摘要
利用人工模拟降雨试验,定量研究了在90 mm/h降雨强度下20°陡坡面不同被覆条件下(80%,60%,40%,20%)苜蓿草地的产流产沙入渗变化规律,分析了草地侵蚀产沙的水力学参数特征。试验结果表明,不同草被覆盖条件下草地累积径流量和累积产沙量与降雨时间呈显著的幂函数关系,随着草地覆盖度的减小而增大。随着草被覆盖度的增加,坡面径流量呈减小的趋势,草地入渗率呈增加的趋势,草被坡面径流量和入渗率呈明显负线性相关。分析了不同草被覆盖条件下草地的坡面水流平均流速、水力半径、雷诺数、弗罗德数和阻力系数特征,从水力学角度揭示了不同覆盖度草地的拦沙效应。
Runoff, infiltration and hydraulic parameters characteristics of grassland was studied under different grass coverage （80%, 60%, 40%, 20%）with 20% slope gradient using simulated rainfall experiment of 90 mm/h rainfall intensity. The results showed that cumulative runoff and cumulative sediment yields of grassland had an obvious positive correlation with the decrease of grass coverage. With the increase of grass coverage, slope runoff showed a decrease trend, but infiltration rate kept an increase level. Slope runoff of grassland had an obvious negative relation with infiltration rate. Hydraulic parameters such as average flow velocity, hydraulic radius, Reynolds number, Froude number and Darcy-Weisbach coefficient were got. The function of reducing sediment under different grass coverage was analyzed based on hydraulic theory.
出处
《水土保持学报》
CSCD
北大核心
2009年第4期50-53,共4页
Journal of Soil and Water Conservation
基金
国家基础研究发展计划(2007CB407201)
黄河水利科学研究院科技发展基金(黄科发200806)
水利部黄河泥沙重点实验室基金(200905)
关键词
覆盖度
径流入渗
水力学参数
草地
grass coverage
runoff and infiltration
hydrodynamies parameters
grassland
