摘要
通过室内放水冲刷试验,研究不同草被格局(随机格局、草方格、带状、斑块状及光滑玻璃对照)下的坡面流水力学特性变化。试验在8种流量(0.15,0.30,0.45,0.60,0.75,0.90,1.05,1.20 L/s)和3种坡度(3°,6°,9°)下进行。结果表明:(1)与光滑玻璃面相比,草被覆盖坡面可以雍高水位1.02~1.38倍,减缓流速6.52%~36.73%;随着流量和坡度的增大,流速呈幂函数递增(R^(2)>0.95)。(2)雷诺数与流量间存在显著的线性正相关关系(R^(2)>0.99),与坡度和草被格局无明显相关关系;草被覆盖可以有效降低坡面弗劳德数。(3)随流量和坡度的增大,草被覆盖下的坡面流型态从层流—缓流或急流过渡到紊流—急流。(4)随着流量的增大,坡面流阻力系数呈幂函数递减(R^(2)>0.86),坡度对坡面流阻力系数无显著影响(p>0.05)。(5)不同草被格局雍高水位的作用为随机格局>斑块状>草方格>带状,对流速的减缓作用为随机格局>带状>斑块状>草方格,坡面弗劳德数为斑块状>带状>草方格>随机格局,抗蚀能力为随机格局>草方格>带状>斑块状。
In order to study the changes of the hydraulic characteristics of overland flow,a series of laboratory flume simulation experiments were conducted on smooth and vegetated beds under three slope gradients,eight flow discharges and four vegetation spatial patterns.The results showed that:(1)The water level of grass covered slope was 1.02~1.38 times that of smooth glass slope,and the flow velocity was 6.52%~36.73%slower than that of glass covered slope.With the increase of flow discharge and slope gradients,the velocity increased with a power function(R^(2)>0.95).(2)There was a significant linear positive correlation between Reynolds number and discharge(R^(2)>0.99),but no significant correlation between Reynolds number and slope gradient and grass cover pattern.Grass cover effectively reduced Froude number on slope.(3)With the increase of discharges and slope gradients,the overland flow pattern of grass-covered slope changed from laminar—slow or rapid flow to turbulent—rapid flow.(4)With the increase of discharges,the overland flow resistance coefficient decreased with a power function(R^(2)>0.86).Slope gradient had no significant effect on resistance coefficient(p>0.05).(5)The effect of raising water level was random pattern>patch>grass square>belt.The effect of slowing down velocity was random pattern>belt>patch>grass square.Froude number on slope was patch>belt>grass square>random pattern.The ability to resist erosion was random pattern>grass square>belt>patch.
作者
薛梦华
马岚
刘京晶
张金阁
孙旭
王福星
张旖璇
XUE Menghua;MA Lan;LIU Jingjing;ZHANG Jin’ge;SUN Xu;WANG Fuxing;ZHANG Yixuan(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083;Haihe Basin Soil and Water Conservation Monitoring Center,Haihe River Water Conservancy Commission,MWR,Tianjin 300170)
出处
《水土保持学报》
CSCD
北大核心
2021年第3期23-29,共7页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(51779004,42077059)。
关键词
坡面流
放水冲刷
草被格局
水力学特性
overland flow
water flushing
grass pattern
hydrodynamics
