黄土区露天煤矿排土场重构土壤孔隙分布的多重分形表征

发布时间：2018-07-04 16:50

本文选题：土地复垦 + 黄土区　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：土壤是一个复杂的多孔物质,疏松的土壤微粒所形成孔隙的大小,数目,几何形状以及分布都是极为复杂的。露天煤矿排土场土壤的孔隙结构在排土过程中由于受到大型机械压实而遭到破坏,因此重构一个适合于复垦植被生长的土壤孔隙结构是矿区土壤重构的基础。当前对于土壤孔隙结构的定量化表征是一个难题,以往研究中的土壤孔隙度、连通性等描述土壤孔隙的参数只能反映孔隙的部分特点,不能充分表征孔隙的复杂性质。为了更好的定量表征排土场重构土壤孔隙结构,分析排土和复垦对土壤孔隙结构的影响,本文采用现代化先进的高精度无损计算机断层扫描技术(CT)对山西省平朔矿区安太堡露天煤矿排土场平台全黄土覆盖的不同复垦年限(0年、20年、23年)以及原地貌的土壤进行分层扫描成像,引入土壤多重分形理论,对土壤孔隙分布的多重分形参数广义维数谱D(q)、多重分形奇异性指数α(q)以及多重分形谱函数f(α(q))等参数进行计算,并对不同分形参数之间的关系进行分析。通过研究发现:(1)用CT扫描和计算机图形软件相结合的方法可以准确地分析出排土场重构土壤孔隙的大小、数目等分布状况;(2)随着复垦年限的增加,复垦后土壤孔隙数量及孔隙度有较大改善,但仍未达到原地貌水平;(3)黄土区大型露天煤矿排土场重构土壤孔隙分布具有明显的多重分形特征,容量维D(0)、信息维D(1)、容量维数与信息熵维数的差值D(0)-D(1)、多重分形谱谱宽度Δα和Δf都能较好地从不同角度反映土壤孔隙分布的非均质特征;(4)复垦植被改善土壤孔隙的效果比较明显,复垦年限较长的土壤孔隙孔径的分布范围较宽、土壤孔隙分布测度集中、土壤孔隙变异程度大、孔径分布离散度较小,土壤多重分形的各指标都较好,而刚复垦还未进行植被恢复的土壤孔隙各项指标与原地貌比较差异明显;(5)重构土壤孔隙分布多重分形参数之间具有较好的相关性,可以简化选择D(0)、D(1)和Δα(或D(0)、ΔD和Δf)三个参数实现对黄土区重构土壤孔隙组成分布的定量表征。本研究可为黄土区露天煤矿排土场土地复垦以及重构土壤孔隙的定量化表征提供理论依据。
[Abstract]:Soil is a complex porous material. The size, number, geometry and distribution of pores formed by loose soil particles are extremely complex. The pore structure of soil in the dump of open pit coal mine is destroyed by large mechanical compaction in the process of dumping, so it is the basis of soil reconstruction to reconstruct a soil pore structure suitable for the growth of reclamation vegetation. At present, the quantitative characterization of soil pore structure is a difficult problem. The parameters such as soil porosity and connectivity in previous studies can only reflect some of the characteristics of the pore, but can not fully characterize the complex properties of the pore. In order to quantitatively characterize the pore structure of the soil in the dump, the effects of soil dump and reclamation on the pore structure of the soil were analyzed. In this paper, modern and advanced computerized tomography (CT) technique is used to reclaim different reclamation years (0, 20, 23 years) and original geomorphology of the flat loess covering the dump of Antaibao opencast coal mine in Pingshuo mining area, Shanxi Province. The soil is scanned by stratification, Based on soil multifractal theory, the generalized dimension spectrum D (q), multifractal singularity exponent 伪 (q) and multifractal spectrum function f (伪 (q) of soil pore distribution are calculated, and the relationships among different fractal parameters are analyzed. It is found that: (1) the size and number of soil pores can be accurately analyzed by using the method of CT scanning and computer graphics software; (2) with the increase of reclamation years, the size and number of soil pores can be accurately analyzed. After reclamation, the amount of soil porosity and porosity have been improved, but still not up to the original geomorphological level. (3) the distribution of soil pore in the reconstructed dump of large open pit coal mine in loess area has obvious multifractal characteristics. The difference between capacity dimension D (0), information dimension D (1), capacity dimension and information entropy dimension D (0) -D (1), multifractal spectrum width 螖伪 and 螖 f can better reflect the heterogeneous characteristics of soil pore distribution from different angles. The distribution range of pore size of soil with longer reclamation years is wider, the distribution of soil pore is concentrated, the variation degree of soil pore is large, the dispersion of pore size distribution is small, and all indexes of soil multifractal are better. However, the indexes of soil pores which have not been reclaimed by vegetation have significant differences with the original landforms. (5) there is a good correlation between the multifractal parameters of soil pore distribution and the reconstruction of soil pore distribution. It can be simplified to select D (0) D (1) and 螖伪 (or D (0), 螖 D and 螖 f) to characterize the distribution of pore composition of reconstructed soil in loess area. This study can provide theoretical basis for land reclamation in open pit dump and quantitative characterization of soil porosity in loess area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152

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