Lajeado Passo dos Índios em Chapecó/SC: qualidade da água e uso do solo nas áreas de nascentes

Abstract

Firstly, this work aims to evaluate the water quality by sources in the neighborhoods Boa Vista, Paraíso, São Pedro, Bom Pastor and Linha São Pedro A. These waterways belong to the basin of the Lageado Passos dos Índios that drains the east of the Chapecó municipality. Then, water samples were collected at eight points during September, October and November to identify the main pollutants and associated with land use in the study area. The following variables were measured: pH, Turbidity, Electrical Conductivity, BOD, temperature, nitrate, Total Phosphorus, Total Solids, Soluble Iron, Ammonia, Total Coliforms and Escherichia coli. The analysis results showed that the higher the surrounding occupation, the higher the levels of pollution of the waters. Water samples taken near the sources indicate lower than those of the samples collected which had the highest urban population concentration. It was found that urbanization contributes to environmental degradation study area in order there disorderly placement processes. The main environmental problems identified in the study area in the region were: inadequate land use, lack of riparian vegetation and the systematic eviction of urban effluents directly or indirectly in rivers. There are some differences in the types of land use in the study area. Near the springs vegetation is more preserved and there are fewer homes, but there is a cattle activity on the banks of waterways. Downstream there is a higher concentration of very close residences of watercourses and little or no vegetation on the banks, there are also shops, machine shops and the garage hall. At points where the density of residences is bigger, is the wastewater discharge directly into streams. By results of the collections there has been a rise in pollution levels in places where land use is higher. In the collections that were preceded by larger volumes of rainfall there was an increase in pollution levels, the soil entrainment and bank erosion caused by rain. Then, charts and tables were made to perform the comparison of the test results, where the land use contributes to increases pollution was established. The data of the samples obtained in the laboratory analysis were also compared with the maximum values allowed by the Federal Law Number 357 -CONAMA 2005, this comparison indicated that there is pollution by Total Coliform and tolerant term, organic matter, and chemical elements. Finally, to change this situation requires measures such as implementation of environmental protection programs, environmental education and awareness campaigns, and implementation of sewage collection network throughout the city