Your search found 27 records
1 Getahun, M.; Adgo, E.; Atalay, A. 2011. Impacts of irrigation on soil characteristics in selected irrigation schemes in the Upper Blue Nile Basin. In Melesse, A. M. (Ed.). Nile River Basin: hydrology, climate and water use. Dordrecht, Netherlands: Springer. pp.383-399.
Soil salinity ; Irrigation schemes ; Water quality ; River basins ; Soil properties / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: 551.483 G136 MEL Record No: H044039)
2 Erkossa, Teklu; Awulachew, Seleshi Bekele; Denekew, Aster. 2011. Soil fertility effect on water productivity of maize in the Upper Blue Nile Basin, Ethiopia. Agricultural Sciences, 2(3):238-247. [doi: https://doi.org/10.4236/as.2011.23032]
Soil fertility ; Water productivity ; Crop production ; Maize ; River basins ; Farming systems ; Simulation models ; Water balance / Ethiopia / Upper Blue Nile Basin / Abbay River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H044239)
http://www.scirp.org/journal/PaperDownload.aspx?paperID=6783&returnUrl=http%3a%2f%2fwww.scirp.org%2fjournal%2fPaperInformation.aspx%3fpaperID%3d6783%26publishStatus%3d2
https://vlibrary.iwmi.org/pdf/H044239.pdf
https://vlibrary.iwmi.org/pdf/H044239.pdf
(0.69 MB) (702.66KB)
Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub- Saharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its pro- ductivity is severely constrained by poor soil, water and crop management practices. This study simulated water productivity of the crop under varying soil fertility scenarios (poor, near optimal and non limiting) using hybrid seeds under rainfed conditions using the FAO Aqua- Crop model. The result indicated that grain yield of maize increased from 2.5 tons·ha–1 under poor to 6.4 and 9.2 tons·ha–1 with near optimal and non-limiting soil fertility conditions. Corres- pondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Conse- quently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpi- ration without significantly affecting water left for downstream ecosystem services. Therefore, this has a huge implication for a basin scale water management planning for various pur- poses.
3 Wale, A.; Rientjes, T. H. M.; Dost, R. J. J.; Gieske, A. 2008. Hydrological balance of Lake Tana, Upper Blue Nile Basin, Ethiopia. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.160-181.
Hydrology ; Lakes ; River basins ; Flow ; Regionalization ; Water balance ; Runoff ; Simulation models ; Calibration ; Sensitivity analysis / Ethiopia / Upper Blue Nile Basin / Lake Tana
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044321)
(1.30 MB)
4 Asres, M. T.; Haile, Alemseged Tamiru; Abebe, Yenenesh. 2014. Opportunities and challenges of a community based rainfall observation network in Meja Watershed of the Upper Blue Nile Basin [Abstract only] In Arba Minch University. A base for building climate resilient green economy: proceedings of the 14th Symposium on Sustainable Water Resources Development, Arba Minch, Ethiopia, 27-28 June 2014. Arba Minch, Ethiopia: Arba Minch University. pp.30-31.
Rainfall patterns ; Measurement ; Watersheds ; River basins / Ethiopia / Jeldu / Upper Blue Nile Basin / Meja Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H046869)
5 Habib, E.; Haile, Alemseged Tamiru; Sazib, N.; Zhang, Y.; Rientjes, T. 2014. Effect of bias correction of satellite-rainfall estimates on runoff simulations at the source of the Upper Blue Nile. Remote Sensing, 6(7):6688-6708. [doi: https://doi.org/10.3390/rs6076688]
Rain ; Runoff ; Satellites ; River basins ; Hydrology ; Simulation models ; Calibration ; Catchment areas ; Stream flow / Africa / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H046873)
(608 KB)
Results of numerous evaluation studies indicated that satellite-rainfall products are contaminated with significant systematic and random errors. Therefore, such products may require refinement and correction before being used for hydrologic applications. In the present study, we explore a rainfall-runoff modeling application using the Climate Prediction Center-MORPHing (CMORPH) satellite rainfall product. The study area is the Gilgel Abbay catchment situated at the source basin of the Upper Blue Nile basin in Ethiopia, Eastern Africa. Rain gauge networks in such area are typically sparse. We examine different bias correction schemes applied locally to the CMORPH product. These schemes vary in the degree to which spatial and temporal variability in the CMORPH bias fields are accounted for. Three schemes are tested: space and time-invariant, time-variant and spatially invariant, and space and time variant. Bias-corrected CMORPH products were used to calibrate and drive the Hydrologiska Byråns Vattenbalansavdelning (HBV) rainfall-runoff model. Applying the space and time-fixed bias correction scheme resulted in slight improvement of the CMORPH-driven runoff simulations, but in some instances caused deterioration. Accounting for temporal variation in the bias reduced the rainfall bias by up to 50%. Additional improvements were observed when both the spatial and temporal variability in the bias was accounted for. The rainfall bias was found to have a pronounced effect on model calibration. The calibrated model parameters changed significantly when using rainfall input from gauges alone, uncorrected, and bias-corrected CMORPH estimates. Changes of up to 81% were obtained for model parameters controlling the stream flow volume.
