Trend analysis of water quality in some rivers with different degrees of development within the São Paulo State,Brazil |
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Authors: | Juliano Daniel Groppo Jorge Marcos de Moraes Carlos Eduardo Beduschi Abel Maia Genovez Luiz Antonio Martinelli |
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Affiliation: | 1. Laboratório de Ecologia Isotópica CENA‐USP, Av. Centenário, 303, CEP 13400‐970‐Piracicaba, SP, Brazil;2. Escola de Engenharia de Piracicaba, EEP‐FUMEP, Av. Monsenhor M. Salgot, 560, CEP 13414‐040, Piracicaba, SP, Brazil;3. Departamento de Recursos Hídricos—UNICAMP, CEP 13083‐970, Campinas, SP, Brazil |
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Abstract: | Time series of dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate, total phosphorus, chloride, ammonia and faecal coliforms (FC), monitored by CETESB (‘Companhia de Tecnologia de Saneamento Ambiental’), in the period from 1979 to 2001, were analysed in seven river basins located in the São Paulo State, one of the most developed regions in Brazil. The selected rivers, Piracicaba, Mogi‐Guaçu, Turvo Grande, Peixe, Aguapeí, São José dos Dourados and Alto Paranapanema have different degrees of development concerning industrial, agricultural and population growth. Trend analysis methodology was based on graphical exploratory analysis followed by confirmation through statistical tests. Results showed impoverishment of the water quality conditions in most of the studied basins, represented by the positive trends of the parameters (BOD, nitrogens, total phosphorus, clorate and FC) and negative trend of the parameter (DO). Among the analysed basins, the Piracicaba River is the most severely affected with higher variations in the magnitude followed by the basins of the Mogi‐Guaçu, Turvo Grande, Peixe and Aguapeí Rivers. On the other hand, the Alto Paranapanema and São José dos Dourados basins are the least affected. Copyright © 2008 John Wiley & Sons, Ltd. |
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Keywords: | trend analysis time series water quality human intervention land use rivers State of Sã o Paulo Brazil |
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