LAND AND GEOGRAPHY
Indonesia is the largest archipelago in the world. It consists of five major islands and about 30 smaller groups. The figure for the total number of islands is 17,508 according to the Indonesian Naval Hydro-Oceanographic office. The archipelago is on a crossroad between two oceans, the Pacific and the Indian, and bridges two continents, Asia and Australia. This strategic position has always influenced the cultural, social, political, and economic life of the country.
The territory of the Republic of Indonesia stretches from 6.08' north latitude to 11.15' south latitude. The Indonesian sea area is four times greater than its land area, which is about 1.9 million sq km (including an exclusive economic zone) and constitutes about 81% of the total area of the country.
The five main islands are: Sumatra, which is about 473,606 sq km in size; the most fertile and densely populated islands, Java/Madura, 132,107 sq km; Kalimantan, which comprises two-thirds of the island of Borneo and measures 539,460 sq km; Sulawesi, 189,216 sq km; and Irian Jaya, 421,981 sq km, which is part of the world's second largest island, New Guinea. Indonesia's other islands are smaller in size.
The archipelago is divided into three groups. The islands of Java, Sumatra, and Kalimantan, and the small islands in-between, lie on the Sunda Shelf which begin on the coasts of Malaysia and Indo China, where the sea depth does not exceed 700 feet. Irian Jaya which is part of the island of New Guinea, and the Aru Islands lie on the Sahul Shelf, which stretches north wards from the Australia coast. Here the sea depth is similar to that of the Sunda Shelf.
Located between these two shelves is the island group of Nusa Tenggara, Maluku and Sulawesi, where the sea depth reaches 15.000 feet. Coastal plains have been developed around the islands of Sumatra, Java, Kalimantan and Irian Jaya.
The land area is generally covered by thick tropical rain forests, where fertile soils are continuously replenished by volcanic eruptions like those on the island of Java.
The country is predominantly mountainous with some 400 volcanoes of which 100 are active. Mountains higher than 9000 feet are found on the islands of Sumatra (Mt. Leuser and Mt. Kerinci); Java (Mt Gede; Mt. Tangkubanperahu, Mt. Ciremai, Mt. Kawi, Mt. Kelud, Mt. Semeru and Mt.Raung), Sulawesi (Mt. Lompobatang and Mt. Rantekombala), Bali (Mt. Batur and Mt. Agung), Lombok (Mt. Rinjani) and Sumbawa (Mt. Tambora). The highest mountain is the perpetually snow-capped Mandala Top (15,300 feet) in the Jaya Wijaya mountain range of Irian Jaya.
Many rivers flow throughout the country. They serve as useful transportation routes on certain islands, for example, the Musi, Batanghari, Indragiri and Kampar rivers in Sumatra; the Kapuas, Barito, Mahakam and Rejang rivers in Kalimantan; and the Memberamo and Digul rivers in Irian Jaya.On Java rivers are important for irrigation purposes, i.e., the Bengawan Solo, Citarum and Brantas rivers.
A number of islands are dotted with scenic lakes, like the Toba, Maninjau and Singkarak lakes on Sumatra; the Tempe, Towuti, Sidenreng, Poso, Limboto, Tondano, and Matana lakes on Sulawesi; and the Paniai and Sentani lakes on Irian Jaya.
The climate and weather of Indonesia is characterized by two tropical seasons, which vary with the equatorial air circulation (the Walker circulation) and the meridian air circulation (the Hardley circulation). The displacement of the latter follows the north-south movement of the sun and its relative position from the earth, in particular from the continents of Asia and Australia, at certain periods of the year. These factors contribute to the displacement and intensity of the Inter-Tropical Convergence Zone (ITCZ) which is an equatorial trough of low pressure that produces rain. Thus, the west and east monsoons, or the rainy and dry seasons, are a prevalent feature of the tropical climate.
The Main Seasons
The climate changes every six months. The dry season (June to September) is influenced by the Australian continental air masses; while the rainy season (December to March) is the result of the Asian and Pacific Ocean air masses. The air contains vapor which precipitates and produces rain in the country. Tropical areas have rains almost the whole year through. However, the climate of Central Maluku is an exception. The rainy season is from June to September and the dry season from December to March. The transitional periods between the two seasons are April to May and October to November.
Temperature and Humidity
Due to the large number of islands and mountains in the country, average temperatures may be classified as follows:
Coastal plains : 28 Degree Centigrade
Inland and mountain areas : 26 Degree Centigrade
Higher mountain areas: 23 Degree Centigrade, varying with the altitude.
Being in a tropical zone, Indonesia has an average relative humidity between 70% and 90% with a minimum of 73%,and a maximum of 87%.
As of January 1, 1988, Indonesia's three time zones have been changed as below:
1. Western Indonesia Standard Time equals GMT plus 7 hours (meridian 105,E), covering all provinces in Sumatra and Java, and the provinces of West and Central Kalimantan.
2. Central Indonesia Standard Time equals GMT plus 8 hours (meridian 1200E), covering the provinces of East and South Kalimantan, all provinces in Sulawesi, and the provinces of Bali, West and East Nusatenggara and Timor.
3. Eastern Indonesia Standard Time equals GMT plus 9 hours (meridian 1350E), covering the provinces of Maluku, North Maluku, Papua and West Papua.
The population policy is directed toward development of the population as human resources in order that the national development can be effective and valuable, while the quality of life is gradually improving.
Meanwhile, the control of population growth is carried out through efforts to lower the birth and mortality rate, especially that of infants and children. These efforts in particular have been implemented through family planning programs which also have the purpose of improving the welfare of mother and child and at the same time create a small, happy, and prosperous family.
There are about 583 languages and dialects spoken in the archipelago. There normally belong to the different ethnic groups of the population. Some of the distinctly different local languages are: Acehnese, Batak, Sundanese, Javanese, Sasak, Tetum of Timor, Dayak, Minahasa, Toraja, Buginese, Halmahera, Ambonese, Ceramese, and several Irianese languages. To make the picture even more colorful, these languages are also spoken in different dialects.
The national language of Indonesia is "Bahasa Indonesia". Originally it was the Malay language mainly spoken in the Riau Islands. In its spread throughout the country, its vocabulary and idioms have been enriched by a great number of local languages. To keep pace with religious, social and cultural progress, many words and terms have been derived from foreign languages, including Dutch, Chinese, Sanskrit, Arabic and, later, Portuguese.
Although Bahasa Indonesia has become the lingua franca, local languages and dialects continue to be spoken and will not be abolished.