Avaliação da influência do entorno e do Canal de Pereira Barreto na qualidade da água do Baixo São José dos Dourados
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Data
2009-02-27
Autores
Igrecias, Luís Filipe Militão [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este trabalho apresenta o estudo desenvolvido no Baixo rio São José dos Dourados, localizado no Noroeste Paulista, durante o período de novembro de 2006 a setembro de 2007, para avaliar a influência do seu entorno e do canal de Pereira Barreto sobre a qualidade de suas águas. Foram selecionados quatro pontos de coleta ao longo do rio, onde foram efetuadas coletas trimestrais de amostras na superfície, meio e fundo da coluna d’água, para aferições do IQA proposto pela CETESB (2004) e do IET proposto por Toledo Jr. et al (1983) e Lamparelli (2004). Além disso, foram realizadas análises da condutividade, nitrato, nitrito e amônia para complementação das análises. As águas do reservatório foram classificadas predominantemente como Ótimas pelo IQA, apresentando a classificação Boa em alguns pontos analisados, principalmente no ponto localizado na transição entre rio e reservatório, recebendo influência direta da bacia. Com relação ao IET, foram classificadas predominantemente como Oligotróficas pelo IET proposto por Toledo Jr et al. e Mesotrófico pelo IET de Lamparelli, apresentando um padrão de melhora no grau de trofia no sentido longitudinal do reservatório, com o melhor IET médio situado próximo à sua foz. Para os parâmetros da água analisados, verificou-se a diferença espacial e temporal, as quais foram mais acentuadas nos períodos seco e chuvoso, recebendo influência direta do canal de Pereira Barreto ao transpor águas do rio Tietê, reduzindo a turbidez e a concentração de nutrientes, mas também reduzindo a concentração de oxigênio dissolvido e aumentando a concentração de clorofila-a. Também foi constatado o grande potencial do entorno promover alterações no sistema, com a substituição de áreas de pastagens pelo cultivo da cana-de-açúcar em solos com predominância de alta e muito alta suscetibilidade à erosão, em uma região...
The present work shows the study developed in Low São José dos Dourados river, located at northwest of São Paulo State, from november 2006 to september 2007, to assess the influence of their surroundings and channel of Pereira Barreto on the quality of the water. Four sampling stations were selected along the river, where quarterly sampling were performed on the surface, middle an botton of the water column, for measurements of Water Quality Index proposed by CETESB and Trophic Estate Index proposed by Toledo Jr. et al. (1983) and Lamparelli (2004). Also, analysis of conductivity, nitrate, nitrite and ammonia were performed for complementation analysis. The waters of the reservoir were classified predominantly as “Great” by WQI, showing the classification “Good” in some stations analyzed, mainly at the station located in the transition between the river and reservoir, receiving direct influence of the watershed. Whith respect to TEI, were classified predominantly as “Oligotrophic” by TEI proposed by Toledo Jr. et al. and “Mesotrophic” by Lamparelli’s TEI, showing a pattern of improvement in the trophic level in the longitudinal direction of reservoir, with the best average TEI located near your mouth. For the parameters of water analysis, the difference spatial and temporal was observed, which were more pronounced in drougth and wet periods, receiving direct influence of the channel of Pereira Barreto transferring water from the Tietê river, reducing the turbidity and the concentration of nutrients, but also reducing the dissolved oxygen and improving the chlorophyll-a. It was also noted the great potential of promoting changes in the environment, with the replacement of areas of grassland by cultivation of sugar cane in soils with a predominance of high and very high susceptibility to erosion, in a region that shows high degree of degradation of natural vegetation... (Complete abstract click electronic access below)
The present work shows the study developed in Low São José dos Dourados river, located at northwest of São Paulo State, from november 2006 to september 2007, to assess the influence of their surroundings and channel of Pereira Barreto on the quality of the water. Four sampling stations were selected along the river, where quarterly sampling were performed on the surface, middle an botton of the water column, for measurements of Water Quality Index proposed by CETESB and Trophic Estate Index proposed by Toledo Jr. et al. (1983) and Lamparelli (2004). Also, analysis of conductivity, nitrate, nitrite and ammonia were performed for complementation analysis. The waters of the reservoir were classified predominantly as “Great” by WQI, showing the classification “Good” in some stations analyzed, mainly at the station located in the transition between the river and reservoir, receiving direct influence of the watershed. Whith respect to TEI, were classified predominantly as “Oligotrophic” by TEI proposed by Toledo Jr. et al. and “Mesotrophic” by Lamparelli’s TEI, showing a pattern of improvement in the trophic level in the longitudinal direction of reservoir, with the best average TEI located near your mouth. For the parameters of water analysis, the difference spatial and temporal was observed, which were more pronounced in drougth and wet periods, receiving direct influence of the channel of Pereira Barreto transferring water from the Tietê river, reducing the turbidity and the concentration of nutrients, but also reducing the dissolved oxygen and improving the chlorophyll-a. It was also noted the great potential of promoting changes in the environment, with the replacement of areas of grassland by cultivation of sugar cane in soils with a predominance of high and very high susceptibility to erosion, in a region that shows high degree of degradation of natural vegetation... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Água - Qualidade, Solo - Uso, Canal de Pereira Barreto, Ilha Solteira, barragem de (SP), São José dos Dourados, Rio (SP), Eutrofização, Reservoir of Ilha Solteira, Land use, Eutrophication, Erosion
Como citar
IGRECIAS, Luís Filipe Militão. Avaliação da influência do entorno e do Canal de Pereira Barreto na qualidade da água do Baixo São José dos Dourados. 2009. 117 f. Dissertação (mestrado) – Universidade Estadual Paulista, Faculdade de Engenharia de Ilha Solteira, 2009.