CONSERVING EFFECTS OF ROUGH GRANULAR ELEMENTS ON ERODIBLE GROUND

The effects of rough granular elements on lightening wind erosion of ground were studied by considering the distribution of the friction stress exerted by the turbulent boundary layer on rough wall. It was recognized that the rough granular elements scattered on ground with a certain density (such as coarse sands, gravels, etc.) play two key roles in controlling wind erosion: increasing the ground coverage and reducing the wind friction stress on the exposed ground. Then a mathematical formula was presented by dimensional analysis, which describes dependence of the wind erosion rate on the wind speed above the boundary layer and the density of the rough elements. Finally the validity of the formula was confirmed by comparison of the calculated results with experimental data.