How does population change affect individuals and societies?

Demography is the statistical study of human populations. Demography examines the

size, structure, and movements of populations over space and time. It uses methods
from history, economics, anthropology, sociology, and other fields.Demographers seek
to understand population dynamics by investigating three main demographic processes:
birth, migration, and aging (including death). All three of these processes contribute to
changes in populations, including how people inhabit the earth, form nations and
societies, and develop culture.A demographic refers to distinct characteristics of a
population. Researchers use demographic analysis to analyze whole societies or just
allgroups of people. Some examples of demographics are age, sex, education,
nationality, ethnicity, or religion, to name a few.

Demographers study five processes: fertility, mortality, marriage, migration and social
mobility. These processes determine populations' size, composition and
distribution.Demography is useful for governments and private businesses as a means
of analyzing and predicting social, cultural, and economic trends related to population.
The birth and death rates are the most important determinants of population growth;
hence their inclusion in population studies is essential. In addition, factors such as
marriage and migration are also equally important.

When demographers attempt to forecast changes in the size of a population, they

typically focus on four main factors: fertility rates, mortality rates (life expectancy),
the initial age profile of the population (whether it is relatively old or relatively
young to begin with) and migration

Overpopulation is an undesirable condition where the number of the existing human

population exceeds the actual carrying capacity of Earth. Overpopulation is caused by a
number of factors. Reduced mortality rate, better medical facilities, depletion of precious
resources are few of the causes which result in overpopulation. It is possible for a sparsely
populated area to become densely populated if it is not able to sustain life.

Growing advances in technology with each coming year has affected humanity in many
ways. One of these has been the ability to save lives and create a better medical treatment
for all. A direct result of this has been the increased lifespan and the growth of the
population.

Various Causes of Overpopulation

● The Decline in the Death Rate. ...
● Agricultural Advancements. ...
● Better Medical Facilities. ...
● More Hands to Overcome Poverty. ...
● Child Labor. ...
● Technological Advancement in Fertility Treatment. ...
● Immigration. ...
● Lack of Family Planning.
More people means an increased demand for food, water, housing, energy, healthcare,
transportation, and more. And all that consumption contributes to ecological degradation,
increased conflicts, and a higher risk of large-scale disasters like pandemics

Population distribution denotes the spatial pattern due to dispersal of population,

formation of agglomeration, linear spread etc. Population density is the ratio of people
to physical space. It shows the relationship between a population and the size of the
area in which it lives.

The world population, its distribution, density and growth reflect the advancement and development
of each geographical zone. The world population has a huge impact on the world economy and
climate change.

Patterns of Population Distribution in the World

The term population distribution refers to the way people are spaced over the surface of the earth.
Broadly, 90% of the world’s population lives in about 10% of the earth’s land area. The 10 most
populous countries of the world contribute about 60% of the world’s population (the six countries out
of the ten are located in Asia).

Population Density
Population density is the ratio between the number of people to the area of the land. It is measured
in persons per square kilometre or km². The densely populated parts of the world are the north-
eastern part of the U.S.A, north-western part of Europe, south, south-east and east Asia. The thinly
populated regions of the world are near the north and south poles, the hot and the cold deserts and
high rainfall zones near the equator. The population density of India in 2011 was 382 per sq. km.
Density of population = Total Population / Total Area
 Patterns of population distribution and density give the demographic characteristics of any area.
Factors influencing the distribution of population
The following factors affect the population distribution:
1. Geographical factors
2. Economic factors
3. Social and cultural factors
Geographical Factors-
1. Water availability – Water is the most essential factor for the existence of life. It is used for
multiple purposes like cooking, drinking, agriculture, etc. People prefer to inhibit areas which
have water in abundance, that is why river valleys are among the most densely populated
areas of the world.
2. Landforms – The Ganga Plains are among the most densely populated areas of the world
while mountainous regions of the Himalayas are thinly populated. People prefer flat plains
and gentler slopes which are favourable for agricultural purposes, to build better road
connectivity and for industries.
3. Climate – A climate which is neither too hot nor too cold attracts more people. Areas with
very heavy rainfall or extreme and harsh climate have low population density.
4. Soil – Areas with fertile, loamy soils are preferred by people as this type of soil supports
intensive agriculture.
Economic Factors-
1. Minerals -The regions with rich mineral deposits attract industries which in turn generate
employment opportunities. People move to such places and make them thickly populated.
For example, Katanga Zambia copper belt in Africa.
2. Urbanisation – Urban centres offer better employment opportunities, educational and
medical facilities, have better means of transport and communication. This results in rural to
urban migration and cities become densely populated.
3. Industrialisation – Industrial areas provide job opportunities thereby attracting a huge
number of people. For example, the Kobe-Osaka region of Japan is densely populated due to
the presence of a large number of industries.
Social and Cultural Factors-
Religious or cultural importance also affects the population density of a place. Such places attract
more people and if there is social and political unrest in a region, people tend to move away from
such places. Sometimes the government offers incentives to people to move to thinly populated
areas or move away from overcrowded places.

