降雨条件下云南红土理化特性对坡面侵蚀的影响研究

发布时间：2019-01-08 08:33

【摘要】：针对不同初始状态的云南红土,在一定雨强、坡度、坡长条件下,研究红土理化特性对坡面侵蚀的影响。采用人工模拟降雨方法进行试验研究,运用Excel分析试验数据。结果表明:(1)红土颗粒组成中黏粒含量对降雨作用下的红土坡面侵蚀影响显著,当黏粒含量增加8.1%时,其侵蚀模数则减小25.8g/(m~2·h);(2)红土初始含水率偏离最优含水率越远,红土侵蚀模数越大。当红土初始含水率从接近最优含水率的24.6%增加到36.5%时,侵蚀模数从110.4g/(m~2·h)增加到121.3g/(m~2·h);(3)在初始干密度为1.0,1.1,1.2,1.3,1.4g/cm~3条件下,红土侵蚀模数呈先增大后减小的二次曲线变化趋势(R~2=0.927)。初始干密度在1.1~1.2g/cm~3之间,红土侵蚀模数存在极大值[126g/(m~2·h)];(4)降雨作用使坡面红土铁铝氧化物含量减少,接近坡脚处Fe_2O_3含量从初始状态的8.591%减小到8.143%,Al_2O_3含量从初始状态的22.242%减小到20.967%;而坡内红土铁铝氧化物含量则随深度增加,坡体中段坡内的Fe_2O_3含量增加0.407%,Al_2O_3含量增加0.861%。降雨作用改变了红土理化特性,而红土理化特性的变化会对红土坡面侵蚀产生显著影响。
[Abstract]:The effects of physical and chemical properties of red soil on slope erosion were studied under certain rainfall intensity, slope and slope length in Yunnan red soil under different initial conditions. The artificial simulated rainfall method was used to study the experiment and Excel was used to analyze the test data. The results are as follows: (1) the clay content in the composition of laterite particles has a significant effect on the erosion of laterite slope under rainfall. When the clay content increases 8.1, the erosion modulus decreases 25.8g/ (mt2 h);). (2) the further the initial moisture content of red soil deviates from the optimal water content, the larger the erosion modulus of red soil is. When the initial moisture content of red soil increased from 24.6% to 36.5% of the optimal moisture content, the erosion modulus increased from 110.4g/ (mt2h) to 121.3g/ (mt2 h);). (3) under the condition of initial dry density of 1.0 ~ 1.1g / cm ~ (-3), the erosion modulus of red soil increased first and then decreased (R _ (2 +) _ (0.927). The initial dry density is between 1.1~1.2g/cm~3 and the modulus of red soil erosion exists maximum value [126g/ (mt2h)]; (4) the content of iron-aluminum oxide in laterite was decreased by rainfall, and the content of Fe_2O_3 decreased from 8.591% in initial state to 8.143Al2O3 content in Al2O3 from 22.242% to 20.967. However, the content of iron and aluminum oxides in laterite increases with the depth of the slope, and the content of Fe_2O_3 in the middle of the slope increases by 0.407% and the content of Al _ 2O _ 3 increases by 0.861%. Rainfall changed the physical and chemical properties of red soil, and the change of soil physical and chemical properties had a significant effect on the erosion of red soil slope.
【作者单位】：昆明理工大学电力工程学院;
【基金】：国家自然科学基金项目(51269006,51168022,51568031) 云南省教育厅科学研究基金(2011Y354)
【分类号】：S157.1

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