Rivers have been polluted due to the mining in the area and soil erosion is a serious problem as the protective canopy of trees is removed. This then means the land cannot be used for growing anything else.
The global effects are significant. Of the 30+ million known species on Earth, 28 million of these are in the rainforest. Deforestation is destroying habitats and species at an ever-increasing rate – one estimate is that an area the size of 15 football pitches is destroyed every minute. Some of the rainforest species have proved to be valuable to humankind. For example, we obtain ingredients for over half our medicines from the rainforest. If we continue to destroy this environment, we risk losing these species forever.
Deforestation is also contributing to climatic global change. Fewer trees mean less evapotranspiration and therefore less water vapour in the air. This means reduced rainfall, possibly leading to droughts. At the same time, the burning of the forests releases huge amounts of carbon dioxide, one of the main gases causing global warming, it is very difficult to minimise the amount of deforestation in the Amazon Basin. The majority of the rainforest is located in Brazil, which has a huge national debt so they cannot afford to minimise deforestation in the Amazon due to other financial problems. Selling off parts of the forest to big co-corporations in MEDCs country for space is also a source of income. Consequently, in order to reduce this debt the Brazilian government wishes to exploit the rainforest’s resources so that overseas trade in rainforest products will generate income for the country.
However, there are a number of ways that rainforests can be used that are sustainable. One of the most popular is agro forestry and this could be attempted in the Amazon Basis as a way of reducing deforestation. The natural rainforest is a strong, productive ecosystem and that one of the best ways of making use of the land is by imitating this ecosystem. Farmers can create an ecosystem that is useful to them and is similar in many ways to a rainforest. This is called agro forestry and is sustainable because it is a way of using the land that will not cause long-term damage to ecosystems and prevent them being used by future generations.
In a typical agro forestry farm, several layers of vegetation and a variety of species of trees and plants can be found, creating a variety of habitats for animals, birds and insects. There will therefore be plenty of vegetation to intercept rainfall; shade the ground, crops absorb and store soil moisture, and the roots will bind the soil together, preventing erosion. Plenty of organic matter will fall as leaf litter to provide a nutrient supply, maintaining soil fertility. The trees can be used for timber and fruit among many other resources. Moreover, bushes and ground crops can be used for food and commercial crops such as coffee, manioc and rice.
Brazil could also learn from countries such as Cameroon, where National Rainforest Parks have been established to protect areas of rainforest. The Korup National Park, for example, aims to protect 125,000 hectares of virgin forest.
Companies such as Burger King and Habitat refusing to sell products that originate from the rainforest can also reduce deforestation.
Another effect that human activities are having on countries in the Southern part of South America is the rise of shanty towns that are built by many who lived in the rural part of Brazil who move to the urban area with promises of a better life.
Urbanisation in Brazil
Large numbers of people (as many as 500,000 a year) are migrating to Sao Paulo, Brazil in the hope of finding employment, housing, education and prosperity. The city struggles to cope with the large number of poor inhabitants. Yet for a very small number of rich people, the quality of life is good with high quality housing, well paid jobs and the ability to pay for good education, healthcare among many things.
For the vast majority the quality of life is poor. Most of the migrants, who have arrived in recent years, live in shanty town areas called "favelas" in Brazil. These slum area dwellings are built of cardboard, plastic sheets, corrugated iron and scrap wood: built illegally on land that does not belong to them. There is no running water, sewage system, gas, electricity, schools or hospitals. Jobs are unlikely to be available nearby so unemployment has become a major problem.
In the LEDCs, there is a high proportion of noise pollution; this is because so many people live in such close quarters. There is also a high level of sulphur dioxide and other atmospheric pollutants in the air due to pollution from cars and factories because the favelas and the areas around it are so close to the city and are very busy.
However, this does happen in both LEDCs and MEDCs due to congestion and cars becoming more of a “necessity” in the capital areas in many countries. However, wildlife and people living in LEDCs suffer far greater. For example, asthma is said to be triggered off by pollution and the equipment to help cope with asthma is very expensive in countries in poorer countries. The physical environment cannot be maintained or protected from the perils of pollution. In the favelas, life expectancy is short because disease such as TB and cholera spread quickly through bad sanitation and unhygienic living conditions.
