The World Population Distribution, Density and Growth
A country is known by its people. It is estimated that the world population reached one billion for the first time in 1804. The United Nations, however, estimated that the world population reached seven billion in October 2011.
The way in which people are spread across a given area is known as population distribution. Population distribution patterns can be studied at different scales namely, local, regional, national and global.
The measurement of the number of people per unit area is known as the ‘population density’ of that area. It is calculated by dividing the number of people by the area of that region. It is usually shown as the number of people per square kilometre.
An area with more than 200 persons per sq km is known as a densely populated area. Eastern Asia, Southern Asia, North-eastern part of the USA, Central and North-western Europe are the densely populated parts of the world.
Moderate Density of Population regions are Central part of America, Tropical Western Africa, Eastern Europe, Central China, Southern portion of the plateau of Mexico, North-eastern Brazil and Central Chile in Latin America.
About half of the land area of the world has a very thin population, which are even less than 10 persons per square kilometre. These areas are called low density areas.
The expansion of cities with various facilities is known as urbanisation. People move to cities because, the cities offer better employment opportunities in various fields such as manufacturing, building and construction, transportation and education.
The three components of population change are Fertility (births), Mortality (deaths) and, Migration.
Migration is broadly divided into internal migration and international migration. Internal migration can further be sub-divided into:
Rural to Rural
Rural to Urban
Urban to Urban and,
Urban to Rural
International migration can further be sub-divided into:
There are certain ‘push factors’ and ‘pull factors’ that cause people to leave their place of residence.
Propaganda and free availability of contraceptives, further tax disincentives for large families, etc., are some of the measures, which may help in population control.