草被覆盖下坡面—沟坡系统坡面流阻力变化特征试验研究  

Experimental study on runoff resistance of hilly slopegullied surface with grass coverage

作　　者：李勉[1] 姚文艺[1] 陈江南[1] 丁文峰[2] 

机构地区：[1]黄河水利科学研究院水利部黄河泥沙重点实验室,河南郑州450003 [2]长江科学院,湖北武汉430010

出　　处：《水利学报》2007年第1期112-119,共8页Journal of Hydraulic Engineering

基　　金：国家自然科学基金黄河联合基金重点项目(50239080)

摘　　要：本项研究旨在通过室内放水冲刷试验,揭示坡面—沟坡系统坡面不同草被覆盖面积比、不同空间配置、不同放水流量下坡面阻力的变化过程及特征。试验共涉及坡面—沟坡系统坡面5种草被覆盖面积比、3种空间配置和2种放水冲刷流量。结果表明:坡面—沟坡系统坡面流各段面平均曼宁糙率系数和平均阻力系数与放水流量关系密切,随流量的增大在有草被覆盖断面两系数呈减小趋势,在无草被覆盖断面呈增大趋势。有草覆盖面积大小对阻力影响较大,随面积比的增加阻力系数增大;坡面流阻力在整个坡面—沟坡系统中沿流程增加而下降。在有草覆盖条件下各断面径流平均曼宁糙率系数和平均阻力系数均呈增加趋势,无草坡面则变化不大。因此可得出结论认为草被覆盖和坡度对坡面流阻力大小起着决定性的影响。Grass coverage has great influence on the variation of overland flow resistance. The experiment on revealing the changeable process and characteristics of overland flow resistance for different percentages of grass coverage by area, different spatial distributions of grass on the slope and different water inflow rates in the hilly slope-gullied surface was carried out in laboratory. In the experiment five grass coverage percentages by area, three spatial distributions of grass and two water inflow rates were used. The results showed that the mean Manning roughness coefficient and mean Darcy-Weisbach hydraulic friction factor have close relationship with the flow rate. The coefficients decrease following the increase of flow rate if the slope surface covered with grass, but they increase in case the surface without grass coverage. The coverage ratio may significantly affect the friction and the flow friction reduces along the flow path. Under the condition of having grass coverage both the cross sectional Manning coefficient and mean friction coefficient tend to increase, whereas, they vary only a little on the slope surface with grass coverage. It may conclude that the grass coverage and slope have significant influence on runoff resistance of hilly slope-gullied surface.

关 键 词：坡面-沟坡系统 草被覆盖 坡面流 阻力特性 冲刷试验 

分 类 号：S157.2[农业科学—土壤学]