Brunei - Geography
Brunei Darussalam lies on the northwest coast of Borneo island, where it faces the South China Sea. With a land area of 5,765 square kilometres, it shares a common border with Sarawak, an east Malaysian state, which divides Brunei Darussalam into two, The eastern part is the Temburong District while the western portion consists of Brunei-Muara, Tutong and Belait districts.
The 570-sq.km. Brunei-Muara District, where the capital, Bandar Seri Begawan is located, is the smallest, but the most important and populous of the four districts.
The Belait District, the centre of the oil and gas industries, is about 100 klms from the capital.
Hilly lowlands, swampy plains and alluvial valleys dominate the BruneiMuara, Tutong and Belait districts in the larger western portion of the sultanate.
Mountainous terrain dominates in the eastern district of Temburong which has a land area of 1,288 sq.km. To the east, the wide coastal plain reach up to 1,841 metres above sea level on Mount Pagon in the Temburong District.
River System
Four main river Systems irrigate the four districts of Temburong, Belait, Tutong and Brunei-Muara.
Temburong, the smallest of the rivers, drains nearly the whole district.
The 2,700 sq. km. Belait basin has the largest area.The upper catchment is mostly jungle and is sparsely populated. Sandbars at the river mouth restricts shipping and water flow to the South China Sea.
The Tutong river covers the 1,300-square kilometre Tutong Basin. Sand-pits and sandbars make a complex estuary system at the Tutong river. Subject to fairly high tidal influence, its lower catchment area has a flood plain. Dense mangroves and nipah palms, a rich breeding ground of coastal fisheries, cover the lower parts of rivers near estuaries. Pristine tropical jungles and valuable freshwater sources are the upper reaches of Brunei riverThe Brunei River runs into the Brunei Bay.
Islands
Within the Brunei border are 33 islands with a total area of 7,939 hectares or 1.4 per cent of the total land area. Offshore are two of these islands while the others are in inner Brunei Bay and in the country's major rivers. Mostly jungle covered, their sandy beaches face the open sea and mangroves of areas facing inland.
Largely uninhabited, the islands are an undisturbed environment, and a breeding grounds for endangered species.
Mangroves
Primary tropical jungles cover about 75 per cent of Brunei. About three per cent of the total land area, or 18,814 hectares, are relatively unexploited and among the best preserved mangroves in the region.
Of Brunei mangrove flora identified, 88 species are flower plants while 33 are ferns. There are a variety of insects, crabs, snails, shrimps, prawns, fish, otters, turtles, lizards, bats, flying foxes, bird species, especially king-fishers, monkeys (including the rare proboscis monkey) and crocodiles in the less accessible swamps.
