Gravel covering reduces the exposed surface area directly, increases the surface roughness height and weakens the wind strength in the near-surface region, especially below the gravel height. Current researches on the flow over gravel-covered surface are mainly through wind tunnel experiments. Reynolds stress equation model (RSM) is used to simulate the turbulent flow over surfaces covered with repeated transverse rod roughness and staggered arrays of cubic roughness elements respectively in this paper, the...