坡面不同土地利用类型土壤抗剪强度影响因素分析

发布时间：2018-04-23 10:31

本文选题：内摩擦角 + 黏聚力　；参考：《水土保持学报》2017年01期

【摘要】：通过野外调查与室内试验相结合的方法,选取不同坡度(10°,15°,20°)的针阔混交林、灌木林、园地、坡耕地、荒地5种土地利用类型,观测土壤抗剪强度指标、含水率、容重、干密度、总孔隙度、有机质、土壤团聚体MWD值(干筛和湿筛),运用模糊贴近度法和逐步回归分析法分析影响不同土地利用类型土壤抗剪强度的因素。结果表明:相同土地利用类型土壤黏聚力随着坡度的增加先增大后减小;在针阔混交林中,团聚体湿筛MWD值与土壤黏聚力的贴近度最大,在荒地中则是有机质,而在其他3个土地利用类型中,容重与干密度对土壤黏聚力的贴近度较大;在针阔混交林、灌木林、荒地中,4种贴近度计算影响其土壤内摩擦角较大的因素为总孔隙度,而容重和干密度是影响园地和坡耕地土壤内摩擦角的重要因子;在针阔混交林中,建立基于干密度和容重的土壤抗剪强度方程(R2=0.865);在坡耕地中,建立基于干密度、容重和团聚体干筛MWD值的土壤抗剪强度预测模型(R2=0.964);在灌木林、园地、荒地中,对土壤抗剪强度影响显著的因子分别为干密度、团聚体干筛MWD值、容重。
[Abstract]:Through the method of field investigation and indoor experiment, five types of land use were selected, such as coniferous and broad-leaved mixed forest, shrub forest, garden land, sloping farmland and barren land with different slopes of 10 掳~ 15 掳~ 20 掳). The indexes of soil shear strength, moisture content, bulk density and dry density were observed. Total porosity, organic matter, MWD value of soil aggregates (dry sieve and wet sieve), the factors affecting soil shear strength of different land use types were analyzed by fuzzy closeness method and stepwise regression analysis. The results showed that the soil cohesion of the same land use type firstly increased and then decreased with the increase of slope, and in coniferous and broad-leaved mixed forest, the MWD value of aggregate wet sieve was the most close to the soil cohesion, and in the wasteland it was organic matter. In the other three land use types, the closeness of bulk density and dry density to soil cohesion was greater, and the total porosity was the main factor affecting the soil friction angle in coniferous and broad-leaved mixed forest, shrub and wasteland. But bulk density and dry density are the important factors that influence the angle of internal friction between garden land and sloping farmland; in coniferous and broad-leaved mixed forest, the equation of soil shear strength based on dry density and bulk density is established; in sloping farmland, the equation of soil shear strength based on dry density is established; and in sloping farmland, the equation based on dry density is established. The prediction model of soil shear strength based on bulk density and MWD value of aggregate dry sieve was 0.9640.In shrub, garden and wasteland, the significant factors affecting soil shear strength were dry density, MWD value of aggregate dry sieve and bulk density.
【作者单位】：沈阳农业大学水利学院;
【基金】：辽宁省自然基金(201102193)
【分类号】：S157

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