Water quality longitudinal profile of the Paraíba do Sul River, Brazil during an extreme drought event

Abstract

This work addresses the relationships between Land Use/Land Cover (LULC) and water quality in the Paraíba do Sul River (PSR), located in one of the most populated regions in Brazil. We conducted a water sampling program (analyzing nitrate, ammonium, phosphate, turbidity, total carbon, oxygen concentration, and conductivity) during a severe drought period from 2014 to 2016. The 210 samples were spaced about 5 km apart from headwaters to the Atlantic Ocean and taken over 63 d. We calculated a water quality index and applied a self‐organizing map (SOM) to explore the relationship between LULC and water quality. There was a significant influence on water quality from the urban area's socioeconomic profile. This observation reflects the influence of cities with a high population density and a low economic condition, which leads to further degradation and erosion of the riverbanks. The most degraded reservoir of the PSR (Funil) partially buffers these effects by retaining deposited sediments and nutrient loads, leading to downstream water quality improvement. Better management practices of the riverbanks in the lower reach contribute to additional water quality improvements. Three major clusters identified using the SOM had completely different and explainable water quality patterns, suggesting an abrupt change in water quality due to human interventions. This information is crucial to improve management projects for the river at a watershed level, and with the expectation of future water shortages.

Monitoramento De Parâmetros De Qualidade Da Água Do Rio Paraíba Do Sul Em Campos Dos Goytacazes – Rj

“…Em seu trabalho, Pacheco et al (2017) analisaram diferentes parâmetros de qualidade de água, em 210 pontos amostrais localizados da cabeceira até a foz do rio Paraíba do Sul, com o intuito de confrontá-los com o uso e ocupação do solo da área durante o período de 2014 a 2016. Foi possível constatar que o parâmetro condutividade apresentou altos valores no cluster 6, que corresponde a 44% da extensão do trecho do rio Paraíba do Sul em que foram coletadas as amostras, encontrando valores de condutividade máximos próximos a 100 µs cm -1 .…”

Water quality assessment based on multivariate statistics and water quality index of a strategic river in the Brazilian Atlantic Forest

“…The assessment of Poyang Lake 28 , China and the upper Selenga River 31 , Mongolia showed that WQIs are suitable for the assessment of both interannual trends and seasonal variations 28 . Multivariate statistical techniques associated with WQI have been used for numerous water bodies world-wide, including the Nag River 30 , India, the Paraíba do Sul River 32 , Brazil, and the before mentioned Selenga River 31 . CA grouped the monitoring stations according to their similarities, while the PCA highlighted components that were related to its pollution sources 30 – 32 .…”

“…Multivariate statistical techniques associated with WQI have been used for numerous water bodies world-wide, including the Nag River 30 , India, the Paraíba do Sul River 32 , Brazil, and the before mentioned Selenga River 31 . CA grouped the monitoring stations according to their similarities, while the PCA highlighted components that were related to its pollution sources 30 – 32 .…”

“…Another water transfer system connects the Paraíba do Sul river to the Cantareira system, complementing with 5 m 3 /s the water supply to over 9 million people in the metropolitan region of São Paulo 41 . These systems went through an intense water scarcity between 2014 and 2016 with severe impacts on water quality and availability 32 .…”

Diversidade funcional do fitoplâncton em reservatórios em cascata e funções ecossistêmicas associadas

“…Ainda, outros autores afirmam que tanto o nitrogênio quanto o fósforo podem ser limitantes para o fitoplâncton e que essa condição varia de acordo com a localização e características ao entorno do corpo hídrico (HUSZAR et al, 2006;KOSTEN et al,2009;RANGEL et al, 2012). É conhecido que o uso e ocupação do solo está diretamente relacionado à qualidade da água e rios e reservatórios que estão sob influência de cidades com alta densidade populacional e baixa condição socioeconômica sofrem com a maior degradação e erosão das suas margens, aumentando a quantidade de nutrientes no sistema (matéria alóctone) (PACHECO et al, 2017).…”