Determining the relationship between average concentration of saturated aquifer and groundwater outflow subject to nonpoint source contaminants

Abstract

In the stream-aquifer setting entered by nonpoint source contaminants, numerical simulation analyses for the coupled advection-dispersion and Richards equations were performed to evaluate and quantify the impacts of transport controlling factors on the relationship between average concentration of saturated aquifer and groundwater outflow concentration , and on the dynamic responses of and variables. As compared to the previous studies, the unique features of this study were to include unsaturated flow effect and to provide the physical basis and quantification for the — relationship. Numerical simulation results showed that — relations exhibited nonlinear, looping behaviour and were sensitive to the changes of dispersivity and aquifer thickness parameters. Furthermore, and responses were significantly affected by these two factors of dispersivity and aquifer thickness. For unsaturated-saturated flow condition, the significant impact of dispersivity values on the groundwater outflow concentration response might have an important implication for modeling the responses.