Health care improvements affect population change. Image credit

ZIMSEC O Level Geography Notes: Population: Population Change

  • The difference between the size of the population to the end and the beginning of a period.
  • This change is developmental, that is, it has stages through which a population passes
  • This theory can be shown on a diagram known as the demographic transition model
  • Demographic transition is the movement of a population from high to low birth and death rates
  • The model  has four stages or phases

  • These stages represent the change in a given population from high to low birth and death rates, overtime
  • The change is usually accompanied by a society’s move from a rural agrarian economy to an urban industrial economy
  • The transition follows four stages:
  • High fluctuating
  • Early expanding
  • Late expanding
  • Low fluctuating

Stage 1. High fluctuating

  • This stage is also known as the high stationary stage or pre-industrial stage
  • It is characterized by high birth rates and high death rates
  • In most cases, these are in areas with a low level of medical care or knowledge resulting in high death rates
  • These will in turn result in high birth rates to make up for the dead
  • This will mean that the population will grow at a very slow pace and remain relatively stable sometimes stationary (no growth)
  • This is usually the case in primitive societies like the pygmies of the Democratic Republic of the Congo, Cameroon and in parts of Mozambique

Stage 2. Early expanding

  • This stage is also known as the transitional stage
  • It is characterized by the high birth rate, a drooping death rate and a high growth rate
  • The drop in the death rate means that more girls will survive and become mothers whose survival rate will be high resulting in a high growth rate
  • This is mainly observed in Zimbabwe and Kenya
  • The reduction in death rates is due to improved medical care and knowledge as well as a better diet

Stage 3. Late expanding

  • This stage is characterized by a declining birth rate, a further declining death rate though population growth continues at a slower pace
  • Birth rate drops due to modern population control measures sometimes offered free of charge (for example, family planning)
  • It can also be caused by new values emerging for example need for a car and a good house thus children become too expensive to bring up
  • Women go to school and work thus reducing fertility
  • Therefore their status is enhance and they can choose and have control over their fertility matters
  • Moreover, research and development in medicine keeps death rate falling at this stage
  • Examples of countries that show this stage are Hong Kong, South Korea and Singapore

Stage 4. Low fluctuating

  • This stage is also known as the low stationary or post-industrial stage
  • It is characterized by a sharp decline in both birth and death rate resulting in very low population growth rates
  • Sometimes birth rate drops below death rate resulting in negative population growth where more people die than are born
  • At this stage a country can achieve zero population growth (ZPG) or a decline
  • Examples of countries that show this stage are Germany,Sweden, United Kingdom, Denmark, USA and France

To access more topics go to the O Level Geography Notes page