倒伏植被茎秆粗度对坡面水流特性的影响

为深入探索植被倒伏条件下水流结构的内在规律,开展植被茎秆直径对坡面流水流特性影响的试验研究。试验固定坡度为1. 0%,倒伏角度为20°,取茎秆直径为2 mm、3 mm、4 mm进行室内明渠流模拟试验。结果表明:在相同直径条件下,随水深增大,Darcy-Weisbach阻力系数逐渐增大,雷诺数呈线性增大,弗劳德数呈幂函数形式下降;在相同水深条件下,随茎秆直径增大,DarcyWeisbach阻力系数增大,雷诺数与弗劳德数随之而减小,且当茎秆直径每增加1 mm,阻力系数平均增大33. 76%,雷诺数平均减小2. 57%,弗劳德数平均减小8. 33%。

Effects of lodging vegetation stem diameter on overland runoff characteristics

In order to deeply explore the internal law of water flow structures under the condition of vegetation lodging, experimental research on the influence of vegetation stem diameter on the characteristics of overland flow was carried out. Indoor open channel flow simulation tests were performed with a fixed slope of 1. 0%, a lodging angle of 20°, stem diameters of 2mm, 3mm and 4mm. The results show that the resistance coefficient of Darcy-Weisbach increases gradually with the water depth under the same diameter, the Reynolds number increases linearly, while the Froude number decreases as a power function. Under the same water depth, with the increase of the stem diameter, Darcy-Weisbach resistance coefficient increases, Reynolds number and Froude number decreases respectively. Moreover, if the stem diameter is increased for every 1mm, Darcy-Weisbach resistance coefficient increases 33. 76%, Reynolds number and Froude number decreases 2. 57% and 8. 33% respectively in average.