  Application of nonlinearity continuation method to numerical solution of
steady-state groundwater flow in variably saturated conditions is presented. In
order to solve the system of nonlinear equations obtained by finite volume
discretization of steady-state Richards equation, a series of problems with
increasing nonlinearity are solved using the Newton method. This approach is
compared to pseudo-transient method on several test cases, including real site
problems and involving parallel computations.
