Geography

Indonesia, in southern Asia comprises of more than 13600 islands lying along the Equator (6°N to 11°S) in about 5000 Km length and between the longitudes of 94° to 141°E. Many of these islands cover only a few Sq.Km. although half of New Guinea (called Irian Jaya) and three fourths of Borneo (Kalimantan) also belong to Indonesia. After the Greenland, two of Indonesia’s islands, New Guinea and Borneo are ranked as second and third largest islands in the world. The total area of the country is 19,19,443 Sq.Km. Most of the Indonesia’s larger cities are located in Java including its capital city of Jakarta.

Population and land use

The population of the country is more than 268 Million, as per Population Bureau, 2019; of which a little less than 53% are involved in agriculture. It ranks fifth in the world in population. Indonesia has 931 islands, out of its total 6000 islands, which are inhabited and the principal islands are Java, Madura, Sumatra, Kalimantan (Borneo), Sulaweri (Celebes), West Irian (West New Guinea) and the Moluceas. Tropical rain forests cover much of Indonesia. Its forests contain many hardwood trees like Teak and Ebony. About two third of the country has rain forests.

Climate and rainfall

Indonesia has a hot and humid climate. The lowlands have an average annual temperature of 27°C, but lower in highlands. Average local temperatures vary little throughout the year resulting in the determination of the seasons on the rainfall differences. Java and lesser Sunda have distinct dry season with little rainfall. The rainfall is fairly and evenly distributed throughout the year in other parts of the country with somewhat heavier rain in the wet season. The wet and dry seasons are distinguished with monsoons. The driest regions of Indonesia receive 500 to 1000 mm rain in a year, the lowlands in the country receive 1800 to 3200 mm, while Kalimantan and Sumatra have 3000 to 3700 mm of rainfall. Sumatra has higher rainfall in the highlands. Some mountainous areas in Irian Java receive about 6400 mm a year. Rain forests flourish in Indonesia’s hot rainy climate.

Food and agriculture

Agriculture is Indonesia’s major economic activity. The farms are large plantations where coffee, palm oil, rubber, sugarcane, tea and tobacco are raised for export. Indonesia is a large producer of rice which is the main crop grown on small farms. Bananas, cassava, coconuts, maize, peanuts, spices and sweet potatoes are also grown. Major cash crop in Indonesia is rubber which is exported. The total land area of Indonesia is 181 Mha of which arable and permanently cropped area is 30 Mha, while non-arable lands contribute 151 Mha. Forests and woodlands enable Indonesia to produce a large amount of valuable hardwoods like teak and ebony. Bamboo is also produced in abundance. Estate management and agriculture is widely practised in Java and Sumatra, whereas on other islands the estates are fewer. Soils in Kalimantan, Sulaweri and Sumatra are poor because of excessive leaching by heavy rains and irrigation is needed where rainfall is less than 1000 mm while the extensive swampy soils of the alluvial plains of Sumatra, Kalimantan and West Irian require drainage before being put to useful cultivation.

Irrigation and drainage

The irrigated area at present is just over 5.5 Mha excluding the farmer managed systems which serve an additional 1.6 Mha. Irrigation has been practised in the Java Island for rice from ancient times with their rough and unsophisticated structures. Indonesia has several streams in the large islands of Sumatra, Java, Kalimantan and Irian. Drainage needs have been found to be necessary in several islands of Indonesia particularly large areas in Kalimantan and Sumatra. The practice of drainage and reclamation has been followed in Indonesia for long. Large rice fields are connected by digging channels and connecting them to tidal rivers which inundate the fields in high tide and drain off during low-tides, thus converting a marsh land into a fertile track in about 2 years time. During one of the five year plans (1974-1979), nearly 272000 ha of tidal areas and swamp lands were reclaimed.

