Aplicação da teoria fuzzy em modelos de transporte de massa para o cálculo do risco na concessão de outorga para lançamento de efluentes em rios

Abstract

This research developed a methodology, based on application of fuzzy theory in the pollutant transport models, to study the fuzzy risk of contamination, in awarding grants for discharge of effluents into rivers. In such way, the differential equations of the transport model are transformed into fuzzy differential equations, so that, the field of concentrations, represented by the mathematical model is transformed into fields of concentration membership functions. The study makes use of parameters defined in the law to establish the class of the river, so that, it calculates, for each type of release, the risk and its assimilative capacity of the river to receive effluents. For the solution of the mathematical model the finite difference method was used, with implicit scheme on order to get the difference equation. For the accomplishment of the simulations a computational program, in FORTRAN language, was developed, that gave support in the obtaining of the results for the most several proposed sceneries. The results have shown that the fuzzy theory can become a safe alternative to help control pollution of rivers in general, providing, in such way, subsidies for resources management.