2DNEMM: a numerical environmental multimedia modeling method for landfill case study

摘要

This paper presents a two-dimensional numerical multimedia modeling method (2DNEMM) which is developed to evaluate the fate and behavior of pollutant in a contaminated site with complex multimedia conditions. Using alternating direction implicit method, the developed 2DNEMM including source, unsaturated and groundwater modules can estimate spatially and temporally resolved contaminant concentrations in all media. The present model is applied to a landfill site in Canada and validated against monitoring data for chromium (Cr) concentrations. Furthermore, Morris screening method is used to examine the sensitivities of input parameters. Vertical hydraulic conductivity and longitudinal hydraulic conductivity are identified as the most sensitive parameters in source and groundwater zones, respectively. This study also investigates the effect of spatial heterogeneity through a spatial uncertainty analysis of model parameters. Based on the case study, the possible distribution and probabilistic risks of Cr contaminant in the landfill area are further assessed. The 2DNEMM approach can not only address the fate and transport of contaminant in complicated multimedia environments but also serve as a risk assessment tool to provide better spatial and temporal exposure risk assessment.