Page 30 - Health, Population and Environment Education 9

Table No.1: Flow model on population change
Increase Decrease
1. Birth 1. Death
2. Migration 2. Migration
3. In– migration (National migration) 3. Out–migration (National migration)
4. International migration (Immigration) 4. International migration (Emigration)
Birth and migration increase Death and migration decrease
5. 5.
population in a place population in a place
The above table on flow model on population change explains about the increase and
decrease of population in a place. Birth and migration increase population in a place.
When there is birth of a child in a family, it increases the number of family members. When
some people from other places come to live in our place, that type of internal migration
within the same country increases population. Similarly, when some people from other
country migrate to our country, that type of international migration called immigration
also increases population. Death and migration decrease population in a place. When a
person dies, there is decrease of family members. Similarly, when some people from our
place migrate to other places, that type of external migration within the same country
decreases population. Likewise, when people from our country migrate to other countries,
that type of international migration called emigration decreases population in a place.

Activity: 1
Prepare a list regarding recent birth, death and migration in your locality and present
in your class.

Factors affecting birth
Birth is the natural factor of population change. There is increase of population with the
birth of children. There are various factors affecting birth which are discussed below:

a. Social factors
Those factors which are related with social traditions, cultural activities and religious
practices in our day to day life are called social factors. People are highly guided by many
social traditions and social values. Though they are false, people cannot strongly avoid
them. Such factors support in bearing more children. There are various social factors
affecting birth. They are explained below:

i. Illiteracy
Many people are illiterate in our context. The illiterate
people are ignorant about the effects of population
growth as well as ways to control it. Moreover, they
are superstitious and believe on superstitious beliefs.
They consider children as the gift of god. They think
they need to bear as many children as they can Fig: 6
30 GREEN Environment Population and Health Education Book-9