Population Growth/Population Change

It refers to the change in the number of inhabitants of a territory over a specific period of time.
Population growth is expressed either in terms of percentage or absolute numbers. It can be positive
as well as negative. Population change indicates the economic development, social upliftment and
historical and cultural background of the area.
Some Basic Concepts of Population Geography
1. Growth of population – It is the change of population in a particular area between two points
of time.
 2. Growth rate of population – When the change in population is expressed in terms of
percentage, it is the growth rate of population.
3. Natural growth of population – Natural Growth = Births – Deaths (It is the population
increase by the difference between births and deaths in a particular region between two
points of time).
4. Actual growth of population – Actual Growth = Births – Deaths + In Migration – Out
Migration.
5. Positive growth of population – This happens when the birth rate is more than the death
rate between two points of time or when people from other countries migrate permanently to
a region.
6. Negative growth of population – This happens when the population decreases between two
points of time, either when the birth rate falls below the death rate or people migrate to other
regions.
Components of Population Change
There are three components of population change – births, deaths and migration.
1. Crude Birth Rate (CBR) – It is expressed as the number of live births in a year per thousand
of the population.
2. Crude Death Rate (CDR) – It is expressed in terms of the number of deaths in a particular year per
thousand of population in a particular region. It is a simple method to measure the mortality of any
area.

The region’s demographic structure, social advancement and economic development largely affect
the mortality rates of that particular region.
3. Migration – The population size also changes by way of migration. Migration refers to the
movement of people from one place to the other, the place they move from is called the place of
origin and the place they move to is called the place of destination. Migration may be permanent,
temporary or even seasonal. The people who move are called migrants. Migrants who move into a
new place are called immigrants and migrants who move out of a place are called emigrants. The
main purpose of migration is to attain better economic and social life.
Factors that influence migration-
1. Push factors – The factors like poor living conditions, unemployment, unpleasant climate,
political turmoil, epidemics, natural disasters and social-economic backwardness make the
place of origin seem less attractive.
2. Pull factors – The factors like better living conditions, job opportunities, peace and stability,
security of life and property, and pleasant climate make the place of destination more
attractive

Trends in Population Growth

During the early periods, the population of the world grew very slowly. The world population
exploded in the 18th century after the Industrial Revolution. Technological developments helped in
reducing the death rate thereby, paving the way for accelerated population growth.
The human population increased more than ten times in the past 500 years.
● In the 20th century itself, population growth has increased four times.
● The annual population growth rate in India is 1.64%.
 Demographic Transition
It is a theory which is used to represent the movement of high birth and death rates as the society
progresses from rural agrarian and illiterate to urban industrial and literate society. It studies to the
relationship between economic development and population growth. This theory can be used to
describe and predict the future population of any area. These changes occur in stages which are
collectively called a demographic cycle.
1. Stage 1 – The first stage is characterised by high birth and death rates, and therefore,
population growth is slow. This stage is associated with under-developed, low output and
agriculture-dominated conditions. Two hundred years ago, all the countries of the world were
in the first stage of demographic transition.
2. Stage 2 – It is characterised by a high birth rate and reduced mortality rate leading to an
increased population. Improvements in medical care, water supply and sanitation result in
decreased death rates.
3. Stage 3 – In this stage both birth and death rate decline appreciably. The population is either
stable or grows slowly. The population becomes urbanised, literate and has a high technical
know-how and controls the family size.
In the present times, different countries are at different stages of demographic transition.