A numerical model for an unsaturated flow problem by using the finite
element method is established in order to simulate liquid moisture flo
w in an unsaturated zone with homogeneous soil and deep subsurface wat
er, and with different initial and boundary conditions. For infiltrati
on or evaporation problems, a traditional method usually yields oscill
atory non-physics profiles. However, nonoscillatory solutions are obta
ined and non-physics solutions for these problems are evaded by using
the mass-lumped finite element method. Moreover, the kind of boundary
condition is handled very well.