The lower Ruvuma river is formed by the junction at 11° 25' S., 38° 31' E. of two branches of nearly equal importance, the longer of which, the Lujenda, comes from the south-west, the other, which still bears the name Ruvuma, from the west.
Lower down it varies greatly in breadth, containing in many parts long wooded islands which rise above the flood level, and are often inhabited.