Morphology, water discharge and suspended load distribution along the Mara River Wetland, Tanzania

Abstract

The transboundary Mara River, Kenya and Tanzania, is the only perennial source of inflowing surface water of a vast area including the Mara-Serengeti region. The river sustains millions of wild animals as well as a human population of nearly one million (McClain et al., 2014; Gereta et al., 2009). The basin receives two rainy seasons: a lighter in October- December and a heavier in March-May. The
river is rich in suspended sediments, which has further increased by recent deforestation, change of land uses and mining (Defersha & Melesse, 2012). Before flowing into the Lake Victoria in Tanzania, the river forms a wide
wetland that acts as a natural filter, sinking the large amount of suspended load and releasing clean water to the lake (Fig. 1). The wetland is fed by sediments and nutrients transported by the river and represents an essential but, at the
same time, fragile ecosystem. The vegetation, here dominated by papyrus, plays an important role in the stability of the wetland system. However forest fire and
farming are intense along the wetland and have deeply modified the vegetation spatial distribution.