Avaliação do Índice de Qualidade da Água (IQA) de pontos selecionados do Ribeirão Taquara e Cambé em Londrina - PR

Abstract

The great technological leap which started in the seventeenth century with the Industrial Revolution that brought the mechanization of production systems generating negative impacts on the environment. Water degradation is a type of man-induced disturbance that deserves attention. Water bodies should be monitored since they can be affected by polluting activities. Techniques of mapping and evaluation of pollution of water sources are emerging to this end. This research aimed to analyze the water quality in three points of the watersheds of the Cambé and Taquara riverbanks located in the municipality of Londrina in the interior of Paraná. The evaluation of the use and occupation of the soil in the sub-basins of contribution to the points was correlated with the Water Quality Index obtained for each point. Soil use and occupation maps were constructed based on parameters analyzed as water temperature, pH, electrical conductivity, turbidity and percentage of dissolved oxygen, thermtolerants coliforms (TtC), ammoniacal nitrogen, Total Kjeldahl Nitrogen (TKN), total phosphorus, Biochemical Oxygen Demand (BOD) and Total Solids. It can be observed that the stretch of the Cambé river presented the highest percentage of its covered area by the urbanized spot that of the Taquara stream which in turn is under greater influence of agriculture, pastures and soil exposed by fallow or newly planted culture. According to the IQA proposed by Cetesb (2013), the water quality resulted in classificanting as reasonable all the points sampled in both streams. However, it was chosen to analyze each variable individually. It was not found a pattern of variation of the analyzed parameters related to the level of urbanization of each one of the streams as other studies have been able to establish. Then, it was possible to conclude that it is necessary to increase the number of samples and periodicity of collections in order to improve the accuracy of results, the standardization of results and the identification of failures of collections and analyzes. In addition, it might improves the perception of the variations to the over time. Finally, the inclusion of other parameters such as nitrogenous series, toxic substances and metals, oils and greases could offer more significant results for water quality.