Determination of the water quality index in two rural properties in the Municipality of Guatambu-SC/ Determinação do índice de qualidade da água em duas propriedades rurais no Município de Guatambu-SC

Abstract

Knowing the quality of water resources is fundamental to guarantee its different functions in the environment. In this sense, this study highlighted the relationship between land use and occupation with water quality, since the objective was to assess water quality in two rural properties in the municipality of Guatambu in the state of Santa Catarina, Brazil. Five points for analysis and their geographic coordinates were demarcated in each property using the Global Positioning System (GPS) and inserted into the Quantum GIS (QGIS) software for spatial assessment. For the water quality analysis of each point, the following parameters were determined: pH, electrical conductivity, dissolved oxygen, color, turbidity, alkalinity, chlorides and biochemical oxygen demand. According to these results, the Bascarán surface water quality index (SWQIB) was estimated. As demonstrated by the results, both properties presented an SWQIB ranging from “medium” to “good”. However, when comparing the points intended for human consumption with the Brazilian Decree 2,914 of December 2011, it was found that the color and turbidity parameters were in disagreement in some cases. However, these two parameters can easily vary. In addition, it was noted that points classified with SWQIB "good" have a better protection area when compared to points classified with SWQIB "medium".