Topic 8.1 - Human Populations and Dynamics Flashcards
Crude Birth Rate
The number of births per thousand individuals in a population per year
Crude Death Rate
The number of deaths per thousand individuals in a population per year
Natural Increase Rate
The rate of human growth expressed as a percentage change per yer
Doubling Time
The time it takes for the population to double in size
Total Fertility Rate
The average number of children each woman has over her lifetime
How do you calculate ‘CBR’?
Total numbers of birth/total population x 1000
How do you calculate ‘CDR’?
Number of deaths/total population x 1000
What is the weakness of ‘CDR’ as a measure of death rates?
It is a poor indicator as populations with many old people (MEDCs) have higher CDRs than countries with more younger populations (e.g. Denmark)
Why is the world’s population increasing so fast?
Factors such as education, health, poverty, place of residence and social class.
Where is population growth more common and why?
Less economically developed countries as they are less educated, and believe they need more children to help them make a living and take care of them in the future.
Why is population growth slower in MEDCs?
More economically developed countries believe they cannot raise children with a low income which means they can only have children if it does not affect their standard of living
What is exponential growth?
When the population is growing, and there are no limiting factors slowing the growth.
What are the impacts of exponential growth?
Huge amounts of extra resources needed to feed, house, clothe and look after the increasing number of people
How do humans exploit the Earth’s resources using fossil fuels?
The burning of fossil fuels leads to an increase in atmospheric sulfur dioxide –> causes acid rain.
How does acid rain impact the environment?
Devestating consequences on biodiversity as many plants and animal species cannot survive in these conditions. As the rain becomes more acidic biodiversity decreases
How does untreated sewage impact the environment?
If untreated sewage is released into rivers it provides food for bacteria, which will increase in number and use up the oxygen supply of the water –> results in a decrease in species diversity
How does deforestation impact the environment?
Can result in habitat destruction, a reduction in soil fertility and poor soil structure leading to a decrease in biodiversity
How does desertification impact the environment?
Decreases biodiversity as only species that can survive in a dry habitat will remain in these areas
How does grazing impact the environment?
Low grazing intensisties –> the biodiversity of grassland is low because of a few species of plants are able to outcompete the others
As intensity increases the biodiversity increases as the dominant plant species are kept in check by grazers and the weaker competitors are able to grow
At very high intensities –> biodiversity decreases because only plants with adaptations can tolerate the effects of grazing
How do pesticides impact the environment?
Can have adverse effects on environment if they are not biodegradeable and accumulate in the bodies of organisms over time
Up the foodchain the concetration of pesticides found increases resultig in the toxicity reaching fatal levels in the organism
What does the DTM (demographic transition model) show us?
Countries progress through recognized states in the transition from LEDC to MEDC.
Suggests that death rates fall before birth rates and the total population expands
Discuss how cultural, historical, religious, social, political, and economic factors can influence population dynamics.
Some agriculture cultures see that having more children help with working the land. While other cultures where women are employed and education have low birth rates.
Religious believes include family planning. Most religions are pro-natalists.
Social pressures are put on many women in more traditional societies to have children
Governments may be pro-natalist or anti-natalists
Availability of clean water, sanitation, adequate housing, reliable food supply, diseases, healthcare, occupation, civil conflicts
Policies that reduce population growth rate:
Pension schemes reduce parents reliance on their children for care when they are elderly.
Taxes and poor job security can lead to a decision to have a smaller family.
Any policy that stimulates economic growth usually leads to increased education and therefore knowledge of birth control.
Urbanisation limits physical space to have large family.
Policies directed at educating and liberating women.
Policies that increase population growth rate:
Agricultural development, improved public health and sanitation etc. may lower CDR and stimulate rapid growth without lowering fertility (stage 2 of DTM)
Lowering income tax or giving incentives and free education may increase CBR. E.g. Australian baby bonus
Encourage immigration, particularly of workers. Especially if immigration is from less developed countries.
Analyse age-gender pyramids and diagrams showing demographic transition models
a wide base indicates a high birth rate
narrowing base suggests falling birth rate
straight or near vertical sides reveal a low death rate
concave slopes characterize high death rates
bulges in the slope indicate immigration or in-migration
deficits in the slope indicate emigration or out-migration or age-specific or sex-specific deaths (epidemics, war)
Birth rates decline because
children are very costly
the government looks after people through pensions and health services
more women want their own career
there is a more widespread use of family planning
as the infant mortality rate decreases there is no need of child replacement
Death rates decline because
clean water
reliable food supply
good hygiene and sanitation
lower population densities
better vacations and healthcare
rising standards of living
People want children: ( High Birth rates)
for labour
to look after them in old age
to continue the family name
prestige
to replace children who have died
People die from: (High Death rates)
lack of clean water
lack of food
poor hygiene and sanitation
overcrowding
contagious disease
poverty
China - Anti-natalist policy
China instilled an anti natalist policy to help combat population explosion. Imbalances between population and available resources were steadily increasing. China has 7% of the world’s agricultural land and 23% of the world’s population.
The idea was to encourage economic development and improve the standard of living for the population.
1953 - First modern census takes place in China. The population comes in as 583 million.
Between 1953 and 1964 the population increased by 112 million as Mao Zedong encouraged larger families in an attempt to make China stronger.
Attempts to slow down population growth were started in the 1970s using the slogan “Later, longer, fewer”. People were encouraged to limit families to two children.
1979 - One child policy introduced.
