The river White Nile flows through Southern Sudan .
Southern harlem has been described as `` a large basin gently sloping northward '' , ( Roth 2003 ) through which flow the Bahr el Jebel River , the ( White Nile ) , the Bahr el Ghazal ( Nam ) River and its tributaries , and the Sobat , all merging into a vast barrier swamp . *
Dinka people