黄土坡面细沟水流流速试验研究  

Experimental Study of Rill Flow Velocity on Loess Hillslope

作　　者：焦念[1,2] 王占礼[3,2] 刘俊娥[1,2] 谭贞学 王莎[1,2] 申楠[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5期117-121,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：流速是最基本、最重要的水流水力学参数之一,阐明细沟水流流速变化的特征对于揭示坡面细沟侵蚀动力学过程机理具有重要作用。采用具有定流量人工放水的组合小区模拟降雨试验方法,对黄土坡面细沟水流流速进行了试验研究。结果表明:(1)细沟径流流速随径流历时的变化过程在不同雨强下不断递减,可用指数方程很好地描述,递减速率在产流后6min内较大,以后减小,各雨强下递减速率基本分别一致;(2)细沟径流流速随径流历时的变化过程在不同坡度下也不断减小,可用指数方程很好地描述,各坡度下变化趋势一致,整个径流过程中减小速率也基本一致;(3)细沟水流平均流速随雨强增大而增大,可用对数方程很好地描述;随坡度增大而增大,可用幂函数方程很好地描述;随雨强及坡度的变化可用二元对数方程描述。Flow velocity is one of the most basic and important hydraulic parameters.Clarifying the variation of rill flow velocity is of importance to reveal the mechanisms of dynamic rill erosion processes.Rill flow velocity on loess hillslope is studied through a multi-plot experiment under simulated rainfall with the addition of a steady in-flow at the top of the multi-plot system.The main findings are as follows：（1） Rill flow velocities for different rainfall intensities decrease with runoff duration,which can be well described by an exponential equation.The decrements are great 6 min after runoff generation and then decline.The tendencies are basically consistent for the decrements at different intensities.（2） Rill flow velocities for different slopes also decrease with runoff duration,which can be described by an exponential equation.The tendencies for the decrements on different slopes are consistent.The decrements are basically consistent during the whole runoff process.（3） The mean flow velocity increases with increased rainfall intensity,which can be well described by a logarithmic equation,and increases with increased slope steepness,which can be well described by a power equation.A dual logarithmic equation can be used to describe the variation of the mean flow velocity with rainfall intensity and slope.

关 键 词：黄土坡面 细沟水流 流速 组合小区 

分 类 号：S157.1[农业科学—土壤学]