植被排列方式及坡度对坡面流Fr影响的试验研究

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。表明在非淹没状态下,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Fr1时,同一K值下,走向角越大对应的Fr值越小,当Fr1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。得出在坡度一定的条件下,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。

Impact of vegetation arrangement and slope gradient on the overland flow Froude number

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.