Population and Environment, population change Flashcards
1
Q
What are the vital rates which affect natural population change?
In this context, rate = measurement of an aspect of the population
A
- Birth rate
- Death rate
- Infant mortality rate
- Replacement rate
2
Q
What is birth rate and how is it measured?
A
- Birth rate is the most common measurement of fertility - how many babies are born.
- It is measured per 1000 - e.g., around 11.3 births per 1000 people in the UK.
- Formula = (total number of births per year÷total mid-year population) x1000
3
Q
Where are birth rates highest in the world?
A
Birth rates are highest in poorer countries where infant mortality rates are high and children are valuable working assets to support their parents.
-E.g., subsistence farmers need children to help farm.
4
Q
What is death rate, how is it measured?
A
- The death rate is the number of deaths per 1000 in a population.
- Formula = (total number of deaths in a year ÷ total mid year population) x1000
5
Q
Why is death rate important and how has it changed in the 20th century?
A
- It is important because it impacts population growth. Generally more death = less growth, and less death = more growth.
- The 20th century has seen a global reduction in death rate due to improvements in medical services, diet, and immunisation.
6
Q
What is infant mortality rate and where is it highest?
A
- Infant mortality rate is the number of deaths of infants before the age of 1 per 1000 births.
- Tends to be highest in LDEs.
7
Q
What is replacement rate and how is it measured?
A
- The replacement rate shows the extent to which a population is replacing itself.
-
Can be measured in a few ways:
>Fertility rate = the average number of children a woman will have. Can be higher than 5 in some LDEs but is often lower than 2 in HDEs.
> Replacement level = the number of children needed per woman to maintiain the population size. It is usually considered to be around 2.11, though does not account for migration.
> Net reproductive rate = the average number of daughters produced by a woman in her life. A stable population has a rate of 1.
8
Q
What is the demographic transition model?
A
- The demographic transition model is a model to show the stages of change in population size, birth rate, and death rate that a population experiences through time and development.
9
Q
What does a age-sex pyramid show?
A
- rising growth rate results in a youthful population
> flared base - galling or negative growth rate results in an aging population
> top heavy pyramid
> will also show female longevity - lesser influences are also shown
> slight bulges could be for net immigration
> slight indentations could be for net emigration
> after war or natural disaster there will be a decrease in young people but a post-war baby boom - proportions for each age group can be shown using raw population data or as a percentage of the total
10
Q
What is the dependency ratio?
A
- children and the aged are unproductive do are dependent on the wealth-producing economically active adults
- in LDE its more common for children to work at a young age
- in HDE is the reverse
Formula = (dependent population ÷ working population) x 100
11
Q
What are the types of migration?
A
- Temporary migration
> diurnal (daily) movement to and from home
> seasonal movements associated with agriculture, transhumance
> international migrations - step migration
> migration in a series of shorter movement from the place of origin to the final destination - forced migration
> after natural disaster, persecution, or wars
> can be local or international scales
> asylum seekers - permanent migration
>permanent change of residence
> has distance decay: the shorter the move the less upheaval, so there is more migrants involved/the further away, the less migrants involved - Voluntary migration
> current circumstances and the hope that a better standard of living is possible elsewhere
> may form a migration stream if there are many from a particular country/religion going to a certain destination
12
Q
What are the push and pull factors for migration?
A
- push factors repel
> physical factors such as soil and natural disaster
> economic and social issues such as poverty
> lack of job opportunities - pull factors attacts
> seeking better job opportunities
> better standard of living and education
13
Q
What are the positive outcomes of migration on the origin country?
A
- overpopulation pressures may be reduced
- less demand for services like education and health care
- remittances support relatives
14
Q
What are the positive outcomes of migration on the host country?
A
- labour pool increases and new trades and skills are introduced
> doctors, scientific researchers - migrant workers are mobile, pay taxes, and spend money
> creates jobs and wealth - cultural and racial variety promotes diversity and encourages integration and understanding
15
Q
What are the negative outcomes of migration on the origin country?
A
- skilled labour shortages
> especially in professionals like doctors - gender imbalances
> more men than women migrate - ageing population structures
> those of working age are more likely to migrate, reducing productivity and economy of rural communities
