Skip to main content
ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #310734
Title: Gully development processes in the Ethiopian Highlands

Author
item ZEGEYE, A - Cornell University
item DAMTEW, S - Bahir Dar University
item TILAHUN, SEIFU - Bahir Dar University
item Langendoen, Eddy
item DAGNEW, D - Bahir Dar University
item GUZMAN, C - Cornell University
item TEBEBU, TIGIST - Cornell University
item STEENHUIS, TAMMO - Cornell University

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/15/2014
Publication Date: 5/16/2014
Citation: Zegeye, A.D., Damtew, S., Tilahun, S.A., Langendoen, E.J., Dagnew, D.C., Guzman, C.D., Tebebu, T.Y., Steenhuis, T.S. 2014. Gully development processes in the Ethiopian Highlands. In: Proceedings of the 2nd International Conference on the Advancement of Science and Technology (ICAST-2014), May 16-17, 2014, Bahir Dar, Ethiopia. pp. 220-229.

Interpretive Summary: Gully erosion is a major cause of land degradation in northern Ethiopia. Reducing gully erosion has been fairly successful in the semi-arid regions of Ethiopia such as Tigray, however not in the humid Amhara region. For developing more effective gully rehabilitation measures for humid northern Ethiopia, scientists at the USDA, ARS, National Sedimentation Laboratory in collaboration with researchers at Cornell University and Bahir Dar University, Ethiopia, are investigating the gully evolution processes in the Debre-Mewi watershed, about 30 km south of Lake Tana. Data were obtained directly from field topographic surveying, measuring flow and sediment transport, shallow ground water sampling, and laboratory investigation of soil mechanical strength. Gully sidewall failures were the most widely observed mode of soil loss in the study area. The result showed that saturation of soil was the major cause of gully incision and expansion. About 96% of the sediment load measured at the gully outlet emanated from the gully sidewalls, indicating that gully erosion control measures should focus on stabilizing head cuts and gully sidewalls instead of slowing down the runoff on the contributing hillslopes.

Technical Abstract: Gully erosion is an important soil degradation process in a range of environments, causing considerable soil losses and producing large volumes of sediment. In Ethiopia, gully erosion is a major problem expanding at alarming rate and devastating cultivated and grazing lands. The objective of the study was to investigate the gully evolution processes for developing better gully rehabilitation measures in the Debre-Mewi watershed, about 30 km south of the Lake Tana. Data were obtained directly from field surveying, shallow ground water sampling, and laboratory investigation for geotechnical parameters. Most input data were collected in the representative cross-section of four soil layers comprising the gully banks. Bank failures such as planar, cantilever and seepage were the most widely observed types of gully bank failures in the study area. The result showed that saturation of soil was one of the main causes for gully incision and expansion. About 96% of the sediment load measured at the gully outlet emanated from the gully banks indicating that gully treatment has a paramount importance to reduce siltation of reservoirs more than the up lands.