World population

Population: 

The ratio of a country's total population to its total area gives the per square kilometre density of population. Total world population now comes to about 650 crores. World’s population is not evenly distributed over the land surface of the -.earth. 
Some parts of the world are very densely populated. In other parts,' the population is sparse. As a matter of fact the density population must be considered in the background of the resources of an area. If local resources can easily meet the needs of a dense population, the density does not matter. 

World population (Characteristics)

The important characteristics of world population are the following: Almost 85% of the world population lives in the Northern Hemisphere Almost 80% of the population is concentrated on less than 20% of the earth's surface. 
A study of the distribution of population in different regions and various countries shows startling differences in its density. Looking at the population map of the world we find that the greater part of humanity is concentrated in well marked areas. These relatively small areas support huge populations. 
 Three-fourths of mankind is concentrated in four big zones, two of them are in Asia, one is in Europe and the fourth one is in North America. 

Four Big Zones of the world

Asiatic Zone 
South Asia 
Central and Western Europe 
North America and Southern.Canada 

 Asiatic zone

One of the Asiatic zones comprises East China, Korea, Japan and the Island of Taiwan.

South Asia

The second one is South Asia i.e., Pakistan, Bharat, Bangladesh and Sri Lanka. If we add to these two Asiatic Zones the lands that lie between them, this tract of Asia accounts for more than half of the world population. 

Europe

The zone of thick populations in Europe occupies the central and western parts of the continent. It includes Germany, France, Holland, Belgium, Denmark and England. About one-fifth of the world population is concentrated in this zone.

North America

 North America has a relatively small zone of thick population. It comprises the ndrth eastern parts of the United States and the South-eastern part of Canada.

 Smaller Areas of Thick Population: 

Besides these four large zones, some smaller areas of thick population clearly stick out. 
Examples are: 
the island of Java in Indonesia, the Nile Valley in Egypt, areas to the South of the Lake Victoria in Central Africa, Niger and Ghana coast in West Africa, part of the California coast in North America, Eastern Brazil and the areas close to the north-eastern coast of Argentina in South America. 

 Thickly Populated Areas of Pakistan: 

In all parts of Pakistan population is not equally thick. In the Indus Plain: The river valleys are thickly populated'. 
In the Punjab: The heaviest pressure of population is in the Lahore and Multan Divisions.
 In the Province of Sindh: The districts of Sukkur, Larkana, Dadu and Nawab Shah are thickly populated. Karachi is the most thickly populated region in the entire country. 
In the North Western Fronteir Province: The districts of Peshawan-and Mardan have dense populations. 

Areas of Sparse Population in Pakistan: 

Areas of sparse population in Pakistan include the districts of Bahawalnagar, Bahawalpur, Rahim Yar Khan, Mianwali, Muzaffargarh, Dera Ghazi Khan, Mirpurkhas, Sanghar and Tharparkar, the whole of Balochistan and the NWFP, excluding the districts of Peshawar and Mardan.

 Reasons for Differences in the Density of Population:

 Differences in the density of population arise because of physical, social, cultural and historical reasons. Favourable physical conditions encourage growth of population.Physical Factors: About a third of the land surface of the earth lies almost uninhabited. It includes areas that are either too hot or too cold, or.too wet or too dry for man to live. It also includes the high mountainous regions of the world. Areas due to which Differences Arise.

 Vast Deserts: 

A look at the population map of the world will show that a vast desert stretches from the coast of North Africa and sprawls across North Africa in the form of the 'Sahara’, the Arabian desert, the Iranian desert, the deserts of Central Asia, and finally that of Mongolia. In these huge stretches of territory, the only populated areas are the tiny patches of‘green river valleys like the valley of the Nile. 

The ice-Bound Waste-Lands: 

The ice-bound waste-lands of the world include the whole-continent of Antarctica, girdling the South Pole. In the Northern Hemisphere, the ice-bound lands are: the island of Greenland and the northern parts of Asia and Europe, known as the Tundra. These vast stretches of land arc inhospitable to man. their total population comes to less than a million. Several Parts of the Equatorial Region: . Several parts of the ‘equatorial region’, especially the basins of the Amazon and the Congo, and the Island of Borneo also have sparse population. 

 High Mountain Peaks and Steep Slopes: 

High mountain peaks and steep slopes are simply not habitable. Cultivation here is ruled out. Also there is no solution to the transport problem. At very high altitudes, the inadequate supply of oxygen makes breathing difficult. That explains why the Himalayan and Karakoram region in the Indo-Pak Subcontinent, the Rockies region in North America, and the Andes region in South America lie almost uninhabited. 

 Reasons for the Increase in Population of Cities: 

During the past two hundred years urban population across the globe has been steadily increasing At present, about 40% of. the world population lives in urban areas. 

In advanced countries like Great Britain, Sweden and Germany, 80% of the people are city dwellers. In some industrially developed countries, cities have.expanded to merge into one another. 

The increase in population of urban areas is due to the following reasons: 

 Job Opportunities: 

The dramatic growth of cities is due to the job opportunities they offer. They are surrounded by various kinds of factories and are also centres of trade and commerce. 

 Discovery of Valuable Minerals: 

Discovery of valuable minerals in inhospitable regions induces people to flock there. New towns' spring up over-night. industries: Industries have to be set up around towns and cities. Once they are set up, they attract swarms of workers. Administrative Area: The administration of the area or of the country is also controlled from urban centres. Railway and bus services, banks etc., all have their central offices in cities. In short, modern cities are the nerve centres, controlling the economic, social and political life of the people. It is only natural that more and more people from rural areas should throng to cities.