1.1 Population dynamics

Theme 1. Population and Settlement

1.1 Population dynamics

Reasons for recent rapid population growth (‘population explosion’):

-improved medical care – vaccinations, hospitals, doctors, new drugs and scientific inventions

-improved sanitation and water supply

-improvements in food production (quality & quantity)

-improved transport – moving food, doctors etc.

-decrease in child mortality

Population growth terms:

            -Migration:  the movement of people (or animals) from one country or region to another

            -Birth rate: average number of live births in a year for every 1000 people

            -Death rate: average number of deaths for every 1000 people

Population growth is related to the amount of resources available for example water, wood and minerals

Carrying Capacity – The number of people the environment can support without there being negative effects to the population.

Optimum Population – This is the amount of people that a region/country can ecologically support, usually less than carrying capacity.

Under-population – This is when country has declined too much that it can’t support its economic system.

Overpopulation – Too much population of an area: overcrowding, depletion of resources.

HIV/AIDS

Origins

HIV-1 – arose in Central Africa

HIV-2 – arose in West Africa

HIV mostly occurs in women. When women give birth, they infect the child as well resulting in low death rate for infants.

Death rate of mothers results in a higher orphan generation. (Year 2000 – 600000 orphans). Due to the countries being poor, there is a lack in state welfare, resulting in poverty and lack of education.

Population pyramid general format:

Stage 1: high birth rate; high death rates; short life expectancy; less dependency (since there are few old people and children have to work anyway)

Stage 2: high birth rate; fall in death rate; slightly longer life expectancy; more dependency as there are more elderly

Stage 3: declining birth rate; declining death rate; longer life expectancy; more dependency

Stage 4: low birth rate; low death rate; highest dependency ratio; longest life expectancy

High death rates in LEDCs are caused by:

• poor health care/few hospitals/doctors/nurses/clinics;
• poor sanitation/poor hygiene/lack of toilets/dirty places;
• poor access to safe/clean water/water borne diseases;
• limited food supplies/malnutrition/starvation;
• HIV/AIDS;
• Natural disasters/drought/floods;
• Lack of vaccinations/medicines/cannot cure diseases;
• Lack of education about healthy lifestyles e.g. smoking/diet;
• Lack of provision for elderly e.g. pensions/old people’s homes

Birth rates are low in MEDCs because:

• availability of contraception/family planning/abortions;
• educated re. contraception/family planning;
• able to afford contraception/family planning/abortions;
• traditionally small families/don’t need to prove virility/not traditional to have large families;
• expense of bringing up children/childcare/don’t have to send children to work/can afford
• to bring up children;
• many women have careers/women are educated;
• availability of pensions/do not need children to look after parents in old age;
• low infant mortality rate;
• Lack of religious beliefs/don’t object to contraception

The Demographic Transition Model:

Population distribution and density factors:

-Human: better housing opportunities, education, health, entertainment, retirement areas,

-Physical: relief (for farming, defence), climate, water supply, resources

-Economic: ports, transport links, industrial areas, tourist areas, money available for high-tech industries

Dependency ratio = non-economically active / economically active × 100 %

Migration: the movement of people (or animals) from one area to another, some types are:

Voluntary migration causes:

• find a job, or a better paid job
• pioneers developing new areas
• trade and economical expansion
• territorial expansion
• better climate
• social amenities
• be with friends/family

Forced migration causes:

• avoid religious/political persecution
• avoid war
• slavery/forced labour as a prisoner of war
• racial discrimination
• famine
• natural disasters
• overpopulation

Problems for international migrants include:

•    lack of qualifications/skills/education/no experience/they have to do 
•    unskilled jobs/work informally;
•    many are doing low paid jobs;
•    poor working conditions/dirty jobs/long hours/exploitation by employers;
•    many cannot speak the language;
•    some are unable to obtain employment/not enough jobs;
•    can’t afford education/health care/food/housing etc.;
•    live in poor conditions/overcrowding/lacks sanitation;
•    some may have to live away from their families;
•    discrimination may occur/racism;
•    some may lack documentation/have to hide from authorities;
•    trouble adapting to culture/religion etc.

Internal migration is within a country e.g. rural/urban depopulation, regional

External or international is between countries e.g. Negro slaves to America (forced) or Mexicans into the US (voluntary)

(There are other types: seasonal, daily, permanent, temporary, semi-permanent etc.)

Advantages	Disadvantages
Losing country
Reduces pressure on resources	Loss of people in working age group
Decline in birth rate	Loss of the educated and skilled people
Migrants can bring back new skills	Division of families
Money is sent back	Left with an elderly population – high death rate
Receiving country
Overcomes labour shortage	Pressure on jobs
Dirty unskilled jobs are done	Low quality& overcrowded housing = ugly
Will work long hours & low salary	racism
Cultural advantages and links	Language problems
	Less healthy
	Less religious amenities for immigrants (but more are built, this is a problem in Switzerland as the Swiss don’t like when Arabs build their religious place thingy)