Atlantic Coast water quality in Santa Catarina (Southern Brazil): multivariate analysis and influence of land use and occupation

Abstract

This study analyzed data from the quarterly analysis of water quality monitoring in the State of Santa Catarina (Southern Brazil) from the Qualiágua Program. The results of collections carried out in 2019–2021 of 23 analytical parameters in 40 municipalities that comprise the Santa Catarina State coastal slope are presented. The Principal Component Analysis (PCA) technique was applied to the analyzed parameters to verify those that refer to the same sources of contamination and the correlations between them. The data on land use and occupation of the hydrographic basins of each monitoring point were also analyzed complementarily, using data from MonitoraSC. The results showed that the parameters: electrical conductivity, total and dissolved solids and chloride concentration are responsible for most of the data variability, having more influence at monitoring points close to the ocean. On the other hand, nitrate and turbidity are influenced by soil management. Finally, total phosphorus, ammoniacal nitrogen and thermotolerant coliforms had a greater relationship with points that are influenced by urban areas. The PCA analysis was successfully used in establishing these relationships at the points analyzed along the coast in Santa Catarina State. The results obtained will help inspection and decision-making processes related to public policies for water uses in the State and can be used for other locations.