A biophysical and economic assessment of a community-based rehabilitated gully in the Ethiopian highlands

Authors: AYELE, GETANEH - Bahir Dar University; GESSESS, AZALU - Bahir Dar University; ADDISIE, MESERET - Bahir Dar University; TILAHUN, SEIFU - Bahir Dar University; TEBEBU, TYGIST - Cornell University; TENESSA, DAREGOT - Bahir Dar University; Langendoen, Eddy; NICHOLSON, CHARLES - Pennsylvania State University; STEENHUIS, TAMMO - Cornell University

Submitted to: Land Degradation and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/13/2015
Publication Date: 2/1/2016
Publication URL: https://handle.nal.usda.gov/10113/62705
Citation: Ayele, G.K., Gessess, A.A., Addisie, M.B., Tilahun, S.A., Tebebu, T.Y., Tenessa, D.B., Langendoen, E.J., Nicholson, C.F., Steenhuis, T.S. 2016. A biophysical and economic assessment of a community-based rehabilitated gully in the Ethiopian highlands. Land Degradation and Development. 27(2):270–280.

Interpretive Summary: Since deforestation in the 1970s sediment concentrations have increased significantly because of severe gully erosion. Gully rehabilitation has a small success rate as community participation in planning these conservation measures is very limited. In 2013 scientists at the USDA-ARS National Sedimentation Laboratory in collaboration with researchers at Bahir Dar University (Ethiopia), Cornell University and Penn State University have initiated a community participatory gully rehabilitation project conducted in the Birr watershed located south of Lake Tana, Ethiopia. The planning and design of the project consisted of discussions with the religious leaders and local respected elders, followed by meetings with local village farmers about approaches to rehabilitate a 0.71 ha upland gully that was advancing into the grazing land in the middle of a village. The rehabilitation measures were reshaping the gully head at 45 degrees, constructing check dams from locally available materials (soil, stone and wood), and planting local grasses and Sesbania sesban. At the end of the first rainy season after implementation, 2300 tons of soil was conserved by the newly planted vegetation, compared with soil losses of 1900 and 1500 tons in two untreated, nearby gullies. In 2014, an additional 3300 tons of soil was conserved. The marginal rate of return on the gully rehabilitation investment was 2.5 based on the value of increased forage production alone. The success of this effort motivated farmers to voluntarily undertake rehabilitation of five other gullies in the area.

Technical Abstract: In the last fifty years, sediment concentrations in the Ethiopian highlands have increased two- to three-fold. The current severity of gully erosion is a major cause of increased sediment loads, but gully rehabilitation has proven to be challenging, with limited success. This paper describes gully rehabilitation efforts in the Birr watershed in the Blue Nile basin begun in early 2013, where low-cost gully rehabilitation has been effective with community participation. Initially farmers were reluctant to participate for religious reasons but with the aid of local priests and respected elders, community discussions and a visit to a rehabilitated gully, a consensus was reached to rehabilitate a 0.71-ha upland gully. The rehabilitation measures consisted of regrading the gully head at a 45° slope, constructing low-cost check dams from locally available materials, and planting Pennisetum purpureum grass and Sesbania sesban. At the end of the first rainy season after implementation, 2300 tons of soil was conserved by the newly planted vegetation, compared with soil losses of 1900 and 1500 tons in two untreated, nearby gullies. In 2014, an additional 3300 tons of soil was conserved. The marginal rate of return on the gully rehabilitation investment was 2.5 based on the value of increased forage production alone. The success of this effort motivated farmers to voluntarily undertake rehabilitation of five other gullies in the area.