Simulating groundwater transport process using a vertical heterogeneity model: A case study

It is important to simulate a groundwater transport process, e.g., pollutant migration, through the vadose zone and subsequent mixing within the saturated zone to assess potential impacts of contaminants in the subsurface in preliminary stages. It is challenging to simulate heterogeneous soil characteristics and non-uniform initial contaminant concentration. This paper proposes a vertically heterogeneous model of combining heterogeneous vadose zone transport model and saturated zone mixing model using one-dimensional finite difference method to simulate the transport processes of liquid-phase advection, liquid- and vapor-phase dispersion, sorption, and decay of the contaminant. The proposed model was verified by comparing to an analytical solution and laboratory soil column experiments.