is seen that the pollutant reduces vertically throughout the wetland as the degradation increases. Also, this study uses a depth-averaged function and dimensionless parameters to show the maximal area and duration of the region impacted by the steady-state transport of pollutants under the influence of wind. Furthermore, for the typical structure of contaminant constituent Pb, the influenced duration of the region and maximal area are illustrated with a certain standard water quality level in the wetland and analysed.