Knowt
Human Population Chapter 8 EVM 0608
Human Population Distribution and Density
Population density: population per area (figures providing an average value).
Population distribution: how the population is spread over an area.
For example: very few or no people live in deserts and mountains, whereas populations are very high in coastal areas due to availability of fresh water.
Changes in Population Size
Population: all the organisms of one species living in a defined area at the same time.
Lag phase: the period in population growth when an organism is adapting to its new environment and the growth is slow.
Log/exponential phase: when the growth rate of a population increases over time as all requirements are in superabundance.
Stationary phase: when the growth rate of a population has slowed down to zero as the carrying capacity is reached.
Carrying capacity: the maximum size of a population that an environment can support in terms of food, water and other resources.
Birth and Death rate
Birth rate: the number of live births per thousand of the population per year.
Death rate: the number of deaths per thousand of the population per year.
Natural increase: the difference between birth rate and death rate.
Factors affecting birth rate:
Family planning - contraption, abortion, sterilization, even tho it is ultimately a couple’s choice, but governments can intervene, e.g. providing free contraception or making it unavailable
Improved health and education - education can create tendencies of late marriages and late child bearing, but aids in better family planning. Better health care decreases infant mortality, decreasing birth rates.
National population policies - pronatalist policies (government encouraging increased childbirth, through benefits and pensions) and anti-natalist policies (discouraging childbirth through provision of family planning, contraceptives and education, to laws limiting number of children)
Factors affecting death rate:
Health care access - access to better health care helps combat illnesses and increase living standard.
Social factors - conflicts and levels of violent crimes, effect the safety and lives of people.
Economic conditions - LEDCs with lower economic conditions have higher death rates due to inadequate healthcare and nutrition.
Migration
Migration: the movement of people into (immigration) or out of (emigration) a region, country or area.
The most common worldwide movement is from rural to urban areas in LEDCs.
Sometimes, urban-to-rural migrations also occur, mostly in MEDCs.
Population growth: (birth rate + immigration) – (death rate + emigration)
Push factors: factors that encourage people to move away from an area. | Pull factors: factors that encourage people to move into an area. |
|---|---|
Drought/famine; | Good supplies of food, whatever the weather; |
Poverty; | Well-paid jobs; |
Poor links with the outside world; | Good roads; |
Poor services; | Hospitals, schools, water, electricity; |
Work on the land only, subsistence; | Factory, shops, and office work for a wage. |
Desertification; | No comparable pull factors |
Sea-level rise; | |
Seasonal weather events. |
Population Structure
Population/age pyramid: a diagram that shows the proportion of the population that is male and female in different age groups (usually 5-year interval).
Expanding (young) populations (Afghanistan 2015): a typical pyramid for LEDCs with a high proportion of young people due to a high birth rate.
Stationary populations (USA 2016): a population that is almost stationary, with a rectangular shape, except at the top when older adults die.
Contracting (old) populations (Japan 2016): the population is declining because of low birth rates, and its pyramid is top-heavy because of low death rates.
Dependant: those people in the population who are not economically active (working), i.e., the young (<16) and old (65+) and thus rely on those who are working for their needs.
Independent: those people in the population who are economically active (working), i.e., the middle-aged (between 17 and 65).
Taxes from the independent population are used for:
Education for the youngsters and provision of school places for the children yet to reach school age.
Creating care-home places and hospitals for the aging population.
Managing Human Population Size
Family planning: methods used by couples to decide the number of children to have and when, which is mostly encouraged by governments
Contraception: used to prevent pregnancy.
Improved health and education: make people more aware of methods to limit family size.
Educated women may plan a career as well as have children, the former frequently limiting how many children are born.
Education can also lead to a tendency for later marriages and, thus, later childbearing.
High infant mortality causes couples to have more children. When it is reduced by better healthcare and sanitation, the trend is reversed.
National population policies:
Pronatalist policy: a national or regional policy that aims to encourage couples to have children.
In countries like France, couples were encouraged to have more than 2 children.
Parents are paid the equivalent of the minimum wage for a year after they have a third child.
They enjoy subsidised train fares, pay less tax for the more children they have, and subsidised daycare.
Antinatalist policy: a national or regional policy that aims to discourage couples from having children.
In LEDCs, the population increases too fast, and these policies can form weak measures such as the provision of family planning, contraceptives and education, to laws encouraging couples to have only one child.
Some countries have no population policies at all and usually have high birth rates.