6 Asres, S. B. 2016. Evaluating and enhancing irrigation water management in the upper Blue Nile Basin, Ethiopia: the case of Koga large scale irrigation scheme. Agricultural Water Management, 170:26-35. (Special Issue: Water Management Strategies in Irrigated Areas). [doi: https://doi.org/10.1016/j.agwat.2015.10.025]
Irrigation water ; Water management ; Irrigation schemes ; Large scale systems ; Performance evaluation ; Crops ; Water requirements ; Water demand ; Water supply ; Models ; River basins ; Reservoirs / Ethiopia / Upper Blue Nile Basin / Koga Irrigation Scheme
(Location: IWMI HQ Call no: e-copy only Record No: H047527)
(1.61 MB)
This paper deals with the objective of evaluating and enhancing irrigation water management of Koga large scale irrigation scheme located in the Blue Nile basin of Ethiopia. Disturbed and undisturbed Soil samples were collected from selected irrigation blocks within the irrigation system. Soil moisture, texture, field capacity, permanent wilting point and bulk density data were obtained from laboratory analysis of the samples. Results of demand versus supply analysis of the scheme showed that there was excess supply at the beginning of reservoir release and upto 7.13 MCM of excess flow water was estimated in year 2015. Results also showed that crop water requirement value varied for each block and for different crops in the same block, assuming the climatic conditions of the site constant. The crop water requirement variations were caused by differences in soil water holding capacity of each block. Based on crop water demand analysis result with appropriate crop water provision of 50% efficiency, the maximum irrigable area which could be accommodated by the reservoir storage was 5635.8 ha as compared to the design command of 7000 ha. The paper also investigated the status of reservoir water availability as compared to the demand and annual release. The findings of this research will have greater implications in creating awareness to the water user associations, farmers and gate operators of Koga irrigation scheme on how to measure the amount of water they are using during the whole crop growth so that optimum irrigation water shall be delivered to a crop for maintaining water management.
7 Yalew, S. G.; Mul, Marloes L.; van Griensven, A.; Teferi, E.; Priess, J.; Schweitzer, C.; van Der Zaag, P. 2016. Land-use change modelling in the Upper Blue Nile Basin. Environments, 3(3):1-16. [doi: https://doi.org/10.3390/environments3030021]
Land use ; Land cover change ; Environmental modelling ; Environmental factors ; River basins ; Catchment areas ; Socioeconomic environment ; Plantations ; Forest management ; Erosion ; Vegetation ; Grasslands / Ethiopia / Upper Blue Nile Basin / Abbay Basin / Jedeb Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H047679)
(1.24 MB)
Land-use and land-cover changes are driving unprecedented changes in ecosystems and environmental processes at different scales. This study was aimed at identifying the potential land-use drivers in the Jedeb catchment of the Abbay basin by combining statistical analysis, field investigation and remote sensing. To do so, a land-use change model was calibrated and evaluated using the SITE (SImulation of Terrestrial Environment) modelling framework. SITE is cellular automata based multi-criteria decision analysis framework for simulating land-use conversion based on socio-economic and environmental factors. Past land-use trajectories (1986–2009) were evaluated using a reference Landsat-derived map (agreement of 84%). Results show that major land-use change drivers in the study area were population, slope, livestock and distances from various infrastructures (roads, markets and water). It was also found that farmers seem to increasingly prefer plantations of trees such as Eucalyptus by replacing croplands perhaps mainly due to declining crop yield, soil fertility and climate variability. Potential future trajectory of land-use change was also predicted under a business-as-usual scenario (2009–2025). Results show that agricultural land will continue to expand from 69.5% in 2009 to 77.5% in 2025 in the catchment albeit at a declining rate when compared with the period from 1986 to 2009. Plantation forest will also increase at a much higher rate, mainly at the expense of natural vegetation, agricultural land and grasslands. This study provides critical information to land-use planners and policy makers for a more effective and proactive management in this highland catchment.
