migration

• population explosion: a dramatic increase in the number of people in the world
• demography: the study of population
• factors that affect population: food supply, improved technology, war, health, role of women and education
• population density: number of people in an area per square km
• population distribution: spread of people in an area
• densely populated: a lot of people
• why are population pyramids used?

  government planners see if schools need to be built and need to plan for health and transportation needs
• individual migration: when one person or family decide to migrate
• organised/planned migration: when a government or organisation decide on a more widespread migration
• intranational migration: migration from one area to another area in the same country
• push factors: reasons that make migrants decide to leave
• pull factors: reasons that attract migrants to another place
• barriers to migration: factors that slow down or prevent migrants from moving
• social barriers: language barrier, cultural differences, prejudice