The Sudd is a vast swamp in South Sudan, formed by the White Nile's Baḥr al-Jabal section. The Arabic word sudd is derived from sadd (سد), meaning "barrier". The problem of floating islands on Lake Naivasha. Regional Remote Sensing Facility, Nairobi, Kenya. 4p. The term "the sudd" has come to refer to any large solid floating vegetation island or mat. The area which the swamp covers is one of the world's largest wetlands and the largest freshwater wetland in the Nile basin.
For many years the swamp, and especially its thicket of vegetation, proved an impenetrable barrier to navigation along the Nile. For this reason, the search for the source of the Nile was particularly difficult; it eventually involved overland expeditions from the central African coast, so as to avoid having to travel through the Sudd.
The Sudd stretches from Mongalla to just outside the Sobat confluence with the White Nile just upstream of Malakal as well as westwards along the Bahr el Ghazal. The shallow and flat inland delta lies between 5.5 and 9.5 degrees latitude North and covers an area of 500 kilometres (310 mi) south to north and 200 kilometres (120 mi) east to west between Mongalla in the south and Malakal in the north.
Sudd was designated as a Ramsar Wetland of International Importance on 5 June 2006. (Full article...)