不同风沙土壤颗粒的分形特征

Fractal Dimension of Particle Size for Different Aeolian Sandy Soils

应用土壤颗粒的重量与粒径分布原理来描述了古尔班通古特沙漠地风沙土壤颗粒的分形特征。通过对10种样品颗粒的机械组成进行分析,分别计算出了它们的分形维数(D=2.3237～2.9347),并分析了其与流动风沙土、半固定风沙土和固定风沙土之间的关系。分析结果表明,风沙土壤结构具有明显的分形特征,其粒径分布分形维数为2～3。土粒表面分形维数与2～0.2mm间的土粒含量存在显著的负相关;而与0.02～0.002mm和<0.002mm的颗粒含量存在显著的正相关,表现为随着土壤质地从流动风沙土、半固定风沙土到固定风沙土的变化,其土粒表面的平均分形维数呈依次增高。土粒表面分形维数与三种典型风沙土壤有机质含量为极显著正相关,而与其硬度为显著负相关。

Numerous studies have shown that soil particle size and weight distribution are fractals, which are generally described with fractal geometry. Ten sampling soils from Aeolian sandy soil in Kurbantunggut desert were analyzed to calculate fractal dimensions. The results showed that the fractal dimensions ranged from 2.3237 to 2.9347 and the sandy soil structure had clear fractal scaling. The range of soil PSD （particle size distribution） of fractal dimensions behavior was strictly limited to 2〈D〈3. Statistic analysis indicated that fractal dimensions were in highly significant negative correlation with content of particle size between 0.2mm to 2mm, and in very significant positive correlation with content of particle size less 0.02mm. Average fractal dimensions of soil particle surface were increasing along with soil texture from floating sandy soil to semi-immobile soil, and to immobile soil in respectively. Fractal dimensions were in highly significant positive correlation with content of organic matter of typical 3 sandy soils, and in highly significant negative correlation with rigidity of sandy soils.