Topic 3 Flashcards
(49 cards)
What is demography
Demography is the science that statistically studies the structure
and characteristics of human populations in an INTERDISCIPLINARY
manner.
Geographers study population to understand the area
distribution of the Earth’s peoples. They are also interested in
the reasons and consequences of the distribution of
populations from the international to the local level.
Concept of human population
Every population is characterized by the number of
people that integrate it, by its size or volume, by its
composition/structure according to biological and social
variables by sex, age, marital status, level of education
at a given time, all these characteristics provide us with
the static image of the population in a defined location.
Demographics (statistic study)
1) volume
2) population composition
3) geographical distribution
Demographics (dynamic study)
1) Natality
2) Mortality
3) Migrations
Why they do a Census
to count the population
* to know the structure of the population
* to know the evolution of the population
* to enable demographic analysis
but used increasingly for all sorts of applications from
predicting election results to shaping economic forces.
What is the census in concrete
A census is a count of the number of people in a
country, region, or city. Undertaking a census
and establishing an accurate count, however,
are not simple. Most censuses are also directed
at gathering other information about people,
such as previous residences, number of people
in a household, and income. Many countries
usually many this general count every 10 years
Characteristics or conditions of the Census
- It has to be delivered and collected in each household
- It must be universal , include all of the inhabitants of the country, without excluding or , of course repeating the data
- It must collect information on an individualized basis
-It is mandatory
- Finally the census must be carried out simultaneously throughout the country
Demography ( They have their own limitations)
- Census are extremely expensive and labor -intensive
- In many less-developed countries, governments are not always able to finance a decennial census such as the
comprehensive surveys undertaken in more developed countries. - This creates incompatibilities making difficult comparisons among and within countries.
- Despite the massive and costly efforts to count population no census is entirely accurate
-
How do population geographers helps demography
Population geographers bring to demography a special perspective that emphasizes description and explanation
of the “where” of population distribution, patterns, and processes
Human population is takings its toll on the planet?
1) Economic stagnation
2) Political Unrest (Youth unemployment
Nutritional density
Is the ratio between the total population and the amount of land under cultivation in a given unit of area
Agricultural density
It is the ratio of the number of farmers per unit of arable land in a specific area
Health density
Can be measured as the ration of the number of physicians to the total population
Why is knowing population composition useful?
Enables geographers to gather important information about population dynamics.
Most common way for demographers to graphically represent the composition of the population ?
Age- sex pyramid
Sequence of population pyramid
- Males are portrayed on the left side of the vertical axis
- Females on the right
- Age categories are ordered sequentially from the youngest at the bottom of the pyramid to the oldest at the top
-
What is a cohort?
set of individuals in a population who have
shared the same event during a specific period of time,
Population pyramid (Pagoda)
- Pagoda. Wide base and sharp apex
- Young populations with high birth rate
- Developing countries.
Expansive pyramid: A population pyramid with a broad base
and with a successive decrease in the proportion of population in the higher age groups is known as an
expansive pyramid.
This pyramid represents a situation of high fertility, high
mortality, low life expectancy, high population growth rates
and low proportion of older people
POPULATION PYRAMID: BELL
- Intermediate base and progressively tapering vertex.
- Stationary populations tending to aging.
- Developed countries.
Stationary pyramid: A pyramid is described as stationary
when the percentage of the population remains constant in
the different age groups over time.
It represents a situation of low fertility, low mortality and
high life expectancy. It indicates slow population growth or a
stable population. The stationary or near-stationary
population pyramid shows a somewhat equal proportion of
youth and adult age groups.
POPULATION PYRAMID: BULB
CHARACTERISTICS:
* Narrow base, wide middle zone and very progressive
apex.
* Regressive populations with aging.
* Developed countries.
Constricted pyramid: A pyramid with a narrow base is called
a constricted pyramid.
It represents low fertility, low mortality, high life
expectancy and aging of the population. It is usually
associated with very advanced countries that have a high
level of literacy, access to birth control measures and very
good sanitation and medical facilities.
Pyramid for peripherial countries
If there is a considerable narrowing of the pyramid toward the top indicates that the population has been growing very rapidly in recent years.
How is the dependency ratio calculated
Demographers divide the total population into three age cohorts,
sometimes further dividing those cohorts by sex:
- The youth cohort, members of the population under 15,
considered too young to be fully active. - The middle cohort (15-64), considered economically active and
productive. - The elderly cohort (65+), who are considered beyond their
economically active and productive years.
What is CBR (Crude birth rates)
Number of live births in a year per thousand persons in the population
What influences birth rates
by the educational level of women, religion, social customs,
and diet and health, as well as by politics and civil unrest.
