Rio Negro (Amazon)
The Rio Negro (Portuguese: Rio Negro Portuguese: [ˈʁi.u neɡɾu]; Spanish: Río Negro Spanish: [ˈri.o ˈneɣɾo] "Black River"), or Guainía as it is known in its upper part, is the largest left tributary of the Amazon River (accounting for about 14% of the water in the Amazon basin), the largest blackwater river in the world, and one of the world's ten largest rivers by average discharge. Geography Upper course The source of the Rio Negro lies in Colombia, in the Department of Guainía where the river …