Multi-fractal Characteristics Of Reconstructed Soil Particle In Opencast Coal Mine Dump In Loess Area

Reconstructed soil from opencast mine dump in loess area was a complex unitythat made up by human in different reconstruction technology. It is composed bydifferent soil particles with irregular shapes, and has self-similar structure. Thereconstructed good soil structure for vegetation growth is the core work of landreclamation. In order to better quantify the soil structure reconstructed in dump, thesoil particle size distribution from four kinds of soil reconstruction mode in ShanxiPingshuo ATB Opencast Coal Mine dump was analyzed using the soil multi-fractaltheory. Soil reconstruction modes included soil covered using loess with gravel, soilcovered using loess with coal gangue, covering the whole loess material, and soilcovered using loess with Liao Jiangtu. Generalized dimension spectrum D(q),multi-fractal singularity exponent α(q), multi-fractal spectrum function f(α(q)) andother multi-fractal parameters were calculated. Relationships between soil propertiesand fractal parameters and relationships among different fractal parameters wereanalyzed in this paper.The results indicate the following conclusions.(1) The particle distribution ofreconstructed soil had significant multi-fractal characteristics in opencast coal minedump in loess area. D(0), D(1), D(1)/D(0),Δα and Δf can reflect the non-uniformparticle size distribution characteristics from different perspectives.(2) There was asmaller range of soil particle size distribution, a higher degree of measurementconcentration, a lesser discretization extent, a lower non-uniformity of soil particlesize distribution in the soil reconstruction mode of covering the whole loess material,the function of the mode in changing soil particle size distribution was superior to themodes containing gangue and gravel. There were good correlations amongmulti-fractal parameters of reconstructed soil particles distribution. D(0),D(1)/D(0)and Δf (or D(0),D(1)/D(0)and Δα) can be simplified as three parameters toquantitatively express multi-fractal characterization of reconstructed soil particledistribution in opencast coal mine loess.(3) Soil multi-fractal parameters inreconstruction loess section0-90cm changed significantly, and soil thickness coveringloess should be more than90cm. Gangue and gravel have a certain impaction thedispersion degree of reconstruction soil particles distribution, and which should beabandoned in the soil layers below90cm to reduce its effect on soil particlescomposition and improve vegetation restoration.(4) soil physical properties wereimpacted by reconstruction mode; soil nutrient were influenced by eitherreconstruction mode or soil depth; soil available nutrient were impacted soil depth,but neither reconstruction mode nor soil depth could affect pH.(5) According to therelevance of multi-fractal parameters and soil properties, Δα is well respondent to soilbulk density, field capacity, EC, available P and available K; pH, organic matter, totalN and available N have a good correlation to Δf; soil gravel content and saturatedwater content and the parameter D(1)/D(0) had a good relativity.(6) Gravel in soilwould increase the number of soil macro pores and decrease soil water holdingcapacity. There’s an impact on soil physical, chemical, biological reconstructionprocess. Topsoil plays an irreplaceable role in soil reconstruction progress, as soil bulk density, pH and EC of topsoil were better than other depths of every profile inthe study.This study can provides a theoretical basis for land reclamation and quantitativeexpress of reconstruction soil quality in opencast coal mine dump of loess area.