Study area description

The study area, Lake Tana is the source of the Blue Nile River and has a total drainage area of approximately 15,000 km², of which the lake covers 3,060 km² at elevation 1,786 m amsl (Abeyou 2008). The lake is the largest lake in Ethiopia and the third largest in the Nile Basin.

The lake is located in the north-west highlands at 12^o00’N, 37^o15’E which is 564 km from the capital Addis Ababa see Figure -2. The lake has more than 40 tributary rivers, but the major rivers feeding the lake are Gilgel Abay from the south, Ribb and Gumara from the east and Magetch River from the north, while there are no large rivers that flow from the western side of the lake. According to Kebede (2006) those four rivers contribute 93% of the lake inflow.