黄土坡面细沟水流阻力的试验研究  

Experimental Study of Rill Flow Resistance on Loess Hillslope

作　　者：申楠[1,2] 王占礼[3,2] 刘俊娥[1,2] 谭贞学 王莎[1,2] 焦念[1,2] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]西北农林科技大学水土保持研究所,陕西杨凌712100 [4]钦州市水土保持监测分站,广西钦州535000

出　　处：《水土保持通报》2012年第6期34-37,42,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"黄土坡面细沟侵蚀动力学过程组合小区试验研究"(40971172);国家自然科学基金项目"黄土坡面细沟侵蚀关键参数及其耦合关系试验研究"(41171227)

摘　　要：水流阻力是重要的水力学参数之一,阐明细沟水流阻力系数变化特征对于认识细沟水流水力学性质及细沟侵蚀动力学过程机理具有重要意义。采用具有定流量人工放水的组合小区模拟降雨试验方法,对黄土坡面细沟侵蚀过程中的水流阻力进行了试验研究。结果表明:(1)细沟水流阻力系数随径流历时的变化,在不同雨强条件下不断增加,增大趋势总体一致,产流15min后增速出现差异,可用指数方程很好地描述。(2)细沟水流阻力系数随径流历时的变化,在不同坡度条件下也不断增大,变化过程总体一致,产流15min后增速也出现差异,可用指数方程很好地描述,不同坡度下阻力系数差异较不同雨强下稍大。(3)细沟水流平均阻力系数随雨强增大而减小,可用对数方程进行描述;随坡度增大而增大,但增幅很小,可用指数方程描述;随雨强与坡度的变化可用二元指数方程描述。Water flow resistance is one of the important hydraulic parameters.Elucidating the variations of rill flow resistance coefficient is critical to understand the hydraulic properties of rill flow and the mechanisms of dynamic rill erosion process.The flow resistance involved in rill erosion processes on loess hillslope was studied by a multi-plot experiment under simulated rainfall with addition of steady in-flow through the tops of the plots.The results showed that rill flow resistance coefficients for different rainfall intensities showed a consistently increasing tendency increase with runoff duration.Fifteen minutes after the initiation of runoff,the increasing trend changed and could be well described by an exponential equation.The resistance coefficients for different slopes exhibited the exactly same trend.The average resistance coefficient of rill flow decreased with increasing rainfall intensity,which can be described by a logarithmic equation,while it increased slightly with increasing slope steepness,which can be described by an exponential equation.A dual exponential equation can be used to describe the variations of the average resistance coefficient with various rainfall intensity and slope steepness.

关 键 词：黄土坡面 细沟水流 水流阻力 阻力系数 

分 类 号：S157.1[农业科学—土壤学]