Study On Fractal Features Of Soil Particle Under Different Land Use Types In Karst Mountain

Soil is composed of different size particles with irregular and the self-similar structure of porous media, the fractal characteristics of fractal dimension describes the fractal structure of the soil that reflects the soil structure and properties. Therefore, the thesis mainly selects the soil profile of southeast karst region of cultivated land and abandoned land in Chongqing as the object of study, Malvern laser particle size analyzers distribution data gets the soil particle size, the fractal model calculates of the fractal dimension number of soil particles body, explores the fractal dimension the relationship between the number and soil grain size, and the two surface soil sample analyzes multifractal as an example.Quantitative describes of the impact of agricultural activities on soil structure and texture of the situation, in order to study deep soil degradation mechanism of typical karst ecologically fragile areas, restoration of the ecological environment provides scientific theory and technical support. There are the main conclusions:(1) Volume fraction of arable’s soil clay is greater than the abandoned land, the calculated results show that volume fractal dimension D value of the cultivated’s soil particle is greater than the abandoned land. The correlation analysis showed that through the two sections of the fractal dimension and soil grain size percentage of soil particle volume fraction:It is significant positive correlation of the percentage both D value of soil particles’s volume fractal dimension and soil clay (<0.002mm), the higher the volume fraction of clay, the finer the soil texture; soil particle volume fractal dimension D value greater; The two section is showing the same variation between D value of soil particle’s volume fractal dimension and volume fraction of soil clay. It indicates that the fractal dimension’s D value of volume fraction of soil particle is mainly affected by the impact of the clay volume fraction, while it can also become the indicators of soil texture differences.of quantitative assessment. (2) The calculation reflects uniformity index of the lu of uniformity degree of soil texture.The results show that uniform index lu of farmland profile is more than profile of abandoned land.lt shows that soil texture of the abandonment’s profile is more homogeneous than the arable’s profile. Correlation analysis results show that it is showing highly significant linear relationship both the the fractal dimension’s D value of abandoned soils and uniformity index lu.lt is suggested that volume fractal dimension’s D value of the soil particle in addition to the clay volume percentage contents of soil texture, the uniform degree of soil’s fractal features is also affected. D value of soil particle’s volume fractal dimension can reflect the uniformity degree of soil texture.(3) The results show that the two sections’distribution data of surface soil particle size using multi-level shape.The change of cultivated soil’s D(q) values of the parameters of the generalized dimension spectrum is greater than the abandoned land in the entire q range. It shows that the surface’s soil particles of irregular distribution of is greater than the abandoned land. Multifractal spectrum function f[a(q)]-a(q) is an asymmetric convex curve, the multifractal structure of the arable land is more obvious than the abandoned soils, the degree of the asymmetry is greater than the abandoned land. Farming activities in the upper soil makes the homogenization of soil particles.(4) The results show that the two profiles the composition analysis of the soil particles. Human farming activity can increase volume percentage of contents in the soil clay, it is obvious impact on the upper cultivated soil,it means small change that D value of soil fractal dimension. Deep soil is less affected by human activities,Both soil the argillic role and clay illuviation produce more fine-grained clay material, the changes are in non-uniform. It increases Naturally as the fractal dimension D value mainly reflects the changes both soil clay and big variations.Fractal dimension of soil can be used as one of the evaluations of regional farmland soil quality.