Human Activity Along The Amazon River example essay topic

INTRODUCTION TO THE AMAZON RIVER Physical Characteristics The Amazon is the second longest river on earth, measuring 6,280 kilometres in length. The flow volume is the largest of any river on earth (My references do not give the actual flow). The area of the drainage basin is 6.2 million square kilometres. At the main mouth, the river is 150 kilometres wide.

The Amazon has many sources, mainly in mountains surrounding the basin. The Andes, to the east (see map), are the highest and most significant source. Other sources include the Matto Grosso Plateau, Chap ada Diamanti na, and the Guiana Highlands. The Amazon flows into the Atlantic Ocean through deltas with several channels and river mouths. The deltas are some 450 kilometres wide and there are two main estuaries. Other rivers join the Amazon in the deltas.

Belem, the largest city in the coastal part of the Amazon, is at the junction with Tocantins River. The Amazon has a range of biophysical environments. It starts in cold, wet mountains and ends in hot, tropical, swampy deltas. On the way, it passes through cold, temperate and tropical rainforests.

Away from the main river, there are also some grassland and forest environments in the Amazon basin. In the cold steep mountains the tributaries are fast flowing, and the vegetation is smaller, hardy, and less dense. In the basin, there is little slope so it gets wider and slower. The water gets warmer and supports more plant life, fish, animals and reptiles. The nearby plants provide nutrients for life in the river. Because of its location on the Equator, the temperature, rainfall and humidity are all very high in the basin, so much of the vegetation is dense tropical rainforest.

The Amazonian jungle lies in the lower part of the basin. The delta is cooler than the jungle, due to sea breezes, mangroves and swamps. Importance of rivers as physical elements Rivers are an extremely important part of the water cycle. They collect runoff from rain and melted snow, feed lakes and swamps, and return water to the sea.

Rivers assist with eroding steep land, and carry eroded sediments down stream and deposit them in floodplains, making the soil rich and fertile. Different sections of rivers create different environments, making the Eco-system more varied. Rivers have been important for the development for human society. They provide fertile land in floodplains, enable irrigation of crops, and supply drinking water for humans and animals, such as cattle and horses. By providing a permanent water supply and enabling the production of adequate food, rivers have been important in the growth of human settlements and to the development of civilisation. Human settlements and populations The Amazon did not support any major settlements until Europeans arrived.

The native Indians lived in small nomadic groups in the forests. Recent settlements along the Amazon are not large relative to other cities in Brazil. Manaus, the largest, is a trading centre. It was only accessible by river until the Pan-American Highway was built. There are few settlements away from the river. HUMAN USES OF THE AMAZON RIVER AND HUMAN'S EFFECT ON THE RIVER Transport of people and goods Besides walking, the main form of transport for the Amerindians along the rivers is by canoe.

These canoes are often quite long, approximately 10 metres in length, and carry great loads of goods. Unfortunately, though, they are not very stable, a small wave can rock and capsize the boat. The crew would lose their cargo and most probably their lives to the piranhas and alligators in the water below. During the season when the Amazon floods, strong torrents occur, strong enough to rip up enormous trees and great bundles of roots that appear like miniature islands. These torrents hurl the trees down the river. The Amerindians take advantage of these floating rafts and travel downstream on them.

This is a very dangerous form of transport, but the only one available during the flooding. The Amazon is wide and deep enough for large boats to travel from the coast to far into the basin. Once boats along the river were the only form of transport, but now there are many planes flying up and down the Amazon, including seaplanes, which land on the river. Although conventional planes using runways are increasingly important, the Amazon is still highly important for boats and seaplanes that transport goods from the basin to the rest of Brazil and overseas. There are two major roads through Amazon basin, one is east west going from the coast to Peru through the Andes. The other road is north south and connects Brazil with Venezuela and Central America.

Fishing and agriculture Fishing and agriculture are large parts of the economy in the Amazon basin. Cattle ranching is the only major livestock industry. Unfortunately, many ranchers clear jungle to make grasslands for cattle. By doing this, they destroy habitat, and pollute the soil and water. The soil in the basin is incredibly fertile, there is adequate rainfall, and due to the heat, many crops grow at abnormally rapid rates. Because there is no frost, crops can be grown throughout the year.

