Unit 3 Managing human population

What’s the formula for population density?

What’s the formula for population density?

total population/land area

• # of ppl per km²

What’s the formula for intrinsic growth rate?

dN/N₀

• dN = (births + immigration) - (deaths + emigration)

• N₀ = original population

What is doubling time and its formula?

period of time required for a population to double in size

• Rule of 70: 70/percent

How can environmental factors impact population density + distribution?

natural resources, geographic & climatic factors

• Large, flat lowland plains are easier to access + better for food production than mountainous areas

• Areas w/ few extreme weather events are more appealing

• Areas w/ fertile soil like river deltas tend to have higher populations than areas with high rainfall (leached soil) & cold areas with permafrost

• A secure water supply

• Areas w/ a wealth of natural resources

How can economic factors impact population density + distribution?

• Agriculture is a primary industry & is manufactured by a secondary industry

  • These increase job opportunities & standard of living, causing population growth

• Areas w/ good transport links are often more densely populated due to trade links

How can political factors impact population density + distribution?

• Government policies have an impact on population density

  • Can encourage/discourage investment in an area

  • War is a ‘push’ factor & causes out migration + decrease in food production

How does high infant mortality rates in LICs impact birth rates?

causes high birth rates

• Due to: spread of disease & lack of both medical care + access to clean water

What’s death rate influenced by?

climate, medical facilities, living standards, & social conflict + crime rates

How does life expectancy increase?

increased standards of living, access to both clean water & nutrition, & education improvements

What’s a Stage 1 population pyramid?

• (pre-industrial): high birth & death rate w/stable population

  • Rarely found & low life expectancy

What’s a Stage 2 population pyramid?

• (transitional): declining death rate (due to medicine, better nutrition, & clean water)

What’s a Stage 3 population pyramid?

• (industrial): birth rate declines from stage 2, death is still declining/low

  • Less population growth than stage 2; birth rates can typically be controlled by contraceptives

  • Avg. life expectancy increases & mortality rates stabilize

What’s a Stage 4 population pyramid?

• (late-industrial): low birth & death rates

  • Population size fluctuates due to economic conditions; slow growth

What’s a Stage 5 population pyramid?

• (post-industrial): birth rate is lower than death rate

  • Older population reaches full life expectancy

What’s a dependency ratio?

relationship b/t a country’s working & non-working populations

• Dependent: ages 0 to 14 (young)& 65+ (old)

• Independent: age 15-64

What’s the formula for dependency ratio?

[young population (0 to 14) + old population (65+)] × 100 / population aged 15 to 64

• Expressed as # of dependents per hundred ppl in the workforce

• Considered high when it’s above 62%

How can dependency ratio decrease?

• young population reaching working age

• anti-natalist policy

• immigration of working age ppl

• lower birth rate

What’s an ageing population?

population w/ a high percentage of older people

• Occur when birth rates decline & life expectancy increases — typically stage 5

• Average age is increasing due to: better nutrition, sanitation, standard of living, & care

What are some impacts of an ageing population?

• Shrinking workforce impact economy

• Pensions may be insufficient to care for older populations - higher spending

• Health care systems have more pressure since older ppl need more care

• Increased retirement age, so gov’ts can collect extra taxes

What is the Club of Rome?

aims to alert the world about consequences of a rapidly growing population → focused on sustainable economic growth + limited population growth

What is UN Agenda 21?

plan of action to limit human impact on the environment

What are pro-natalist policies?

encourage ppl to have children & increase birth rates

What are some examples of pro-natalist policies?

• Shrinking populations pressure a country’s workforce + financial stability

• Monetary incentives, childcare assistance, free schooling, & monthly grants

What is anti-natalist policy?

discourage ppl from having children & decrease birth rates

What are some examples of anti-natalist policy?

• Increasing populations that cause declining mortality rates & high rates of poverty

  • e.g) China’s One Child Policy

• Other policies include:

  • encouraging marriage later in life

  • increasing access to contraceptives & family planning

  • improving education + employment opportunities for women

  • making abortions legal + safe

What’s a limitation of anti-natalist policy?

Can cause an ageing population + declining workforce