  The hydrodynamics and intrinsic properties of galactic-scale gaseous outflows
generated by violent starbursts are thoroughly discussed, taking into account
the hot gas chemical evolution and radiative cooling. It is shown that the
metallicity of superbubbles vary with time and can easily exceed the solar
value. Galactic superwinds driven by compact and powerful starbursts undergo
catastrophic cooling and establish a temperature distribution radically
different to that predicted by adiabatic solution. The observational properties
of supergalactic winds in X-rays and visible line regimes derived from our
calculations are compared with the standard adiabatic model predictions.
