3. North-West Europe (UK, France, Germany, Netherlands, Poland, Belgium, Luxembourg, Ireland, Denmark, Spain, Portugal and Italy).
4. Eastern North America (North-East United States and South-East Canada).
All these areas of dense population lie in the northern hemisphere and are so placed that more than 75 per cent of the world’s population is now concentrated between the Tropic of Cancer and 70° north.
Of these, China and the subcontinent of India have been having large populations from the earliest times. Europe is less ancient, and the United States has become densely populated only during the last two hundred years.
Except in Japan, Hong Kong, Macau, South Korea, Singapore and Taiwan, the population of East and South Asian countries is living mainly in rural areas.
The people are directly or indirectly engaged in agriculture. They are largely dependent on primary activities (agriculture, forestry, fisheries, and mining) which reflect the food-producing potential of the land.
In these countries also, the areas having fertile alluvial soils, gentle slopes and available water (from surface and underground or rainfall) have the highest densities of population.
In China, the valleys of Yangtezekiang, Hawang Ho and Sikiang have great clustering of population. In India, the Sutlej-Ganga-Brahmaputra plains, the eastern coastal plains and the valleys of the perennial rivers are densely populated. In Pakistan, the province of Punjab, traversed by the five rivers (Indus, Jhelum, Chenab, Ravi, and Sutlej) and the delta of Indus are densely populated.
The entire alluvial tracts of Bangladesh, excepting parts of the Chittagong Hills, have high density of population. The valley of Nepal and the coastal areas of Sri Lanka also have heavy concentrations of population.
In contrast to the distributional pattern of population is South-East Asia, the European and North American areas of high population densities consist of urban agglomerations.
The industrial development and tertiary activities (services) in cities and towns have drawn people from the villages and countryside and over three-fourth of the populations in Europe and America today live in cities (for details, see Chapter 9).
While the highest population densities occur in China and India, the highest urban densities are found in Singapore (100%), Kuwait (98%), Belgium (97%), the Netherlands (92%), and the United Kingdom (91%). The European and American population agglomerations could become large because of certain other favourable physical factors.
The climate of these regions is mild and temperate in which a variety of crops can be grown. Wheat, barley, oats, rye, sugar beet, potatoes, fodder, maize, fruits, grapes and oilseeds grow well up to Ireland, Scotland, Sweden, Norway and Faroes Islands (Denmark).
The rise, development and expansion of large manufacturing industries in and around cities also resulted in latter’s growth.
The cumulative improvement of the various kinds of work, and consequently of the workers, shows that the European population agglomeration is the result of physical and cultural factors.
Trade relations and colonization of the African, Asian and American countries greatly contributed to the increase in population of Europe. The expansion of British, Dutch, French, German, Belgian, Portuguese and Spanish empires in other continents enabled the imports of food and raw materials.
The fast growth of European population thus may largely be attributed to industrial development and exploitation of resources of the colonial countries for food and raw materials.
The densely populated regions of North America have a very short history. Up to 1492, America was not known to Europeans and it was Columbus who discovered it in 1492 and provided a virgin land for the growing population of Europe. The population of America started growing fast only after the Industrial Revolution in 1779.
The North American concentration developed as an outlet for the European population. By 1750, small numbers of British, Dutch, German, French, Irish, Spanish, Portuguese and Italian emigrants settled along the north-eastern coast of North America.
They superseded the Native Americans (Red Indians) who were displaced westward and were decimated by war, disease and other traumatic effects of cultural contact.
The urbanized belt from Boston to Washington D.C. in the United States and the areas along the St. Lawrance River in Canada has remained the main regions of attraction for European people.
In fact, this belt is the hub of economic, commercial, cultural and political activities in North America.
Apart from the above described four major regions of dense population, there is also isolated and scattered nuclei population density in higher. Among these small centers of dense population, the deltas of Mekong, Chao-Phraya, Menam and Irrawaddy rivers as well as the Indonesian island of Java are noteworthy.
Africa’s most densely populated areas include the linear concentration along the Nile Valley in Egypt, the ring of settlement around Lake Victoria and the coastal areas of Nigeria. The Latin American areas of high population concentration include the central part of Mexico, where nearly half the nation’s population lives.
In Central Mexico, rural densities exceed 2,600 persons per square kilometer, and Mexico City (with a population of about 20 million) is a leading world metropolis.
The coastal areas of Venezuela, Peru, Brazil and Argentina, with cores around the cities of Caracas, Santiago, Lima, Bogota, Rio-de-Janeiro, Sao Paulo, and Buenos Aires, respectively, are also areas of high population density.