Hidrografhy of the estuarine-lagunar complexo of Cananéia (25º S í 48º W), São Paulo, Brazil. I í Salinity and temperature (1973 a 1980)

Abstract

A global view of the estuarine lagunar system of Cananeia, regarding to mean values of surface salinity and temperature, is presented based on data collected in 18 stations from 1973 to 1980, at intervals of 3 days, approximately. Consequences of a dam, built in 1978 across Valo Grande, were considered. BEFORE dam building, the lowest salinities varied between 1^O/oo and 23^O/oo, and the highest, between 15^O/oo and 33^O/oo; AFTER dam building the lowest salinities were between 17^O/oo and 23^O/oo, and the highest, between 25^O/oo and 35^O/oo. The temperature varied from 23.3°C to 25°C BEFORE dam building, and from 23.8°C to 30.5°C AFTER. The salinity remained heterogeneous. In spite of the total reduction of the fresh water discharge from Rio Ribeira de Iguape, the system of Cananéia maintains estuarine characteristics due to its own hydrographic basin.