The investigation was carried out from May 1981 to december 1983 in a small hydrografic basin (area ca. 1,3 km2) drained by the stream "Βarrο Branco", situated in INPA's forest Reserve "Adolfο Ducke" (Highway AM 010, km 28).
The area is covered by tropical rainforest of the amazonian "Terra firme" typo (i. e. situated above the levels of annual inundations).
Stream discharge was 32,3%, interception by the canopy 22% and the remaining 45,7% fall on transpiration by the vegetation, thus resulting in a total of 67,7% evapotranspiration.
Accordingly, one may expect significant changes in the water balance as a consequence of indiscriminate and massive deforestation, specifically reduced rainfall and a much higher percentage of stream discharge, accompanied by erosion and sedimentation.