Physical factors affecting population distribution
Relief
Rough mountains and hills are unsuitable for the construction of highways, railways, and agriculture because of the short growing season,
The lack of cultivable land and snowy winters do not encourage population settlement. The mountainous areas do not support a large population.
On the other hand, the low lands or plains such as Areas of Rivers Ganga, Brahmaputra, etc. in India, Hwang-Ho in China, and plains of North-Western Europe and the USA support a high concentration of population.
This is because river plains or flat level land are fertile and provide favourable conditions for agriculture, long growing season,s and suitable condition for the settlements.
Accessibility
Well-connected areas with railways, roads, shipping, canals, air transport are densely populated.
In earlier times most of the Islands remained virtually uninhabited due to the absence of water transport. The mountain regions are less populated because of the lack of accessibility.
Adequate water supply
Water has great influence over the population distribution of any region. The water supply is basic for human and life survival.
The area with a good water supply naturally or artificially has a dense population compared to the drier areas.
Great North India plains with hundreds of rivers support dense population and where are drier or drought-prone regions such as deserts regions, example Sahara, support less population.
Soil
Fertile alluvial soil found along the river valley around the world supports dense population settlement. This is fertile soil supports agricultural activities.
The world’s most densely populated areas such as East and South East Asia is heavily dependent on fertile soil.
Examples, are the Great North India Plains of India with Ganga, Brahmaputra and its tributaries, Indus valley of Pakistan, and Hwang-Ho valley of China.
Whereas, the desert soil of the Sahara region is sparsely populated.
Economic and political factors
Unfavourable conditions such as poor economic conditions, unemployment, religious intolerance, conflicts, and wars do not favour more population.