The region comprising the other 21 provinces in Sumatra, Java, and Kalimantan is known as Western Indonesia. ^{[1] [2]}

Geography

Geology

The main islands of Sumatra, Java, Madura, and Kalimantan lie on the Sunda Plate. Indonesia has relatively high tectonic and volcanic activities. It lies on the convergence between the Eurasian, Indo-Australian, Pacific, and Philippine Sea Plate. The Sunda megathrust is a 5,500 km long fault located off southern coasts of Sumatra, Java and Lesser Sunda Islands, where the Indo-Australian Plate is thrusting northeastward towards the subducting Sunda Plate.Tectonic movement in this fault is responsible for the creation of the Sunda Trench, and mountain ranges across Sumatra, Java. ^[3] Mount Merapi, located in the Java portion of the megathrust, is the most active volcano in Indonesia and is designated as one of world's Decade Volcanoes due to the hazard it poses to the surrounding populated areas. ^[4]

Ecology

Borneo is the third largest island in the world and the native vegetation was mostly Borneo lowland rain forests although much of this has been cleared with wildlife retreating to the Borneo montane rain forests inland. Kalimantan and Sumatra, experience only slight differences in rainfall and temperature between the seasons, whereas others, such as Nusa Tenggara, experience far more pronounced differences with droughts in the dry season, and floods in the wet. Rainfall in Indonesia is plentiful, particularly in West Sumatra, Northwest Kalimantan, West Java.

Economy

Below are the top 13 provinces in Western Indonesia ranked by GDP in 2019:

Rank	Province	Region	GDP (in billion Rp)	GDP nominal		GDP PPP
				(in billion $)	Comparable country	(in billion $)
-	Indonesia	South East Asia	16,073,257	1,136.72	Mexico	3,329.17
1	Jakarta	Java	2,840,828	200.91	New Zealand	588.42
2	East Java	Java	2,352,425	166.37	Algeria	487.27
3	West Java	Java	2,125,158	150.30	Ukraine	440.19
4	Central Java	Java	1,362,457	96.35	Ethiopia	282.18
5	North Sumatra	Sumatra	801,733	56.70	Uruguay	166.06
6	Riau	Sumatra	765,198	54.12	Lithuania	158.51
7	Banten	Java	664,963	47.03	Azerbaijan	137.74
8	East Kalimantan	Kalimantan	653,677	46.23	Azerbaijan	135.40
9	South Sumatra	Sumatra	455,233	32.19	Estonia	94.28
10	Lampung	Sumatra	360,664	25.51	El Salvador	74,71
11	Riau Islands	Sumatra	268,080	18.96	Sudan	55.53
12	West Sumatra	Sumatra	246,423	17.42	Mali	51.01
13	Jambi	Sumatra	217,712	15.40	Albania	45.10

In 2012, the DMO was 24.72%. Starting from 2014, no low-grade coal exports are allowed, so the upgraded brown coal process that cranks up the calorie value of coal from 4,500 to 6,100 kcal/kg will be built in South Kalimantan and South Sumatra. ^{[5] [6] [7]} Major Japanese factories are concentrated east of Jakarta with high concentrations in Bekasi, Cikarang and Karawang, West Java.

Demographics

Population

Jakarta is the largest city and the only megacity in Indonesia, with a population of 10.70 million. As a primate city, Jakarta is nearly four times larger than the second largest city Surabaya. Jakarta's status is unique compared to other cities in Indonesia, since it is technically a province with a city management. It is subdividied into five administrative cities and an administrative regency, which are not self-governed (without municipal council nor government budget). All five of Jakarta's satellite cities also have passed one million mark in population, with the largest one being Bekasi.

The other largest cities by region include Medan ( Sumatra, also the largest outside of Java), Samarinda ( Kalimantan).

Below are the populations of each provinces which make up the total population of Western Indonesia:

Languages

Indonesia recognizes only a single national language, and indigenous languages are recognized at the regional level, although policies vary from one region to another. For example, in the Special Region of Yogyakarta, the Javanese language is the region's official language along with Indonesian. ^[8] The next most widely spoken regional languages in the country are Sundanese, local Malay, and Minangkabau. There are hundreds of indigenous languages spoken in Indonesia. Most of them are locally used indigenous languages, ^[9] a category of languages referring to those spoken at the local, regional level, spoken by a small number of people, ranging from a few to a few thousands of people. These include small languages such as Benggoi, Mombum and Towei. ^{[10][ page needed]} Other languages are spoken at the regional level to connect various ethnicities. For this reason, these languages are known as regional lingua francas (RLFs). According to Subhan Zein, there are at least 43 RLFs in Indonesia, categorized into two types: Malayic RLFs and Non-Malayic RLFs. The former refers to a group of regional lingua francas that are thought of as indigenised varieties of Malay or Indonesian. These include such languages like Banjar Malay among others. The latter refers to regional lingua francas that are not associated with Malay or Indonesian, like Iban. ^{[11] [10][ page needed] [a]}

The population numbers given below are of native speakers, excepting the figure for Indonesian, which counts its total speakers.

Religion

Religion was a census variable in the 1961, 1971, 1980, 1990, 2000, and 2010 and in various intercensal surveys. Being deemed divisive, the 1961 census data regarding religion was not published. In 1971, three groups of Christians were recorded: Catholic, Protestant and other. The U.N. Demographic Yearbook 1979 only lists data collectively for all Christians. In the 2000 census, only Catholics and Protestants were available as categories. ^[14]

Religious composition by ethnic group ^[15]

See also

• Regions of Indonesia
• Eastern Indonesia

Notes

References