  We have modelled ultracompact HII regions (UCHIIR) in terms of steady
subsonic ionized flows in a clumpy medium. Mass loss from neutral clumps allows
the regions to be long-lived. We examine the form of global flows for different
dependences of the volume mass injection rate, $\dot{q}$, on radius and Mach
number, and describe the solutions in detail. We find that three observed
UCHIIR morphologies are reproduced with these models. Mach number independent
flows that include a radial variation can give centre- brightened core--halo
morphologies. Mach number dependent flows reproduce naturally the uniform
UCHIIR morphology. In a hybrid model, including subsonic and supersonic flows,
we allow a supersonic wind to shock in the ionized region. The ionized subsonic
gas has a high density and so dominates the emission. The shell produced has a
velocity structure very different from that of fully supersonic models. Several
morphologies of spherical UCHIIR can be understood in terms of these various
models; however, kinematic data are crucial as a discriminant between them.
