Amazon Life - Hidrography

The hidrography of Amazon is composed by the largest basin of the world, with an area of 7,050,000 square meters, that drains the lands of Brazil, Venezuela, Colombia, Ecuador, Peru and Bolivia, corresponding to 25% of South America.

Rio Negro River and Solimões River came across to form Amazonas River, the largest river of the world in flow of water, with 230,000 cubic meters of water per second. This volume occurs because the river flows in a plain, with a declivity about 2 centimeters per kilometer. This physical condition promotes slow water flow that become accumulated in determined points of the river. It ranks as the largest in the world in terms of catchment area, number of tributaries, and volume of water discharged.

The width of the river Amazonas, in dry season, has an average of 4 to 5 kilometers, increasing, in some places, to 50 kilometers, in wet season. The average speed of river water is 2.5 kilometers per hour, increasing to 7, in wet season. The annual outflow from the river accounts for one-fifth of all the fresh water that drains into the oceans of the world. The outpouring of water and sediment is so vast that the salinity and color of the Atlantic Ocean are altered for a long distance.

Amazonas River - Location

The river begins in a Peruvian lake, named Apurimac, at Andes Mountain Range, passing later to be called Ucaiali, and soon after, Solimões. This immense river, that receives four names along its course, is the second largest fluvial artery of the world, with a length of 6,571 kilometers, just losing for the Nile river, in Africa, that has a length of 6,696 kilometers. The third place is occupied by Mississippi-Missouri Rivers, with 6,418 kilometers.

The Amazon basin has fundamental importance in the development of its drained area. The navigation of its rivers was, until little time ago, the unique important way of locomotion in the whole area. Its navigable fluvial potential is about 20,000 kilometers.

Despite centuries of effort to overcome the dominance of nature, the impact of humans has only been large in the last few decades. No bridge spans the river. Except near its mouth, the Amazon watershed constitutes one of the most thinly populated regions in the world. Much of the territory drained by the river system has never been thoroughly explored.