滨岸带植物对水流结构影响的试验研究

Experimental Study on Effects of Littoral Plant on Water Flow Structure

以滨岸带植物为例,针对河道断面形式与植被分布影响河道水流结构、进而影响河流生态功能和河岸稳定等问题,通过种植3种高度模拟植物的梯形断面渠道的12组次水槽试验,分析了梯形生态渠道的沿程水面线、沿程流速及植物带中断面横向与中垂线流速分布、等效糙率。结果表明,植物带前壅水水位随植物高度增加而增大、植物带末端出现水位降低和流速升高区域、植物带断面中垂线流速分布呈大"S"型分布,流速梯度反转值位置随植物高度的增加而升高;断面横向流速对称分布,主槽流速大于边坡区流速,最大流速发生于主槽与边坡交界区。

The shape of river section and vegetation distribution has impact on flow structure, which influences the river ecological function and bank stability. Taking the riparian zone plants for an example, 12 groups of flume experi- meres are used to simulate plant trapezoidal channel with three height plants. And then it analyzes the water surface line, profile velocity, perpendicular bisector velocity and transverse section velocity distribution in vegetation zone and the e- quivalent roughness. The results show that the backwater level before vegetation zone is increasing with the plant grows; there is water [eve[ falling and velocity increasing in plants bottom zone; the perpendicular bisector ve｜oeity distribution appears large S-type distribution; with the plant height increasing, the reversal value position of velocity gradient increa- ses; the distribution of section transverse velocity is symmetric; the main channel area velocity is larger than that of slope area; the maximum velocity of vegetation zone occurs in interactive zone between main channel and slope area.