8 Allam, M. M.; Figueroa, A. J.; McLaughlin, D. B.; Eltahir, E. A. B. 2016. Estimation of evaporation over the Upper Blue Nile Basin by combining observations from satellites and river flow gauges. Water Resources Research, 52(2):644-659. [doi: https://doi.org/10.1002/2015WR017251]
Evapotranspiration ; Water resources ; River basins ; Soil moisture ; Water budget ; Models ; Satellite observation ; Water storage ; Water holding capacity ; Hydrology ; Stream flow ; Runoff ; Precipitation ; Estimation ; Farmland / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047776)
(2.28 MB)
Reliable estimates of regional evapotranspiration are necessary to improve water resources management and planning. However, direct measurements of evaporation are expensive and difficult to obtain. Some of the difficulties are illustrated in a comparison of several satellite-based estimates of evapotranspiration for the Upper Blue Nile (UBN) basin in Ethiopia. These estimates disagree both temporally and spatially. All the available data products underestimate evapotranspiration leading to basin-scale mass balance errors on the order of 35 percent of the mean annual rainfall. This paper presents a methodology that combines satellite observations of rainfall, terrestrial water storage as well as river-flow gauge measurements to estimate actual evapotranspiration over the UBN basin. The estimates derived from these inputs are constrained using a one-layer soil water balance and routing model. Our results describe physically consistent long-term spatial and temporal distributions of key hydrologic variables, including rainfall, evapotranspiration, and river-flow. We estimate an annual evapotranspiration over the UBN basin of about 2.55 mm per day. Spatial and temporal evapotranspiration trends are revealed by dividing the basin into smaller subbasins. The methodology described here is applicable to other basins with limited observational coverage that are facing similar future challenges of water scarcity and climate change.
9 Haile, Alemseged Tamiru; Akawka, A. L.; Berhanu, B.; Rientjes, T. 2017. Changes in water availability in the Upper Blue Nile basin under the representative concentration pathways scenario. Hydrological Sciences Journal, 62(13):2139-2149.
Water availability ; Water resources ; Climate change ; Temperature ; Drought ; Hydrogeology ; Intensification ; Rainfall-runoff relationships ; Evapotranspiration ; Catchment areas ; Stream flow ; Soil moisture ; Meteorological stations ; Calibration ; Land cover / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048259)
http://www.tandfonline.com/doi/pdf/10.1080/02626667.2017.1365149?needAccess=true
https://vlibrary.iwmi.org/pdf/H048259.pdf
https://vlibrary.iwmi.org/pdf/H048259.pdf
limatic and hydrological changes will likely be intensified in the Upper Blue Nile (UBN) basin by the effects of global warming. The extent of such effects for representative concentration pathways (RCP) climate scenarios is unknown. We evaluated projected changes in rainfall and evapotranspiration and related impacts on water availability in the UBN under the RCP4.5 scenario. We used dynamically downscaled outputs from six global circulation models (GCMs) with unprecedented spatial resolution for the UBN. Systematic errors of these outputs were corrected and followed by runoff modelling by the HBV (Hydrologiska ByrånsVattenbalansavdelning) model, which was successfully validated for 17 catchments. Results show that the UBN annual rainfall amount will change by -2.8 to 2.7% with a likely increase in annual potential evapotranspiration (in 2041–2070) for the RCP4.5 scenario. These changes are season dependent and will result in a likely decline in streamflow and an increase in soil moisture deficit in the basin.
