This facilitates defining a free surface along a set of nodes. Soil Properties Hydraulic conductivity and volumetric water content as a function of pore-water pressure. The pore-water pressure dependent soil properties of hydraulic conductivity and volumetric water content are supported. Anisotropic and heterogeneous soil properties. Anisotropy refers to the directional dependence of material properties.
Heterogeneity refers to the spatial dependence of material properties.
For example, a system with different soil strata is a heterogeneous system. Isoparametric quadrilateral and triangular finite elements. Isoparameteric quadrilateral and triangular finite elements are implemented and each may have various numbers of optional secondary nodes to provide higher order interpolation of nodal values within the element. Infinite elements can be used at the boundaries of the problem domain that are for practical purposes unbounded. An example of an unbounded problem is radial flow to a well.