摘要
为了为黄土高原陡坡水蚀预报模型的建立提供科学依据,通过组合不同坡度(21°、24°、27°)、不同流量(6.5、8.5、10.5L/min)的陡坡室内放水冲刷试验,对坡面细沟侵蚀发生过程中的坡面流水动力学特性进行了研究。结果表明,在试验的坡度和流量范围内,坡面流的雷诺数Re在798～4620之间变化,且雷诺数Re变化幅度随冲刷历时的增大而增大。而坡面流弗劳德数Fr在整个试验过程中均大于1,表明坡面流处于急流范围。坡面流阻力系数f随雷诺数Re的增大而增大,其变化还受坡度的影响。坡面在径流冲刷侵蚀过程中,流速随冲刷时间的延长和冲刷形态的变化呈现出先减小后增大又减小的变化趋势。
In order to provide scientific basis for loess plateau water erosion forecast model, the hydrodynamic characteristics of runoff in the process of rill erosion were studied by using runoff scouring experiment under the different steep slope gradients（21 ° , 24° , 27° ） and the different flow discharges（6.5, 8.5, 10.5 L/min）. The results show that the Reynolds number of the slope flow varies between 798 and 4620 in the erosion process and their changes ranges increase with time. The Froude number of slope flow is larger than 1 in the whole experiments, which indicates that the slope flow belongs to the supercritical flow condition. Roughness coefficients of rills flow increases with the increase of Reynolds number and are easily affected by the slope gradient. During the scouring and erosion of runoff on slop, flow velocity increases first, then decreases and then decreases with the prolongation of scouting time and the variation of scouring patterns.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2008年第6期64-68,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家科技支撑项目(2006BAD09B02)
关键词
陡坡
细沟侵蚀
水动力学特征
steep slope
rill erosion
hydrodynamic characteristics
