%0 Tesis de Doctorado %A Machado Sotomayor, Guillermo Edvin %E Di Gregorio, Salvatore %I Catanzaro / Universidad de la Calabria / 2015 %D 2016 %G eng %T Automatas celulares para la modelizaci?n y simulaci?n de sistemas complejos: lahares. Estudio de casos de lahares primarios y secundarios en Ecuador %U http://repositorio.educacionsuperior.gob.ec/handle/28000/2422 %X Lahars represent one of the most destructive natural disasters regarding the loss of human lives and property damage in their path. Lahars are very complex surface flows of two types: primary lahars originated directly from eruptive volcanic activity, and secondary lahars originated in post-eruptive events or quiescent periods. Lahars are a complex combination of many interrelated processes besides the process of surface flow: rainwater percolation in the soil (secondary lahars), volcanic stratum erosion, water inclusion and extrusion in lahar, ice melting and mixing with volcanic emissions (primary lahars). Evaluating the hazard posed by lahars constitutes a significant challenge within the framework of modeling and simulation of complex systems for reducing hazard in many, sometimes very populous, inhabited areas next some dangerous volcanoes. A variety of approaches has been taken to modeling the behaviors of lahars and the hazards posed to downstream communities: empirical models based on smart correlations of phenomenon observables, simple rheological and hydrological models and Partial Differential Equations (approximating numerical methods of fluid dynamics). Cellular Automata (CA) represent an alternative approach for modeling and simulating complex systems evolving on the base of local interactions of their elementary components. Lahars may be classified as such a type of phenomenon. Moreover, a CA modeling methodology has been developed for simulating surface flows. CA are a parallel computational paradigm for modeling complex systems by defining ?simple? laws at a local level that generate a global ?complex? evolution. The research, reported in this thesis, adopts a Multicomponent (or Macroscopic) Cellular Automata (MCA) approach that was applied to other complex surface flows. The model LLUNPIY has been developed in this frame, and successful simulations of real events were performed. The goal of this thesis has been to develop a CA model, LLUNPIY (Lahar modeling by Local rules based on an UNderlying PIck of Yoked processes, from the Kichwa word llunp?iy meaning flood), which is based on the CA semi-empirical approach to macroscopic phenomena of Di Gregorio and Serra, in order to simulate the complex dynamics of lahars, taking into account experience of models like SCIDDICA, SCIARA, PYR, VALANCA and SCAVATU. Before and during the development of the model, a comprehensive study was carried out on models not only for modeling complex macroscopic phenomena with Cellular Automata, but also two main models have been studied, which have previously modeled the lahars. LAHARZ is an empirical model, which computes the inundation area on the base of lahar volume and channel sections. TITAN2D model (for simulating granular, mud, debris flows and lahars) is based on physical Partial Differential Equations (PDE), related to the Coulombmixture theory. Both LAHARZ and TITAN2D did not account for all the processes of the previous cited three phases. An example is the erosion process. The erosion process does not exist in LAHARZ, because of the simplicity of the model. In the case of TITAN2D, it was necessary to omit the erosion process because the calculation times are not sustainable because of the complexity of the complete differential equations system. The MCA incremental method of modeling, applied in this research, permitted to LLUNPIY model to manage the erosion process and other ones with satisfactory results. This research considered real events of primary and secondary lahars to develop and validate the model. CA modeling and simulation of lahars needs a time-space correspondence, which may be explicitly established between the model and the real world to compare phenomenon development with simulation progress. To find sufficient data with an appropriate precision according to MCA methodology was not easy. Data about 1877 Cotopaxi primary lahar were found, analyzed, compared and interpreted. Analog study was performed with less effort for the more recent 2005 and 2008 Tungurahua secondary lahars. The candidate collected important data for developing the model directly on the field in the first person. The LLUNPIY model was validated through simulations of the three selected events: the 2005 and 2008 Tungurahua secondary lahars and afterward the 1877 Cotopaxi primary lahar. Results of the LLUNPIY simulations demonstrate that modeling choices, allowed by CA properties, permit to account for more processes (e.g., erosion process) that are not considered in other models. Therefore, LLUNPIY extends the potentiality of analysis and scenarios development in applications that needs computer simulations of real or conjectured lahar events.