A diffusion equation with a functional drift (generalized Smoluchowski equation) has been derived from the clannish random walk (nonlinear discrete master equation) for both probability density and velocity fields, in case of 1D. A relation between Burgers and generalized Smoluchowski equations as well as between concentration and velocity fields, has been discussed.

PACS numbers: 05.40.Fb, 05.10.Gg