Índice de qualidade das águas superficiais nos rios Renato e Caiabi, afluentes do rio Teles Pires

Abstract

Resulting from urban and rural activities, water pollution is observed in most Brazilian rivers, with different levels of intensity. Water quality is one of the indicators used in decision-making and actions related to maintenance or change in land use and occupation, as well as in waste management. Thus, the objective of this work was to determine the water quality index (WQI) of the Renato and Caiabi rivers, in Mato Grosso. For the determination of the WQI, six expeditions were made to collect water samples, being chosen six sampling points in the main channel of Renato river, and another two points in the river's tributaries. For the river Caiabi, 5 water sample collections were carried out, with five sampling points along the main channel of the river. The results for the WQI showed that the waters in the basins are good and excellent quality. Despite these classifications for the WQI, it was observed that some parameters that make up the index did not comply with its classification, class II, defined by CONAMA Resolution 357/2005. The parameters that showed nonconformity, apparently are result from the use and occupation of land close to river channels, such as improvised housing and impacted springs, without protection.