[关键词]
[摘要]
为探究植被的排列方式及坡度大小对坡面流弗劳德数Fr的影响,以期揭示坡面流弗劳德数Fr的内在规律。 利用人工模拟试验,系统研究了6个坡度、3种植物排列方向与水流方向呈不同走向角的条件下Fr与单位底面积的空间摩阻表面积K值的特征关系。在非淹没状态下,Fr与K值的关系为随K值的增大Fr呈现先减小后趋于平稳的趋势;Fr的取值随坡度的增大而增大;在一定的坡度范围内,同一坡度下,当Fr>1时,同一K值下,走向角越大对应的Fr值越小,当Fr<1时则相反;同一走向角下,在同一K值下,坡度越大对应的Fr就越大。结果表明坡度一定的条件下,坡面植被的排列方式不同,弗劳德数Fr的取值也不相同;坡度是影响Fr取值范围的重要因素之一。
[Key word]
[Abstract]
To explore the impact of vegetation arrangement and slope gradient on the overland flow Froude number Fr, in order to reveal the inherent law of overland flow Froude number Fr. [Method] Using artificial simulation tests, we systematically studied the relationship between Fr and K value, which is the friction surface area of a unit floor area, under different conditions including six slope gradients and three angles between the vegetation arrangement direction and water flow direction. [Results] In non-submerged flow, with the increase of K , Fr would decrease first and then tend to be steady, and the value of Fr would increase with the increase of slope gradient. Within a certain range of slope gradient, with the same gradient, when Fr>1, with the same K value, the bigger the direction angle, the smaller the Fr; when Fr<1, the situation was the other way around. With the same angle and the same K, the greater the gradient, the greater the corresponding Fr. [Conclusion] At a certain gradient, when the slope vegetation arrangement varies, the Froude number Fr value varies as well. The slope gradient is one of the important factors that influence Fr value range.
[中图分类号]
[基金项目]
国家自然科学基金项目(40971021;41471025);山东省自然科学基金项目(ZR2014DM004)