摘要
选取活跃冲沟、半活跃冲沟和稳定冲沟3类典型发育的冲沟,探明不同活跃程度冲沟的侵蚀分异情况。结果表明:(1)不同活跃程度冲沟的容重、砂粒含量大致表现为活跃冲沟>半活跃冲沟>稳定冲沟;土体总孔隙度、田间持水率、粘粒含量、粉粒含量和有机质含量则呈相反趋势。(2)土体的平均内摩擦角φ随着冲沟发育程度的增加而增大,平均粘聚力C随着冲沟发育程度的增加而降低。(3)活跃冲沟容重、总孔隙度与土体抗剪强度呈较好的线性拟合关系;半活跃冲沟的土体抗剪强度与相关理化性质无明显线性关系;稳定冲沟中,有机质、粘粒和粉粒与土体抗剪强度呈线性正相关,与砂粒含量无明显线性关系。不同活跃程度冲沟的土体抗剪强度大致表现随容重、有机质的增高而增强,随总孔隙度的增大而减小,与田间持水率呈现先增加后减小的趋势。(4)主成分分析中,田间持水率和土体的机械组成是影响活跃冲沟抗剪强度的重要因子;田间持水率、土体机械组成和有机质是影响半活跃冲沟的重要因子;容重、机械组成和有机质是影响稳定冲沟土体抗剪强度的重要因子。
Different active gullies made different erosion degree.Its objective was to determine the impact of different active degree type of gully on soil shear strength（cohesion Cand angle of internal frictionφ）and related physical-chemical properties.Three different active degree type of gullies refer to the active gully,semi-active gully and stable gully.The results indicated that：（1）The soil bulk density and sand content in active gully were the highest,which in stable gully was lowest.On the contrary,the soil total porosity,field moisture capacity,clay content,silt content and organic matter content in active gully were the lowest,whereas they were highest in stable gully.The above mentioned physical-chemical properties in semi-active gully were somewhere between in active gully and stable gully.（2）With the increasing of gully active degree,the cohesion Cshowed a trend of decreasing,the frictionφshowed an opposite trend.（3）Both the soil bulk density and total porosity,had displayed a good linear relationship with soil shear strength in active gully.However,between the soil physical-chemical properties and the soil shear strength had little relationship,without overt linear relationship in semi-active gully.All of the soil organic matter content,clay content and silt content had displayed well linear correlation with soil shear strength except the sand content which had little related to soil shear strength in stable gully.It was found that the soil shear strength increasing with the soil bulk densityand organic matter content but decreasing with the increasing of total porosity,while increases firstly and then decreases with the field moisture capacity in different active degree type of gullies.（4）In the principal component analysis,both the field moisture capacity and soil mechanical composition were the key factors to the soil shear strength in active gully.Meanwhile,the organic matter content with two factors appeals mentioned were the key factors to the soil shear strength in semi-active gully.Furthermore,either the soil bulk density,soil mechanical composition or the organic matter content was an important parameter to the soil shear strength in stable gully.
出处
《水土保持学报》
CSCD
北大核心
2014年第6期124-129,160,共7页
Journal of Soil and Water Conservation
基金
中国科学院水利部成都山地灾害与环境研究所"青年百人团队"项目(SDSQB-2011-01)
中国科学院"西部之光"重点项目(Y4R2060060)
四川省应用基础研究计划项目(2014JY0067)
国家人力资源与社会保障部留学人员科技活动择优项目(2013)
