ABSTRACT
Synthetic chemicals cause soil and groundwater contamination by polluting the seepage water and the soil. This is an important environmental issue that cannot be ignored. This chapter introduces the contaminant transport equation and the water flow equation in the upper unsaturated soil, the latter of which is known as the Richards equation. The numerical and analytical models of contaminant transport in soils are then introduced, followed by the introduction of linear system theory in soil transport modeling. Examples and case studies are presented to demonstrate the integrated use of GIS and the simple index model for modeling contaminant transport in upper soils. Soil contamination eventually leads to groundwater contamination. This chapter finally introduces the numerical and analytical models for simulation of contaminant transport in groundwater. By taking Beretania in southern Oahu Island, Hawaii as an example, this chapter presents the application of SUTRA model for studying salinity intrusion into the island’s groundwater.
