Your search found 5 records
1 Addisie, M. B.; Ayele, G. K.; Gessess, A. A.; Tilahun, S. A.; Moges, M. M.; Schmitter, Petra S.; Steenhuis, T. S. 2015. Hydro-geomorphological features at gully heads in the humid northern Ethiopian Highlands, Birr Watershed. Paper presented at the 3rd International Conference on the Advancements of Science and Technology [ICAST], Bahir Dar, Ethiopia, 8-9 May 2015. 7p.
Hydrogeology ; Geomorphology ; Morphology ; Humid zones ; Highlands ; Watersheds ; Water table ; Soil properties ; Gully erosion ; Landscape ; Case studies / Ethiopia / Ethiopian Highlands / Birr Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H047312)
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The study was conducted in the Birr watershed at twelve gully heads located close to each other. The survey includes measurements of morphological features, soil properties, water table elevations and catchment characteristics including erosion at each gully head. The analysis showed that gully head morphology could be explained by the role of different gully head controlling factors. The result suggested the maximum rate of head cut retreat reaches from 0 to 22.5m. There was no head retreat recorded from the arrested heads relative to unprotected heads. Compared to semiarid highlands of northern Ethiopia, the average short term head cut retreat was 12 fold greater. From the direct shear test, angle of internal friction by far greater than the slope of gully heads which are located at flat lands. The width depth ratio showed that the shallow depth heads were controlled by fluvial erosion whereas for the deep gully heads both fluvial and mass wasting due tension cracks are operating. In this study a significant power relationship established between the volume of the gully head and the length of retreat at the active gullies with V = 4.85 L1.05 (R2 = 0.91 and P= 0.042) which is different from the relation obtained from the entire gully system as a result of varies controlling factors.
2 Addisie, M. B.; Ayele, G. K.; Gessesse, A. A.; Tilahun, S. A.; Moges, M. M.; Zegeye, A. D.; Mekuria, Wolde; Schmitter, Petra; Langendoen, E. J.; Steenhuis, T. S. 2016. Rehabilitating gullies with low cost methods, in the sub humid Ethiopian highlands. Paper presented at the International Conference of the Advancement of Science and Technology, Bahir Dar, Ethiopia, 17-18 July 2016. 10p.
Gully erosion ; Humid zones ; Highlands ; Environmental degradation ; Ecosystems ; Watersheds ; Riverbank protection ; Vegetation ; Plantations ; Sedimentation
(Location: IWMI HQ Call no: e-copy only Record No: H047636)
(691 KB)
Gully erosion in the highlands of Ethiopia has reduced agricultural productivity and degraded ecosystem services. To better understand the processes controlling gully erosion and design effective control measures, a study was conducted in the headwaters of the Birr watershed for three consecutive years (2013-2015). Fourteen gullies with similar morphology were studied in three adjacent sub-watersheds. Stabilization measures were applied to 5 of the 14 gully heads. Three gully control measures were compared: a) reshaping gully banks and head to a 45 degree slope with stone rip rap on the gully heads, b) controlling gully bed grade, and c) planting grasses and trees on shallow gullies (i.e., < 3 m deep). Results demonstrated that gully control measures were effective in controlling the expansion of gullies as no further retreat was observed for the 5 treated gully heads, whereas the average retreat was 3 meters with a maximum of 22.5 m for the 9 untreated gullies. The migration of untreated gully heads produced an average soil loss of 38 tons per gully. Compared with simple reshaping of gully heads, the additional integration with stone rip rap was an effective and low cost measure. Vegetative treatment by itself could not stop the upslope migration of gully heads, though it had the potential to trap sediments. Re-vegetation at gully heads stabilized with stone rip rap occurred faster than at unprotected, reshaped heads and banks. From the fourteen rehabilitation treatments, gully head protection integrated with plantation showed the largest potential in decreasing gully development in terms of labor, time and material it requires.
3 Addisie, M. B.; Ayele, G. K.; Gessess, A. A.; Tilahun, S. A.; Zegeye, A. D.; Moges, M. M.; Schmitter, Petra; Langendoen, E. J.; Steenhuis, T. S. 2017. Gully head retreat in the sub-humid Ethiopian Highlands: the Ene-Chilala Catchment. Land Degradation and Development, 28(5):1579-1588. [doi: https://doi.org/10.1002/ldr.2688]
Gully erosion ; Erosion control ; Humid zones ; Highlands ; Catchment areas ; Sedimentation ; Wet season ; Monitoring ; Soil texture / East Africa / Ethiopia / Ene-Chilala Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H048152)
In the northern highlands of Ethiopia, gully erosion is severe. Despite many efforts to implement gully prevention measures, controlling gully erosion remains a challenge. The objective is to better understand the regional gully erosion processes and to prevent gully head retreat. The study was conducted in the Ene-Chilala catchment in the sub-humid headwaters of the Birr River located southwest of Bahir Dar, Ethiopia. Twelve gully heads were monitored during the 2014 and 2015 rainy monsoon phase. We measured gully head morphology and retreat length, soil shear strength, ground water table levels, and catchment physical characteristics. Two active gully head cuts were treated in 2014 and an additional three head cuts in 2015 by regrading their slope to 45° and covering them with stone riprap. These treatments halted the gully head advance. The untreated gullies were actively eroding due to groundwater at shallow depths. The largest head retreat was 22.5 m, of which about half occurred in August of the first year when the surrounding soil was fully saturated. Lowering both the water table and protecting the gully heads can play a key role in reducing gully expansion and soil loss due to gully erosion in the Ethiopian highlands.