This means yields are very high, and it is attractive for farmers to clear land to grow crops such as: manioc, Brazil nuts, maize, sugar cane, cashews, caster, linseed, coffee and many others. Not all the crops are legal. Coca, the plant from which cocaine is made, is a traditional crop of the Amerindians who live in the Andes. The upper Amazon, especially in Peru and Columbia are centres of illegal cocaine production and smuggling.

The incredibly diverse range of fish in the waters of the Amazon make it irresistible for fishing. Until recently, the fish caught in the Amazon were only for local use, and there was limited fishing. This has changed now, due to refrigeration and increased demand. Fish caught in the Amazon are now being exported all over the world. Fish stock is now declining with over fishing. Not all the fish caught are for eating.

The Amazon is an important source of tropical fish for aquariums. Social The native Amerindians were hunter-gatherers and animist, believing that all material objects have a soul or spirit. The lived off food and resources provided by the forests and rivers, without destroying their environment. The Amerindians have ritual communal ceremonies, based on drinking "caxiri", a brew made from yams, coconut milk and sugar cane.

This ceremony was to keep the peace with the river and forests. They also had communal bathing in the early morning, when the forest was at its coldest but the river was still warm. They lived in harmony with their surroundings and had little impact on the river. Spanish explorers first visited the Amazon in 1500, and Portuguese set up their first settlements along the river early in the 16th century. The first settlers were missionaries, miners and traders. The missionaries that settled along the river tried to convert the Amerindians from their animist ways to Christianity.

Portuguese colonists founded sugar-cane plantations along the river because of the fertile land and abundant water. The colonists began clearing forest to make way for the new plantations, this was the start of deforestation in the Amazonian jungle. Slaves were used to work the plantations. Amerindians did not make good slaves, so the Portuguese plantation owners imported African slaves. The Portuguese, Africans and Amerindians interbred creating a multi-racial society.

Tourism and other economic activities Traditionally there wasn't much tourism in the Amazon. Recently though, the Brazilian Government has tried to increase the amount of tourism in the Amazon. They are promoting attractions such as: bird watching, recreational fishing, canoe and boat trips down the Amazon amongst many other things. While this is better than clearing forests, it is not as good for the environment as no activities at all. Some habitats are protected, but others are being destroyed, and the river has become polluted by human activities.

There has been no major economy along the banks of the Amazon besides ranching, crop growing and mining. One tributary is now used to generate electrical power. While this is better than using coal for power stations, it effects the river and will promote industry and urban growth. Scientists are now studying the Amazon to discover plants and animals, which may have compounds and genes that may be used in making drugs and medicines, and to find plants that can be used in plant breeding. The Amazon is a rich resource for new compounds and genes. Human pollution Humans cause pollution in many different ways.

Towns and settlements put sewerage and rubbish into the river. Agriculture and forestry increase soil erosion, which leads to sedimentation in the river. Pesticides and fertiliser add to the pollution from farming. Cattle and water buffalo also added a lot of mud and excrement to riverbanks adding to the pollution. Industries also pollute, for instance, sugar cane factories produce pulp, which add excessive nutrients to the water and changes the ecology of the river. Gold mining leaves mud and mercury in the river.

Boats and seaplanes travelling along the river spill fuel and cargo. All these things contribute to a pollution problem that is quickly getting out of hand. Water quality The Amazon's water quality was almost perfect until 1500 when Spaniards started to explore and settle along the river. Ever since, the Amazon's water quality has been deteriorating due to increasing human activity along the river.

The large population along the river has caused a major increase of the pollution in the river. Many of these people are very poor and it is hard to make a living without jobs, such as those in mining, tree cutting and farming. At the same time, these jobs are major factors of pollution in the Amazon. It is difficult to make a stable balance between the economic interests of the human population in the basin and the wider concern for the ecology. However, without intervention, the Amazon will have a much-changed ecology and many species of plant and animal will become extinct.

Bibliography

Goulding M., Smith N. and Mahar D. Floods of Fortune: Economy and Ecology Along the Amazon. New York: Columbia University Press, 1996.
Reader's Digest. Great World Atlas. Reader's Digest: Proprietary Press, 1975.
Sperry, A. The Amazon. Britain: Frederick Muller, 1962.
Rand McNally Cosmopolitan. World Atlas. Chicago: Rand McNally press 1949.