Can you imagine a world without human beings? Humanbeings are important to develop the economy and society. The Latin word 'populus' means 'people'. Population is the total number of people living together in a particular place at the given point of time.
‘It is easy to add but difficult to maintain’ Population is a dynamic phenomenon where the number, distribution and composition are constantly changing. Human population increases as babies are born and decreases as people die. For most of human history, births have only slightly exceeded deaths every year. As a result, human population grow slowly. About the time of Industrial Revolution, it began to increase rapidly.
Natural increase of population is the difference between the birth rate and death rate. In fact population is always increasing but only in very rare cases it may decrease through natural or man-made disasters such as famine, landslides, earthquakes, tsunami, epidemics, extreme weather conditions and war.
Population change refers to an increase or decrease in the population of an area influenced by the number of births, deaths and migration. The population of the world doubled from 500 million in 1650 to 1000 million in1850.The projected population for 2025 and 2050 is about 8 billion and 9 billion respectively.
Population growth refers to an increase in the number of people who reside in a particular area during a particular period.
Population increases when there are more births and immigration. It decreases when there are more deaths and emigration. Population growth, can be calculated as
Population growth = (Birth rate + Immigration) - (Death rate + Emigration).
The important features associated with the population studies in Tamil Nadu are as follows:
Population distribution refers to the way in which people are spread out across the earth’s surface.
The world population is not uniformly distributed, owing to the following factors.
Physical factors include temperature, rainfall, soil, relief, water, natural vegetation, distribution of minerals and availability of energy resources.
Regions with historical importance (river valley civilizations), war and constant invasions fall under historical factors responsible for population distribution.
Educational institutions, employment opportunities, manufacturing industries, luxurious amenities, trade and commerce and other facilities encourage dense population in an area.
Density of population refers to the number of people living per square kilometre. An area is said to be sparsely populated when it has a large area with less number of people. Similarly, smaller the area with a large number of people, it is said to be densely populated.
Population Density = Total Population / Total land area
The world’s population density is divided into three main groups.
· Areas of high density (above 50 people per sq.km) - East Asia, South Asia, North West Europe & Eastern North America.
· Areas of moderate density (10 to 50 people per sq.km) - The sub tropical regions like Angola, Congo, Nigeria and Zambia in Africa.
· Areas of low density (less than 10 people per sq.km) - Central Africa, Western Australia, Northern Russia, Canada, etc…
Activity: The population data of the five most densely populated districts of Tamil Nadu is given below. (Findout the population density and their rank)
Migration is defined as the permanent or semi-permanent change of home of an individual or a group of people over a significant distance from their place of origin.
The causes of migration may be physical (climate, drought, flood, earthquake, volcanic eruption, epidemics etc.), social inequalities, economic opportunities, technology, education, cultural clashes, war or political issues.
The movement of people within a country i.e. between states, districts, villages, etc is called as Internal migration.
The movement of people from one country to another, across international borders is called as International migration.
Push and pull factors of migration
Push factors are those factors which force people to move to new areas to live, while pull factors are those factors that attract migrants to a new location. Given below are some of the push and pull factors of migration.
Emigration means moving out or to leave a place.
Immigration means to enter or come into a new country for the purpose of settling there.