geography

• Population Trends


  How population has changed over time, demographic transition model, space, and global population distribution
• Demographic Transition Model (DTM)


  A model that represents the stages of population change over time, from high birth and death rates to low birth and death rates
• Demographic Transition Model


  • It is a simplified and generalized version of real events, from which the incidental details have been removed
  • It is useful as a framework against which reality can be measured, evaluated and understood
• Population Density


  The number of people living on a unit area of land
• Population density is defined as the number of people divided by the area
• Population density categories

  • High (200-1000+ persons/km2)
  • Moderate (10-199 persons/km2)
  • Low (0-9 persons/km2)

  
• Calculating population density


  Population / Area

  
• USA has lower population density than Singapore


  USA has larger area so each person has more living space, while Singapore has limited land so density is higher
• 85% of Singaporeans live in HDB flats
• Global population density

  • Areas with low population density (0-4 persons/km2) include Greenland, Australia, northeastern Russia, and southern Africa
  • Areas with high population density (250+ persons/km2) include India and China

  
• Physical environment factors affecting population distribution

  • Climate (temperature and rainfall)
  • Relief (steepness and height of ground)
  • Soils (fertility)
  • Resources (water, materials, food, minerals)
• Technology


  • The knowledge, skills and tools that people use to meet their needs
  • Advances in technology can make previously unsuitable environments livable
• The map shown is not an accurate representation of population density as it does not account for differences in lighting and wealth between countries

  
• High population growth is a characteristic of Less Developed Countries (LDCs)
• India is an example of an LDC with high population growth
• Factors leading to declining death rates in LDCs

  • Improvements in medical and health care
  • Better hygiene
• Improvements in medical and health care

  Availability of hospitals, clinics, doctors, immunisation, and nutritional knowledge to improve quality of life and reduce infant mortality
• Better hygiene


  Less prone to diseases due to availability of clean water and sanitation
• Consequences of high population growth include higher demand for resources, housing, and education
• Higher demand for resources

  Need for increased food supplies, using technology like irrigation and high-yielding crop varieties
• Higher demand for housing

  Competition leads to insufficient housing, particularly in cities due to rural-urban migration, resulting in informal settlements and slums
• Higher demand for education


  More babies born means a need for more schools and teachers
• Overpopulation leads to insufficient housing
• Particularly in cities due to migration in the country
• Insufficient land for building of homes ⇒ shanty towns or squatter settlements
• Informal, poor quality housing with no/limited basic services (e.g. water, waste disposal, electricity) built illegally on available land
• Shanty towns


  Informal, poor quality housing
• Squatter settlements


  Housing built illegally on available land
• No access to resources, no address
• Materials used to build these houses are flimsy and flammable
• Nearby river used as a dumping ground for rubbish
• Difficult to put out electrical fires due to the flammable building materials
• Higher demand for education due to more babies being born
• LDCs may lack the funds to build more schools, not everyone will be able to attend school and obtain a good education
• Consequences of not obtaining a good education include poor job prospects, unemployment, and being stuck in low-skilled, low-paid work
• Higher demand for jobs with a lot of people competing for a limited number of jobs
• Larger population creates more waste, which can lead to land and water pollution if not properly disposed of
• Family planning


  Carefully considering the cost of raising a child and having fewer children
• Educating people about family planning can lead to a fall in birth rate
• Cultural norms and customs that encourage having many children are a barrier to reducing birth rates