Amazon River
Amazon River
The Amazon River is the longest river in the world and also the first in terms of water flow.
This river that flows in South America, has its source in Nevado Mismi at 5,600 meters above sea level in the department of Arequipa, Peru, crosses Peru, Colombia and Brazil and flows, with a gigantic estuary more than 200 km wide, in the Atlantic Ocean after crossing from west to east a vast geographical area defined as the Amazon Basin, including the Amazon forest.
Etymology
The origin of the name of this river is not certain; it seems that the name can be traced back to the fact that the discoverers, led by Francisco de Orellana would have seen indigenous warrior women and therefore would have named the river inspired by the Amazons. According to other authors it is thought that one of the indigenous peoples had a similar name and that in Latin characters it would have been transliterated with Amazonas. Still others see the origin of the current name in the noun Amassunú, with which the Tupis are thought to have characterized the river. Finally, according to still others, they would be the Indian words amazonassa, amacunu for “water noise”, as the Indians of the upper course called it, or Amassonas for “ship disturber”, as the Indians called it up to the Rio Negro .
Geographic Features –
The Amazon River, in addition to being the longest in the world, is the one that crosses almost an entire continent (South America), crossing Peru, Colombia and Brazil before flowing into the Atlantic Ocean.
As mentioned, it was born in Nevado Mismi at 5600 meters above sea level (Department of Arequipa, Peru). Initially it is called Apurimac and further downstream it is called Ene. Then it takes the name of Rio Tambo. When the Tambo joins the Rio Urubamba, the river is called the Ucayali.
At the confluence of the latter with the Marañón River it takes the name of Amazon River. From the Colombia-Brazil border, the river is called by the Brazilians “Solimões” (for the stretch up to the confluence with the Rio Negro).
Once this stretch has passed, it also takes the name of “Rio Amazonas” from the Brazilians. Considering the source furthest from the sea, precisely the Rio Apurimac, the Amazon River is the longest watercourse in the world, 6937 kilometres.
The Amazon River, in addition to being the longest river in the world, is also the largest in terms of volume of water, number of tributaries and hydrographic basin (6,915,000 km2); just think that about 10,000 rivers flow into it, of which 18 have a length of more than 1,000 km.
It is interesting to note that the Amazon River is significantly affected by seasonality.
In periods of higher water quantities it can overflow into neighboring forests up to 100 km away. The flooding of the affected forests creates the Vàrzea, an ecosystem unique in the world. In the area of the mouth of the Amazon River is the fluvial marine island of Marajò. If this large island (49,000 km2) is included together with the rivers flowing south of it (particularly the Tocantins) the Amazon River estuary has a width of several hundreds of kilometres. It crosses from west to east a geographical area defined as the Amazon Basin.
A bold thesis assumes that the direction of the Amazon River is due to its formation prior to continental drift and that the great river was therefore originally born in Chad. But there is no need for this to link Brazil to Africa and the two Lusophone traditions.
Historical Notes –
The history of the Amazon River basin is lost in the mists of time, characterized by the presence of tribes or real populations which were then gradually ousted from their territories, starting above all from the discovery of the Europeans.
The history of the Amazon River is rooted in myth, in the different languages, in the life of the 190 indigenous tribes, in the vicissitudes of the garimpeiros (gold seekers), in the cycle of rubber which made the fortune and the fall of the cities along the river.
History following the arrival of European colonizers tells us that the mouth of the Amazon River was discovered by the Italians between 1499 and 1500: the Florentine explorer Amerigo Vespucci and the sailor Vicente Yáñez Pinzón arrived there almost simultaneously with their ships, hence for which Vespucci is usually considered its discoverer.
Francisco de Orellana was the first European to navigate the river between 1541 and 1542 from the source of the Napo in Ecuador to its mouth in the Atlantic, participating in the expedition of Gonzalo Pizarro, but actually looking for the legendary El Dorado: for this reason for a long time the Amazon River was called Rio Orellana.
