The environment has considerably affected human beings right from his evolution. The environment affects humans in many ways. Population on the earth varies due to variation in the environment. The main factors which affect the distribution of population and human settlement are:
1) Relief of Land
The populations in the high mountainous areas, such as the Himalayas in India, Andes in South America, Rocky in North America, etc., have very low settlement level. This is because the relief is rugged here which represents obstacles in the construction of roads, railways and communication. Due to steep slopes, agriculture is done with a great difficulty and industries also could not be established. These places having very less economic activity have less population and hence have small isolated settlements.
Whereas the plain areas of the world are most suitable for human settlement. Fertile plains of Ganga in India, Indus in Pakistan, Hwang-Ho in China and plains of Europe have huge population concentration having compact or huge semi-compact type of settlement.
2) Climate
Most of the areas of the earth having density less than two persons/sq. km are not favorable for settlement because of their unfavorable climate.
Areas of cold climate-North Siberia, North Canada, Alaska etc. have low density of population. Hot and arid regions of -Sahara, Kalahari Desert in Africa, Great Australian Desert etc are not suitable for human settlement. In tropical regions due to heavy rain and temperature, the density of population is