Juliana Moccellin,Maria do Carmo Calijuri,Frederico Fábio Mauad, Escola de Engenharia de São Carlos - Universidade de São Paulo, Hidráulica e Saneamento, jumocc@gmail.com
ABSTRACT
Models are simplified representations of reality. An advantage of using mathematical models is that different scenarios can be simulated and the researcher can consider the worst possible situation. Since the creation of first water quality model, by Streeter and Phelps, several other models were elaborated and developed, introducing the nitrogen and phosphorous cycles, algae production and other components. All are elaborated to solve the several problems of water quality and they possess an objective in common, that is auxiliary managers of water resources on their decisions. The chosen model for this work was QUAL2K. It is applied in water quality simulation of streams and rivers. A simulation on Jacupiranguinha River was made, covering 24 km, which took into account mainly diffuse sources in rural and urban areas and domestic sewage. QUAL2K model was calibrated to dissolved oxygen and BOD. Simulations showed good agreement with the observed data. Scenarios have been suggested for visualization of possible future conditions of Jacupiranguinha River, which were targeted according to population growth. The scenarios have the ability to show how each variable can change the water quality. Scenarios of different treatment variables were evaluated and showed that treatment of domestic and industrial effluents is presented as a key element in maintaining the quality of Jacupiranguinha River.
Key-words: water quality models, QUAL2K, Jacupiranguinha River.