草被覆盖度对坡面流水动力学参数的影响

坡面流流速U、径流深h、雷诺数Re、佛汝德数Fr、沿程阻力系数λ以及径流切应力(?)等水力要素是反映水动力学特征的主要指标。通过室外人工模拟冲刷试验,分析了草被覆盖度大小对坡面流水力学参数的影响及各水动力学参数沿坡面的分布特征。研究表明:坡面草被措施降低了坡面流流速和水深,且草被覆盖度越大,其削弱径流流速和降低径流水深的作用就越明显;坡面草被措施明显地降低了坡面流的紊动性,降低了坡面流速及其挟沙能力,且草被覆盖度越高,这种作用就越明显;草被措施增加了坡面入渗,降低了径流深,减弱了径流剪切力,从而起到了减蚀作用,且随着覆盖度的增加减蚀作用越加明显。

Influence of Grass Cover Degree to Hydrodynamic Parameters of Slope Water

The hydraulic elements of slope velocity U,runoff depth h,Reynolds number Re,Froude number Fr,coefficient of resistanceλand run- off tangential stress(?)are the main indexes of hydrodynamic characteristics.It analyzes the influence of grass cover degree of slope to slope hydrodynamic parameters and distribution characteristic of each hydrodynamic parameter along slopes through field artificial simulation scou- ring tests.The study shows that the measure of slope grass vegetation reduces slope velocity and water depth and the greater of grass cover the more obvious function on the reduction of velocity and runoff depth;the measure of slope grass cover remarkably reduces the turbulence of slope flow,slope velocity and its sediment carrying capacity and the higher of grass cover degree the more obvious function will be and;the measure of grass cover increases slope infiltration and reduces runoff depth,runoff shearing force and erosion and the function of erosion re- duction will be greater along with the increase of cover degree.