半干旱草地土壤粒径分形维数及空间变异特征

本文以毛乌素沙区内半干旱草地土壤颗粒为研究对象,运用地质统计学方法分析土壤颗粒大小含量及其分形维数的空间变异性,认为分形维数与沙粒含量线性负相关,与粘黏粒含量线性正相关。土壤黏粉粒损失导致土壤沙化加剧,分形维数减少,说明分形维数可以反映土壤颗粒物质的损失状况及土壤沙质荒漠化的程度。在20m采样尺度上,各空间变量由随机因素引起的变异占总变异的比例较小,自相关引起的变异比例较大。以分形维数的空间变异性表示土壤质地的分布,不但方法简单且更经济实用。

Spatial variability of fractal dimension for soil particle in semi-arid grassland

In this paper,we had studied the spatial variability of the content of soil particle and fractal dimension for arid grassland in Maowusu desert.We considered that soil fractal dimension is a negative correlation with sand content,and positive correlation with proportion content of silt and clay.Decreasing in silt and clay can result in desertification and the decreasing in fractal dimension.So,soil fractal dimension can be considered to be one of quantitative indices for evaluating desertification.In the scale of 20 meters,the proportion of variability which is produced by stochastic factors is very little,the spatial variability of fractal dimension is complex and representative,and it is a very simple,economical and applied method in indicating distributing of soil texture.