(iii) Mountainous regions. (iv) Tropical rain forests.
(i) Deserts and Arid Lands:
All those areas where the rate of evaporation is higher than the rate of precipitation (arid lands) are most sparsely populated. The main problem with the settling of arid lands is the deficiency and non-availability of water. In the arid areas where water is available, agriculture is often successful because desert soils are generally rich in minerals and in many places the growing season is long.
The Nile Valley, the Indus Valley, the Sonara desert in Mexico and United States and other scattered oases in Central Asia are the main exceptions to the general condition of barrenness and relative emptiness. Excepting these fertile valleys and oases, the great series of deserts, especially along the Tropic of Cancer and Tropic of Capricorn on the western margins of continents, the population is most sparse. In the deserts of Libya, Algeria, Egypt, Niger, Western Sahara, Mali, Sudan, Chad and Mauritania, the average density of population is about one person per 15 sq. kms. In such deserts of hostile climate and scarce water, people deliberately check the number of births by imposing monogamy or even celibacy on large scale proportions of their numbers, as is done in Ladakh and Tibet. In some cases, this anxiety of over-population may lead to the rise and survival of barbarous customs.
For example, in some Somali tribes, until very recently, a man might not get married until he had killed with his own hands a certain number of men of his tribe. In brief, the deserts (both hot and cold) are almost uninhabited or else thinly populated by nomadic herders, hunters and gatherers (e.g., Bushmen of Kalahari), and nomads (e.g.
, Bad wins of Arabia and Sahara). In Central Asia and the peripheries of Australian desert, the communities keep sheep and goats and live a life of deprivation. There are exceptional cases in which the extraction of precious metals has attracted men into the heart of deserts. Many towns have emerged in deserts owing to the mining of gold and other precious metals. These miners and workers have to get their whole subsistence and even drinking water from outside the region.
In this way, gold mines right in the desert have caused the growth of Kalgoorlie and Coolgardie in Australia and Cripple Creek in the United States. In the heart of Arabia and Libya, oil has made the presence of only a few groups of workers and scientists felt, who do not altogether form a true self-supporting community. It is believed that at present, the desert areas are expanding and are being occupied by an increasingly smaller proportion of the world’s population. Gold and petroleum have, however, made some of the desert regions as the areas of great attraction for labourers and technicians.
(ii) Ice Caps and Cold Regions:
The second most sparsely populated are the areas of extreme cold, located in both the northern and southern hemispheres. The Arctic region and the Antarctica continent are the areas of severe cold in which winters are dreaded, gloomy and long.
The continent of Antarctica is almost exclusively uninhabited. In the Tundra region of Arctic, the hunting and fishing peoples live, who are just few in number. In fact, only a few seal-hunting Eskimos have been able to penetrate northward up to 82 degrees. Wherever minerals are available men have settled there to exploit them.
For example, miners are extracting iron ore in Gallivare (Sweden), gold in the Yukon Valley of Canada, Fairbanks and Fort Yukon in Alaska, and gold, oil, coal and salt are precious metals in Siberia and Asiatic Tundra. For their subsistence, these miners have to depend largely on the neighbouring developed areas.
(iii) Mountainous Regions:
The rugged and folded mountains are also sparsely populated. In fact, on mountains population becomes sparse with altitude. Lofty mountains are almost uninhabited. In Himalayas, Alps, Rockies and Andese mountains, the areas above 2,500 metres are almost uninhabited.
In higher latitudes, sparseness of population descends to much lower levels. In Scotland, Wales, Norway, Sweden, Russia, Canada and Greenland, sparseness begins only a few metres above the sea. The areas of minerals are, however, exceptions. For example, in Peru and Bolivia, mining of precious metals is done above 4,000 metres. These mining places have quite substantial populations. In Kishtwar (Bhadarwah district of Jammu division), precious stones are mined at an altitude of about 5,500 metres.
At the source of Indus River, the gold mines at Tok-Dschalung have helped in the development of human settlements at an altitude of 5,000 metres above the sea level. In the tropical regions where the climate at lower altitudes is not conducive, most of the towns, cities and settlements have developed around 2,000 metres above the sea level. Addis Ababa (Ethiopia), Kampala (Uganda), Quito (Ecuador), Nairobi (Kenya), Ooty (India) and Kandy (Sri Lanka) are all situated over 2,000 metres above the mean sea level. Throughout the interior of Western Asia, clusters of towns are found in the heart of mountainous regions.
For example, Sana (2,130 m) and Taiz (2,000 m) in Yemen, Tehran (1,130 m) in Iran, Pahalgam, Gulmarg (2,600 m) and Leh (4,600 m) in India and Lhasa (3,550 m) in Tibet are situated at a fairly high altitude.
(iv) Tropical Rain Forests:
The tropical rain forests are also sparsely populated. These are the low-lying areas on both sides of equator where rainfall and humidity remains high and the mean monthly temperatures are over 30°C throughout the year. These regions are covered by dense evergreen equatorial forests. The Amazon basin, the Congo basin, and the islands of South-East Asia, excluding Java, are covered by such forests. The hot and humid climate, luxurious evergreen forests, infested with insects, mosquitoes, snakes, tsetse fly, etc., are least conducive for human habitation.
Cultivation of crops, keeping of cattle for ranching and herding are difficult in these areas Tropical rain forests offer some prospects for future frontier development. One advantage is the proximity to densely populated areas. It is difficult to form settlements in equatorial forested regions. At present, the Amazon and the Congo basins have a very scattered population. It is predicted that an increased population in these areas will result in a deterioration of earth’s resources. In fact, often forest clearance has led to soil erosion, increased run-off and siltation of rivers. The clearance of these forests in Thailand has adversely affected works down streams and thus reduced the country’s agricultural output. Some experts even believe that destruction of the tropical rain forests will affect the world’s climatic balance by reducing the amount of moisture that is returned to the atmosphere by transpiration from luxuriant vegetation.
Encroachment in tropical rain forests may also destroy the culture of hunters, gatherers and shifting cultivators. It has been evidenced in Brazil in the destruction of these societies through violence, disease and cultural disorientation. Thus, all the sparsely populated areas have an irregular and sporadic type of settlement. In these regions, large areas remain uninhabited, whilst relatively small points swarm with people.
The best examples of dense population are found in the larger oases of Africa and Western Asia, the islands of Java and Philippines, the isolated towns in the Congo and Amazon basins. The Himalayas and Alps have some of the large towns and resorts. It is believed that population in the sparsely populated regions shall increase at a faster rate in coming decades which may create many ecological and demographic problems.