Why are some countries sparsely populated

Populous regions
The map shows the population concentration in Asia, especially in the area affected by the monsoons. The monsoon region stretches from India through Southeast Asia, China, Korea to Japan. The two most populous countries in the world are located here: The People's Republic of China with 1.3 billion inhabitants and India with 1.2 billion inhabitants (2009). Together they make up more than a third of the world's total population. Overall, Asia accounts for around 60 percent of the world's population. Bangladesh, Indonesia, Russia, Pakistan and Japan are also among the nine most populous countries, each with well over 100 million inhabitants. Within Southeast Asia, the agrarian favored area of ​​the island of Java (Indonesia) emerges with the highest population densities. The difference to the other islands in Indonesia is particularly striking.

Sparsely populated regions
In a clear difference to the densely populated regions are other, very sparsely populated regions of the Asian continent. Unfavorable climatic conditions and a remote location prevented dense settlement. North Asia, which is only a little more densely populated in a few small areas, is one of these areas. Due to its remote location and its permanently frozen permafrost soils, settlement was very difficult and only attracted a few people to this inhospitable region. And Central Asia is also extremely sparsely populated due to its climatic disadvantage. Likewise parts of the extremely dry desert areas in Central Asia, Arabia and the highlands of Iran and finally the inland of Southeast Asia and the large islands, such as Borneos, which are covered with tropical rainforests.
The unfavorable climate, vegetation and soil conditions did not allow extensive settlement in the regions mentioned. At most, there is a punctual or linear settlement. These settlements are mostly located at important deposits of natural resources, along major transport routes such as the Trans-Siberian Railway or in isolated oases in the desert regions. In the sparsely populated Middle East, higher population densities can be seen, especially in the coastal areas of the Persian Gulf, the Caspian Sea and the Red Sea, as well as on large rivers such as the Euphrates and Tigris.

Cities and metropolises
In South and East Asia, the concentration of large metropolises, that is, large cities with over a million inhabitants, is striking. However, the highest rates of annual population growth are in Western Asia. Some of the cities in this region have doubled their population in the last few decades within a decade, such as Tehran, Riyadh, Jiddah, Karachi and Dhaka. The cause of this explosive growth was mainly the large streams of migration (migrations) from the countryside to the cities. Since the so-called rural-urban escape is largely uncontrolled, it still leads to phenomena that are particularly evident in India. Many people there live in slums that are no longer just on the outskirts of the city, but increasingly also in the centers. Very often the jobs that immigrants hope for do not exist. The poorest, the Pavement Dwellers, spend the night on the sidewalks in Calcutta or Bombay. Hunger and disease spread in such slums.
W. Storkebaum, M. Schneider