Indonesia Geography and Population

By | December 23, 2021

Indonesia Island state in Southeast Asia. The geographical name (comp. Of Indo – and of the Greek νῆσος “island”), which is sometimes preferred that of Insulindia , refers to the set of about 14,000 islands located SE of the Asian mainland from the Bay of Bengal to the Sea of Arafura, between the Indian Ocean, the South China Sea and the Pacific Ocean, which form the largest archipelago in the world. The Republic of Indonesia includes the Greater Sunda Islands (Sumatra, Java, Celebes and Borneo), the Lesser Sunda Islands (Bali, Flores etc.) and the Moluccas, as well as, since 1963, the western sector of New Guinea (since 1973 called Irian Jaya and since 2002 Papua), which from a physical point of view does not belong to the archipelago.

Physical characteristics

The structure and morphology of Indonesia were dictated by the Himalayan orogeny which, in the Cenozoic, folded and raised the prevailing Mesozoic sediments. The tectonic formation of the Indonesia it is therefore recent, despite the emergence of more ancient materials, and the large archipelago is a sort of ‘bridge’ between the two continental Asian and Australian masses, still the scene of a lively evolution, as evidenced by seismicity and volcanism. It should be remembered, among the most recent seismic events, the violent earthquake, with its epicenter off the coast of Sumatra, which in December 2004 produced a tidal wave (tsunami) causing hundreds of thousands of victims in Indonesia (particularly in ‘ Aceh), and investing all regions bordering the Andaman Sea and on the Bay of Bengal. About a hundred volcanoes are active on the island of Java; others are in Sumatra (Kerinci, 3800 m), Celebes, Sumbawa, Flores and in the Banda islands. Borneo lacks active volcanoes, but has many of the country’s approximately 300 dormant systems. The morphological unity of the archipelago, which results from a set of arch-pit systems (➔ tectonics), is well indicated by the alignment that the Sumatran mountain ridge forms with the Sunda Islands festoon. The islands face S on the Java Trench (-7125 m), while the Java Sea reaches just -70 m; E of the straits of Lombok and Makassar, the seabed has large sinks (Mar di Celebes, 5520 m; Mar di Banda, 7440 m), but also shoals, reefs, islets, coral atolls. For Indonesia geography, please check

The climate of the Indonesia it is equatorial to N, with an average annual temperature of about 26 ° C, irrelevant thermal excursion, precipitation from 1400 to 4000 mm per year; and subequatorial in the southern islands. The rains are more abundant and continuous in the W (Padang, on the island of Sumatra, 3800-4000 mm per year) than in the E (Kupang, in the island of Timor, 1400 mm per year), and longer along the coasts than in the interior. of the islands.

Borneo is the longest river of the Indonesia (Kapuas, 1150 km); other notable ones are in Java (Solo, 530 km) and Sumatra (Hari, Musi). The irregular regime makes it difficult to use, but especially in Borneo, rivers are often the only way into the interior. The greater lake of the Indonesia is that of Toba (1300 km 2), in the northern sector of Sumatra.

The vegetation is generally very rich and the rainforest covers all the low-lying uncultivated regions; along the coasts, mangroves are frequent. Where rainfall is less, the forest is interrupted by savannas. Indonesia is the contact area between the Indo-Malaysian and Australian faunal regions, whose typical fauna prevails in the eastern islands. Among the monkeys appears the orangutan. On the island of Celebes (and in the Lesser Sunda Islands) the promiscuity between the two zoogeographic regions is manifested: here the easternmost bovid (Anoa depressicornis) and the westernmost marsupial, the cusco (Phalanger maculatus) meet.


Indonesia is the fourth state in the world by number of residents. The average density value (about 127 residents / km 2) is very little significant, as a consequence of a very irregular distribution of the population: if the island of Java (1000 residents / km 2) is one of the areas of maximum population density of the Earth, western New Guinea has just 6 residents / km 2 and Kalimantan (Indonesian part of Borneo) 25. The population of the western Lesser Sunda Islands, particularly Bali, is denser than the eastern ones. Java, the point of arrival of any external cultural contribution, then the heart of the very rich Dutch colonial empire, fertile, easily accessible, is the most vital and evolved part of the Indonesia and has attracted and continues to attract people from the other islands; it hosts 58% of Indonesians on just 7% of the country’s surface. Another 20% of the population lives on the island of Sumatra. The demographic increase of the Indonesia it was very remarkable throughout the twentieth century, oscillating between 2 and 3% per year, supported by the high birth rate; it subsequently marked a gradual reduction (1.3%, 2000-05), although the birth rate still exceeds 20%. Infant mortality is still quite high (34 ‰),

Rural country, Indonesia it is scattered with villages, mostly referred to as kampong (the same name also indicates the informal settlements of the urban suburbs); both fishing boats and agricultural ones, and in any case generally located along the coast or on the banks of rivers, the kampong constitute elementary and spontaneous settlement forms of communities, substantially autarchic, even when they follow one another very close to each other, as in the most fertile areas. About 52% of the population lives in rural villages. The urban phenomenon is very little developed, with the exception of Java, where large cities arose due to the influence of Indian and Arab civilizations and, later, in the colonial era, composing an urban network that is absent in the rest of the country. Maximum industrial, commercial, financial and cultural center of the Indonesia is the capital, Jakarta, predominantly European in appearance, a destination for massive and disordered immigration, which has led the population to exceed 8.3 million residents (about 18 in the urban agglomeration). In Java there are other millionaire cities: Surabaya (2.7 million), port and center of the sugar industry; Bandung, in the center of a thriving inland agricultural area (2.2 million); Tangerang, industrial city (1.5); Semarang (1.4); in the other islands very few cities have reached comparable sizes: Medan (2 million) and Palembang (1.3) in Sumatra, Ujungpandang (1.1) in Celebes; in large areas, in reality, there are no properly urban centers at all.

In the population, among the non-indigenous contributions, generally small in number, the Chinese stand out, called in the 19th century. by Dutch companies for the construction of railways and roads and for the extraction of tin, and then settled mainly in the urban areas of Java, where they specialized in trade and credit.

By far the most followed confession (by over 87% of the population) is the Islamic one, so that Indonesia it is the state in the world that hosts the most Muslims. Christians are about 10%, of which one third are Catholics; Hinduism was preserved in Bali. Coexistence between the various cultural components is not without difficulties; the Javanese elite, which holds political and economic power and has control of the armed forces, aimed to compress local identities and cultures in order to form an Indonesian ‘nation’, but thus provoking resistance, even violent, of the populations of East Timor (which became independent in 2002), of the Accinesi in the northern region of Sumatra, as well as the Papuans of the western sector of New Guinea. Discrimination and popular hostility have prompted many members of Chinese communities to flee the country. Furthermore, animosity has grown between Muslims and Christians, Hindus and Buddhists, which has also resulted in bloody clashes.

Indonesia Geography