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根据UNSODA数据库的土壤颗粒大小分布和水分特征曲线资料,运用差异演化算法和分形模型,计算土壤的体积分形维数,并对分形维数与土壤体积含水量、进气压力及土壤质地等相关属性的关系进行统计分析。结果表明:分形维数反映了土壤中黏粒、粉粒和砂粒的含量变化,可以作为评价土壤质地差异的一个指标;分形维数随土壤黏粒比例的增大而增大,随砂粒比例的增大而减小;没有考虑土壤残余含水量的Brooks-Corey模型更适合运用差异演化算法来优化土壤分形维数;相比其它的拟合方法,用差异演化算法估算的分形维数具有更高的精度。
According to the data of soil particle size distribution and water characteristic curve of UNSODA database, the differential evolution algorithm and fractal model were used to calculate the volume fractal dimension of soil, and the relationship between fractal dimension and soil volumetric water content, inlet pressure and soil texture The relationship between statistical analysis. The results show that the fractal dimension reflects the change of clay, silt and sand content in soil, which can be used as an index to evaluate the difference of soil texture. The fractal dimension increases with the increase of clay content, And Brooks-Corey model, which did not consider the residual water content of soil, was more suitable to use the differential evolution algorithm to optimize the soil fractal dimension. Compared with other fitting methods, the fractal dimension estimated by the differential evolution algorithm had higher The accuracy.