Amazon River - Infy world

Overview:-

The Amazon River in South America is the largest river by discharge of water in the world, and according to some experts, the longest in length.
The headwaters of the Apurímac River on Nevado Mismi had been considered for nearly a century as the Amazon’s most distant source, until a 2014 study found it to be the Cordillera Rumi Cruz at the headwaters of the Mantaro River in Peru. The Mantaro and Apurímac confluence, and with other tributaries form the Ucayali River, which in turn confluences with the Marañón River upstream of Iquitos, Peru, to form what countries other than Brazil consider to be the main stem of the Amazon. Brazilians call this section the Solimões River above its confluence with the Rio Negro to form what Brazilians call the Amazon at the Meeting of Waters at Manaus, the river’s largest city.
At an average discharge of about 209,000 cubic metres per second—approximately 6,591 cubic kilometres per annum, greater than the next seven largest independent rivers combined—the Amazon represents 20% of the global riverine discharge to the ocean. The Amazon basin is the largest drainage basin in the world, with an area of approximately 7,050,000 square kilometres (2,720,000 sq mi). The portion of the river’s drainage basin in Brazil alone is larger than any other river’s basin. The Amazon enters Brazil with only one-fifth of the flow it finally discharges into the Atlantic Ocean, yet already has a greater flow at this point than the discharge of any other river.

History

Precolonial civilization

During what many archaeologists call the formative period, Amazonian societies were deeply involved in the emergence of South America’s highland agrarian systems. This possibly contributed to the social and religious institutions essential to the order of Andean civilization.
There is ample evidence that the areas surrounding the Amazon River were home to complex and large-scale indigenous societies, mainly chiefdoms who developed large towns and cities. Archeologists estimate that by the time the Spanish conquistador Orellana journeyed across the Amazon in 1541, more than 3 million Natives lived around the Amazon. These pre-Columbian settlements created highly developed civilizations. For instance, pre-Columbian indigenous people on the island of Marajó may have developed social stratification and supported a population of 100,000 people. In order to achieve this level of development, the Native Americans of the Amazon rain forest altered the forest’s ecology by selective cultivation and the use of fire. Scientists argue that by burning areas of the forest repetitiously, the indigenous people caused the soil to become rich in nutrients. This created dark soil areas known as terra preta de índio. Because of the terra preta, indigenous communities were able to make land fertile and thus sustainable for the large-scale agriculture needed to support their large populations and complex social structures. Further research has hypothesized that this practice began around 11,000 years ago. Some say that its effects on forest ecology and regional climate explain the otherwise inexplicable band of lower rainfall through the Amazon basin.
Many indigenous tribes engaged in constant warfare. James Stuart Olson wrote The Munduruku expansion dislocated and displaced the Kawahíb, breaking the tribe down into much smaller groups first came to the attention of Europeans in 1770 when they began a series of widespread attacks on Brazilian settlements along the Amazon River.