Water resources management

The total internal water resources of the country stood at 2530 Bm³ (1987) of which a quantity of 16.6 Bm³ was being withdrawn with an allocation of 76% to agriculture, whereas the irrigated area in 1995 was 4.58 Mha. The important rivers are Brantas, the Sola, the Sorajee, Tjetmeek, Tjettarun in Java, Asahan and Musi in Sumatra. Barito, Kapuas, Mahakam, Kajau and Kahajan lie in Kalimantan. It also has rich ground water resources particularly the aquifers of the lava streams.

 

Major River Basins:

 

1.    Alas-Singkil

2.    Batang Natal-Batang Batahan

3.    Rokan

4.    Kampar

5.    Indragiri-Akuaman

6.    Batanghari

7.    Teramang-Muar

8.    Nasal-Padang Guci

9.    Musi-Sugihan-Banyuasin-Lemau

10. Mesuji-Tulang Bawang

11. Cidanau-Ciujung-Cidurian

12. Ciliwung-Cisadane

13. Cimanuk-Cisanggarung

14. Citanduy

15. Progo-Opak-Serang

16. Bengawan Solo

17. Jelai-Kendawangan

18. Barito

19. Mahakam

20. Berau-Kelai

21. Dumoga-Sangkub

22. Limboto-Bolango-Bone

23. Randangan

24. Palu-Lariang

25. Parigi-Poso

26. Kalukku-Karama

27. Pompengan-Larona

28. Saddang

29. Towari-Lasusua

30. Lasolo-Konaweha

31. Omba

32. Aceh-Meureudu

33. Woyla-Bateue

34. Jambo Aye

35. Belawan-Ular-Padang

36. Toba-Asahan

37. Siak

38. Kepulauan Riau

39. Bangka

40. Seputih-Sekampung

41. Citarum

42. Serayu-Bogowonto

43. Jratunseluna

44. Brantas

45. Bali-Penida

46. Lombok

47. Sumbawa

48. Flores

49. Kapuas

50. Mentaya-Katingan

51. Tondano-Sangihe-Talaud-Miangas

52. Paguyaman

53. Walanae-Cenranae

54. Jeneberang

55. Halmahera Utara

56. Halmahera Selatan

57. Ambon-Seram

58. Kepulauan Yamdena-Wetar

59. Kamundan-Sebyar

Water policies

Irrigation in Indonesia is being developed on five year plan basis and a good number of projects Several river basin territories are considered strategic. Therefore, policy measures must continue to be taken. For instance, the implementation of the Coordinated and Integrated River Basin Management Plan is a necessary condition for successful national economic development. The projects implemented include Brantes river valley development, regional plan in West Java, Sampor dam and irrigation project and Bali irrigation project. Indonesia has promulgated a number of laws for governing water resources. A good amount of research and development efforts is on to develop irrigation in Indonesia. Reintroduce institutional and legislative reform at the grassroots level, including the traditional rules and regulations, so that rural people are again aware of their rights and responsibilities to participate in national development programs.

ICID and National Committee

Indonesia joined ICID in 1950 as a founder member country. Mr. Suyono Sosrodarsono (1972-1975), Dr. A. Hafied A. Gany (2007-2010) and Dr. Ir. Basuki Hadimoeljonoe (2013-2016) were the Vice Presidents Hon. Dr. Mochammad Amron is currently the Vice President of ICID from 2019 to 2022. The National Committee’s publication ‘Sejarah Irigasi Di Indonesia’ by Ir. Abdullah Angoedi, published in 1984 gives an account of historical development of irrigated agriculture in Indonesia and a list of dams and irrigation systems constructed prior to 1969. The INACID has hosted the 49^th International Executive Council Meeting and the 10^th Afro-Asian Regional Conference in July 1998 at Bali, Indonesia. The 61^st International Executive Council Meeting and 6^th Asian Regional Conference was held at Yogyakarta in October 2010. The 3^rd World Irrigation Forum (WIF3) and the 70^th International Executive Council Meeting was hosted by the INACID during 1-7 September 2019, Bali, Indonesia. Currently, the President of the INACID is Dr. Airlangga Mardjono and he can be contacted at  inacid.indonesia@gmail.com.