Balanço de macro elementos e composição isotópica de um bacia hidrográfica na Amazônia Central.

Abstract

The study was conducted in a 3 .5 km² watershed located approximately 60 Km north from Manaus. Itrs main objective was to quantify major elements inputs through rainfall and outputs via river run-off, and to study the water routing by using water stable isotopes. The sampling was conducted in four differents pluviometers and in the main channel of the watershed. The major elements Ca++, K+, P and Al do not showed significant temporal variability, however with a lower concentration in relation to other studies. The major elements budget showed a net gain of Mg++, Na++ and NO3-, or the input fluxes were higher than the output fluxes. On the other hand, there was a net loss of K+, Al, Fe, and Cl-. The average values of the delta ¹³o e delta Deuterium of the rain water was equal to -3,3% and -14,8% respectively. For the river water the average concentration was lighter than the rain, being equal to -5,1% and -26,1%