Modelagem da qualidade da água na bacia hidrográfica do Rio Piracicaba (MG)

Abstract

This paper aims to apply a model of water quality, the Sistema de Apoio à Decisão/Instituto de Pesquisas Hidráulicas (SAD‑IPH), in the Piracicaba River basin. The quality parameters were modeled biochemical oxygen demand (BOD), dissolved oxygen (DO), total phosphorus, nitrogen and thermotolerant coliforms. The flow data were obtained through the application of the hydrological model Modelo de Grandes Bacias/IPH (MGB‑IPH). The quality model was calibrated using data from stations monitoring the water quality of the Instituto Mineiro de Gestão das Águas (IGAM). The curves of BOD, DO and total phosphorus showed good adherence to data from monitoring campaigns. The parameters organic nitrogen, ammonia, nitrite, nitrate, and coliforms were underestimated by the model. Most streams have the quality of its waters compatible with Class 4. Current concentrations are well above what would be ideal for the basin, as its current framework is in Class 2.