草被格局对坡面土壤侵蚀特征的影响  

Effects of Different Components of Grass Pattern on Slope Soil Erosion Characteristics

作　　者：李佳辉 魏淑娥 刘程龙 张宽地[1,2] LI Jiahui;WEI Shue;LIU Chenglong;ZHANG Kuandi(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]西北农林科技大学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

出　　处：《水利与建筑工程学报》2023年第5期179-190,共12页Journal of Water Resources and Architectural Engineering

基　　金：中央高校基本科研业务费专项资金(2022HHZX003);国家自然科学基金(41877076,52179079)。

摘　　要：为揭示草被格局对坡面土壤侵蚀特征的影响,采用模拟降雨试验的方法,对60 mm/h、90 mm/h和120 mm/h降雨强度下,6个草被格局坡面土壤侵蚀特征进行研究。结果表明:(1)坡面径流率和侵蚀率随降雨历时的变化均受降雨强度、草被格局以及草种垂直结构的共同影响;(2)与裸坡相比,不同草被格局植草坡面和留根坡面的减流效益分别为6.85%~65.34%和2.19%~23.15%,减沙效益分别为22.88%~70.46%和10.49%~50.61%,沿等高线带状格局的减流减沙效益最佳;(3)在不同降雨强度条件下,草本冠层对坡面径流率的削减占主导作用,根系对土壤侵蚀率的削减占主导作用;(4)土壤侵蚀率与水流剪切力和单位水流功率均呈良好的线性关系,草被覆盖能有效增大坡面临界水流剪切力和临界单位水流功率。坡面侵蚀率和各水动力学参数以及试验变量之间可近似呈线性关系,其相关顺序依次为:P_(u)>ω>Re>G_(d)>R_(i)>Fr>f>τ。研究结果可为黄土高原坡面侵蚀及生态环境治理提供理论依据。In order to reveal the effects of different components of grass pattern on soil erosion characteristics of slope,the soil erosion characteristics of six grass patterns under 60,90 and 120 mm/h rainfall intensity were tested by simulated rainfall experiment.The results are as follows.(1)The changes of slope runoff rate and erosion rate with rainfall duration were affected by rainfall intensity,grass pattern and vertical structure of grass species.(2)Compared with the bare slope,the runoff reduction benefits of the grassplanting slope and the rootremaining slope were 6.85%~65.34%and 2.19%~23.15%,respectively,and the sediment reduction benefits were 22.88%~70.46%and 10.49%~50.61%,respectively,and the crossslope band pattern has the best benefit of reducing flow and sediment.(3)Under different rainfall intensity conditions,herb canopy played a dominant role in the reduction of slope runoff rate,and roots played a dominant role in the reduction of soil erosion rate.(4)The soil erosion rate has a good linear relationship with the water flow shear force and the unit water flow power.The grass coverage can effectively increase the critical water flow shear force and the critical unit water flow power.There is a good correlation between the slope erosion rate and the hydrodynamic parameters and the experimental variables,and the correlation order is:P_(u)>ω>Re>G_(d)>R_(i)>Fr>f>τ.The research results can provide a theoretical basis for slope erosion and ecological environment management in the Loess Plateau.

关 键 词：草被格局 模拟降雨 植物垂直结构 土壤侵蚀 减流减沙 

分 类 号：S157.1[农业科学—土壤学] TV121.1[农业科学—农业基础科学]