1.2 Changing population and places Flashcards
(164 cards)
Define demography
The study of population dynamics and changes.
Key demographic terms
-Crude birth rate (CBR)
-Crude death rate (CDR)
-Natural increase (NI)
-Life expectancy
-Fertility rate
-Infant mortality rate
Define crude birth rate (CBR)
The number of live births per 1,000 people per year in a region.
Spacial and temporal variations in crude birth rate (CBR)
-In pre-industrial societies, the rate is around 45/1,000/year: today, only a few remaining isolated rainforest tribes have a CBR close to this figure.
-The European average is 11/1,000/year.
-The CBR becomes lower not only on account of falling fertility but also due to increasing life expectancy (which means a higher proportion of each 1,000 people are not of child-bearing age).
Define crude death rate (CDR)
The number of deaths per 1,000 people per year in a region (a measure of mortality).
Spacial and temporal variations in crude death rate (CDR)
-In pre-industrial societies, the rate is 40–50/1,000/year.
-Today, the European average is 10/1,000/year.
-The CDR can increase due to disasters or disease: in Haiti, in 2010, it rose from 8 to 32/1,000/year on account of a large earthquake.
Define natural increase (NI)
-The difference between the CBR and CDR.
-It can be recorded either as the net change per 1,000 people or as a percentage.
Spacial and temporal variations in natural increase (NI)
-It is rare for a country’s rate of NI to exceed 3 per cent per annum.
-Youthful migrant populations, such as those found in developing world megacities, have a high rate of NI due to the presence of a large proportion of fertile adults and relatively fewer older people.
Define life expectancy
The average number of years a member of a particular society can expect to live.
Spacial and temporal variations in life expectancy
-The average world life expectancy is now 71 (in 1960 it was 52).
-In most of Latin America and Asia, the figure is 70 years or higher.
-In 2015, the world’s lowest was 49 in Swaziland; the highest was 84 in Japan (South Korea is predicted to overtake Japan soon, however).
-In most countries, national averages obscure a difference between men and women of around six years (Japan’s female life expectancy is 87; for men it is 81).
Define fertility rate
The average number of children a woman gives birth to during her lifetime.
Spacial and temporal variations in fertility rate
-Today, most countries have an average fertility rate of three children or fewer, whereas in 1950 the world average was five.
-Fertility has fallen throughout Asia.
-Some sub-Saharan African countries still have a high rate of seven or eight.
Define infant mortality rate
The number of deaths of infants under one year old per 1,000 live births per year.
Spacial and temportal variations in infant mortality rate
-Globally, estimates of the average rate vary between 42 and 49.
-This uncertainty reflects the difficulties of recording the data in an accurate and consistent way in different states.
-Afghanistan had the world’s highest rate in 2015 (115 per 1,000).
Graph showing falling fertility in Asia between 1950 and 2014
What does the term ‘population structure’ refer to?
The division of a population into a series of groups according to age and gender.
How is population structure shown?
As a population pyramid for a particular historical year.
How do population pyramids work?
-People are divided into cohorts (age groups) placed either side of the vertical axis, with males on one side and females on the other.
-The size of each age group can be shown either as an actual number (in thousands or millions) or as a percentage of the total population.
Define population structure
The make-up of a population in terms of age, gender, occupation, ethnicity or any other selected criterion.
What is a population pyramid?
A type of bar chart used to show the proportion of males and females belonging to different cohorts (age groups) for a place or country.
What do population pyramids allow us to see?
-How fertility rates and life expectancy have affected a country or smaller-scale place’s population structure.
-We may also be able to see what the effects of past migration, wars, disasters, economic recessions or epidemics have been on particular age groups, or men and women.
Example of how population pyramids can show economic changes
-Most European population pyramids for 2015 show a dip in the number of people aged 40 compared with those aged 45: this reflects a global economic crisis in the early 1970s which led many couples to delay having children.
-As a result, fewer babies were being born in 1975 (the people aged 40 in 2015) compared with 1970 (the people aged 45 in 2015).
When comparing the population pyramids of different countries, which important characteristics can be identified to offer clues about their relative levels of economic development?
-Concave sides
-A wide base
-Perpendicular sides
What do concave sides indicate on a population pyramid?
-This can indicate low life expectancy and a very high death rate.
-This is because few individuals survive to move from one cohort to the next (but note that concave sides for a city’s population pyramid might be caused by youthful in-migration rather than high mortality).