Managing change in the human environment Population Change How do populations change?
Population Key Terms
Birth rate – the number of births per 1000 people
Death rate – the number of deaths per 1000 people
Fertility rate – the number of births to women aged 15 to 45
Infant mortality – the number of children who dies within the first year of life, per 1000
Life expectancy – the average age a person can expect to live from birth
Rate of natural increase – the difference between death and birth rate
Migration – the movement of people from one place to another
Population growth – an increase in an area as a result of death rate, birth rate and life expectancy
Population change – change in a population measured
in terms of birth rate, death rate and migration figures
Dependent population – people who are too old or too young to look after themselves
What has happened to word population? World population has doubled between 1950 and 2000 Today and into the future more people are likely to be living in LEDCs than MEDCs A greater proportion of people are living in LEDCs which tend to be poorer and less developed countries 90% (est.) 4.7 billion 80% 1.7 billion 68% LEDC 10% (est.) 1.3 billion 20% 0.8 billion 32% MEDC 2050 (est.) 9 billion 2000 6 billion 1950 2.5 billion World Population
What has happened to word population?
Physical and human factors of population change
Natural disasters - floods, earthquakes and storms
Disease - AIDS
Religion/culture (may encourage family size)
Migration (usually from LEDC to MEDC)
Physical and human factors can have different effects in LEDCs and MEDCs.
What are the causes of population change? Stage 1 – high birth rate, high death rate, low growth rate, stable population Stage 2 – high birth rate, death rate begins to fall, growth rate rises, population total rises Stage 3 – Death rate continues to fall, birth rate begins to fall, growth rate begins to slow down, total population rises Stage 4 – Death rate stays the same, birth rate falls, growth slows, total population may decline Demographic Transition Model
Population structure The total population will keep growing, typical of an LEDC Increasing number of middle aged people Proportion of young people under 15 is large (young dependents) Proportion of elderly people small The proportion of older people increasing The number of young people under 15 is decreasing (young dependents) The elderly dependent population is increasing Growth is static, typical of MEDC