Abstract: In this paper,coupled equations between wind and saltating particles are presented for a stable wind blowing over an infinite plane bed and the equations are solved for examining the effects of moving sand and Magnus force on the effective roughness.The calculated results show that the effect of the moving sand in the fluid outside the region to which saltation is confined,is similar to that of solid roughness,and the effective roughness can be depicted as the quadratic function of the friction velocity of the wind.Magnus force has notable effects on the effective roughness,but it does not change the quadratic function relation between the effective roughness and the friction velocity of the wind.

Key words: the effective roughness, wind-blown sand movement, Magnus force