May 12, 2014

Adapt new models and tools for planning, implementation and capacity building – NBDC key message #5

Posted by Ewen Le Borgne under ASSP, Capacity Strengthening, CRP5, East Africa, Ethiopia, Film and Video, ILRI, NBDC, Nile, Nile 2, Nile 3, Nile 4, NRM | Tags: , , , , , |
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In late 2013, the Nile Basin Development Challenge developed eight key messages. Taken together, these messages form a new paradigm that can help further transform policies and programs and better enable poor smallholder farmers to improve their food security, livelihoods and incomes while conserving the natural resource base.

The fifth key message from the Nile Basin Development Challenge is to ‘adapt new models, learning and planning tools and improved learning processes to increase the effectiveness of planning, implementation, and capacity building’.  Planners, development agents and farmers, together with researchers, can use a variety of tested tools to plan and implement rain water management solutions, and to develop capacities of all actors along the way. Tools such as Wat-A-Game, hydrological modeling, Cropwat modeling for crop-water productivity, the Nile Goblet tool and feed analysis tools etc. have been all used and tested in the NBDC and are available for anyone.

See the overall digital story ‘An integrated watershed rainwater management paradigm for Ethiopia: Key messages from the NBDC‘.

Download the brief covering the full set of key messages.

Read the full technical report “A new integrated watershed rainwater management paradigm for Ethiopia: Key messages from the Nile Basin Development Challenge, 2009–2013“

This digital story was produced to communicate the key messages resulting from the Nile Basin Development Challenge (NBDC). The Nile BDC aimed to improve the livelihoods of farmers in the Ethiopian highlands through land and water management and was funded by the Challenge Program for Water and Food. The eight key messages constitute a ‘new integrated watershed rainwater management paradigm’ and are based on the outputs and outcomes of trans-disciplinary scientific research for development

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March 21, 2014

Runoff estimation and water management for the Holetta river in Ethiopia – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 2, Presentation, Report, Water | Tags: , , , , , , |
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The hydrology of Holetta River and its seasonal variability is not fully studied. In addition to this, due to scarcity of the available surface water and increase in water demand for irrigation, the major users of the river are facing a challenge to allocate the available water.

Therefore, the aim of this research was to investigate the water availability of Holetta River and to study the water management in the catchment. Soil and Water Assessment Tool (SWAT) modelled the rainfall runoff process of the catchment. Statistical (coefficient of determination [R2], Nash- Sutcliffe Efficiency Coefficient [NSE] and Index of Volumetric Fit [IVF]) and graphical methods used to evaluate the performance of SWAT model.

The result showed that R2, NSE and IVF were 0.85, 0.84 and 102.8, respectively for monthly calibration and 0.73, 0.67 and 108.9, respectively, for monthly validation. These indicated that SWAT model performed well for simulation of the hydrology of the watershed. After modelling the rainfall runoff relation and studying the availability of water at the Holetta River, the water demand of the area assessed. CropWat model and the survey analysis performed to calculate the water demand in the area. The total water demand of all three major users was 0.313, 0.583, 1.004, 0.873 and 0.341 MCM from January to May, respectively. The available river flow from January to May obtained from the result of SWAT simulation. The average flow was 0.749, 0.419, 0.829, 0.623 and 0.471 MCM from January to May respectively. From the five months, the demand and the supply showed a gap during February, March and April with 0.59 MCM.

Therefore, in order to solve this problem alternative source of water supply should be studied and integrated water management system should be implemented.

See the presentation:

Read the paper

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.

 

March 17, 2014

Arresting gully formation in the Ethiopian highlands – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 4, NRM, Report, Water | Tags: , , , , , |
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Over the past five decades, gullying has been widespread and has become more severe in the Ethiopian highlands. Only in very few cases, rehabilitation of gullies has been successful in Ethiopia due to the high costs.

The objective of this paper is to introduce cost effective measures to arrest gully formation. The research was conducted in the Debre-Mewi watershed located at 30 km south of Bahir Dar, Ethiopia.

Gullying started in the 1980s following the clearance of indigenous vegetation and intensive agricultural cultivation, leading to an increase of surface and subsurface runoff from the hillside to the valley bottoms. Gully erosion rates were 10–20 times the measured upland soil losses. Water levels, measured with piezometers, showed that in the actively eroding sections, the water table was in general above the gully bottom and below it in the stabilized sections.

In order to develop effective gully stabilizing measures, we tested and then applied the BSTEM and CONCEPT models for their applicability for Ethiopian conditions where active gully formation has been occurring. We found that the model predicted the location of slips and slumps well with the observed groundwater depth and vegetation characteristics.

The validated models indicated that any gully rehabilitation project should first stabilize the head cuts. This can be achieved by regrading these head cuts to slope of 40 degrees and armoring it with rock. Head cuts will otherwise move uphill in time and destroy any improvements. To stabilize side walls in areas with seeps, grass will be effective in shallow gullies, while deeper gullies require reshaping of the gullies walls, then planting the gully with grasses, eucalyptus or fruit trees that can be used for income generation. Only then there is an incentive for local farmers to maintain the structures.

Read the paper

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.

