黄土高原坡耕地水土保持措施效益评价试验研究 (Ⅰ)坡耕地水土保持措施对降雨入渗的影响

Experiment of the evaluation on benefits of soil and water conservation measures for slope land——Ⅰ.effect of soil and water conservation measures on the infiltration of rainfall ln slope land

本试验采用二次止交旋转回归组合试验设计方法,研究了地面坡度、平均降雨强度、暴雨雨型、水土保持措施和植被覆盖度对降雨入渗的影响,经分析,已得到两个描述与入渗结果有关的多维反应面回归方程。试验表明,坡耕地上实施水土保持措施对拦蓄降雨,增强入渗有显著效益。在供试的几种水土保持措施中,以水平梯田效果最佳,其次为隔坡梯田,再次为水平沟种植。在59～70min 时间内,降水80～90mm,基本上能全部就地拦蓄入渗,不发生径流。随着地面坡度和平均降雨强度的增大,发生径流或者蓄水超渗的起始时间提前;增加农田植被覆盖,将有利于拦蓄降雨,增大入渗,保护土壤;随着降雨雨型的变化,土壤入渗速率依时间变化曲线与常态有压入渗时迥然不同。

Using the method of quadratic cross regression with rotation,the benefits of retaining water and soil of soil and water conservation measures are experimented on slope land of the loess plateau with simulated rainfall.Two sets of multi-regression models about both rainfall retained and sediment,which are affected by five major factors including slope,intensity and type of rainfall,soil and water conservation measures and cover rate of vegetation,were obtained.Through analysis the effects of each factor on soil and water conservation and of each soil and wa^er conservation measures on the benefits of retaining water and soil were gotten.