TROPHIC STATE INDEX OF THE WATER OF RIO BRANCO, BOA VISTA, RORAIMA

The Brazilian Amazon is known worldwide for its different ecosystems and its water availability. The Amazon river basin has an estimated area of 6.3 million km², of which 3.8 million km² are in Brazilian territory and the rest divided between Bolivia, Colombia, Ecuador, Venezuela and Peru. Within the context of the Amazon basin, the Rio Branco, the main drainage system of the State of Roraima is a tributary of the left bank of the Rio Negro; The capital Boa Vista has developed historically the left banks of the Rio Branco, which use its waters for the supply of the city. The present research evaluated and classified the quality and trophic state of the water of the Branco River, using physical-chemical and biological parameters as measures.