关键词: 稀疏天然植被, 风沙流, 输沙率

Abstract: Different types of sparse natural vegetation occurring in inland deserts and coastal dune-fields exert a certain influence on the blown sand activity and the development of aeolian sand landforms.However,in most cases their densities are insufficient to halt blown sand damages.To be effective in halting blown sand damages,the natural vegetation in excess of critical density is required.Simulation experiments on 10 plant-density levels of three types of plant species showed that when mean sand transporting quantity over moving sand surface decreases by 50% or so,the corresponding plant densities should be 6 individuals·m^-2 for the dense structure planted in semi-sphere,7 individuals·m^-2 for the funnel-shaped structure planted in top-dense and base-thin and 6~10 individuals·m^-2 for the linearly but bent elastic planted structure.Under different plant densities,the sand transporting quantity is directly positive proportional to the effective threshold wind velocity of sand grain:q=a(V_L-V_t)^b.

Key words: sparse natural vegetation, wind-sand current, sand-transporting quantity