云南昌宁“9.16”群发性浅层滑坡与植被关系研究

发布时间：2018-06-23 14:58

本文选题：植被发育斜坡 + 浅层滑坡　；参考：《昆明理工大学》2017年硕士论文

【摘要】：本文主要对云南省昌宁县“9.16”群发性浅层滑坡与植被类型的关系进行研究,旨在进一步认识山区流域环境下不同植被类型(草本、灌丛、乔本)对滑坡孕育的作用,探讨不同植被类型对斜坡失稳的影响。主要通过滑坡现场调查与滑体特征参数测量,对区域内高植被覆盖率下的滑体特征进行分类分析,再对不同植被类型发育下滑体内的植被根系含量与土体物理指标进行测定,测定内容为不同深度下植被根系质量密度、土体天然密度、土体天然含水率、土体饱和含水率、土体比重、土体孔隙率、土体有机质含量、土体容重。分析不同植被类型滑体上各指标随土层深度变化的原因及其与植被根系深度间的关系。通过线性回归和偏相关性分析,探讨各指标与滑体侵蚀特征间的关系。结果表明:区域内草本植被的根系影响深度在0～30 cm,灌丛植被的根系影响深度在0～50 cm,乔本植被的根系影响深度在0～70 cm。研究成果对边坡治理与水土保持具有一定的指导意义。本文获得的主要结论如下:(1)相同条件下,不同植被类型发育的斜坡上,滑体特征呈现出明显的差异性。(2)植被根系会对根系范围内的土体物理指标产生影响,不同植被类型的根系在同一土层深度内对土体物理指标的影响存在显著差异。(3)植被根系、土体有机质含量、土体孔隙率对滑体侵蚀强度具有促进作用,而土体天然密度与土体容重对滑体侵蚀强度表现出抑制作用。植被发育斜坡土体内,相邻层间的土体物理指标差值最大值对应其根系含量减少速率最快的土层,在该深度范围内,滑体侵蚀深度与侵蚀强度与根系延伸深度有着紧密的联系。(4)降雨作用下植被“群根”的导流效果优于“独根”,导致浅层土体内降雨聚集,土体指标发生“突变”,引发植被发育斜坡失稳。(5)滑坡前数日内的长时间降雨及前夜的高强度降雨是本次滑坡的主要诱发因素,而区域内灌丛植被与乔本植被的高密度发育在较大程度上促进了本次滑坡的产生。
[Abstract]:This paper mainly studies the relationship between the "9.16" mass shallow landslides and vegetation types in Changning County, Yunnan province. The purpose of this study is to further understand the effect of different vegetation types (herbs, shrubs, joben) on landslide inoculation in the environment of mountain area, and to explore the effect of different vegetation types on slope instability. The characteristics of the sliding body under the high vegetation coverage rate in the region are classified and analyzed, and the content of the root system and the physical index of the soil are measured. The content is the root mass density, the natural density of the soil, the natural water content of the soil, and the saturated water content of the soil. The proportion of soil mass, soil porosity, soil organic matter content and soil bulk density. The relationship between the changes of each index on the slide body of different vegetation types and the depth of the vegetation root is analyzed. The relationship between the indexes and the erosion characteristics of the slide body is discussed by linear regression and partial correlation analysis. The results show that the herbaceous vegetation in the region is in the area. The root influence depth is 0~30 cm, the root influence depth of the shrub vegetation is 0~50 cm, the root influence depth of the jo based vegetation is 0~70 cm., which has certain guiding significance to the slope control and soil conservation. The main conclusions of this paper are as follows: (1) under the same condition, the slope of different vegetation types and the characteristics of the slide body There are obvious differences. (2) the roots of vegetation will affect the physical indexes of soil in the root range, and there are significant differences in the influence of the roots of different vegetation types on the soil physical indexes in the same soil depth. (3) the vegetation root, the content of soil organic matter and the porosity of the soil have a promoting effect on the erosion intensity of the soil. The natural density of body and the bulk density of soil have an inhibitory effect on the erosion strength of the slide body. The maximum value of the physical index difference between adjacent layers corresponds to the fastest soil layer in the adjacent layers. In this depth, the depth of the erosion of the slide body is closely related to the depth of the root extension. (4) Under the action of rainfall, the diversion effect of "group root" is better than that of "only one", which leads to the accumulation of rainfall in the shallow soil soil, and the soil index has "sudden change", which causes the slope instability of the vegetation development. (5) the long time rainfall in the first few days of the landslide and the high intensity rainfall in the previous night are the main inducing factors of this landslide, and the irrigated vegetation in the region and Qiao Ben are in the region. The high density development of vegetation has promoted the occurrence of the landslide to a large extent.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948

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