Cellular automata modeling of environmental systems

Abstract

Flow and transport processes in unsaturated soil are analyzed through a simulation environment based on cellular automata (CA). The modeling proposed in this chapter represents an extension of the original computational paradigm of cellular automata, because it uses a macroscopic CA approach where local laws with a clear physical meaning govern interactions among automata. This CA structure, aimed at simulating a large-scale system, is based on functionalities capable of increasing its computational capacity, both in terms of working environment and in terms of the optimal number of processors available for parallel computing. Specifically, the performance of a three-dimensional unsaturated flow model has been verified comparing the results with reference multidimensional solutions taken from benchmarks in literature, showing a good agreement even in the cases where non-linearity is very marked. Furthermore, some analyses have been carried out considering quantization techniques aimed at transforming the CA model into an asynchronous structure. The use of these techniques in a three-dimensional benchmark allowed a considerable reduction in the number of local interactions among adjacent automata without changing the efficiency of the model, especially when simulations are characterized by scarce mass exchanges.