Nile 4


Waterlogged Vertisols are amongst the high potential soils where management interventions could result in positive impacts.

This study utilized soil, climate and crop and livestock productivity data and models to demonstrate intensification strategies which increase crop–livestock system productivity and to understand the effects of alternative land use and water management options on water productivity in the Vertisols areas.

The areas have been classified into three slope classes including areas where artificial drainage is not feasible, where Broad Bed and Furrows (BBF) can be used to drain the excess water and naturally drained areas, represented by areas with 0–2%, 2–5% and over 5% slope steepness, respectively. Early planting of wheat (Triticum spp) using BBF on drainable areas and rice (Oryza sativa) or grasspea (Lathyrus sativus) on the flat areas were compared with the traditional practices. Yield and biomass data were obtained from research stations in the area whilst the effective rainfall and crop water requirement were estimated using CROPWAT Model. The feed value of the native grass and crop straw was estimated based on previous works.

With respect to effective rainfall, the water productivity increase due to BBF over the control ranged from 5 to 200%, with an average increase of 57%. Despite higher water consumption of the rice, feeding its residues to livestock enhanced the overall economic water productivity of the system over the natural grazing or grasspea cultivation. Consequently, use of BBF enables growing high value or food crops of choice that may be sensitive to waterlogging whilst tolerant crops can be grown on flat lands allowing utilization of the full growing period. Coupled with livestock integration into the system, the alternatives can enhance food production and resource use efficiency from these ‘marginal’ areas.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

The current paper discusses the use of hydrological modelling tool to understand sustainable land management interventions in the Blue Nile basin of Ethiopia.

A micro-watershed named Mizewa with a drainage area of 27 km2 in Fogera district was selected and instrumented with hydrological cycle observation networks in the year 2011. The SWAT hydrological modelling tool was used to simulate landscape-wide Soil and Water Conservation (SWC) investments.

Simulations of the selected investments modelled in this analysis suggest that improvements in infiltration, decreases in surface runoff and decreases in erosion are achievable in the watershed. Further simulations suggest that a landscape-wide approach of terrace and bund construction has the greatest effect in terms of decreasing surface runoff, decreasing sediment yield and increasing groundwater flow and shallow aquifer recharge.

A comprehensive landscape investment of terraces on slopes greater than 5% and bunds maintained on slopes less than 5% would decrease surface flow by almost 50%, increase groundwater flow by 15% and decrease sediment yield from erosion by 85%. However, constructing terraces in areas with greater than 5% slope (without constructing bunds in areas under 5% slopes) has a similar effect whereby surface flow and sediment yield decreases by 45 and 83%, respectively and groundwater flow increases by 13%. Residue management also has a significant effect on surface flow and erosion in the Mizewa watershed. Average annual surface flow decreased 17 when adopting residue management on all agricultural land and 26% when coupling terracing on steep slopes with residue management in mid-range slopes.

These analyses provide the foundation for understanding feasible outcomes given a more comprehensive investment strategy. Results stemming from the current work can be paired with household level socio-economic data in order to assess program investment alternatives taking into account household constraints to Sustainable Land and Watershed Management (SLWM) investment and maintenance on private and public lands.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

Although Ethiopia has a large potential to develop irrigation, only 5% of the 3.5 million hectares of land potentially available has been developed. To examine the underlying causes, this study evaluates the suitability of surface water irrigation for the Lake Tana Basin development corridor.

Surface water availability and land potentially suitable for medium and large-scale irrigation development (200 ha and larger) was considered. Surface water potential was examined by considering river discharges. Land suitable for irrigation was determined with a GIS-based multi-criteria evaluation (MCE), which considers the interaction of various factors, such as climate, river proximity, soil type, land cover, topography/slope and market outlets.

