Flooding and drying mechanisms of the seasonal Sudd flood plains along the Bahr el Jebel in southern Sudan

Abstract

The flooding and drying mechanisms of the seasonal flood plains of the Sudd swamps in southern Sudan are, while dependent on the river levels, influenced by a complex interaction between soil, vegetation, topography and seasonal trends in rainfall and evapotranspiration. Based on field measurements, these components have been assessed in detail and evaluated regarding their function in the seasonal cycle of flooding and drying. A detailed analysis of soil and evapotranspiration conditions, as well as the interaction with vegetation and meteorological conditions, has been conducted using field and laboratory experiments. Sources, processes, flow directions and the fate of the floodwaters on both the river-fed seasonal flood plains and the rain-fed grasslands have been established. The results show that river spill is responsible for flooding these areas while no return flow occurs, and drying is caused by evapotranspiration. Rainfall can only cause temporary flooding in extreme events.

Citation Petersen, G. & Fohrer, N. (2010) Flooding and drying mechanisms of the seasonal Sudd flood plains along the Bahr el Jebel in southern Sudan. Hydrol. Sci. J. 55(1), 4–16.