Soil physical parameters used to define the material properties in FEMWATER were determined from saturated hydraulic conductivity and moisture characteristic data for samples collected at the site.
A summary of the material properties, including the van Genuchten (1980) parameters used to define the shape of the moisture characteristic curves used in the FEMWATER simulations, is given in Table 2.
Removal of water by evapotranspiration from the groundwater table, particularly water extraction by plant roots at depth, is difficult to model explicitly by FEMWATER. Rather, evapotranspiration from the surface was simulated using a variable water flux boundary condition at the mesh boundary by using the difference between daily rainfall and calculated evapotranspiration.
The material properties required for SWACROP are the same as those required for FEMWATER, which are shown in Table 2.
The FEMWATER simulation for the existing drained situation is in good agreement with the observed groundwater elevation data.
All the water management options simulated using FEMWATER and SMASS were effective in reducing the oxidation of pyrite in the sulfidic soil relative to the existing over-drained situation.