Upper Amazon

Upper Amazon

While the point at the Ucayali-Marañón confluence is where most geographers mark the beginning of the Amazon River, in Brazil the river at this point is known as the Solimőes das Águas. Those river systems and floodplains in Brazil, Peru, Ecuador, Colombia and Venezuela whose waters flow into the Solimőes and its tributaries are known as the "Upper Amazon". In some places, the river is divided into several, often very long, inland and lateral channels, connected by a complex system of natural channels that divide the low, flat igapó land, which never rises more than 5 meters above the low river level, into a number of islands. From Canaria, a town on the great bend of the Amazon, to the Negro River, large areas of land are flooded at high tide, above which only the upper part of the forest can be seen. From the mouth of the Rio Negro to Serpa, almost facing the Madeira River, the banks of the Amazon are shallow, rising into hills as you approach Manaus. In the upper basin of the Amazon River in South America, rainforests recycle rainfall, mainly from the eastern trade winds. Surface transpiration and evaporation account for about half of the rainfall in the whole region, and in densely forested basins far from the ocean, these local processes can account for a large proportion of local rainfall. If the Amazon rainforest, which accounts for 30 percent of the equatorial belt's land area, were to disappear, drought would likely follow, affecting the global energy balance.