Key words geography

• Population dynamics


  The study of changes in population size and structure
• Key definitions


  • Population
  • Population explosion
  • Birth rate
  • Death rate
  • Rate of natural change
  • Rate of net migration
  • Model of demographic transition
  • Total fertility rate
  • Infant mortality rate
  • Life expectancy at birth
  • Depopulation
  • Optimum population
  • Under-population
  • Over-population
  • Underemployment
  • Population policy
• Pro-natalist policies


  Policies that promote larger families
• Anti-natalist policies


  Policies that aim to reduce population growth
• Migration


  The movement of people across a specified boundary, national or international, to establish a new permanent place of residence
• Push and pull factors

  Push factors are negative conditions at the point of origin, which encourage or force people to move. Pull factors are positive conditions at the point of destination, which encourage people to migrate
• Refugees


  People forced to flee their homes due to human or environmental factors and who cross an international border into another country
• Internally displaced people


  People forced to flee their homes due to human or environmental factors who remain in the same country
• Rural-to-urban migration


  The movement of significant numbers of people from the countryside to towns and cities
• Remittances


  Money sent back to their families in their home communities by migrants
• Population structure


  The composition of a population, the most important elements of which are age and sex
• Population pyramid


  A bar chart arranged vertically, that shows the distribution of a population by age and sex
• Dependency ratio


  The ratio of the number of people under 15 and over 64 years to those 15-64 years of age
• Population density


  The average number of people per square kilometre in a country or region
• Population distribution


  The way that the population is spread out over a given area, from a small region to the Earth as a whole
• Dispersed settlement


  When farms or houses are set among their fields or spread along roads
• Nucleated settlement


  Houses and buildings are tightly clustered around a central feature
• Linear pattern


  Settlements are found along a geographical feature such as a river valley or a major transport route
• Site


  The actual land on which a settlement is built
• Situation


  The relationship between a settlement and its surrounding area
• Low-order functions


  Basic functions found in smaller settlements (e.g. hamlets)
• High-order functions


  More specialised functions and services found in larger settlements (villages and market towns)
• Range of a good


  The maximum distance a person is prepared to travel to buy a good
• Threshold population


  The minimum number of people needed to support a good or service
• Sphere of influence


  The area that a settlement serves
• Urban land use


  Activities such as industry, housing and commerce that may be found in towns and cities
• Bid rent


  Where land value and rent decrease as distance from the central business district increases
• Central business district (CBD)


  An area of an urban settlement where most of the commercial activity takes place
• Suburbs


  The outer part of an urban settlement, generally consisting of residential housing and shops of a lower order
• Rural-urban fringe


  The boundary of a town or city, where new building is changing land use from rural to urban
• Urban sprawl


  Occurs when urban areas continue to grow without any form of planning
• Urban redevelopment


  Attempts to improve an urban area
• Urban renewal


  When existing buildings are improved
• Gentrification


  The movement of higher social or economic groups into an area after it has been renovated and restored
• Urbanisation


  The process by which the proportion of a population living in or around towns and cities increases through migration and natural increase
• Millionaire city


  A city with over 1 million inhabitants
• Megacity


  A city with over 10 million inhabitants
• Urbanisation is one of the most important geographical features of the twentieth and twenty-first centuries
• Over 50 per cent of the world's population now live in urban areas
• People are also living in larger settlements