OBJECTIVE:

To investigate the spatiotemporal variation and multivariate correlations among hydrochemical indicators in the Maguari-Açu River basin, located in the Metropolitan Region of Belém, Pará State, Brazil.

MATERIALS AND METHODS:

Six sampling campaigns were carried out at 11 sites throughout the hydrological cycle. Analyses included in situ physicochemical parameters and quantification of metals by inductively coupled plasma optical emission spectrometry. Principal component analysis and hierarchical cluster analysis were applied.

RESULTS:

The data revealed wide variability in the analyzed parameters, influenced by seasonal factors and anthropogenic pressures such as sewage discharge and unregulated land use. Multivariate analyses identified three main clusters related to salinization, redox dynamics, and human activities.

CONCLUSION:

Water quality in the Maguari-Açu River basin is compromised in several stretches, mainly due to anthropogenic interference and climatic seasonality. The results highlight potential impacts on environmental health and the local population, emphasizing the need for continuous monitoring, management interventions, and public policies aimed at ensuring water security. This study provides technical evidence to support mitigation of environmental impacts and conservation of aquatic ecosystems, particularly in the context of climate change and the upcoming COP30 in Belém.