Modeling Multifractal Features of Soil Particle Size Distributions with Kolmogorov Fragmentation Algorithms

摘要

We have developed a new type of fragmentation algorithm that was inspired by a theoretical question raised by A.N. Kolmogorov—and still unanswered after 60 yr—regarding the characteristics of fragment size distributions when the size of the fragments, r beta, exhibits a power-law dependence on the size of the original material, r, with 0 ≤ beta ≤ 1. Our fragmentation algorithm uses beta and N (which denotes the number of particles produced in the fragmentation) as input parameters and was used for various simulations performed with N values of 2, 3, and 4 and beta values from 0 to 1. Simulations with beta = 0 resulted in lognormal distributions according to the Kolmogorov–Smirnov goodness-of-fit test at a confidence level of 95%. On the other hand, simulations with fractional values of beta > 0 gave highly heterogeneous distributions exhibiting multifractal characteristics. Rényi dimensions (Dq ) and Holder exponents [α(q)] at q = 0 and 1 were defined with coefficients of determination R 2 >0.95 in 78.3% of samples. The resulting α(0), box dimension D 0, and entropy dimension D 1 = α(1) values spanned the ranges 0.55 to 1.82, 0.52 to 1, and 0.48 to 0.94, respectively, and were thus suggestive of a multifractal nature in the simulated fragment size distributions. The multifractal characteristics of the simulated distributions were consistent with similar analyses performed on actual soil particle size distributions. These results suggest that the new algorithm can be useful for modelingnatural fragmentation processes.