The Amazon River, stretching approximately 6,800 kilometers, is not only south america biggest river but also holds the title of the longest river in the world.
The Amazon River
The Amazon River, second only to the Nile as the world’s longest river, holds the record for the highest water volume, with an astonishing average discharge of 219,000 m³/s. It is estimated that about one-sixth of all freshwater flowing into the world’s oceans passes through the Amazon’s 320-km-wide delta as it meets the Atlantic Ocean.
The river’s width varies significantly with the seasons; during the dry season, it can measure between 4 km and 5 km across, while in the wet season, it expands to an impressive 50 km. At the peak of the wet season, the current can reach speeds of up to 7 km/h.
Major Roles of the Amazon River
As the main drainage system of the Amazon Basin, the river and its approximately 1,100 tributaries are crucial to the region’s ecology. Before the construction of roads and airstrips, these waterways served as the primary access routes to the interior of Brazil and northern South America. For instance, the only way to reach Iquitos, Peru, located along the Amazon River, is by plane or boat, as there are no roads leading to it.
Origin and Flow of the Amazon River
Due to the complexity of its river system, the exact starting and ending points of the Amazon are uncertain. However, it is generally thought to originate from Apacheta Creek at the base of Nevado Quehuisha in Arequipa, Peru, where the creek eventually flows into the Atlantic Ocean.
The Amazon River Basin
The Amazon River basin is the largest in the world, with an alluvial plain ranging from 19 to 50 kilometers wide, covering an area of 7,413,827 square kilometers and containing 20% of the Earth’s freshwater. This basin spans eight countries: Brazil (68%), Peru (14%), Bolivia (10%), and Ecuador (2%), with the remaining 6% shared among Colombia, Venezuela, Guyana, and Suriname, collectively known as the Amazon region.
Soils of the Amazon River
Despite the lush vegetation of the Amazon rainforest, the underlying soil is not very fertile. Nutrients are primarily stored in the vegetation and recycled through decay. Soils above flood level are typically well-drained, porous, and often sandy, featuring low natural fertility due to a lack of phosphate, nitrogen, and potash, along with high acidity. Some areas have fertile reddish soils (terra roxa) and the superior terra preta dos Indios, formed by ancient settlements.
Agriculture and Forestry in the Amazon
Upland rice, manioc, and corn are cultivated on small plantations, providing essential carbohydrates for the caboclo diet. Minor commercial crops include jute and guarana. Cattle pastures dominate cleared areas, with large ranches in southern Pará and Mato Grosso. Valuable timber comes from species like mahogany and Brazilian rosewood, though some are threatened. Rubber and Brazil nut trees contribute significantly to the economy, but illegal land clearing for soybean farming has increased disputes in the region.
Observing the River from Afar
The brown waters of the Amazon River can be detected up to 100 km offshore, well before the mainland becomes visible.
During the early days of colonization, this phenomenon provided a helpful navigation aid for ships traveling from Europe to South America, allowing them to confirm their course before spotting land.
Reference
1.The Longest River in South America:
https://www.whatarethe7continents.com/longest-river-south-america/
2.Amazon River
https://www.britannica.com/place/Amazon-River
