Qualidade da água na Bacia do rio Pirapó, no trecho entre sua nascente e a foz do rio Bandeirantes

Abstract

With the process of urbanization around rivers and nearby, a series of environmental impacts has been influencing the water bodies. In this way, cities that depend on their rivers for development reduce the quality of their waters, which suffer from considerable human activities. The present study aimed to evaluate the water quality in the Pirapó River Basin, Paraná, Brazil. Water samples were collected at 14 points along the basin, in the stretch between the sources, in the municipality of Apucarana, next to Colorado, where the Rio Bandeirantes ends its course in the Pirapó River. Most of the analyzed parameters presented values according to the legislation for water resources. Exception to this pattern was observed for the electrical conductivity that was high in some environments, especially in tributaries, and the PH with reduced values in three of the points studied. For the Trophic State Index, the values were slightly variable, however, presenting a high degree of trophic (eutrophic). Regarding the Water Quality Index, the results show that most of the points in both periods (drought and rain) are within the range of quality considered reasonable or good, and are generally better in tributaries, especially in the Dourados stream, which indicated an index of quality superior to the others. The results suggest a tendency of smaller values in the region of greater urban influence, near the city of Maringá, mainly in the rainy season, whereas in the dry season the lowest values of Water Quality Index were verified in the region of the headwaters, in the municipality of Apucarana. From the perspective of the results found, it was not evidenced that the tributaries surveyed in the Maringá city are polluting sources of the Pirapó River. For this reason, in the context of this research, it can’t be said that the tributaries surveyed receive loads of untreated sewage pollutants. However, even if there were no evidence of pollutant loads in these tributaries, it would be important to adopt management and conservation tactics, as well as environmental education initiatives, in order to sensitize the population of the Basin region about the importance of resource conservation natural resources, especially where the streams merge and contrast with the cities, is that interventions are necessary: a set of public policies aimed at environmental preservation, among them public policies in the area of sanitation, that could establish programs capable of consolidating perennial recovery and as a whole, setting goals that would result in effective improvements for the waters of the Basin.