The result indicates that nearly 11% of the Lake Tana Basin is suitable for surface irrigation. However, by analysing 27 years of river discharge, less than 3% of the potential irrigable area (or less than 0.25% of the basin area) could be irrigated consistently by run-of-the river-systems. Thus, the irrigation potential in the Lake Tana Basin can only be met by increasing dry season flows (if proven feasible) and by supplying water from existing or future reservoirs or by using water directly from Lake Tana.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

Using a multi-criteria optimization technique for system analysis, this paper quantitatively characterizes baseline production activities, resource management and environmental relationships of the mixed crop–livestock farming system at the Jaba micro-watershed, upper Blue Nile Basin, to get insights that inform sustainable intensification of small-scale agriculture.

The paper characterizes and models system relationships at a landscape scale under the business as usual land use and resource management scenario (including rainwater management), in the light of social, economic and environmental sustainability indicators (employment, farm income and sediment loss and water generation, respectively). The analysis is based on an optimization technique that weighs the socio-economic and environmental costs and benefits of current land use and resource management practices at spatial and temporal scales, using farm level survey data.

The results show that, under the business as usual scenario, the crop sub-sector will remain the major source of farm income and rural employment. Agricultural income, though trending positively, will not significantly drift from its current level, indicating the limited possibility for rural income growth from agricultural activities under the current pattern of land use, resource management and socio-economic circumstances.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

The main objective of this research was to study soil erosion and sediment yield in Mizewa watershed using SWAT model.

The study involved hydrological and erosion modelling using primary data collected in the watershed. Hydrological and meteorological data were collected from the stations installed in the watershed by the International Water Management Institute (IWMI) in collaboration with the Ministry of Water and Energy and the National Meteorological Service Agency.

Suspended sediment data was collected at Mizewa River in the watershed, used for sediment rating curve development. The land use/ land cover map was prepared using field survey and Land Sat image and the soil map for the watershed was prepared from Abay basin soil as per the United Nations’ Organisation for Food and Agriculture (FAO)’s world soil database.

The average monthly soil loss was estimated in July with pick suspended sediment concentration despite the pick flow and sediment yield at the outlet being recorded in August – which is believed to happen due to the sediment data developed by the sediment rating curve. The predicted rate of soil loss and sediment yield at the subbasins and watershed outlet were high, leading to consider the watershed as an erosion-sensitive area according to Setegn (2009) and Hurni (1985)’s criteria of erosion sensitivity.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

Understanding the basic relationships between rainfall, runoff, soil moisture and ground water level are vital for an effective and sustainable water resources planning and management activities. But so far there is no hydrological study in Meja watershed that aims to understand the watershed characteristics and runoff generation processes.

This study was conducted to understand runoff generation processes and model rainfall runoff relationship in Meja watershed having a drainage area of 96.6 km2. The watershed is one of the three research sites of International Water Management Institute (IWMI) developed in early 2010 in the upper Blue Nile Basin of Ethiopia. In the study, primary data of soil moisture, shallow ground water level, rainfall and runoff were collected from the hydrological monitoring network in the watershed.

Hydrological models like HBV and RRL SMAR were configured to understand the relationship between rainfall and runoff in the watershed. Relationships between rainfall, soil moisture, shallow ground water level and discharge were developed to understand runoff generation processes in the watershed.

According to one year and three months data, there is no strong daily rainfall and runoff relationship (r2 <0.5) in Meja and Kolu which is a nested sub-watershed; this may be due to abstractions such as irrigation and human interventions in the watershed. There is a strong linear relationship of rainfall and monthly averaged volumetric soil moisture in most layers of Meja and its nested sub-watersheds. The general relationship between runoff and monthly averaged soil moisture at different layers in Meja watershed and Kolu is strong and linear. Analysis of rainfall runoff models indicated better performance of HBV than RRL SMAR model.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

With the construction of the new Renaissance Dam at the Ethiopian Sudan border, reducing sediment load in the Blue Nile is becoming increasingly important. Past attempts of decreasing sediment concentrations have been only partially successful. In this paper, we examine the temporal distribution of sediment generation within small watersheds and systematically compare this with the observed sediment concentration at various watershed scales using the Parameter Efficient Distributed (PED) model.

The model is based on the concept that runoff and erosion are generated mainly from areas that become saturated during the rain storm. These runoff source areas consist of shallow soils over a dense hardpan or areas where the water table is close to surface. Saturated areas are also prone to gullying. Simulation of watershed evaluations indicate that most erosion occurs from degraded areas, from temporarily saturated agricultural land and from gullies in the saturated bottomlands near the river.

