Digul

The Digul River (Digoel) is a major river in South Papua province, Indonesia, on the island of New Guinea. It is the fourth longest river in New Guinea after the Sepik River, Mamberamo River, and Fly River. With a total length of 853 km and a drainage basin of 45,900 km2.

History
The swamplands upstream were known by the name "Boven-Digoel" (Above the Digul, in Dutch) and hosted a penal colony at Tanahmerah (Red Earth) in the early 20th century, when Indonesia was a colony of Holland. As a result of the abortive 1926 revolt by the Communist Party of Indonesia (PKI), the Dutch exiled 823 of the most troublesome revolutionaries here.

Hydrology
Rising on the southern slopes of the Maoke Mountains, the Digul flows first south and then west to empty into the Arafura Sea. For much of its length, it travels across a low region of extensive swamps and creates a delta near Dolak (Yos Sudarso Island, formerly Frederik Hendrik) Island. The river has a length of 853 km and is navigable as far as Tanahmerah.

Geography
The river flows in the southern area of Papua with predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification). The annual average temperature in the area is 22 °C. The warmest month is April, when the average temperature is around 24 °C, and the coldest is June, at 20 °C. The average annual rainfall is 3,072 mm. The wettest month is January, with an average of 464 mm rainfall, and the driest is July, with 28 mm rainfall. The average rainfall for the whole catchment area between 2002 and 2011 was 3,522 mm.

Discharge
* Monthly flow (m3/s):

Tributaries
The main tributaries from the mouth:
 * Period: 1971–2000