摘要
以风洞实验研究了通过干扰气流而影响土壤风蚀的植被之影响作用。在研究中，将植被的影响作用视为其本身特征参数的函数。全部研究分为两部分：首先探讨了植物特征对粗糙度或零风速平面位移高度的影响。其次研究了植被覆盖度对土壤风蚀率的影响，得出如下结论：（１）位移高度与植被覆盖度之间存在幂函数关系；（２）位移高度与植被作用区面积之间的关系为线性函数关系；（３）对于行状排列的植物而言，位移高度与植物排列方向和风向之夹角的平方根成正比；（４）在覆盖度相同的条件下，均匀散布的植物对土壤风蚀的减弱作用较簇状大；（５）土壤风蚀率随植被覆盖度的减少呈指数增加。
Vegetation,which influences soil erosion by wind through its interference with air flow,is studied here,with repect to its contributing role in wind ercaqion.Taking that vegetation'seffects on wind erosion is a function of its characteristics,this paper deals with the influences ofvegetation density,vegetated area and arrangement on wind ercaqion by means of wind tunnel.The whole research falls into two categories.First,the relationships between vegetation charac-teristics and roughness length or displacement height(d)are studied,with the following results:(1)There exists power relationshp between vegetation coverage ratio and displacementheight;(2)The relationship between vegetated area and displacement height can be expressed bylinear function.(3)Displacement height is proportional to the square root of the angle betweenwind direction and arrangement direction of alined vegetation.(4).Given the same coverage,evenly scattered vegetations have more influence on wind erosion than the clustered ones.Then the relationship between vegetation coverage ratio and wind erosion rate are studied.The result is that wind erosion rate increases exponentially with the derease of vegetation cover-age ratio.
基金
国家"八五"科技攻关项目资助
