Estudo de planícies de inundação através da análise dos parâmetros hidráulicos do canal principal e sua influência na avaliação do risco fuzzy de enchentes

• Ano de defesa: 2006
• Autor(a) principal: Andrade, Carla Freitas de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Engenharia hidráulica; Sistemas difusos; Modelagem matemática; Rios
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/16353

In order to analyze flood plains in natural channels, subject to the propagation of a flood wave, formulated a mathematical model based on the equations of hydrodynamics, together with the fuzzy theory. The model is able to assess, on the basis of hydraulic and hydrologic parameters of the basin, the behavior of the control variables relevant to the flow. The model is also able to evaluate the fuzzy risk for such areas susceptible to flooding during heavy rains. For the solution of partial differential equations contained in the model, we used the method of finite differences, and to the solution of algebraic equations resulting nonlinear, was used with the Iterative Method of Newton-Raphson. A computer program QUARIGUA (Quantitative Analysis of Flood Risk in Urban Rivers), coded in FORTRAN 90 language, and developed for this research, was used to perform the simulations. The computer program QUARIGUA was organized in a modular fashion, with two main modules, namely the deterministic module, where the depth of the results of the flow and channel flow is calculated as discrete values, and the fuzzy module, based on the theory fuzzy risk, where the depth of the results of the flow and channel flow are calculated as membership functions. To evaluate the behavior of the control variables, various scenarios for the main channel, a bowl of fictitious flood, as well as the waves of full, were considered and different simulations were performed using the computer program QUARIGUA. The introduction of fuzzy logic in the hydrodynamic model, for calculating the membership functions related to the control variables, provides a suitable and readily effective procedure for the analysis of risk fields in a full wave propagation process and hence also provides a more consistent risk assessment of areas near the banks of natural channels. We were also carried out some specific simulations for analysis of flood risk behavior, and warranty, depending on the hydraulic and hydrologic characteristics of the channel, evaluating thus how certain changes in the roughness coefficient, or the channel slope, for example, may affect the behavior of the hazard function. The results show that the process of spreading a flood wave, as well as the behavior of risk functions and assurance, are highly influenced by the hydraulic and hydrologic parameters of the channel. Moreover, the results also show that the proposed model is a consistent alternative procedure for the assessment of flood risk, and therefore provides important information for analysis and planning of risk areas of employment actions.