 

March 5, 2014

Hydrological modelling of a catchment using the SWAT model in the upper Blue Nile basin of Ethiopia – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 2, Presentation, Report | Tags: , , , , |
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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.

See the presentation:

Read the paper

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.

 

February 25, 2014

Management practices and agro-ecological effects on crop water productivity in Meja watershed, Ethiopia – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 4, Report, Water | Tags: , , , |
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Mixed crop–livestock farming system is a major livelihood strategy in most sub-Sahara African countries. Low water use efficiency and water scarcity characterize the dominant rainfed agricultural production system in the densely populated highlands of Ethiopia. Improving water productivity in the rainfed system is among the ways of overcoming the water scarcity challenge.

This study was conducted in Meja watershed, located in Jeldu district, West Shewa in the Ethiopian part of the Blue Nile Basin to estimate economic crop water productivity based on agro-ecology and crop management practices. The watershed was classified into three landscape positions (local agro-ecologies) and major crops representing at least 70% of each landscape position were identified through discussion with farmers and development agents.

Five farmer fields were randomly selected for each major crop and crop management practices implemented by the farmers were monitored and yield (grain or tuber and straw) was measured at harvest. The local market value of the crops and the production cost was estimated based on the local market value for labour and other inputs. CROPWAT model was used to estimate effective precipitation based on weather data generated using NewLocClim and crop characteristics.

The result indicated that the landscape positions, crop variety and management practices significantly influenced the net economic water productivity. The net economic crop water productivity for barley, wheat, tef, sorghum and maize grains and fresh potato tubers were 3.31, 2.45, 3.09, 3.01 and 5.20 and ETB 13.56 m-3, respectively. Similarly, physical water productivity of the crops ranged from 0.47 for teff to 9.98 kg m-3 for fresh potato tubers. Hence, farmers can enhance economic benefit from the land and water resources they are endowed with rainfed by using improved agronomic practices that could raise grain/tuber and biomass yield. Enhancing improved input use, improving access to market for outputs and integrating livestock with crops may further augment the benefit at system scale.

Read the paper

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.

 

February 21, 2014

Understanding runoff generation processes and rainfall runoff modelling in the Meja watershed of Ethiopia – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 2, Report | Tags: , , , |
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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 are no hydrological studies 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 nested sub-watershed; this may be due to abstractions such as irrigation and human interventions in the watershed. Ground water level and runoff has strong relationship (r2> 0.65) in monthly basis of Kolu nested sub-watershed but there is moderate relationship of rainfall and ground water level. There is 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.

Read the paper

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.

 

February 9, 2014

Prioritizing rainwater management strategies in the Blue Nile basin – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, NBDC, Nile, Nile 3, Presentation, Report | Tags: , , |
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Most farmers in the Blue Nile Basin depend on unreliable rainfed agriculture and are vulnerable to climate variability. Lack of appropriate rain water management in these areas prevents smallholders from addressing the consequences of flooding during the rainy season and droughts during the dry season. This is in turn a major contributory factor to food insecurity and poverty.

Addressing these issues entails designing, targeting and prioritizing rain water management strategies. In support of this, we developed a generic methodology for out-scaling and prioritizing interventions in agricultural systems. The methodology entails a multi-stage and iterative process of:

  1. diagnosis and selection of options,
  2. characterization of the options,
  3. identification of the recommendation domains and out-scaling potential of these options,
  4. assessing the impacts along different dimensions and on different groups of people.

This paper describes how we applied this methodology in the Blue Nile Basin. We consulted several national stakeholders and identified the ‘best-bet’ options as they are currently being promoted by the SLM program. A next step entailed the description and characterization of the options. Previous knowledge about bio-physical and socio-economic conditions influencing suitability was collated, while field studies were undertaken to increase our understanding of adoption of these options. Matching this characterization data with a spatial database allowed us to map the suitability and feasibility of rainwater management options and strategies. For the last stage, the impact assessment, we identified the most-likely-to-be-adopted strategy for each of the watersheds based on the feasibility maps. We translated this into maps compatible with the SWAT model.

Results from the impact assessment should eventually feed back into the assessment of alternative options. The framework is applicable in many different forms and settings. The steps can be gone through qualitatively in a multi-stakeholder setting while the process can also be done quantitatively. It has a wide applicability beyond the Blue Nile Basin.

See the presentation:

Read the paper

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.

 

January 16, 2014

Hydrological modelling of sustainable land management interventions in the Mizewa watershed of the Blue Nile basin – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 4, Presentation, Report | Tags: , , , , , |
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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.

See the presentation:

Read the paper

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.

 

December 31, 2013

Multi-criteria optimization of rainwater management strategies for sustainable intensification – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 4, Presentation, Report | Tags: |
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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.

See the presentation:

Read the paper

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.

 

December 27, 2013

Erosion modeling in the Upper Blue Nile Basin – The case for Mizewa Watershed – A glimpse at NBDC science

Posted by Ewen Le Borgne under Books and Chapters, CRP5, East Africa, Ethiopia, IWMI, NBDC, Nile, Nile 4, Presentation, Report | Tags: , , |
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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.

See the presentation:

Read the paper

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.

 

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