Wave transport along surfaces with random impedance

We study transport and diffusion of classical waves in two-dimensional diso rdered systems and in particular surface waves on a flat surface with rando mly fluctuating impedance. We derive from first principles a radiative tran sport equation for the angularly resolved energy density of the surface wav es. This equation accounts for multiple scattering of surface waves as well as for their decay because of leakage into volume waves. We analyze the de pendence of the scattering mean free path and of the decay rate on the powe r spectrum of fluctuations. We also consider the diffusion approximation of the surface radiative transport equation and calculate the angular distrib ution of the energy transmitted by a strip of random surface impedance.