Population Dynamics

The moderately populated areas are mostly found between the densely and the sparsely populated areas. Most of these areas have developed new industries, facilities for irrigation and mining. Central USA, tropical west Africa, southern parts of Russia, eastern Europe, Deccan Plateau of India, central China and parts of South America are moderately populated.

The moderately populated areas have developed new industries, facilities for irrigation and mining. Hence, in these regions, people have migrated from other areas due to favourable natural and economic factors.

Five physical factors that affect distribution of population are:

1. Relief
2. Climate
3. Natural vegetation
4. Soil
5. Availability of water

The urban areas have diverse economic activities and provide better living conditions than the villages. Thus, people migrate to cities in search of work. That's why urban areas have more population.

Two impacts of overpopulation are:

1. Overpopulation puts pressure on natural resources such as cultivable land, freshwater and mineral resources, and result in their degradation and depletion.
2. The increase in number of factories to meet the needs of the people results in industrial pollution.

When the population of an area is less than what the available resources of that area can support, the condition is called underpopulation.

The causes of underpopulation are:

1. Decrease in birth rate
2. Increase in death rate
3. Migration of people out of the area.

Birth rate — The number of live births per thousand persons in a year is called birth rate.

Death rate — The number of deaths per thousand persons in a year is called death rate.

If death rate in a year is less than the birth rate then their will be increase in population which may lead to overpopulation.

A population pyramid is a graphical representation which shows the distribution of females and males in different age group, at a place. It is also known as age-sex pyramid. It is useful to understand the composition of population of any country.

When the population pyramid is broad at the base and tapering towards the top, it depicts that the death rate as well as the birth rate are high. This type of population pyramid represents the population of underdeveloped countries. The population pyramid shows that although the birth rates are high, still many children die in their infancy, and thus very few people reach old age.

Two causes for the imbalance in sex ratio are:

1. Migration — As mostly the young male population migrate in search of jobs, this creates an imbalance in sex ratio with high sex ratio in the place of origin and low sex ration in the place of destination.
2. Female Infanticide — Due to poverty, illiteracy, dowry system and desire for male child, Female Infanticide is practiced in some regions which creates an imbalance in sex ratio.

1. True
2. False
3. False
4. False

Eastern and Southern Asia are densely populated because the warm climate and fertile soil favour the cultivation of crops almost throughout the year. As a result, intensive cultivation is practised here. Moreover, labour-intensive industries have also developed in most of the countries in these regions.

The countries with high population may need not be considered overpopulated as these countries may have enough resources to support its high population with a good quality of life.

The number of all the people who live in a particular area is referred to as the population of that area.

The total population of India as per the Census of India 2011 is 1.21 billion.

density

Intensive

True

False

gold mines

Two cause of overpopulation are:

1. Increase in birth rate.
2. Decrease in death rate.

under-population

Two negative impacts of under-population are:

1. There is shortage of labour and this hampers the production of goods and services.
2. The available resource of the country remain underutilized.

Seven

Moderate

optimum

urban

narrow

Deccan Plateau

availability of water

overpopulation

literacy

15-59