摘要
通过野外微小区原位观测试验,基于降雨过程中降雨的集中时段对2017—2021年34次侵蚀性降雨雨型进行划分,系统分析雨型变化对黄土坡面细沟间侵蚀的影响及坡度效应。结果表明:研究区以前期型降雨为主,占总场次的52%,中期型和后期型降雨各占24%。中期型降雨对总产流量的贡献(25.56%±3.83%)显著低于前期型(36.70%±2.07%)和后期型(37.74%±4.01%)(p<0.05)。不同雨型场均径流量依次为后期型>中期型>前期型,后期型和中期型降雨显著高于前期型。而降雨的场均产沙量则表现为后期型>前期型>中期型,且后期型降雨显著高于中期型(p<0.05)。雨型对细沟间侵蚀影响的坡度效应变化不明显,但随着坡度增大,后期型降雨的场均径流量和产沙量均大于前期型和中期型,说明后期型降雨的产流产沙对坡度变化相对较为敏感。次降雨径流量、坡度和降雨参数组合与次降雨产沙非线性拟合中,方程决定系数后期型(0.939~0.942)>中期型(0.776~0.845)>前期型(0.220~0.537),说明区分雨型模拟可提高模拟精度。
Through in situ observation experiment in the field micro-plots,the 34 erosive rainfall patterns from 2017—2021 were classified based on the concentrated periods of rainfall during the rainfall process,and the effects of rainfall pattern variation on the interrill erosion on loess slopes and slope effects were systematically analyzed.The results showed that the advanced rainfall pattern was dominant,accounting for 52%of the total rainfall,while the intermediate rainfall pattern and delayed rainfall pattern each accounted for 24%.The contribution of intermediate rainfall pattern to total runoff yield(25.56%±3.83%)was significantly lower than that of the advanced rainfall pattern(36.70%±2.07%)and delayed rainfall pattern(37.74%±4.01%)(p<0.05).The average runoff yield of different rainfall patterns was in the order of delayed rainfall pattern>intermediate rainfall pattern>the advanced rainfall pattern,and the delayed rainfall pattern and intermediate rainfall pattern was significantly higher than that of advanced rainfall pattern.The average sediment yield of different rainfall patterns was in the order of delayed rainfall pattern>advanced rainfall pattern>intermediate rainfall pattern.The rainfall of the delayed rainfall pattern was significantly higher than that of the intermediate rainfall pattern(p<0.05).The variation of slope effect of rainfall pattern on the effect of interrill erosion is not obvious,but with the increase of slope,the average runoff and sediment yield of delayed rainfall pattern were larger than that of advanced and intermediate rainfall pattern,indicating that the sediment yield of delayed rainfall pattern was relatively sensitive to the variation of slope.In the nonlinear fitting models of runoff,slope and rainfall parameter combination and sediment yield,the equation decision coefficients were delayed rainfall pattern(0.939~0.942)>the intermediate rainfall pattern(0.776~0.845)>the advanced rainfall pattern(0.220~0.537),indicating that the classification of rainfall pattern could improve model simulation accuracy.
作者
伍林
张风宝
申楠
李玄添
刘颖
何琪琳
杨明义
WU Lin;ZHANG Fengbao;SHEN Nan;LI Xuantian;LIU Ying;HE Qilin;YANG Mingyi(The Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100;University of Chinese Academy of Sciences,Beijing 100049;Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100)
出处
《水土保持学报》
CSCD
北大核心
2023年第4期31-37,46,共8页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(42177338,41877080,41830758)
陕西省林科院黄土高原生态修复创新团队项目(SXLK2020-03-02)。
关键词
微小区
雨型
细沟间侵蚀
黄土坡面
坡度
micro-plots
rainfall patterns
interrill erosion
loess slope
slope gradient
