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1 Beadle, L. C. 1974. The inland waters of tropical Africa: An introduction to tropical limnology. London, UK: Longman. 365p.
Limnology ; Ecosystems ; Climate ; Rivers ; Lakes ; Swamps ; Fish ; Plankton / Africa / Nile / Niger / River Congo / Zambezi / Lake Albert / Lake Rudolf / The Sahara / Lake Chad / Lake Edward / Lake George / Lake Victoria / Lake Kivu / Lake Tanganyika / Lake Malawi / Lake Chilwa / Lake Kariba / Volta Lake / Lake Kainji / Lake Nasser-Nubia / Jebel Aulyia / Sennar Reservoir / Roseires Reservoir / Lake McIlwaine
(Location: IWMI-HQ Call no: 551.48 G100 BEA Record No: H039368)
2 Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra. (Comps.) 2009. Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Summary report, abstracts of papers with proceedings on CD-ROM. Colombo, Sri Lanka: International Water Management Institute (IWMI). 48p. [doi: https://doi.org/10.3910/2009.201]
River basin management ; Water governance ; Environmental flows ; Simulation models ; Reservoirs ; Sedimentation ; Rainfall-Runoff relationships ; Hydrology ; Water balance ; Erosion ; Soil conservation ; Watersheds ; Irrigation schemes ; Water use / Ethiopia / Sudan / Blue Nile / Lake Tana Subbasin / Gumera Watershed / Roseires Reservoir / Rahad Scheme / Abbay River Basin
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042497)
3 Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra. (Comps.) 2009. Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Colombo, Sri Lanka: International Water Management Institute (IWMI). 310p. [doi: https://doi.org/10.5337/2011.0014]
River basin management ; Watershed management ; Farming systems ; Water balance ; Reservoirs ; Water supply ; Irrigation requirements ; Irrigation programs ; Simulation models ; Sedimentation ; Rainfall-Runoff relationships ; Erosion ; Soil water ; Water balance ; Soil conservation ; Institutions ; Organizations ; Policy ; Water governance ; International waters / Africa / Ethiopia / Sudan / Nile River / Blue Nile River Basin / Abbay River Basin / Roseires Reservoir / Gumera Watershed / Lake Tana Sub Basin / Volta Basin / Koga Watershed / Gumera Watershed
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042503)
(6.52 MB)
This proceeding provides the papers and discussion results of a two-day workshop that was organized at International Water Management Institute (IWMI) office in Addis Ababa during the period of February 6-8, 2009 in relation to CPWF Project 19 – Improved water and land management in the Ethiopian Highlands and its impact on downstream stakeholders dependent on the Blue Nile. Short title: Upstream Downstream (USDS) in the Nile. The project is being under implementation during the last one and half years in partnership with various institutions that include International Livestock Research Institute, Cornell University, Omdurman Islamic University-UNESCO Chair in Water Resources, Addis Ababa University, Bahir Dar University, Amhara Regional Agricultural Research Institute and Forum for Social Studies. The main aims of the workshop had been: Bring together key stakeholders relevant to the project; Present, debate and validate the intermediate results of the project; Disseminate key results to wider audiences through workshop participating stakeholders; Follow up on the progress of the project and plan remaining tasks of the project. The workshop focus themes were: General characterization of the Blue Nile Basin; Watershed modeling and analysis; Water demand and allocation modeling and simulation; Policy and institutions of the water management in the Blue Nile basin.
4 Bashar, K. E.; Mustafa, M. O. 2009. Water balance assessment of the Roseires Reservoir. In Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra (Comps.). Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.38-49.
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042506)
(0.73 MB)
Roseires Reservoir on the Blue Nile River was completed in 1966 to serve the purposes of hydropower generation, irrigation and flood retention. During its lifetime, the reservoir suffered from serious sedimentation, to the limit that its present capacity is less than 2 cubic kilometers (km3). Operation of the reservoir is maintained closely together with the Sennar Dam according to the operation policy. Operation of reservoirs depends on rules set for that purpose, which is based mainly on the water balance of the system among other factors. Such rules are rarely revised during the lifetime of the reservoirs. Roseires is not an exception. This paper presents an attempt to look closely at the different aspects of the operation and water balance parameters to gain an insight into the whole operation of the reservoir. In addition, an attempt is also made to find an accurate balance formula for the system, taking into account the part of the intervening catchment (14,578 km2) that is totally ungauged. The flow from the Ethiopian Highlands is monitored at Eddeim Station. The mean annual rainfall in the area amounts to approximately 700 mm. The daily evaporation rates were derived from monthly data available in the operation rules of the Blue Nile reservoirs. The change in reservoir storage (?s), and surface area were computed from the bathymetric surveys conducted during 1985, 1992 and 2005. Water balance computations were carried out for 1985, 1995 and 2005, corresponding to the availability of data. The ten years bathymetric data survey intervals give enough time for changes in water balance to take place, if any. Daily and 10-day water balances were computed using Eddeim flow data as the only inflow to the reservoir for the whole year, and for the dry and rainy periods. It was found that outflow from the reservoir can be reproduced with an efficiency of 97% R2, indicating that the contribution of the intervening catchment to the inflows is negligible.
