Human population is unevenly distributed across the world. While some areas are densely populated, others have sparse human habitation. Causes for the uneven distribution of population are:

a. Topography: Topography is a crucial factor determining population density. Human beings prefer to live on plains instead of mountains and plateau because plains are most suitable for economic activities like farming, setting up industries etc. The Ganga plains are the most densely populated areas of the world while mountains like Andes, Alps and Himalayas are sparsely populated.

b. Climate: People prefer to live in areas with temperate climate. People usually avoid extreme climates that are very hot or very cold. This is why deserts like Sahara desert and polar regions of Antartica are sparsely populated.

c. Soil: Fertile soils provide suitable land for agriculture. Fertile plains such as Ganga and Brahmaputra in India, Hwang-Ho, Chang Jiang in China and the Nile in Egypt are densely populated.

d. Water: Water is a basic human necessity. Availability of water makes life easier. People prefer to live in the areas where fresh water is easily available. The river valleys of the world are densely populated while deserts have sparse population.

e. Minerals: Areas with mineral deposits are more populated since they provide suitable zones for establishing industries and other economic activities. Diamond mines of South Africa and oil rich areas in the Middle East attract more human habitations.

B. Socio-cultural and economic factors:

a. Social: Areas with better housing, education and health facilities are more densely populated since these amenities improve quality of life. For e.g., Pune in Maharashtra.

b. Cultural: Places with religious or cultural significance attract people since these places are primary tourist attractions and thus a fertile ground for many business activities. Varanasi, Jerusalem and Vatican City are some examples.

c. Economic: Industrial areas provide employment opportunities. Large numbers of people are attracted to these areas. Osaka in Japan and Mumbai in India are two densely populated areas. IT hubs are also some of the most densely populated regions of the world. For eg: Bangalore, Gurgaon etc.