4 Addisie, M. B.; Langendoen, E. J.; Aynalem, D. W.; Ayele, G. K.; Tilahun, S. A.; Schmitter, Petra; Mekuria, Wolde; Moges, M. M.; Steenhuis, T. S. 2018. Assessment of practices for controlling shallow valley-bottom gullies in the sub-humid Ethiopian Highlands. Water, 10(4):1-15.
Gully erosion ; Assessment ; Best practices ; Rehabilitation ; Sediment ; Highlands ; Valleys ; Vegetation ; Slope ; Farmers ; Watersheds ; Dams ; Grasses ; Soil conservation ; Water conservation / Africa / Ethiopia / Ethiopian Highlands
(Location: IWMI HQ Call no: e-copy only Record No: H048964)
Rehabilitation of large valley bottom gullies in developing countries is hampered by high cost. Stopping head cuts at the time of initiation will prevent large gullies from forming and is affordable. However, research on practices to control shallow gully heads with local materials is limited. The objective of this research was therefore to identify cost-effective shallow gully head stabilization practices. The four-year study was conducted on 14 shallow gullies (<3 m deep) in the central Ethiopian highlands. Six gullies were used as a control. Heads in the remaining eight gullies were regraded to a 1:1 slope. Additional practices implemented were adding either riprap or vegetation or both on the regraded heads and stabilizing the gully bed downstream. Gully heads were enclosed by fencing to prohibit cattle access to the planted vegetation. The median yearly head retreat of the control gullies was 3.6 m a-1 with a maximum of 23 m a-1. Vegetative treatments without riprap prevented gully incision by trapping sediments but did not stop the upslope retreat. The gully heads protected by riprap did not erode. Regrading the slope and adding riprap was most effective in controlling gully head retreat, and with hay grown on the fenced-in areas around the practice, it was profitable for farmers.
5 Alemie, B. T.; Defersha, D. T.; Tesfaye, A. T.; Moges, M. M.. 2023. Physical performance of small-scale irrigation scheme: a case study of Tilku Fetam irrigation scheme, Awi Zone, Amhara Region, Ethiopia. Sustainable Water Resources Management, 9(1):11. [doi: https://doi.org/10.1007/s40899-022-00789-9]
Small-scale irrigation ; Irrigation schemes ; Irrigation water ; Indicators ; Crops ; Water requirements ; Water supply ; Sustainability ; Infrastructure ; Land productivity ; Water productivity ; Evapotranspiration ; Irrigated farming ; Soil moisture ; Case studies / Ethiopia / Amhara / Awi / Banja / Tilku Fetam Irrigation Scheme
(Location: IWMI HQ Call no: e-copy only Record No: H051626)
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The present study was aimed to evaluate the performance of Tilku Fetam small-scale irrigation scheme using internal and external indicators, which is found at Banja district, Awi zone, Ethiopia. To achieve the objective of this study both primary and secondary data were collected. The primary data included; soil moisture before and after irrigation, discharge measurement at main and secondary canals, and interview with beneficiaries about the scheme. The secondary data included; climate data, crops grown in the study area, total yield and cost of production. The crop water requirement was estimated using CROPWAT 8.0 model. The conveyance efficiency was evaluated at main and secondary canals and the application efficiency of the scheme was evaluated at head, middle and tail of the farmers’ field. The results indicated that the average conveyance efficiency of main canals and secondary canals were 78.5% and 72%, respectively, and average application efficiency of the scheme was 44%. The comparative performance of the Tilku Fetam irrigation scheme was also carried out and the output per cropped area and output per command area were found to be 1321.45 US$/ha and 726.8US$/ha, respectively. The value of output per unit irrigation supply and output per unit water consumed were found to be 0.38US$/m3 and 0.28US$/m3, respectively. The value of water performance indicators; relative water supply, relative irrigation supply and water delivery capacity of the scheme were 0.992, 0.99 and 0.62, respectively. Performance indicators showed that the scheme was in need of intensive management and infrastructural improvement to enhance productivity and sustainability of the scheme. In addition, adoption of water-saving practices such as deficit irrigation, surge and cutoff application should be conducted to improving the application efficiency and frequent maintenance of water conveyance system can enhance the conveyance efficiency of the scheme.
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