Afedena River
The Afedena is a river of the Nile basin. Rising in the mountains of Dogu’a Tembien in northern Ethiopia, it flows southwestward to empty finally in the Giba and Tekezé River.
Characteristics
The Afedena is a confined ephemeral river, locally meandering in its narrow alluvial plain, with an average slope gradient of 35 metres per kilometre. With its tributaries, the river has cut a gorge.Flash floods and flood buffering
Runoff mostly happens in the form of high runoff discharge events that occur in a very short period. These are related to the steep topography, often little vegetation cover and intense convective rainfall. The peaks of such flash floods have often a 50 to 100 times larger discharge than the preceding baseflow.The magnitude of floods in this river has however been decreased due to interventions in the catchment. At Afedena, exclosures have been established; the dense vegetation largely contributes to enhanced infiltration, less flooding and better baseflow. Physical conservation structures such as stone bunds and check dams also intercept runoff.