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Pesquisas Físicas e Químicas do Sistema Hidrográfico da região lagunar de Cananéia: II - águas de junção. Estudos iniciais das águas comuns da região da Ilha da Casca. "Nota prévia" sobre as águas na junção do Canal de Ararapira e Baía de Trapandé

Resumo

In this "previous note" we are presenting the results obtained by our Researches and referring to the waters of junction around the Island of Casca, located between the Trapandé Bay and the Canal of Ararapira, in the Lagoon Region of Cananéia, in the southern part of the S. Paulo State, Brazil. This note is a continuation of the physical and chemical researches of the Hydrographie System of the Cananéia Lagoon Region. In the Bull. Inst. Paulista de Oceanografia, vol. I, fase. I, pág. 45, 1950, we present the first results of the works carried out in the region. "We give the situation and description of the Island of Casca 's region, situated approximately near the crossing of lat. 25º4' S with long. 48º3'30" W; a bathymétrie study and the results obtained by our preliminary Technical Researches. We referred to the water samples collected from 8-12-48 to 27-10-49, the results of which are shown on table I and II. We discussed all these results, showing some graphics and comparing them with the physical and chemical properties of the surrounding waters - Table II and IIa. We constructed a T-S diagram in order to make evident the particularities which may exist. We discussed the origin of the predominating waters of the Island of Casca's region of junction, having made a tentative essay of dynamics. The previous and undermentioned conclusions will be dully fitted of with the corresponding instruments: 1) As the region under observation has several sand banks the channels leading to Ararapira may suffer or not some modifications; 2) The variation of salinity is of the lagoon type, suffering the influence of tidal currents and the continental contingents; 3) The predominating waters of the region come, first during ebb from the Ararapira channel and second during high tide the superficial layers come in the Bay from the entrance of the region, since the entrance is blocked by the tidal flood, then by the rising of the water level, they enter into the region of junction; 4) The fall of the dissolved oxygen could not be explained, due to the complexity of the interfering factors, and stilJL depends on future studies; 5) The T-S diagram put in evidence the periods of greater or smaller influence of the continental contingents which reach the locality in the months of January, February, March and June, July and August and shows the harmonic variation of the salinity between waters of surface and depth.


Pesquisas Físicas e Químicas do Sistema Hidrográfico da região lagunar de Cananéia. II - Águas de junção. Estudos iniciais das águas comuns da região da Ilha da Casca. "Nota prévia" sobre as águas na junção do Canal de Ararapira e Baía de Trapandé

Labieno de Barros Machado

ABSTRACT

In this "previous note" we are presenting the results obtained by our Researches and referring to the waters of junction around the Island of Casca, located between the Trapandé Bay and the Canal of Ararapira, in the Lagoon Region of Cananéia, in the southern part of the S. Paulo State, Brazil.

This note is a continuation of the physical and chemical researches of the Hydrographie System of the Cananéia Lagoon Region. In the Bull. Inst. Paulista de Oceanografia, vol. I, fase. I, pág. 45, 1950, we present the first results of the works carried out in the region.

"We give the situation and description of the Island of Casca 's region, situated approximately near the crossing of lat. 25º4' S with long. 48º3'30" W; a bathymétrie study and the results obtained by our preliminary Technical Researches.

We referred to the water samples collected from 8-12-48 to 27-10-49, the results of which are shown on table I and II. We discussed all these results, showing some graphics and comparing them with the physical and chemical properties of the surrounding waters - Table II and IIa.

We constructed a T-S diagram in order to make evident the particularities which may exist.

We discussed the origin of the predominating waters of the Island of Casca's region of junction, having made a tentative essay of dynamics.

The previous and undermentioned conclusions will be dully fitted of with the corresponding instruments:

1) As the region under observation has several sand banks the channels leading to Ararapira may suffer or not some modifications;

2) The variation of salinity is of the lagoon type, suffering the influence of tidal currents and the continental contingents;

3) The predominating waters of the region come, first during ebb from the Ararapira channel and second during high tide the superficial layers come in the Bay from the entrance of the region, since the entrance is blocked by the tidal flood, then by the rising of the water level, they enter into the region of junction;

4) The fall of the dissolved oxygen could not be explained, due to the complexity of the interfering factors, and stilJL depends on future studies;

5) The T-S diagram put in evidence the periods of greater or smaller influence of the continental contingents which reach the locality in the months of January, February, March and June, July and August and shows the harmonic variation of the salinity between waters of surface and depth.

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BIBLIOGRAFIA

  • BESNARD, W., 1950, Considerações gerais em torno da região lagunar de Cananéia-Iguape. Bol. do Inst. Paulista de Oceanografia, Tomo II, p. 3-28. São Paulo.
  • MACHADO, L. de B., 1950, Pesquisas Físicas e Químicas do Sistema Hidrográfico da Região Lagunar de Cananéia. I - Cursos de águas. Nota prévia sobre os "rios" Maria Rodrigues e Baguaçú. Bol. do Inst. Paulista de Oceanografia, Tomo I, fase. I, pág. 45-67. São Paulo.
  • MINISTÉRIO DA AGRICULTURA, 1948, Atlas Pluviométrico do Brasil. Depart. Nac. da Prod. Mineral. Divisão de Águas. Rio de Janeiro.
  • RONGEL, A., 1945, Marés, 2. ed., Diretoria de Hidrografia e Navegação. Ministério da Marinha, p. 1-141. Rio de Janeiro.
  • RILEY, G. A., 1941, Plankton Studies III. Long Island Sound. Bingham Oceanogr. Coll. Bull. vol. 7, art. 3, p. 1-93. New Haven.
  • ROUCH, J., 1946, Traité d'Océanographie Physique, vol. II, p. 1-349. Paris.
  • SVERDRUP, H. U., JOHNSON, M. W., & FLEMING, R. H., 1942, "The Oceans", their physics, chemistry and general biology, X + 1087 p. New York.

Datas de Publicação

  • Publicação nesta coleção
    15 Jun 2012
  • Data do Fascículo
    Dez 1952
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