It is also spread by waste disposal and unlike MEDCs, where the government provides a waste disposal system which is well regulated, waste disposal in LEDCs spread more ill health because the waste is piled up into a ‘tip’ and are not disposed of. They may also be built on when new homes need to house more people so rubbish carries on being piled up gradually among the favelas.
In the shanty towns there are no rules or regulations for building homes like the MEDCs, such as the UK so these because a great impact on the surrounding environment compared to MEDCs where housing is closely regulated which helps the levels of the population stay low.
However, the government is clearing some of the favelas and providing a limited number of better quality houses built of brick and concrete with a clean water supply, sewerage system and electricity. Some low paid jobs may be available in factories but they are usually a substantial distance from homes.
However, as Brazil is a LEDC there is not sufficient money to improve the quality of life for all the poor people flooding into an already overpopulated city.
Natural hazards and disasters-how MEDCs and LEDCs cope
In physical environments where there are many natural disasters, LEDCs and MEDCs cope differently when planning ways on preventing these disasters in the future.
There are many different strategies available for authorities to plan for future earthquake events and to cope with the impacts of seismic hazards. However, the degree to which these plans are carried out will depend on factors such as the degree of organisation, preparedness and availability of funds, technology and expertise. In MEDCs, such as the USA, the greater availability of these factors allows a variety of monitoring and preparation strategies.
Firstly, key faults can be monitored visually and electronically for signs of increasing strain and degrees of movement, even on a minute scale. This allows for some degree of warning or at least general prediction of when and where seismic events are likely to occur. However, this is a very uncertain and inexact process.
Secondly, building codes and planning and design guidelines can be revised to make new construction more earthquake-proof by using better materials and limiting heights or allowing buildings to ‘flex’ on their foundations. For example, counterweights can be placed on the roofs of high-rise blocks that will move in the opposite direction to the earthquake force, balancing the building. Cross bracing allows buildings to twist on their foundations, whilst rubber shock absorbers or metal bearings placed in foundations allow buildings to rock and sway. Existing buildings may be ‘retro-fitted’ where possible to improve their resistance to seismic waves. For example, the Golden Gate Bridge is currently being upgraded to resist an earthquake at eight on the Richter scale (it is already designed to be earthquake-proof up to 7). Often, the most severe damage has occurred where landfill or reclaimed land has been used for building - here loose sediments have foundered and liquefied due to the seismic waves, causing extensive damage and collapse. Therefore, city authorities such as San Francisco’s are now stricter when designating land use zones and giving planning permission for new construction to avoid such sites.
Thirdly, city and state authorities may develop evacuation plans and employ practice drills for earthquake safety. They can provide special training programmes for residents and emergency workers. These are intended to improve the general preparedness of the population and the ability of the emergency services to cope with the results of a major quake. Money and equipment can also be set aside to help cope with the immediate relief effort and to speed up the reconstruction after the quake.
In a poorer LEDC, the impacts of an earthquake may be much more severe because of the limitations imposed on these kinds of responses to the hazard by lack of funds, political organisation, technology or expertise and a poorly funded education system. Which means scientific and professional research is not developed to see how the environment works and how hazards such as earthquakes can be foreseen.
MEDCs are able to cope much better with the effects human activity can cause to the physical environment. MEDCs can afford to manage, maintain and protect physical surroundings from damage. MEDCs are also able to protect the inhabitants of the country and because they are able to afford education and research into the physical world, they in turn are able to educate others so they also know how to care for the environment. This means that they can forecast when future disasters are about to occur for such things as evacuation but they are also able but also how to prevent the Greenhouse effect and Global Warming from becoming much worse, for example, warning of the dangers of CFC sprays.
LEDCs are unable to cope with physical damage to the environment due to many countries having crippling National Debts to pay to richer countries so being exploited actually helps pay off debts so that becomes their main priority rather than the country’s inhabitants. They also have other problems to finance so physical environments slides further in the list of priorities. Also becoming a larger city with more people working is better for the economy so countries like Brazil may not be eager to make shanty towns smaller or clear them because less people are working in urban areas.