10 Nigussie, Z.; Tsunekawa, A.; Haregeweyn, N.; Adgo, E.; Nohmi, M.; Tsubo, M.; Aklog, D.; Meshesha, D. T.; Abele, S. 2017. Factors influencing small-scale farmers’ adoption of sustainable land management technologies in north-western Ethiopia. Land Use Policy, 67:57-64. [doi: https://doi.org/10.1016/j.landusepol.2017.05.024]
Small scale farming ; Farmer participation ; Sustainable land management ; Technology ; Water conservation ; Soil conservation ; Land degradation ; Watersheds ; Drought ; Socioeconomic environment ; Multivariate analysis ; Models / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048585)
(0.54 MB)
Land degradation is a serious global problem because it leads to losses in food production and thus jeopardizes food security worldwide, particularly in developing countries. Despite numerous efforts to introduce sustainable land management (SLM) strategies and practices, their adoption by the primary target group, small-scale farmers in developing countries, has been [s]low. This study assesses the problem for the case of Ethiopia. The aim was to analyze the underlying factors that affect the adoption of SLM technologies in the Upper Blue Nile Basin. A detailed survey of 300 households and 1010 farm plots was conducted. Data were analyzed by using both descriptive and econometric analyses. Results show that farmers’ adoption of interrelated SLM measures depended on a number of socio-economic and farm-related factors in combination with the characteristics of the technologies themselves. For example, plot size and the availability of labor, as well as the gender of the household head, affected which SLM technologies were adopted by certain types of households. The adoption of SLM measures depended on the adaptive economic capacity of the farmers, which can be quite diverse even within a small region and can differ from the adoption potential in other regions. Our results suggest that SLM policies and programs have to be individually designed for specific target groups within specific regions, which in turn means that “one size fits all” and “across the board” strategies – which are quite common in the field of SLM – should be abandoned by development agencies and policymakers.
11 Dile, Y. T.; Tekleab, S.; Ayana, E. K.; Gebrehiwot, S. G.; Worqlul, A. W.; Bayabil, H. K.; Yimam, Y. T.; Tilahun, S. A.; Daggupati, P.; Karlberg, L.; Srinivasan, R. 2018. Advances in water resources research in the Upper Blue Nile Basin and the way forward: a review. Journal of Hydrology, 560:407-423. [doi: https://doi.org/10.1016/j.jhydrol.2018.03.042]
Water resources ; Research ; Water conservation ; Soil conservation ; Erosion ; Climate change ; Land use ; Catchment areas ; Water balance ; Hydrology ; Models ; Economic development ; Agriculture ; Remote sensing / Ethiopia / Upper Blue Nile Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048798)
https://www.sciencedirect.com/science/article/pii/S0022169418302087/pdfft?md5=fd653f0a22b3bbc8ecfa4c346eb5cfc9&pid=1-s2.0-S0022169418302087-main.pdf
https://vlibrary.iwmi.org/pdf/H048798.pdf
https://vlibrary.iwmi.org/pdf/H048798.pdf
(1.32 MB) (1.32 MB)
The Upper Blue Nile basin is considered as the lifeline for ~250 million people and contributes ~50 Gm3 / year of water to the Nile River. Poor land management practices in the Ethiopian highlands have caused a significant amount of soil erosion, thereby threatening the productivity of the Ethiopian agricultural system, degrading the health of the aquatic ecosystem, and shortening the life of downstream reservoirs. The Upper Blue Nile basin, because of limited research and availability of data, has been considered as the "great unknown." In the recent past, however, more research has been published. Nonetheless, there is no state-of-the-art review that presents research achievements, gaps and future directions. Hence, this paper aims to bridge this gap by reviewing the advances in water resources research in the basin while highlighting research needs and future directions. We report that there have been several research projects that try to understand the biogeochemical processes by collecting information on runoff, groundwater recharge, sediment transport, and tracers. Different types of hydrological models have been applied. Most of the earlier research used simple conceptual and statistical approaches for trend analysis and water balance estimations, mainly using rainfall and evapotranspiration data. More recent research has been using advanced semi-physically/physically based distributed hydrological models using high-resolution temporal and spatial data for diverse applications. We identified several research gaps and provided recommendations to address them. While we have witnessed advances in water resources research in the basin, we also foresee opportunities for further advancement. Incorporating the research findings into policy and practice will significantly benefit the development and transformation agenda of the Ethiopian government.
