IAS Gyan

Daily News Analysis


27th October, 2023 Geography

Disclaimer: Copyright infringement not intended.


  • The Amazon rainforest is reeling from an intense drought. Numerous rivers vital for travel have dried up. As a result, there is no water, food, or medicine in the villages of Indigenous communities living in the area.
  • The Rio Negro, one of the world’s largest rivers by discharge levels, has fallen to a record low level of 13.59 meters near the city of Manaus.


  • The Rio Negro 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.


Upper Corse

  • The Rio Negro's source is in Colombia's Department of Guaina, where the river is known as the Guaina River.
  • The young river travels roughly east-northeast through the Puinawai National Reserve, passing numerous tiny indigenous towns along the route, including Cuarinuma, Brujas, Santa Rosa, and Tabaquén.
  • After around 400 kilometers, the river becomes the border between Colombia's Department of Guaina and Venezuela's Amazonas State.
  • The river heads southwest after passing through the Colombian towns of Tonina and Macanal. Maroa is the river's first Venezuelan town; 120 kilometers downstream, the river receives the Casiquiare canal from the left (north), establishing a unique link between the Orinoco and Amazon River basins.
  • The river is now known as Rio Negro.

Middle Corse

  • The river now continues in a southeastern direction passing the Venezuelan town of San Carlos de Río Negro, its largest settlement on the river, and Colombia's San Felipe.
  • In this stretch, the river is constantly fed with tributaries from both sides, and it quickly grows in size creating large river islands, a common feature for all rivers in the Amazon basin.
  • After forming the border between Colombia and Venezuela for 260 km the Rio Negro reaches the Piedra del Cocuy, an igneous rock formation from the Precambrian era, belonging to the Guyana Shield.
  • Here the Tripoint of Colombia, Venezuela, and Brazil is found in the middle of the river and it now completely enters Amazonas State, Brazil.

Lower Course

  • After the Marié River enters the Rio Negro, the river continues its eastward course forming many large islands and becoming very wide at several locations.
  • It passes local communities such as Santa Isabel do Rio Negro.

Major Tributaries

  • Taruma-Acu, Cuieiras, Camanau, Jau, Unini, Branco, Jufari, Demini etc.

Fauna and Flora

  • Rio Negro’s rich biodiversity encompasses globally threatened animal species such as the ash-breasted antbird (Myrmoborus lugubris), the giant river otter (Pteronura brasiliensis), the critically endangered Brazilian barefaced tamarin (Saguinus bicolor), the white-bellied spider monkey (Ateles belzebuth), and plants such as the Brazil nut (Bertholletia excelsa).


The Amazon River and its basin hold significant ecological and cultural importance, not only in South America but also globally. Discuss. (150 words)