模拟降雨下枯落物调控坡面产流产沙过程及特征研究

发布时间：2018-05-07 11:43

本文选题：枯落物 + 模拟降雨　；参考：《水利学报》2017年03期

【摘要】：本研究采用模拟降雨实验的方法,研究了30、60和90 mm/h降雨强度下,5种枯落物覆盖坡面径流的水动力学特征,以期揭示枯落物覆盖条件对坡面产流产沙过程及其径流水动力学特征影响。研究结果表明:坡面平均产流率和产沙率随降雨强度增大而增大,随枯落物生物量增加而减小,并且与降雨强度和枯落物生物量之间均为指数函数关系;坡面流量-历时曲线稳定流量值主要受降雨强度的影响;产沙率-历时曲线稳定产沙率受降雨强度和枯落物生物量等多种因素的影响;枯落物覆盖对坡面径流水动力学特性有显著影响,相比于裸坡覆盖有50、100、150、200 g/m~2枯落物坡面径流平均流速相比裸坡减少率分别在17.7%、26.8%、37.9%、53.7%;雷诺数减少率分别在11.2%、18.7%、26.3%、33.4%左右;弗劳德数减少率在21.3%、30.3%、42.9%、61.2%左右,Darcy-Weisbach阻力系数增大了0.5~5.6倍;产沙率与Darcy-Weisbach阻力系数呈对数关系,与剪切力和径流功率呈线性关系,枯落物能显著增大径流临界剪切力和功率;产沙率(Dr)和各水动力学因子间有良好的相关关系,相关程度顺序为:RewVPFrft。
[Abstract]:In this study, the hydrodynamic characteristics of runoff with 5 litter cover on slope surface under rainfall intensity of 30 ~ 60 and 90 mm/h were studied by means of simulated rainfall experiment. In order to reveal the effect of litter cover condition on runoff and sediment yield and runoff hydrodynamic characteristics. The results show that the average runoff yield and sediment yield increase with the increase of rainfall intensity, and decrease with the increase of litter biomass, and are exponential functions with rainfall intensity and litter biomass. The steady flow value of slope flow-duration curve is mainly affected by rainfall intensity, and the stable sediment yield rate of sediment yield curve is affected by rainfall intensity and litter biomass, etc. Litter cover had a significant effect on hydrodynamic characteristics of runoff on slope surface. Compared with bare slope, the average runoff velocity of sloping slope with 50100150200 g/m~2 litter cover decreased by 17.7and 26.8cm, respectively, and the reduction rate of Reynolds number was about 37.4% compared with that of bare slope, and the reduction rate of Reynolds number was about 11.218.7% and 33.4%, respectively. The decrease rate of Froude number is about 61.2%, the resistance coefficient of Darcy-Weisbach increases by 0.55.6 times, the sediment yield is logarithmic with Darcy-Weisbach resistance coefficient, and it is linearly related with shear force and runoff power, and litter can increase the critical shear force and power of runoff significantly. There is a good correlation between sediment yield and hydrodynamic factors, and the order of correlation is: 1 RewVP Frft.
【作者单位】：北京林业大学教育部水土保持与荒漠化防治重点实验室;
【基金】：十二五林业生态科技工程项目(2015BAD07B0302)
【分类号】：S157.1

【参考文献】