金沙江干热河谷区退化土壤结构的分形特征研究

分形理论是近年来兴起的一种新的研究工具。分析结果表明 :土壤粒径分布的分形维数能客观地反映退化土壤的结构状况和退化程度 ,可作为退化土壤结构评价的一项综合性定量指标。退化土壤的分形维数与土壤颗粒组成和微团聚体组成之间存在着明显的相关性。土壤中 <0 .0 0 1mm粘粒含量越高 ,>0 .2 5 mm团粒含量越低 ,则分形维数越高 ,结构性越差。对于同一土壤退化系列 ,分形维数越高 ,土壤退化越严重。

Study on Fractal Features of Soil Structure of Degraded Soil in Dry and Hot Valley Region of Jinsha River

The fractal theory,as a new study tool, is popular in recent years. Analysis indicated the fractal dimensions of soil particle distribution could objectively reflect the structure state and degradation degree of the degraded soil,so they can be used as a comprehensive quantitive index to evaluate the structure of the degraded soil. There are the significance and correlation between fractal dimensions of the degraded soil and the mechanical composition and microaggregate composition of the soil. Higher the content of <0.001 mm clay and lower that of >0.25 mm microaggregate,higher the fractal dimensions and worse the structure property of soil. To the same soil degradation series, higher the fractal dimension, more serious the soil degradation.