Trombetas River

Course

The Trombetas is 750 kilometres (470 mi) long, and is navigable by 500 ton vessels for a stretch of 230 kilometres (140 mi). It is formed by the junction of the Poana and Anuma rivers on the border between Brazil and Guyana. Where it meets the Paraná de Sapucuá it takes the name of lower Trombetas, and reaches up to 1,800 metres (5,900 ft) in width, with the stream divided by several long and narrow islands. It runs through the municipalities of Oriximiná, Terra Santa, Óbidos and Faro. The river basin has an area of about 133,630 square kilometres (51,590 sq mi), with an intricate pattern of tributaries including the Poana, Anamu, Turuna, Inhabu, Mapuera and Paru de Oeste. In the Saracá-Taquera National Forest the main streams in the Trombetas basin are the Papagaio, Água Fria, Moura, Jamari, Ajará, Terra Preta and Saracá.

Its confluence with the Amazon is just west of the town of Óbidos, Pará in Brazil. Its sources is in the Guiana highlands, but its long course is frequently interrupted by violent currents, rocky barriers, and rapids. The inferior zone of the river, as far up as the first fall, the Porteira, has but little broken water and is low and swampy; but above the long series of cataracts and rapids the character and aspect of the valley completely change, and the climate is much better. The river is navigable for 135 mi (217 km) above its mouth. The river reaches its highest levels in April and May, since the rainy season usually peaks in April.

Region

The river basin lies partly within the 4,245,819 hectares (10,491,650 acres) Grão-Pará Ecological Station, the largest fully protected tropical forest conservation unit on the planet. South of the ecological station it flows through the 3,172,978 hectares (7,840,600 acres) Trombetas State Forest from north to south.