Assam - Ministry of Environment and Forests

7.1.11 SonitpurThe district is situated in the northern part of Assam between 26°30'N and 27°02'N latitudes and 92°17'E and93°47'E longitudes. It occupies an area of 492145 Hectares. It is bounded on the east by Lakhimpur district ofAssam, on the west by Darrang district, on the north by Arunachal Pradesh and on the south by the riverBrahmaputra. The topography of the district is almost flat. Along the river Brahmaputra and between thecentral belt and the Brahmaputra are chronically flood affected. Swamps are seen mainly in these areaswhich represent naturally depressed vast wetlands. The major rivers (tributaries of the Brahmaputra) thattraverse this district are Pachnai, Belsiri Nai, Jia Gabharu, Jia Bhoroli, Bardikrai, Bargang and Burai. Therivers are all perennial in nature. Both New Alluvium Soils (Entisols) and Old Alluvium Soils (Inceptisols) arefound in the district. Soils are sandy loam to clay loam in texture and are acidic with pH 4.5 to 6.5. Theaverage annual rainfall is 1563 mm. The maximum temperature recorded is 35°C in the months of July-August and the minimum is 11°C in the months of December-January. As per Census Report, 2001, thedistrict has a total population of 16, 81,513.Total wetland area in the district is 83427 ha that includes 980 small wetlands (