科尔沁沙地沙丘-草甸相间地土壤颗粒的分形特征

发布时间：2018-11-10 10:38

【摘要】：选择科尔沁沙地典型沙丘-草甸相间地为研究区,利用土壤颗粒的体积分形模型计算了研究区49个采样点土壤颗粒的分形维数,并建立了分形维数与土壤颗粒不同粒级间的相关关系,以探讨半干旱寒冷地区土壤颗粒的分形特征与土壤物理性质以及养分含量之间的关系。结果表明:(1)研究区土壤颗粒的分形维数为1.33~2.50,变幅较大,且呈现出自中部的草甸、农田地带向南、北方向的沙丘地带递减的趋势;土壤颗粒的体积分形维数依照流动沙丘-半流动半固定沙丘-固定沙丘-农田-草甸的顺序而递增。(2)土壤颗粒的分形维数与黏粒、粉粒含量显著正相关,与砂粒含量显著负相关,且表现出明显的对数关系。100μm是影响土壤颗粒分形维数变化的分界粒径,大于该粒径的颗粒含量越高,土壤颗粒的分形维数越小;反之越大。(3)分形维数与土壤养分含量相关显著,土壤颗粒的分形维数与电导率、pH值及有机质、全氮、全磷含量均显著正相关,但与全钾含量负相关。在分形维数大于2时,基本与土壤饱和含水率正相关、与干容重负相关。
[Abstract]:The fractal dimension of soil particles in 49 sampling sites was calculated by using the volume fractal model of soil particles in the typical sand dune-meadow interphase area of Horqin sandy land as the study area. The correlation between fractal dimension and different grain-size of soil particles was established to study the relationship between fractal characteristics of soil particles and soil physical properties and nutrient content in semi-arid and cold regions. The results showed that: (1) the fractal dimension of soil particles in the study area was 1.33 ~ 2.50, which showed a decreasing trend from the meadow in the middle, the farmland to the south and the sand dune to the north; The volume fractal dimension of soil particles increased according to the order of flow dunes, semi-flowing semi-fixed dunes, farmlands and meadows. (2) the fractal dimension of soil particles was positively correlated with the content of clay and silt particles. There is a significant negative correlation between sand content and sand content, and the logarithmic relationship is obvious. 100 渭 m is the boundary particle size that affects the change of fractal dimension of soil particle. The higher the particle content is, the smaller the fractal dimension of soil particle is. (3) the fractal dimension of soil particles was positively correlated with conductivity, pH value, organic matter, total nitrogen and total phosphorus content, but negatively correlated with total potassium content. When the fractal dimension is greater than 2, it has a positive correlation with soil saturated moisture content and a negative correlation with dry bulk density.
【作者单位】：内蒙古农业大学水利与土木建筑工程学院;
【基金】：国家自然科学基金项目(51139002;51479086) 教育部博士点基金项目(20111515110003);教育部创新团队发展计划项目(IRT13069) 内蒙古自治区草原英才产业创新创业人才团队内蒙古农业大学寒旱区水资源利用创新团队项目(NDTD2010-6)
【分类号】：S152.3

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