  We show that the well-known discrepancy between the radial dependence of the
Galactic cosmic ray (CR) nucleon distribution, as inferred most recently from
EGRET observations of diffuse gamma-rays above 100 MeV, and of the most likely
CR source distribution (supernova remnants, pulsars) can be explained purely by
PROPAGATION effects. Contrary to previous claims, we demonstrate that this is
possible, if the dynamical coupling between the escaping CRs and thermal plasma
is taken into account, and thus a self-consistent GALACTIC WIND calculation is
carried out. Given a dependence of the CR source distribution on Galactocentric
radius, r, our numerical wind solutions show that the CR outflow velocity,
V(r,z) depends both on r, and on vertical distance, z, at reference level z_C.
The latter is defined as the transition boundary from diffusion to advection
dominated CR transport and is therefore also a function of r. In fact, the CR
escape time averaged over particle energies decreases with increasing CR source
strength. Such an increase is counteracted by a reduced average CR residence
time in the gas disk. Therfore pronounced peaks in the radial source
distribution result in mild radial gamma-ray gradients at GeV energies, as it
has been observed. This effect is enhanced by anisotropic diffusion, assuming
different radial and vertical diffusion coefficients. We have calculated 2D
analytic solutions of the stationary diffusion-advection equation, including
anisotropic diffusion, for a given CR source distribution and a realistic
outflow velocity field V(r,z), inferred from self-consistent numerical Galactic
Wind simulations. At TeV energies the gamma-rays from the sources are expected
to dominate the observed "diffuse" flux from the disk. Its observation should
allow an empirical test of the theory presented.
