Particle size distributions of some soils from the Umbria Region (Italy): Fractal analysis and numerical modelling

Application of principles of fractal geometry has had a strong influence on the understanding of many geological processes. One of the research fields which has benefited of the development of fractal methods is soil science. In this field fractal geometry techniques, mainly applied to the study of Particle Size Distributions (PSD), contributed to shed new light on the complex dynamics involved in soil forming processes. In this contribution we present new data of PSD of a number of soil samples from the Umbria Region (Italy). Particle size distributions are analysed by applying fractal geometry methods and results indicate that they display a fractal behaviour. In addition, two fractal scaling domains are identified, characterizing different ranges of particle sizes. To understand the basic mechanisms responsible for the production of fractal features observed in studied soil samples, numerical models based on computer automata are presented. It is shown that the numerical simulations are in good conceptual agreement with natural data and give the opportunity to explain the basic features observed in the PSD of studied soil samples.