12 Gashaw, T.; Tulu, T.; Argaw, M.; Worqlul, A. W.; Tolessa, T.; Kindu, M. 2018. Estimating the impacts of land use/land cover changes on ecosystem service values: the case of the Andassa Watershed in the Upper Blue Nile Basin of Ethiopia. Ecosystem Services, 31(Part A):219-228. [doi: https://doi.org/10.1016/j.ecoser.2018.05.001]
Ecosystem services ; Economic value ; Land use ; Land cover change ; Estimation ; Watersheds ; Cultivated land ; Forest land ; Scrublands ; Grasslands ; River basins ; Models / Ethiopia / Upper Blue Nile Basin / Andassa Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048818)
(1.40 MB)
Estimating the impacts of land use/land cover (LULC) changes in Ecosystem Service Values (ESV) is indispensable to provide public awareness about the status of ESV, and to help in policy-making processes. This study was intended to estimate the impacts of LULC changes on ESV in the Andassa watershed of the Upper Blue Nile basin over the last three decades (1985–2015), and to predict the ESV changes in 2045. The hybrid land use classification technique for classifying Landsat images, the Cellular-Automata Markov (CA-Markov) model for LULC prediction, and the modified ecosystem service value coefficients for estimating ESV were employed. Our findings revealed that there was a continues expansions of cultivated land and built-up area, and withdrawing of forest, shrubland and grassland during the 1985–2015 periods, which are expected to continue for the next three decades. Consequently, the total ESV of the watershed has declined from US$26.83 106 in 1985 to US$22.58 106 in 2000 and to US $21.00 106 in 2015 and is expected to further reduce to US$17.94 106 in 2030 and to US$15.25 106 in 2045. The impacts of LULC changes on the specific ecosystem services are also tremendous.
13 Nigussie, Y.; van der Werf, E.; Zhu, X.; Simane, B.; van Ierland, E. C. 2018. Evaluation of climate change adaptation alternatives for smallholder farmers in the Upper Blue-Nile Basin. Ecological Economics, 151:142-150. [doi: https://doi.org/10.1016/j.ecolecon.2018.05.006]
Climate change adaptation ; Alternative methods ; Smallholders ; Farmers ; Stakeholders ; Water resources ; Water management ; Agricultural practices ; River basins ; Natural resources management / Ethiopia / Upper Blue Nile Basin / Choke Mountain
(Location: IWMI HQ Call no: e-copy only Record No: H048919)
(0.30 MB)
Climate change is expected to have severe negative impacts on the livelihoods of smallholder farmers in developing countries. However, smallholder farmers and governments in these regions tend to be ill-prepared for the impacts of climate change. We present the results of a stakeholder-based multi-criteria analysis of climate change adaptation options for agriculture, natural resource management and water management in the upper Blue-Nile basin in Ethiopia. We use the PROMETHEE II outranking method to analyse data from a survey in which farmers and experts were asked to evaluate adaptation options based on potentially conflicting criteria. Adaptation options for soil and land management, such as crop rotation and composting, score high based on two sets of criteria for assessing adaptation options for agriculture. River diversion, preventing leaching and erosion, and drip irrigation are ranked highest as adaptation options for water management. Regarding natural resource management, the highest ranked adaptation options are afforestation, water retention and maximizing crop yield. Rankings by farmers and by experts are weakly correlated for agriculture and water management, and negatively correlated for natural resource management, which shows the importance of extension services and of involving farmers in the decision-making process to ensure the feasibility of adaptation options.
