Core Theme 1 - Patterns And Change Flashcards
Exponential growth
An increasing or accelerating rate of growth
How much of the world’s population growth is taking place in developing countries?
Up to 95%
Annual growth rate
Found by subtracting the crude death rate from the crude birth rate and then expressed as a percentage
Crude birth rate
The number of births per 1000 people in a population
General fertility rate
The number of births per 1000 women aged 15-49 years
Age-specific birth rate
The number of births per 1000 women of any specified year groups
Standardised birth rate
A birth rate for a region on the basis that its age composition is the same as for the whole country
Total fertility rate
The average number of births per 1000 women of childbearing age
What proportion of the world’s population is over 60? What will that rise to by 2100?
About 10% of the worlds population is over 60. By 2100, that proportion will have risen to one-third
What is the disadvantage of the Crude Birth Rate?
It doesn’t take into account the age and sex structure of the population
Why do you get high birth rates?
Parents want children
- for labour
- to look after them in old age
- to continue the family name
- for prestige
- to replace other children who have died (high IMR)
- children are net contributors to family income
Why do birth rates come down?
- children are costly
- the government looks after people through pensions and health services
- more women want their own career and have higher status
- widespread use of family planning
- falling IMR reduces need for replacement children
- urbanisation + industrialisation associated with social changes + decline in traditional beliefs + customs
Infant Mortality Rate
The number of deaths of children less than one year old per 1000 live births
Child mortality rate
The number of deaths in children under the age of 5 per 1000 children
Case study: Population growth in Africa
- fastest growing pop. in world
- by 2050 population predicted to be 1.6 billion
- may put burden on foods, jobs, schools, housing, healthcare
- but youthful pop. = large workforce
- worlds highest fertility rate Niger (7.4)
Why does Africa’s population continue to rise?
- low life expectancy
- fertility tends to be high when mortality is high
- in parts of Africa only 28% married women use contraception because
- women may not have control over own bodies
- access to reproductive health services limited due to
- poverty
- underdevelopment
- limited education
- resources
Case study: Falling populations in Serbia
- population is shrinking
- Serbia has 7.2million but declining by 30,000 a year
- war years and economic hardship have led to fewer children, mass emigration and high abortion rates.
- particularly due to the emigration of so many women of childbearing age
When are death rates generally high?
- lack of clean water + food
- poor hygiene + sanitation
- overcrowding
- contagious diseases e.g. diarrhoea
- respiratory infections
Poor rural areas, shanty towns, refugee camps
When do death rates decline?
- clean water
- reliable food supply
- good hygiene + sanitation
- lower population densities
- better vaccination + health care
Why is the crude death rate a poor indicator of mortality trends?
Populations with a large number of aged people (most MEDCs) will have a higher CDR than countries with more youthful populations
Life expectancy
Average number of years that a person can be expected to live, usually from birth, if demographic factors remain unchanged
What does a wide base suggest?
A wide base suggests a high birth rate
What does a narrowing base indicate?
A narrowing base indicates a falling birth rate
What do straight or near-vertical sides show?
Straight sides show a low death rate
What does a concave slope suggest?
A concave slope suggests a high death rate
What do bulges in the slope suggest?
Bulges in the slope indicate high rates of in-migration.
For instance, excess males of 20-35 years could be economic migrants looking for work.
An excess of both male and female cohorts could be due to a baby boom
What do deficits in the slope show?
Deficits in the slope show out-migration / age-specific or sex-specific deaths (such as epidemics or war)
Doubling time
Doubling time is the length of time it takes for a population to double in size, assuming its natural growth rate remains constant
Population momentum
The tendency for population to grow despite a fall in the birth rate or fertility levels. Also the tendency for a population to continue to fall despite a rise in the birth rate.
Why does population momentum occur?
It occurs because of a relatively high concentration of people in the pre-childbearing and childbearing years. As these young people grow older and move through their reproductive years, the greater number of births will exceed the number of deaths in the older populations, and so the population will continue to grow.
Population projections
Population projections are predictions about future population based on trends in fertility, mortality and migration trends
How is the dependency ratio calculated?
Population aged <15 + population aged >64 (dependents)
Divided by
Population aged 16-64 (economically active)
Advantages of youthful population
- large potential workforce
- lower medical costs
- attractive to new investment
- sources of new innovation + ideas
- large potential market for selected goods
- development of services e.g. schools
6 Disadvantages of youthful populations
- cost of supporting schools and clinics
- need to provide sufficient food, housing and water to a growing population e.g. Kibera, Nairobi
- high rates of unemployment
- large numbers living in poor quality housing e.g. in shanty towns
- high rates of population growth
- high crime rates