ANALYSIS OF THE CORRELATION BETWEEN SALINITY AND ENVIRONMENTAL VARIABLES IN THE ESTUARY OF THE PARAÍBA DO SUL RIVER - BRAZIL

• DOI: 10.22533/at.ed.48119090749

• Palavras-chave: ATENA

• Keywords: Paraíba do Sul River (PSR); salinization; PCA of environmental variables; salinization-flow correlation

• Abstract:

  Limnological variables were

  studied in the estuary of Paraíba do Sul River

  (PSR), between July 2014 and December

  2015, to understand the hydrodynamics of

  salinity variation up to 10 km upstream of its

  mouth. Sampling was performed at nine points,

  previously defined, and in the sampled period

  the river presented a historical series of low

  flow when critical values were reached 298

  times. The measurement was performed in the

  locality with the use of a multiparametric probe

  to obtain estimated values for pH, dissolved

  oxygen (mg/L), salinity and water temperature

  (°C). Additional data on the air temperature,

  wind velocity, wind direction and barometric

  pressure were obtained from the meteorological

  station of Farol de São Tomé in the municipality

  of Campos dos Goytacazes of IMNET (2016).

  Principal Component Analysis (PCA) and

  linear regression were performed among the

  limnological variables to verify the influence

  on salinity in the estuary. The results show

  that salinity was the limnological variable most

  sensitive to the dynamics of the sea interaction

  and the PCA analysis indicates that the

  limnological parameters, water temperature, pH

  and dissolved oxygen, had an inverse salinity

  behavior. The influence of the semidiurnal cycle

  of the tide on the limnological characteristics in

  condition of low fluvial flow was evidenced as

  already pointed out in other works. The analysis

  of multiple linear regression shows that there

  was a significant difference between salinity

  and flow (p = 0.024223), showing that flow is

  the main determinant of salinity in the estuary

  of PSR.

• Número de páginas: 15