14 Worqlul, A. W.; Dile, Y. T.; Schmitter, Petra; Jeong, J.; Meki, M. N.; Gerik, T. J.; Srinivasan, R.; Lefore, Nicole; Clarke, N. 2019. Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia. Agricultural Water Management, 226:105767. [doi: https://doi.org/10.1016/j.agwat.2019.105767]
Water resources ; Assessment ; Agricultural production ; Vegetables ; Crop yield ; Tomatoes ; Onions ; Irrigation water ; Rain ; Groundwater recharge ; Watersheds ; Water use efficiency ; Fertilizer application ; Farmers ; Farmer-led irrigation ; Models / Ethiopia / Upper Blue Nile Basin / Robit Watershed / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049376)
https://www.sciencedirect.com/science/article/pii/S0378377418314021/pdfft?md5=769bfc34b80853a9a6b06c0b86106dda&pid=1-s2.0-S0378377418314021-main.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
https://vlibrary.iwmi.org/pdf/H049376.pdf
(2.00 MB) (2.00 MB)
The vast majority of farmers in sub-Saharan Africa depend on rainfed agriculture for food production and livelihood. Various factors including but not limited to rainfall variability, land degradation, and low soil fertility constrain agricultural productivity in the region. The objectives of this study were to 1) estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia during the dry season so as to expand food supply by growing vegetables, and 2) understand the gaps and constraints of vegetable production. The case studies were conducted in the Robit and Dangishta watersheds of the Upper Blue Nile Basin, Ethiopia. To document farmers’ cropping practices, field-level data were collected from 36 households who had been cultivating tomato (Solanum lycopersicum L.) and onion (Allium cepa L.) during the dry season (November – April). Two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) – were respectively used to assess impacts of SSI at the watershed and field-scale levels. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at the watershed scale. The field-scale analysis in the Robit watershed indicated that optimal tomato yield could be obtained with 500 mm of water and 200 to 250 kg/ha of urea applied with 50 kg/ ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained with 400 mm of water and 120 to 180 kg/ha of urea applied with 50 kg/ha of DAP. The field-scale simulation indicated that the average shallow groundwater recharge (after accounting for other groundwater users such as household and livestock use) was not sufficient to meet tomato and onion water demand in the dry season (October to April). The fieldscale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (60% for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could optimize irrigation water for vegetable production by reducing soil evaporation and thereby increasing water availability in the crop root zone.
15 Walker, D.; Parkin, G.; Gowing, J.; Haile, Alemseged Tamiru. 2019. Development of a hydrogeological conceptual model for shallow aquifers in the data scarce Upper Blue Nile Basin. Hydrology, 6(2):1-24. [doi: https://doi.org/10.3390/hydrology6020043]
Groundwater table ; Aquifers ; Hydrogeology ; Models ; Hydrometeorology ; Monitoring ; Surface water ; Discharges ; Wells ; Pumping ; Rain ; Rivers / Ethiopia / Upper Blue Nile Basin / Dangila
(Location: IWMI HQ Call no: e-copy only Record No: H049389)
(5.15 MB) (5.15 MB)
Rural communities in sub-Saharan Africa commonly rely on shallow hand-dug wells and springs; consequently, shallow aquifers are an extremely important water source. Increased utilisation of shallow groundwater could help towards achieving multiple sustainable development goals (SDGs) by positively impacting poverty, hunger, and health. However, these shallow aquifers are little studied and poorly understood, partly due to a paucity of existing hydrogeological information in many regions of sub-Saharan Africa. This study develops a hydrogeological conceptual model for Dangila woreda (district) in Northwest Ethiopia, based on extensive field investigations and implementation of a citizen science programme. Geological and water point surveys revealed a thin (3–18 m) weathered volcanic regolith aquifer overlying very low permeability basalt. Hydrochemistry suggested that deep groundwater within fractured and scoriaceous zones of the basalt is not (or is poorly) connected to shallow groundwater. Isotope analysis and well monitoring indicated shallow groundwater flow paths that are not necessarily coincident with surface water flow paths. Characteristics of the prevalent seasonal floodplains are akin to “dambos” that are well-described in literature for Southern Africa. Pumping tests, recharge assessments, and hydrometeorological analysis indicated the regolith aquifer shows potential for increased utilisation. This research is transferrable to the shallow volcanic regolith aquifers that overlie a substantial proportion of Ethiopia and are prevalent throughout the East African Rift and in several areas elsewhere on the continent.
