Study On Self-Organized Critical Theory And Cellular Automata Model

Form the studies of dynamical behavior of sandpile-like systems the theory of self-organized ciritcal(SOC) was introduced. It could explain the behavior of a spatially extended system consisting of a great amount of elements which interact only at a very short distance. Sand-pile is a deceptively simple system serves as a paradigm for self-organized criticality and cellular automata model is technical method.In this paper the different phenomena and statistical results were present by means of large-scale sand-pile experiment on a slop. The traditional cellular automata model were rebuilt to explain these phenomena. The cellular automata model was used to simulate the slope erosion. Meanwhile the research of parallel computation of large-scale sandpile model was carried on.The main work and conclusions were as follows:1. On the basis of the former experiments, uniform and non-uniform sandpile of single slope experiments were done. From the different tests we find the non-uniform system is divided into three phases according to the non-uniform coefficient. The system doesn't present SOC phenomena when φ <2.85 , while 2.85≤φ<5.0 it shows SOC and φ≥5.0 it doesn't show again.2. We found that the uniform sand didn't present SOC and the non-uniform system showed SOC in our experiments. We made a qualitative explain previously but didn't carry on the quantitative work. In this paper the difference in geometry size of non-uniform sand system is regarded as the diversity in movement friction.A cellular automata (CA) model that can describe the non-uniform property and embody the non-uniform coefficient is designed, i.e., the value of induced by friction is introduced as a token of different roughness of the sand pile surface. Adjusting the value of energy dissipation and the radius, experiments with different non-uniform coefficients and different scales can be simulated. By comparison of the simulation results are similar to those obtained from the sand-pile experiment, it is found that they are similar and the organization principle is concerned with the robustness and the sensitivity of system. It is proved that occurrence of self-organized criticality (SOC) relates with scale effect and organization principle.