On February 12, 1542, Orellana and Pizarro discovered the source of the Marañón, the shortest spring branch; from October 1637 to August 1638 Pedro de Teixeira traveled upriver up the Amazon River to the source of the Napo.
Only in 1971 the source of the Ucayali was discovered by the American Loren McIntrye and in 2001 the source of the Apurímac was established as the source of the Amazon River by the National Geographic Society, to the point that the length data then in force for the Amazon River they had to be revised.
It was Father Samuel Fritz, a German Jesuit missionary, who first mapped the river in 1707.
Ecosystem –
It is estimated that around 60% of all species on the planet live right in the Amazon rainforest and that 30% of these species are still unknown to the scientific community.
The Amazon region has one of the richest biodiversity on Earth.
The Amazon River is the foundation of one of the most diverse ecosystems. It is home to millions of species of animals and plants, many yet to be discovered.
The Amazon River originated about 10 million years ago. The evolution of the flora and fauna of the Amazon region, however, must be traced back earlier. When the movement of tectonic plates originated the Andes mountain range, 20 million years ago.
This is confirmed by a study carried out by the international group of the Superior Council for Scientific Research (CSIC). Work has been done to formulate new theories useful for explaining the complexity and origin of the biological wealth of the Amazon.
We recall that, with the term Amazonia, a vast region is defined which includes the central and northern part of South America and includes the tropical forest of the Amazon basin. Its extension is 7 million square kilometers.
The Amazon is located in the so-called Intertropical Convergence Zone, a region where the trade winds of the Northern Hemisphere converge with those of the Southern Hemisphere.
The particular location and the action of Nature are responsible for the tropical climate of the Amazon. Not surprisingly, it is characterized by abundant rainfall, humidity and high temperatures. Furthermore, the soil is very fertile and ideal for life to abound.
Among the millions of living creatures that can be found in this region, there may be up to 2,500 types of fish, 3,500 types of trees, and 300 species of reptiles, including snakes and lizards.
According to the coordinator of the Indigenous Organizations of the Amazon Basin (COICA, its acronym in English), about 9% of the human population of the Amazon River is still made up of indigenous peoples. Even today, there are around 350 different ethnic groups.
However, the wealth of the Amazon is beginning to be damaged by human activities. In the middle of the last century, the Amazon lost 17% of its tree cover.
The economic exploitation that causes this loss of vegetation affects both the flora and fauna of the region, and risks destabilizing the dynamics of what many call the “Lungs of the Earth”.
The importance of the life that surrounds and accompanies the Amazon River lies in its ability to regulate both temperature and humidity, two elements closely linked to the water cycles. We are talking about the set of phenomena of flow and circulation of water within the hydrosphere.
Flora –
The Amazon forest is a rainforest found predominantly in Brazil. The Amazon occupies a very large area that can be compared to 42% of the European continent and which includes the territory from the Andes to the Atlantic. The territory is characterized by a rich and prosperous flora which hosts:
The forest has a developed and dense undergrowth which makes the Amazonian environment more in dim light and humidity. The Amazonian ecosystem is characterized by the presence of 750 different species of trees.
The Amazonian soil is poor and lives in an extremely delicate balance, as evidenced by some experiments in the creation of plantations in those areas which have proved to be failures. Among the latter we can mention the rubber tree plantations of Ford in the 1920s and the plantations of precious wood.
According to a study conducted by biologists and environmentalists, the Amazon is home to about 390 billion trees and 16,000 different species of these shrubs – obviously calculated on a statistical basis. As we well know, the Amazon holds up to 17% of the world’s terrestrial carbon reserves, but not all trees in the forest are equally important.
According to past research published in the journal Nature Communications, just 1% of Amazonian tree species are responsible for 50% of forest carbon storage. Just recently, sadly, the rate of rainforest deforestation hit its highest level in 15 years.
Not only. Destruction of the environment in this area could lead to the extinction of more than 10,000 species of plants and animals. 18% of the Amazon Basin has already been deforested, while another 17% has been degraded. In short, the Amazon is home to 390 billion trees, but every day this number is reduced more and more … because of us.
