Population and Urbanisation Flashcards
Types of Countries
o More developed countries (MDC)
o Less developed countries (LDC)
• Less industrialised
• Live on approximately $8 per day
• Struggling with overpopulation – rapid growth presents unprecedented problems
• New & affordable engineering solutions are needed
Human Development Index
EDU: education GNI: income HEALTH: health MYS: mean years of schooling EYS: expected years of schooling HDIx EDUx HEALTHx GNIx MYSx EYSx HDI=∛(EDUx × HEALTHx × GNIx) EDUx=(MYSx × EYSx –min(MYSx,EYSx))/(max(MYSx,EYSx) –min(MYSx,EYSx) )
Implications of Population growth
o For the first time in our history, due in large part to the size of the population, we now have the capacity to significantly alter the earth’s biosphere
o Resource consumption
• Resource demand increases with population (along with amount of waste produced)
• Problems caused:
• Climate change, natural disasters intensified, peak oil, water scarcity, food shortages, deforestation, species extinction
o Infrastructure
• Need for housing & accommodation
o Ecological footprint
• The area required to produce our consumables and absorb our waste
• Currently using equivalent of 1.5 planets
• By 2030, we may need equivalent of 2 planets
Carrying Capacity
o Maximum number of people an area can support indefinitely
• Food, water, air, habitat, materials, waste disposal/treatment/recycling
o Cultural carrying capacity: allows a culturally defined standard of living
Predicting Future Populations
o Interested for a range of reasons:
• Roads, wastewater treatments, electricity generation, water supply, cities/urban planning
Key Definitions
o Crude birth rate: birth / 1000 people
o Crude death rate: deaths / 1000 people
o Total fertility rate: births / woman
o Replacement fertility: number of children a woman needs to have to replace herself with one daughter
o Infant mortality rate: deaths of infants (>1 year) / 1000 live births
Population Growth Rates
o Increase/decrease according to events that occur
• E.g. natural disasters / pandemics / famines / contraception
Factors affecting birth and death rates
o Birth rate:
• Level of education & wealth, importance of children in labour, cost of having children, urbanisation, education/employment for women, social security, birth control, cultural norms
o Death rate:
• Nutrition, improvements in medicine & public health, reduced infant mortality, increased average lifespan, social order
Malthusian Approach
Growth of population is indefinitely greater than the ability of the earth to provide existence for man
Population grows geometrically, subsistence grows arithmetically
Population grows infinitely and in uncontainable
Food production is limited, technology is limiting,
Overpopulation: when population has exceeded capacity of its resource base
Unsustainable: depleting & degrading earth’s natural capital at an accelerating rate
Exponential growth:
N_t=N_0 (1+r)^t
N_t→population at time t
N_0→inital population
r→population growth rate
Population doubling time:
t≈70/(r%)
Logistic population growth (resource limitations)
N(t)=(KN_0)/(N_0+(K-N_0 ) e^(-rt) ),r=R_0/(1-N_0⁄K)
K→carrying capacity,r→exp.growth rate when N≪K,
R_0→ instantaneous rate constant
Anti Malthusian
o Based on historical experience of world population
o As population has grown, we become healthier and more better off
o Technology grows growing at a faster rate than population
Demographic Transition
o Development and increased wealth actually decreases population growth
o Economic development (education, lower infant mortality, longer life expectancy etc.) leads to lower birth & death rates
o Most developed countries have sufficient food supply, low fertility rates, and stable populations
Age Structure
See notes for charts
Population Expansion and momentum
o Population continues to expand even after birth rate declines
