19.3 POPULATION ATTRIBUTES:

Population is group of individuals belonging to the same species. All the human beings belong to the species are called Homo sapiens sapiens. The number of individuals in population change from time to time. This changing nature of the population is dynamics of population.

India is the second largest populous country, next to China. From a population of about 35 crore at the time of Independence to more than 100 crore now is a cause of concern. Increasing numbers require resources to sustain them. They add to demands on land, air and water resources. It means provision for more schools, colleges and hospitals, food, shelter and jobs. The rate at which these provisions are made in India fall far short of the increasing numbers. There is therefore, a need to drastically regulate the growth in population.

The study of quantitative and statistical aspects of human population is called Demography. This term was first used by Guillard in 1835. Population is ascertained by census. It is done in every ten years. First census was in 1891 to 1901 . According to 2001 census the population of India is 1,027,015,247. Various factors responsible for population dynamics are as follows:

Natality:

Natality is a rate of production of new individuals in a population per unit time per unit area. For human population the birth of new individuals is taken into consideration.

Mortality:

The mortality is a rate of deaths in a population per unit time per unit area. It is a death rate in a population at any given time. Deaths are due to various causes like natural, diseases, accidents etc.

Growth Rate:

Growth rate is the increase in population due to actual number of individuals added to the population. The growth rate depends on important factors like natality and mortality. The population increases if natality is more than mortality. The population declines when mortality is more than natality. The growth rate is calculated as follows:

In India growth rate in year 1981 to 1991 was 7.6 whereas in years 1971 to 1981 it was 21.2 which is almost three times growth.

Density of Population:

The total number of individuals in a population per unit area is called density of that population.

The main factors which determine the density of any population are the natality and mortality of the population i.e. growth rate. If the growth rate is more, then the density increases and vice-versa.

India has shown increase in density due to high natality and comparatively low mortality.

Density of the population is also influenced by migration. Migration is of two types, emigration and immigration.

When individuals leave the population and move out it is described as emigration. As a result the density of the population decreases.

E.g. People leaving villages to come in cities make village population less dense. When new individuals come into the population from outside, it is described as immigration., It results in increasing the density of the population.

E.g. People coming from villages to cities make city population denser.

Age structure:

The relative proportion of individuals of various age groups in the population is called age structure of the population.

The population is divided in three age groups:

i. Young (0 - 14 years) Pre-reproductive age group

ii. Adults (15 - 59 years). Reproductive age group

iii. Old (60 years and above) Post-reproductive age group

The distribution of these age groups determine the trend of population:

i) Growing population:

population having larger number of individuals of the pre-reproductive age groups shows a very rapid rate.

ii) Steady population:

when the pre-reproductive and post reproductive age group is same then the population remains steady.

iii) Declining population:

larger number of post reproductive and smaller number of pre reproductive make population decline.