Essay About Visual Representations Of Age Structure And Growing Population

Age Structure Diagrams
Age Structure Diagrams: visual representations of age structure within a country for males and females
population pyramid: wider at the bottom and smallest at the top
population momentum: when they try and reduce birth rates so that it catches up with the growing population
What is likely to happen to the population?
Eventually over several generations those actions will bring the population to a more stable-growth rate.
Population Calculations
Calculate birth and death rate
r= CBR-CDR/10
Calculate growth rate
global pop. growth rate= CBR-CDR/10
nation pop. growth rate= (DBR+immigrants)-(CDR+ emigrants)/10
Calculate doubling time
Doubling time (in years)= 70/growth rate
Phases of demographic transition
What are they?
What is happening to cause the changes in phases?
Phase 1: Slow (pre industrial)population grows very slowly because of a high birth rate and a high death rate
represents a population that is nearly at steady state
infant number is low because of disease(AIDS), adults short lifespan because of difficult working conditions
Phase 2: Rapid (transitional)population grows rapidly because birth rates are high and death rates drop
death rates decline while birth rates remain high and as a result the population