In addition, we found that the annual runoff and sediment concentrations increased significantly in the Blue Nile basin at the border with Sudan. The model results would indicate that rehabilitating the degraded and bare areas by planting permanent vegetation and preventing further incision by gullies would be extremely effective in decreasing the sediment concentrations. Reduced tillage would likely result in less sediment transport but would increase use of pesticides and the cattle cannot graze freely anymore. Tentatively, we conclude that decreasing upland erosion might decrease sediment concentration downstream, since there is relatively little sediment storage in the main rivers of the Blue Nile basin.

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This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

Access to safe drinking water services in the Ethiopian Highlands is one of the lowest worldwide due to failure of water supply services shortly after construction. Over hundred water supply systems were surveyed to find the underlying causes of failure and poor performance throughout the Amhara Regional State. The results show generally that systems with decision-making power at the community level during design and construction remained working longer than when the decisions were made by a central authority. In addition, the sustainability was better for water systems that were farther away from alternative water resources and contributed more cash and labour. The results of this study of the importance of decision-making at the local level in contrast to the central authority are directly applicable to the introduction of rain water management systems as shown by earlier efforts of installing rain water harvesting systems in the Ethiopian highlands.

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See the full proceedings of the NBDC Science meeting


This paper was first presented at the Nile Basin Development Challenge Science meeting. The NBDC Science meeting was held on 9 and 10 July 2013 at the ILRI-Ethiopia campus, with the objectives to exchange experiences and research results across NBDC scientists involved in the NBDC projects and to discuss challenges and possible solutions.

NBDC scientists Kindie Getnet and Geremew Kefyalew recently published a research article in the Environment and Development Economics journal to further assess the development impact of rainwater management innovations through the use of a Rainwater-livelihoods-poverty index (RLPI).

The article relates to research ongoing in Diga, one of the three NBDC action sites and proposes working through the comprehensive RLPI, which incorporate intermediate processes and impact pathways to understand the impact of innovations in rainwater management.

The RLPI methodology is further strengthened with participatory household surveys as a way to relate scientifically generated evidence with empirical evidence and eventually inform farmers’ decisions about adopting rainwater management innovations.

Read the research article

2013 is the final year for the Nile Basin Development Challenge (NBDC). On 20 and 21 February 2013, the NBDC convened a meeting of the  National Land and Water Management Platform to review progress and directions for the coming phase.

Group photo: NBDC / Land and Water Management National Platform Meeting 4 (Credit: ILRI/Zerihun Sewunet)

Group photo: NBDC / Land and Water Management National Platform Meeting 4 (Credit: ILRI/Zerihun Sewunet)

The workshop reflected on past work – approaches developed, research findings, key messages – in order to prioritize future interventions. Over 60 participants from partner organizations and other governmental, research and non-governmental institutions participated to the two-day workshop.

After an introduction to the NBDC timeline, some key messages compiled by project staff were presented and discussed. A series of NBDC approaches, methods or areas of work were introduced later in the day: innovation platforms and recent insights, modeling, Wat-A-Game, Happy Strategies game, GIS, Goblet tool and suitability maps, participatory hydrological monitoring, digital stories and participatory video, and local planning processes.

The participants formed groups to discuss the relevance of the messages they heard and to identify priority activities to build upon NBDC work and embed it in organizational and individual practices. A special policy session also looked at possible contributions of the NBDC to priority development challnges in Ethiopia.

At the end of the workshop, the Nile basin leaders Simon Langan and Alan Duncan reflected on the feedback received and the directions that the NBDC will take. Key directions include: repackaging research in accessible ways for farmers, policy-makers and other organizations; focusing on capacity development; finding practical ways to bring farmers’ and scientists’ voices together in crafting common approaches and discourse; addressing the regional gaps between local level work and national level engagement; and joining forces with existing initiatives that can reinforce the messages of the NBDC such as the Sustainable Land Management program.

Read the notes of the meeting.

Discover pictures from the event.

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