  The natural convection of incompressible fluid in a porous medium causes for
some boundary conditions a strong non-uniqueness in the form of a continuous
family of steady states. We are interested in the situation when these boundary
conditions are violated. The resulting destruction of the family of steady
states is studied via computer experiments based on a mimetic finite-difference
approach. Convection in a rectangular enclosure is considered under different
perturbations of boundary conditions (heat sources, infiltration). Two scenario
of the family of equilibria are found: the transformation to a limit cycle and
the formation of isolated convective patterns.