5 Basha, K. E.; Khalifa, E. A. 2009. Sediment accumulation in Roseires Reservoir. In Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra (Comps.). Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.89-99.
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042510)
(0.52 MB)
Sedimentation is a serious problem faced by natural and man-made reservoirs. It is a major problem which endangers and threatens the performance and sustainability of reservoirs. It reduces the effective flood control volume, presents hazards to navigation, changes water stage and groundwater conditions, affects operation of low-level outlet gates and valves, and reduces stability, water quality, and recreational benefits. Reservoirs are often threatened by loss of capacity due to sedimentation. While there being many causes of reservoir sedimentation watershed, sediment and river characteristics are among the main natural contributing factors. Other important factors are reservoir size, shape and reservoir operation strategy. Man-made activities also play a significant role particularly in land use patterns. This paper is an attempt to assess sediment accumulation as well as the rate of sedimentation in the Roseires Reservoir. The basis for the study is the previous bathymetric surveys carried out on the reservoir in the years 1976, 1981, 1985, 1992, 2005 and 2007. Analysis and comparative studies were carried out between the different surveys to quantify the amount of sediment deposited as well the rate at which sedimentation took place. The design storage capacity of 1967 for the different reservoir levels was taken as a baseline. The sediment accumulation rates for the different bathymetric surveys are obtained as the difference between baseline capacity and the computed capacity at the respective levels during the specific survey. It was found that sedimentation in the Roseires Reservoir resulted in the reduction of the reservoir capacity from design storage of 3.0 Bm3 in 1966 to 1.9 Bm3 in 2007, i.e., a loss of approximately 1.1 Bm3 during 41 years of operation. The sedimentation rate varies with both time and levels in the reservoir.
6 Betrie, G. D.; Mohamed, Yasir Abbas; van Griensven, A.; Popescu, I.; Mynett, A. 2009. Modeling of soil erosion and sediment transport in the Blue Nile Basin using the Open Model Interface approach. In Awulachew, Seleshi Bekele; Erkossa, Teklu; Smakhtin, Vladimir; Fernando, Ashra (Comps.). Improved water and land management in the Ethiopian highlands: its impact on downstream stakeholders dependent on the Blue Nile. Intermediate Results Dissemination Workshop held at the International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia, 5-6 February 2009. Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.132-140.
Erosion ; Highlands ; Sedimentary materials ; Simulation models ; River basin management ; Reservoirs / Ethiopia / Blue Nile River Basin / Roseires Reservoir / Sennar Reservoir
(Location: IWMI HQ Call no: IWMI 333.9162 G100 AWU Record No: H042513)
(0.41 MB)
Rapid land use change due to intensive agricultural practices in the Ethiopian Highlands, results in increasing rates of soil erosion. This manifested in significant impacts downstream by reducing the storage capacity of reservoirs (e.g., Roseires, Sennar), and high desilting costs of irrigation canals. Therefore, this paper aims to provide a better understanding of the process at basin scale. The Soil and Water Assessment Tool (SWAT) was used to model soil erosion in the upper catchments of the Blue Nile over the Ethiopian Plateau. The SWAT output forms the input sediment load for SOBEK, a river morphology model. The two models integrated using the principles of the Open Model Interface (OpenMI) at the Ethiopia-Sudan border. The Nash-Sutcliffe coefficient was found to be 0.72 and 0.66 for results of SWAT daily sediment calibration and validation, respectively. The SOBEK results also show a good fit of the simulated river flows at Roseires and Sennar reservoirs, both for calibration and validation. The results of the integrated modeling system showed 86 million tonnes/year of sediment load from the Upper Blue Nile, while SOBEK computes on average 19 Mm3/year of sediment deposition in the Roseires Reservoir. The spatial variability of soil erosion computed with SWAT showed more erosion over the northeastern part of the Upper Blue Nile, followed by the northern part. The overall exercise indicates that the integrated modeling is a promising approach to understand soil erosion, sediment transport, and sediment deposition in the Blue Nile Basin. This will improve the understanding of the upstream-downstream interdependencies, for better land and water management at basin scale.
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