  We study AGN line driven disc winds using time-dependent radiation
hydrodynamics. The key criterion for determining wind launching is the coupling
strength of the UV radiation field via the spectral lines of the gas. The
strength of these lines in turn relies crucially on the gas ionization state,
determined by the local X-ray intensity. We consider a suite of models where
the central ionizing radiation is affected by scattering, absorption and
re-emission by the intervening gas. In a pure attenuation model, the disc
launches an episodic wind, as previous studies have shown. Including scattering
or re-emission tends to weaken the wind, lowering the mass flux and outflow
velocity and if sufficiently dominant, suppressing the outflow entirely.
However, the exponential nature of radiative attenuation means only a modest,
factor of a few, increase in the absorption cross section can overcome the wind
suppression due to scattering and re-emission. We find mass outflow rates of
$\sim 20\%$ or more of the assumed inflow rate through the disk, indicating
that radiation driven winds may significantly alter the structure of the
accretion flow. The winds also supply a large, time-varying column of material
above the nominal constant disk scale height, which will determine the geometry
of reprocessed emission from the central source. Our results suggest the need
for accurate photoionization modeling, radiation transport as well as accretion
disc physics, to study their effects on the AGN disc winds
