摘要:Methodologies that use fuzzy logic, one of the artificial intelligence tools, is being increasingly used in the treatment of uncertainties and inherent subjectivities of environmental problems. This study proposes the creation of a new water quality index, the Fuzzy Water Quality Index (INQA) thru a facilitative interface, the fuzzy inference system. This new index is then compared to the ones already calculated by several existent methodologies. This new methodology is validated using the monitoring analysis of the Pardo river, Ribeirão Preto region, São Paulo, Brazil, disclosed by Companhia de Tecnologia de Saneamento Ambiental de São Paulo (CETESB) and carried out from 2004 to 2006.