Analytical expressions are derived for the mass-transport velocity produced by progressive water waves in the boundary layer over a rippled bed. The effect of bed roughness is found to be to increase the mass-transport velocity, except for very long waves where the velocity may be decreased....
Sleath, J. F.. 1974. "Mass transport over a rough bed." Journal of Marine Research 32, (1). https://elischolar.library.yale.edu/journal_of_marine_research/1274