Spatial patterns of water quality in Xingu River Basin (Amazonia) prior to the Belo Monte dam impoundment/Padrões espaciais de qualidade de água na Bacia do Rio Xingu (Amazônia) anteriores a barragem de Belo Monte

• Published in: Brazilian journal of biology 2015-08, Vol.75 (3), p.34
• Main Authors: Rodrigues-Filho, J L, Abe, D S, Gatti-Junior, P, Medeiros, G R, Degani, R M, Blanco, F P, Faria, C R L, Campanelli, L, Soares, F S, Sidagis-Galli, C V, Teixeira-Silva, V, Tundisi, J E M, Matsmura-Tundisi, T, Tundisi, J G
• Format: Article
• Language: English
• Subjects: Construction; Creeks & streams; Floods; Hydrology; Rivers; Sediments; Studies; Surface water; Water quality
• ISSN: 1519-6984; 1678-4375
• DOI: 10.1590/1519-6984.02914BM

The aim of this study was to analyze the water quality in the Xingu River and its tributaries focusing on spatial patterns by the use of multivariate statistical techniques, identifying which water quality parameters were more important for the environmental changes in the watershed. Data sampling were carried out during two complete hydrological cycles in twenty-five sampling stations. The data of twenty seven variables were analyzed by Spearman's correlation coefficients, cluster analysis (CA), and principal component analysis (PCA). The results showed a high auto-correlation between variables. These variables were removed from multivariate analyzes because they provided redundant information about the environment. The CA resulted in the formation of six clusters, which were clearly observed in the PCA and were characterized by different water quality. The statistical results allowed to identify a high spatial variation in the water quality, which were related to specific features of the environment, different uses, influences of anthropogenic activities and geochemical characteristics of the drained basins.