Hydrogeochemistry variability in the Amazon Estuary waters

Abstract

This study aim to evaluate the water quality of the Guamá river, the Guajará bay and Furo Grande river through statistical methods of multivariate analysis, presenting the results of pH, dissolved oxygen, electrical conductivity and ion concentrations (Cl- , Na+, NO3 - and NH4 ) collected during nine campaigns that occurred in 2013 and 2014 in the municipalities of Belém and Barcarena, PA. The data were evaluated by principal component analysis (PCA) in order to investigate the spatial and seasonal variability of the area, which showed the ionic charge (explained for 51,10% of the total variance) and the consumption of oxygen for degradation of organic matter (explained for 17,9%) as determinants on water quality. However, the meteorological variables showed potential influence on the water quality parameters, especially with the PC1 parameters, just as well the atmospheric temperature that presented positive correlation strong with electrical conductivity (0,8), Cl- (0,82) and Na+ (0,81), and other part of the explanation for the variability of water quality parameters is related to anthropogenic pollution factors.