Causes of sparse population:
- Mountainous area e.g. Himalayas that are hard to build houses and transports links on.
- Very hot or very cold area e.g. Sahara desert or Antarctica
- A heavily forested area e.g. the Amazon Rainforest
- Areas that flood a lot e.g. Mekong river delta
- No jobs
- Poor supply of electricity, gas and water
- Poor communications
- Shortage of natural resources
- No schools or hospitals
- Areas that regularly suffer from natural disasters e.g. volcanoes or droughts
Causes of dense population:
- Coastal areas that are good for fishing, trading etc.
- A flat area of land that is easy to build on
- Areas that are close to a good supply of water e.g. River Thames in London. Water is important for fishing, drinking, washing, etc.
- Areas with good natural resources e.g. wood or good
- Areas that are close to good fertile agricultural land
- Areas with good developed transport links
- Plenty of available jobs
- Available electricity and water supply
- Good communications e.g. internet and mobile phone network
- Good quality schools and hospitals
Why might birth rates be high?
- Lack of contraception e.g. condoms
- Religious beliefs e.g. belief against contraception and abortion (Roman Catholicism)
- Agricultural based society (need for people to farm and collect water)
- High infant mortality (if some babies may die, couples will be tempted to have more children)
- No care homes or pensions so old dependents will need their children to care for them in old age.
- Pro-natalist policies (governments encouraging couples to have more children)
Why might birth rates be low?
- Availability and affordability of contraception e.g. cheap or free condoms
- Emancipation (freedom) of women (freedom to get an education and work)
- Improved levels of education (especially female)
- Reduced infant mortality
- Introduction of pensions and care homes
- Development of economy into secondary and tertiary sectors
- Increasing cost of children
- Delayed marriages and less children
- Anti-natalist policies e.g. China's one child policy
- High cost of raising children
Why might death rates be high?
- Natural disasters (often only causes short term increases) e.g. Indian Ocean tsunami
- Conflicts and wars
- Poor medical care
- Poor hygiene and sanitation
- Poor diet (might be a shortage of food or unhealthy food)
- Drinking alcohol, smoking or taking drugs
- Lack of exercise (sedentary lifestyle)
- Shortage of clean water
- Diseases e.g. cancer and AIDS
Why might death rates be low?
- Immunisation programs e.g. small pox
- Availability of clean water
- Improved diet and knowledge of diet e.g. five portions of fruit and diet
- Improved levels of exercise
- Improved medical care
- Improved preventative testing e.g. for cancer so people can be treated before it kills them
Problems with Overpopulation:
- There could be unemployment because there are not enough jobs for everyone
- There could be a shortage of schools and hospitals
- There could be a shortage of hoses and informal settlements grow
- Congestion may increase as there are more cars, buses, etc. on the road
- Prices may increase as demand for houses, resources, etc. increase (inflation)
- There may be a shortage of clean drinking water, electricity, etc.
- There may be an increase in air, noise and water pollution e.g. open sewers, fires, etc.
- The rural-urban fringe may be damaged as informal settlements are built
Problems with underpopulation:
- There are a shortage of workers
- There will be less people paying tax
- Schools and hospitals may close because there are not enough clients
- Public transport links might close because of less customers
- There may be less innovation and development (lee brain power)
- Not possible to exploit all resources
- Hard to defend country
- Necessary to attract migrants
Causes of high HIV rates:
- Lack of education about HIV (causes, transmission, prevention).
- Availability and affordability of condoms, as well as knowledge of how they are used.
- Pologymy. The tradition of taking more than one wife.
- Lack of testing. Much of the population does not know that it has HIV.
- Prostitution. Many prostitutes are infected but don't know so continue to transmit the disease.
- Sexual crime. There is a high rate of sexual crime in South Africa which helps spread the disease
- Urban myths. Many uneducated people believe myths about HIV that are untrue. For example Jacob Zuma believed a shower after sex would reduce chance of catching HIV.
- Migrant population. When a lot of people move for work HIV can be spread easily between communities.
- Religious beliefs. some religions don't allow the use of condoms. However, it must also be remembered most religions discourage sex before marriage and promote only one sexual partner (husband and wife)
- Poor medical hygiene - possibly dirty medical equipment and untreated blood
Impacts of HIV:
- Individually, people will experience a decline in their immune system, becoming sicker and possibly dieing.
- High cost of having to treat HIV and AIDS patients.
- There will be an effective increase in the dependency ration because less people will be able to work because of sickness.
- The country may see a reduction in tourism and investment as people are reluctant to travel to a country with high infection rates.
- The country will have to pay large amounts of money to be able to buy anti-retroviral drugs (this is not a cure, but it helps support victims immune system).
- Life expectancy rapidly reduces in countries with high infection rates and death rates increase.
- There are a large number of orphans as many parents die.
- There may be a shortage of workers which can lead to economic decline and food shortages. There may not be enough essential workers like teachers.
Solutions to HIV:
- Providing free condoms and educating people about how to use them correctly.
- Educating about what HIV is and explaining how the spread can be reduced and stopped. Because many people in rural Africa may be illiterate education might have to be done through posters or theatre (drama).
- Test more people to find out who is infected.
- Legalise prostitution to encourage more prostitutes to be tested and hopefully reduce the spread of HIV
- Anti-retroviral drugs can be sold cheaper so that more people have access to them
- Hopefully, scientists will eventually find a cure for HIV so that it can be eliminated.
- Encouraging no sex before marriage and trying to reduce the number of peoples sexual partners.
- Try and reduce the stigma of HIV and AIDS so more people talk about it and are happy to be tested.