South Sudan - Sudd Wetland

The Sudd wetland, with an estimated area of approximately 57,000 km2 represents one of the largest freshwater ecosystems in the world. The extent of the Sudd wetlands is highly variable; it depends largely on the seasons and years respectively. In the wet season the size of the wetland increases up to 90,000 km² and gradually decreases to about 42,000 km² depending on high seasonal flood. It is sustained by the flow of the White Nile (or Bahr el Jebel) from Lake Victoria in Uganda, in addition to rainfall runoff from its surrounding areas. The White Nile dissipates northwards from Juba across a shallow depression to produce a network of channels, lagoons and inundated areas, which harness the nutrients of the underlying clay soils. Patterns of flood inundation heavily influence the Sudd’s vegetation, which consists primarily of permanent swamps, river and rain flooded grasslands, and floodplain woodlands. These habitats exhibit strong environmental gradients with pronounced short and long-term variations in biomass production and distribution.