8.1: human population dynamics

Question 1

demographics

Answer 1

study of the dynamics of population change

Question 2

reasons for the uncertainty in predicting the world’s population -

Answer 2

• different models/scenarios/fertility rates might use different figures in their
  calculations
• difficult to determine how the demographic policies of countries might change
• factors outside our control eg. disaster / disease / war

Question 3

demographic tools for quantifying human population include:

Answer 3

crude birthrate (CBR)
crude death rate (CDR)
total fertility rate (TFR)
doubling time (DT)
natural increase rate (NIR)

Question 4

crude birth rate:

Answer 4

the number of live births per 1000 people in a population.

Total number of births/total population X 1000 = CBR.

CBR does not calculate the age and sex structure of the population.

Question 5

crude death rate:

Answer 5

the number of deaths per thousand people in population.

CDR= number of deaths/total population X 1000.

poor indicator as populations with many old people (MEDCs) have higher CDRs than countries with more younger populations. (ex: Denmark 11% and Mexico 5%)

Question 6

natural increase rate:

Answer 6

this excludes migration.

(crude birth rate - crude death rate)/10

Question 7

total fertility rate:

Answer 7

the average number of births per woman of child-bearing age.

(if rate > 2, population is increasing; if rate < 2, population is decreasing)

Question 8

general fertility rate:

Answer 8

the number of births per thousand woman aged between 15-49 years old.

Question 9

age-specific birth rate:

Answer 9

the number of births per 1000 women of any specific year group.

Question 10

doubling rate:

Answer 10

the time it takes for a population to double in size.

doubling time=70/NIR (percentage growth rate)

eg. India
Birth per 1000 per year = 28
Death per 1000 per year = 9

NIR = 28-9/10= 1.9 %
Doubling time = 70/1.9= 36.84 years

Question 11

infant mortality rates:

Answer 11

the number of deaths of children under 1 years old per 1000 live births.

Question 12

birth rates decline because?

Answer 12

• children are very costly
• the government looks after people through healthcare and pension 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

Question 13

reason for large families?

Answer 13

• historically high mortality rate
• modern medicine reduced infant mortality
• security in old age - tradition of families
• children are an economic asset in agricultural societies
• status of women - in some LEDC’s their social status depends on the no. of children they produce
• unavailability of contraceptives - in LEDC’s women are either too poor to pay for them or do not have access to it

Question 14

how to control family size?

Answer 14

1. educate women
2. improve medicine & healthcare
3. make contraception & family counselling available
4. enhance income by small-scale projects focusing on the family level
5. improve resource management

Question 15

low death rates because?

Answer 15

• clean water
• reliable food source
• good hygiene and sanitation
• lower population densities
• better vacations and healthcare
• rising standards of living

Question 16

high death rates because?

Answer 16

• lack of clean water
• lack of food
• poor hygiene and sanitation
• overcrowding
• contagious disease
• poverty

Question 17

as human population grows, increased stress is placed on all of the Earth’s systems by -

Answer 17

• fossil fuels : SO2
• sewage : If untreated sewage is released into rivers it provides food for bacteria, which will increase in numbers and use up the oxygen supply of the water.
  this results in a decrease in species diversity since only species that can live in areas with low oxygen concentrations will survive.
• deforestation
• desertification
• overgrazing
• pesticides : non- biodegradable - bio magnification

Question 18

demographic transition model

Answer 18

pattern of decline in mortality and fertility of a country as a result of social and economic development

Question 19

stages 1 & 2 of the demographic transition model:

Answer 19

stage 1: high stationary (pre-industrial societies) - high birth rate (no birth control), high infant mortality rates, cultural factors encouraging large families, high death rates (due to disease, famine, poor hygiene, little medicine)

stage 2: early expanding (LEDC’s) - death rate drops as sanitation and food improve, disease is reduced so lifespan increases, birth rate is still high so population expands rapidly and child mortality falls due to improved medicine.

Question 20

stages 3, 4 & 5 of the demographic transition model:

Answer 20

stage 3: late expanding (wealthier LEDC’s) - as a country becomes more developed, birth rates fall due to access to contraception, education, emancipation of women. population begins to level off and desire for material goods & low infant death rates mean people have smaller families.

stage 4: low stationary (MEDC’s) - low birth and death rates, industrialised countries. stable population sizes.

stage 5: declining (MEDC’s) - population may not be replaced as fertility is low. problems of ageing workforce.

Question 21

policies that may increase population growth rates:

Answer 21

• agricultural development, improved public health & sanitation, etc may lower death rates & stimulate rapid population growth w/o significantly affecting fertility.
• lowering income tax or giving incentives and free education and healthcare may increase birth rates eg. Australia baby bonus
• encouraging immigration, particularly workers - for eg russia allows migrants to work who do not have qualifications to fill the gap of manual labour

Question 22

policies that may reduce population growth rates:

Answer 22

• parents in subsistence communities may be dependent on their children for support in later years & this creates an incentive to have kids. so if the government introduces pension schemes, the CBR comes down.
• if you pay more tax to have more children or even lose your job, you may decide to have a smaller family.
• policies that stimulate economic growth may reduce birth rates as a result of increased access to education about methods of birth control.
• urbanisation decreases CBR as fewer people can live in the smaller urban accommodation.
• policies directed towards education of women - enables personal & economic independence, thus lowering fertility & population pressures.

Question 23

how a country’s stage in the DTM might
influence its national population policy -

Answer 23

in stages 1/2 it might implement programmes to improve living standards such as:
- improve health care access/facilities
- vaccination policy to reduce child mortality
- invest in campaigns/education informing people on hygienic measures
- fight poverty / improve economic development
- ask for international medical/economic aid

in stages 2/3 it might implement programmes to slow population growth / achieve population stability such as:
- anti-immigration policies
- policies that increase the independence of women
- increase access to contraception/sex education
- support family planning programs (governmental or by NGOs)
- put a limit in number of children per family (one-child policy)

in stages 4/5 it might implement programmes to increase population growth / stop
population decline, such as
- pro-immigration policy
- economic incentives for additional children / eg. baby bonuses / family allowances /
tax deductions
- social incentives for larger families, / eg. maternal and paternal leaves, flexible work
schedules, public office for parents of more than 3 children, free schooling/nursing