  We discuss the likely sources of turbulence in the ISM and explicitly
calculate the detailed grand source function for the conventional sources of
turbulence from supernovae, superbubbles, stellar winds and HII regions. We
find that the turbulent pumping due to the grand source function is broad band,
consequently expanding the inertial range of the cascade. We investigate the
general properties of the turbulent spectrum using a simple approach based on a
spectral transfer equation derived from the hydrodynamic Kovasznay
approximation. There are two major findings in this paper: I. The turbulent
pressure is calculated from the grand source function II. With the scale
dependent energy dissipation from a turbulent cascade the multi-phase medium
concept can be generalized to a more natural continuum description where
density and temperature are functions of scale. Approximate power-law behavior
is seen over a large dynamic range. We discuss some of the implications of
models for the ISM, particularly addressing the energy balance of the warm
neutral phase.
