Question

what are the main process is responsible for change in population​

Answer 1

The natural increase of population is the difference between birth rates and death rates.

Birth Rate:

The number of live births per 1000 persons is called the birth rate. According to 2011 census, the birth rate in India is 20.22 births per 1000 persons.

Death Rate:

The number of deaths per 1000 persons is called the death rate. According to 2011 census, the death rate in India is 7.4 deaths per 1000 persons.

A higher birth rate coupled with a lower death rate results in an increase in population. Because of advancements in healthcare and nutrition, the death rate has reduced over the period.

The birth rates have also reduced because of sustained campaign towards family planning and increased awareness among people.

Migration:

Migration is another factor which changes the size of population. Movement of people from one place to another; in search of livelihood is called migration.

Migration within the country is called internal migration, while that between two countries is called international migration.

Internal migration does not change the size of the population but it changes the population composition of a particular area. 

I hope it helps you

Answer 2

The three main processes of change of population are—birth rates, death rates and migration.

1. Birth rate: It is the number of live births per thousand persons in a year. It is a maj or component of growth because in India, birth rates have always been higher than the death rates.
2. Death rate: It is the number of deaths per thousand persons in a year. The main cause of the rate of growth of the Indian population has been the rapid decline in the death rate.
3. Migration: Migration is the movement of people across regions and territories. Migration can be internal (within the country) or international (between countries).