漳州平原变性土粒径分布分形维数特征

 分形是许多自然事物和现象的客观特征之一。根据不同地形及土地利用/土地覆盖，从漳州平原不同地域分别采集22个0~60cm土层土壤样品，测定土壤各粒径质量分数，结果说明变性土土壤颗粒具有一定的分形特性。在此基础上，论述了漳州平原变性土粒径分布分形维数的变化特征以及土壤粒径分布分形维数与土壤性状间的关系。结果表明，漳州平原22个土壤样品粒径分布分形维数介于2.756~3.002之间，在垂直方向上，土壤粒径分布分形维数具有随着土层深度增加而增大的变异规律。通过回归分析发现，土壤粒径分布分形维数与各粒级颗粒质量分数明显呈线性关系，正负相关性以粒径r=0.1mm为界，即其分形维数与r>0.1mm的颗粒质量分数负相关，与r<0.1mm的颗粒质量分数正相关。土壤粒径分布分形维数随着植被覆盖度的增大而增加，并且土壤粒径分布分形维数随地形发生变化，表现为坡下>平地>坡上。

Fractal Dimension of Vertisol's Particle Size Distribution in Zhangzhou Plain

The fractal dimension is an objective characteristic of many natural phenomena and things. This paper shows that the vertisol's particle-size distribution has the fractal characteristic. In terms of the different terrain and land use / land coverage, 22 soil samples from different profiles (0~20cm, 20~40cm, 40~60cm) were collected from different regions in Zhangzhou Plain. The variations of the fractal dimension of vertisol’s particle-size distribution in Zhangzhou Plain and the relationship between the fractal dimensions and the vertisol's properties were investigated. It is shown that the fractal dimension of the soil particle-size distribution (0~40cm) ranges from 2.756 to 3.002 for the 22 soil samples. The fractal dimension increases with the depth. In addition, the regression analysis indicates that the boundary between positive and negative correlations is 0.1mm. The fractal dimension of the soil particle-size distribution is negatively correlated with the amount of particles with diameter >0.1mm and positively correlated with the amount of particles with diameter <0.1mm. The fractal dimension increases with the increase of the grass cover ratio. Also, the fractal dimension varies with the terrain, among which the downslope has the highest dimension and the terrace has the lowest.