Wildlife –
In the Amazon River basin we can find the most diversified freshwater fish fauna in the world, with more than 1,000 known species and almost all the major groups represented: this very rich fish fauna offers great opportunities to predators such as the giant otter (Pteronura brasiliensis) . Here you can find a shark capable of living up to a few years in fresh water (genus Carcharhinus), also observed at 4,000 km from the mouth, and some fresh water stingrays (family Potamotrygonidae). Or, among the bony fishes, the famous small hatchetfishes (family Gasteropelecidae), or the Cynodontidae, both resembling certain deep sea fishes. The piranhas are characteristic and famous: in reality, the reputation of terrible predators that this name evokes is entirely due to a few species of the family Characidae belonging to the genus Pygocentrus, among the very few group predatory bony fishes, Pygocentrus nattereri and Pygocentrus piraya. Other species of piranhas, i.e. from the same family, are instead parasitic on other fish, or even “myth” vegetarians.
The gymnothes, or electric fish, are capable of emitting very powerful electric discharges (up to 550 volts, for a power of over 1 kilowatt) which seem to be used as communication systems and for electrolocation of preys or obstacles. There are known cases of men being killed by discharges of Electrophorus electricus called “temblador” by the locals.
Some representatives of this extraordinary fauna such as freshwater dolphins, anacondas, caimans and manatees are extremely popular, yet relatively little is known about their biology to this day.
The nailless manatee (Trichechus inunguis) is a sirenid mammal similar to the two other species of manatees or manatees (Trichechus manatus and Trichechus senegalensis), endemic to the Amazon basin, characteristically without nails. Herbivorous, it is like all sirenids linked to aquatic phanerogams for food.
Cetaceans are represented by two species of dolphins: Inia geoffrensis (the so-called boto) and Sotalia fluviatilis (the tucuxi). The Inia belongs to a typically freshwater family (Iniidae), reaches a length of 2 and a half meters and a weight of about 160 kg. Sotalia is a member of the Delphinidae, which are predominantly and classically marine; it usually does not exceed one and a half meters in length and 50-60 kg in weight. Boto and tucuxi often live in the same areas, and sometimes fish together: however, it seems that they share the resources by operating at different levels, with the Inia fishing on the bottom and the Sotalia in the more superficial waters.
The anaconda (Eunectes murinus, the sucurì of the locals) is the largest snake in the Amazon basin, reaching 12-14 meters in length.
The curious mata mata (Chelus fimbriatus) is much sought after as a delicious food by the locals: it is a very particular turtle, with a long neck provided with jagged appendages which, in addition to being used to blend in with the bottom, are used to attract its preys, in especially small fish.
Environmental Protection Actions –
Currently, the Amazon forest is suffering a lot from some settlements in which very large parts of them are being destroyed. In these cases we speak of deforestation, or the process of felling trees for commercial purposes and to exploit the land.
For this reason, ecologists and environmentalists are fighting hard. However, the Brazilian government does not seem to want to give importance to these disagreements and indeed has repeatedly accused environmentalists of interfering with Brazil’s economic interests. The government, being indebted to many countries, is trying to implement a very strong economic development policy. Deforestation, however, is increasing more and more through violent destruction, such as fires caused by farmers and ranchers.
As a result, many indigenous peoples are often forced to flee and leave their land. Countless Amazonian tribes are disappearing, along with their culture and home. Scholars explain that the destruction of this ecosystem which is the Amazon forest leads to more and more serious damage to our planet. In fact, before the beginnings of deforestation, this forest provided half of the planet’s oxygen thanks to the presence of trees and their chlorophyll photosynthesis. Experts believe that this forest clearing phenomenon accelerates global warming. Only 30% of the planet’s surfaces are still covered by forests.
Of course, to end deforestation it is important to get the support and help of the governments that are involved in this killing. “Saying enough to deforestation” is however possible, just think of sustainable agriculture. In 1992 the Rio Conference on the environment was held which launched the GFS, i.e. a more sustainable and environmentalist forest management system. From this, many organizations have been created that operate in this field in order to preserve the environment and forests.
Guido Bissanti