不同植物对黄土边坡产流产沙与抗剪强度的影响  

Effects of Different Plants on Runoff and Sediment Yield and Shear Strength of Loess Slope

作　　者：何伟鹏 胡夏嵩[1] 刘昌义[1] 缪晓星 王延秀 付江涛 卢海静 邢光延 赵吉美 杨馥铖 刘亚斌 HE Weipeng;HU Xiasong;LIU Changyi;MIU Xiaoxing;WANG Yanxiu;FU Jiangtao;LU Haijing;XING Guangyan;ZHAO Jimei;YANG Fucheng;LIU Yabin(Department of Geological Engineering,Qinghai University,Xining 810016,China;Qinghai Soil and Water Conservation Research Center,Xining 810000,China;Academy of Agriculture and Forestry,Qinghai University,Xining 810016,China;College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学地质工程系,西宁810016 [2]青海省水土保持中心,西宁810000 [3]青海大学农林科学院,西宁810016 [4]青海大学农牧学院,西宁810016

出　　处：《水土保持研究》2023年第4期18-26,共9页Research of Soil and Water Conservation

基　　金：青海省自然科学基金(2020-ZJ-906);第二次青藏高原综合科学考察研究项目(2019QZKK0905)。

摘　　要：[目的]探讨不同草本植物对黄土边坡产流产沙与抗剪强度特征的影响,为进一步开展高寒干旱和半干旱地区,有效防治因降雨诱发水土流失、浅层滑坡等地质灾害,提供理论依据和实际指导。[方法]在西宁盆地长岭沟流域自建试验区,选取垂穗披碱草(Elymus nutans)、老芒麦(Elymus sibiricus)、细茎冰草(Agropyron trachycaulum)3种优势草本植物为试验供试种,开展原位人工模拟降雨试验与室内直剪试验,分析了模拟降雨条件下6种不同类型植物边坡坡面产流产沙及根—土复合体抗剪强度特征。[结果]在模拟降雨条件下,草本植物能显著抑制坡面产流产沙,阶梯形边坡相对直形边坡能显著降低坡面产流产沙,且随着草本生长期增加坡面产流产沙显著降低,生长期为2 a的种植垂穂披碱草阶梯形边坡坡面累积产沙量较垂穂披碱草直形边坡降幅为79.68%,生长期为1 a的种植垂穂披碱草阶梯形边坡平均产沙率较阶梯形未种植裸坡降低幅度最大为86.27%,表明种植垂穂披碱草阶梯形边坡有效抑制坡面的产流能力相对显著;进一步研究表明,降雨使边坡土体平均含水率增大,导致边坡浅层土体黏聚力降低;与直形边坡相比较,模拟降雨后阶梯形边坡黏聚力c值降低幅度较小,其中种植垂穂披碱草阶梯形边坡较降雨前降低幅度为19.25%,表明垂穂披碱草阶梯形边坡其增强边坡土体强度效果相对最显著。[结论]垂穗披碱草阶梯形边坡表现出相对更显著的抑制边坡水土流失和提高边坡浅层土体抗剪强度,起到增强边坡土体稳定性的作用。[Objective]The impact of different herbaceous species on sediment yields and shear strength of loess slope was investigated in order to provide theoretical basis and practical guidance for the further development of effective prevention and control of geological disasters such as soil erosion and shallow landslides caused by rainfall in alpine arid and semi-arid areas.[Methods]The Changlinggou Catchment located in Xining Basin was selected as the testing area,three indigenous predominant herbs(Elymus nutans,Elymus sibiricus and Agropyron trachycaulum)were taken as the testing species and artificial rainfall was conducted to quantify the impact of slope types and herb types on the yield rate of sediment and runoff,and the rooted soils of the vegetated slopes were sampled to compare the impact of precipitation on the shear strength of slope soil.[Results]Under artificial rainfall,herbaceous plants significantly reduced in productions of runoff and sediments on the slope.Compared with straight slope,terraced slope significantly reduced runoff and sediment production on the slope.With the increase of herbaceous growth period,runoff and sediment productions on the slope decreased significantly.Among them,the cumulative sediment yield of the terraced slope of E.nutans with 2-years growing period decreased by 79.68%compared with the straight slope,and the average sediment yield of the terraced slope of E.nutans with 1-year decreased by 86.27%compared with the terraced bare slope,indicating their excellent capacities for refraining the yields of sediments and runoff in terraced slopes.Moreover,the mean moisture content in slope soil increased under rainfall situation,which led to a decrease of soil cohesion.Compared with the straight slope,cohesion of terraced slope exhibited a slight decrease,especially in E.nutans terraced slope,which decreased by 19.25%,indicating its excellence in increasing soil cohesion.[Conclusion]E.nutans terraced slope can effectively inhibit soil and water losses and enhance the shear strength

关 键 词：黄土区 寒旱环境 植物边坡 产流产沙 抗剪强度 根—土复合体 

分 类 号：S157.1[农业科学—土壤学]