Population
•WELCOME
CLASS-8
POPULATION.
•Population
– refers to the total number of people inhabiting in a specific area.
POPULATION
AND RESOURCES.
•Population
and resources are unevenly distributed.
•Large
population is a strain on limited natural resources.
•Demography-social
science that deals with the study of human population.
•The
current population growth rate is 1.11%
•The
growth rate shows decline from 1.18% per year in 2016.
POPULATION
GROWTH RATE.
POPULATION
DISTRIBUTION.
•Population
distribution means the population is spread across the World.
•7.6%
of population is concentrated in only 20%of land area
POPULATION
DENSITY
•Population
density means the number of people per square kilometre.
•In
less developed countries- density is higher.
•Density=
Total population/Total area.
•Factors
for higher density:
•Fertile
soil
•Ample
water.
•Suitable
climate
•Thriving
economic activities.
POPULATION
DENSITY.
AREAS
OF HIGH DENSITY:
–Riverine plains of Asia- The Ganga Plains of India.
–Industrial
NW Europe- France, UK, Germany and
Denmark.
–North
America and South America.
–Nile
valley, Mediterranean coast and coastal South Africa.
POPULATION
DENSITY
AREAS
OF MODERATE DENSITY:
–Extremes
of climate, inadequate rainfall, absence of important resources does not
encourage dense population.
–Central
parts of The USA
–Tropical
western Africa.
–Russia,
Eastern Europe
–Deccan
Plateau of India.
–Central
China.
POPULATION
DENSITY
AREAS
OF LOW DENSITY:
–Comprising
the hot deserts and cold deserts of the World, mountainous regions and dense
forests, insufficient arable land, lack of water supply, lack of transport, unfavourable climatic conditions.
–Areas:
Mongolia, Iceland, Suriname, Botswana, Namibia and Northern Canada.
–Australia-
due to vast desert, remote and inaccessible interior is known as outbacks.
OVERPOPULATION
•Overpopulation-very
large number of people for the available resources.
•This
happens either due to sudden increase in population or depletion of resources.
•Optimum
population- the available resources are adequate to support a certain number of
people only. The ratio of people and resources are well balanced.
IMPACT
OF OVERPOPULATION.
•Some
other impacts are: global warming, loss of biodiversity.
•Solutions:
–Population
planning.
–Spread
of education.
–Advanced
healthcare.
–
UNDERPOPULATION.
•Is
a state when the number of people living in a region is so few that there is a
lack of full utilisation of resources.
•Example:
Prairies of North America.
•Impact:
Positive- better job opportunities, absence of competition, sufficient
resources, less pollution.
•Negative: insufficient skilled labour force, poor utilisation of resources, poor
economic growth and low standards of living.
POPULATION
CHANGE.
•Factors
affecting population change are:
–Crude
Birth Rate
–Crude
Death Rate
–Migration
–Population
Growth Rate.
–
•Census-official
enumeration of population, done once in ten years.
•Census
counting is being done since 1881.
CRUDE
BIRTH RATE
•Is
expressed as number of live birth in a year per thousand of population.
•Birth
rate between 10 and 20 are considered
low, while those between 40 and 50 are high.
•In
developed countries, where both men and women are working and where living
standards are high, birth rates tend to be low and vice versa.
CRUDE
DEATH RATE.
•Refers
to number of deaths per 1000 people in a giver geographical area in a year.
•
•In
some developed countries, death rate is high due to aging population.
POPULATION
GROWTH RATE
•Compares
the average annual % change in population, resulting from a surplus of births
over deaths and the balance of migrants entering and leaving the a country.
•The
rate may be positive or negative.
MIGRATION
•Movement
of people from one place to another with the intentions of settling permanently
in the new location.
•Emigrants-
people who move out of the country.
•Immigrants-people
who come to live in another country.
•Migration
leads to increase in population.
COMPOSITION
OF POPULATION
AGE
COMPOSITION:
–Refers
to the number of people in different age groups in a country.
–Age-wise,
people are usually grouped into:
•Children
(less than 15 years)- dependent.
•Working
age (15-59 years)- productive.
•Old
age (above 59 years)- dependent.
SEX
RATIO.
•Sex
ratio- refers to the number of females
per 1000 males in the population.
•It
is an indicator determining equality between male and female population in the
society.
•Discrepancy
in sex ratio in India persists as female foeticide still continues in many parts of the country.
POPULATION
PYRAMID
•It
refers to the graphical representation of the population structure based on an
age-wise increase or decrease of male- female population of a country.
•Population
is distributed on the X-axis. The male
population is shown on the left, while the female population is shown on
the right. The Y-axis represents the age group, which is distributed from 0-100
years , with an interval of 5 years.
•POPULATION
PYRAMID
•It
gives a clear idea of life expectancy, fertility rate and the international
migration of the country.
RURAL-
URBAN POPULATION
•With
the increasing economic development and access to resources, there has been a
trend towards increasing urban
population.
•The
World urban population is expected to surpass 6 billion by 2045.
•This
may result in problems related to housing, transportation, energy consumption
and employment.
•World’s
most populous cities as per the UN estimates for 2016 are Tokyo, Delhi,
Shanghai, Mumbai and Sao Paulo.
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