Population

Population

1. Natural increase of decrease in the population depends on the difference between the birth and death rates

   • Birthrates
     • Birthrates depend mainly on fertility rate
     • Reasons for high birthrates
       • Cultural and social
         • More children/ More prestige
         • More can take care of the eldery
           • Many girls marry and start giving birth at young age
       • Economic reasons
         • In LEDCs to provide labour to wotk in farms etc
           • Without an ability to read people have no knowledge of contraception
             • There is high infant mortality rate, lots of kids die so more have to be born to survive
     • Reasons for low birth rates
       • Cultural
         • more ecucation there fore more knowledge about birth control,
         • Some religions are against birth control
         • more opportunities for empyment, more controls over their actions
       • Economic
         • Families want to save up momney and raising a child costs a lot
           • Beter housing, nutrition and education which reduces infanrt mortality rate hence less children need to be born
   • Deathrates
     • Reasons for high death rates
       • War and natural disasters have an effect for a limited time
       • Diseases, famine
         • Obesity, in MEDCs , alcoholism
     • Reasons for falling death rates
       • Development of new medical knowledge and medicines
         • increased access to clean water and proper sanitation
           • beter diet and healthy lifestyle
             • Improved access to food supplies

2. demographic transition model

   • • The high stationary stage
     • The early expanding stage
     • The late expanding stage
     • The low stationary stage
     • The natural decrease stage
   • Factor affecting population change
     • changing to farming methods////// As technology is introduces less people are needed to work so a need for large families decreases
     • Education and women //// Womrn stay in education for longer therefore they marry and have children later
     • Urbanization /////Less people need to work on land so many people move to urban areas

3. Migration

   • movement of people from one place to another
   • Net migration for an area is calculates by --- number of imigrants - number of migrants
   • Over population and under population
     • These conditions depend on the relationship between the population of an area and its resources
   • Push factors
     • Negative conditions at the point of origin which encourage or force people to move
     • poor employment
     • low income
     • natural disasters
     • social upheaval
   • Pull factors
     • Possitive conditions at the point of destination encouraging the person to migrate
     • improved housing
     • high wages
     • attractive environment
     • high standard of living
   • Types of migration and barriers to migration
     • Forced migration e.g famine, natural disasters
     • Voluntary migration e.h Higher wages , retirement to warmer climate
     • Barriers to return e.g racial and political problems
     • reasons to return e.g earned enough money
     • prevention of voluntary movement e.g lack of money, lack of awareness
   • Impacts of international migration
     • Impact on countries of origin
       • levels of unemployment and underemployment are eased
       • return migrants bring in new skills and ideas
       • loss of young adult workers , aging population
       • Agricultural output may suffer
     • Countries of destination
       • Increasing cultural diversity
       • more avaialble force
       • Increased pressure on housing stock
       • larger population can have negative impacts on the environment
     • migrants themselves
       • wages are higher than in the country of origin
       • some have an opportunity to learn a new language
       • The financial cost may be high
       • Problems settling down in the new culture

4. Population structures

   • Population pyramids are diagrams that are designed to show population structure
     • Changing over time
       • Triangular= high number of young dependants
       • Fairly straight sides + falling birth rate and rising life expectancy
       • Developing countries are changing from triangular to barrel like structures
       • Places with ageing population and a very low birthrate would have a structure that looks like an upsie down pyramid
   • Population structure means 'make up' or composition of the population
   • shows how the population is devided between males and females and different age groups
   • What the pyramid tells us
     • Gives info about birth and death rates as well as lide expectancy
     • tells us how many dependants there are (both eldrly and young(
     • How many economically active there are
     • MEDCs normally have a large number of elderly dependants while LEDCs have a lot of young dependants

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