Influência do uso e ocupação do solo na qualidade da água na bacia hidrográfica do Lajeado São José

Abstract

Anthropogenic activities, forms of land use and occupation in hydrographic basins, reflect on water quality, a resource with increasing demand. Therefore, the monitoring of water bodies, especially those destined for urban supply, becomes fundamental for the diagnosis of quality and the elaboration of actions aimed at protecting water sources. In this context, the present study aimed to verify the influence of land use and occupation on the water quality of the Lajeado São José hydrographic basin, which supplies the municipalities of Cordilheira Alta-SC and Chapecó-SC, and compare the results with the framework established by CONAMA Resolution 357/05. Five points along the basin with distinct occupation characteristics were analyzed. The samples were collected in two periods (dry and rainy) to evaluate the influence of climate on quality parameters. It was found that only the turbidity and BOD parameters were influenced by the rainy season with results above the limit established for Class 2 water bodies in the points with urban contribution 2 in the municipality of Chapecó. Thermotolerant coliforms showed concentrations above the limit established at point P2 in both collection campaigns, and exceeded the resolution limits at points P4 and P5 in the rainy season.