16 Dibaba, W. T.; Demissie, T. A.; Miegel, K. 2020. Watershed hydrological response to combined land use/land cover and climate change in highland Ethiopia: Finchaa Catchment. Water, 12(6):1801. (Special issue: Hydrological Impacts of Climate Change and Land Use) [doi: https://doi.org/10.3390/w12061801]
Watersheds ; Hydrology ; Land use ; Land cover ; Climate change ; Highlands ; Water resources ; Water balance ; Water yield ; Precipitation ; Rain ; Runoff ; Temperature ; Emission ; Evapotranspiration ; Commercial farming ; Models / Ethiopia / Upper Blue Nile Basin / Finchaa Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H049811)
(2.32 MB) (2.32 MB)
Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to plan for potential adaptive capacity. In this research, Cellular Automata (CA)-Markov in IDRISI software was used to predict the future LULC scenarios and the ensemble mean of four regional climate models (RCMs) in the coordinated regional climate downscaling experiment (CORDEX)-Africa was used for the future climate scenarios. Distribution mapping was used to bias correct the RCMs outputs, with respect to the observed precipitation and temperature. Then, the Soil and Water Assessment Tool (SWAT) model was used to evaluate the watershed hydrological responses of the catchment under separate, and combined, LULC and climate change. The result shows the ensemble mean of the four RCMs reported precipitation decline and increase in future temperature under both representative concentration pathways (RCP4.5 and RCP8.5). The increases in both maximum and minimum temperatures are higher for higher emission scenarios showing that RCP8.5 projection is warmer than RCP4.5. The changes in LULC brings an increase in surface runoff and water yield and a decline in groundwater, while the projected climate change shows a decrease in surface runoff, groundwater and water yield. The combined study of LULC and climate change shows that the effect of the combined scenario is similar to that of climate change only scenario. The overall decline of annual flow is due to the decline in the seasonal flows under combined scenarios. This could bring the reduced availability of water for crop production, which will be a chronic issue of subsistence agriculture. The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream. The highly rising demands of water, owing to socio-economic progress, population growth and high demand for irrigation water downstream, in addition to the variability temperature and evaporation demands, amplify prolonged water scarcity. Consequently, strong land-use planning and climate-resilient water management policies will be indispensable to manage the risks.
17 Bogale, A.; Aynalem, D.; Adem, A.; Mekuria, Wolde; Tilahun, S. 2020. Spatial and temporal variability of soil loss in gully erosion in Upper Blue Nile Basin, Ethiopia. Applied Water Science, 10(5):106. [doi: https://doi.org/10.1007/s13201-020-01193-4]
Gully erosion ; Soil loss ; Soil conservation ; Water conservation ; Spatial variation ; Groundwater assessment ; Groundwater table ; Stream flow ; Sediment ; Watersheds ; Catchment areas ; Highlands / Ethiopia / Upper Blue Nile Basin / Chentale Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049937)
https://link.springer.com/content/pdf/10.1007/s13201-020-01193-4.pdf
https://vlibrary.iwmi.org/pdf/H049937.pdf
https://vlibrary.iwmi.org/pdf/H049937.pdf
(1.63 MB) (1.63 MB)
Gully erosion has many negative impacts on both cultivated and grazing lands in Ethiopian highlands. The present study was conducted in Chentale watershed, Ethiopia, to quantify the contribution of gully erosion, and to assess its temporal changes. Within the Chentale watershed, we selected a sub-watershed (104.6 ha) and nested gully catchment, and gauged for stream flow and sediment concentration data in 2015 and 2016. We measured gully dimensions before and after the onset of the rainy season in 2016 to determine soil loss due to gully erosion. The temporal changes of gully expansion were determined by digitizing gully plain area from Google earth images taken in 2005 and 2013. The results support that gullies were expanding at higher rate in recent years. Area covered by gullies in the watershed increased from 1.84 to 3.43 ha between 2005 and 2013, indicating that the proportion of the watershed covered by gullies was nearly doubled in the investigated period. The estimated soil loss from the main watershed and gullies catchment was 6 and 2 t ha-1 year-1 in 2015, and was 7 and 9 t ha-1 year-1 in 2016, respectively. The results support that gullies were the main contributors of soil erosion in the watershed, and that integrated soil and water conservation measures are required to reduce soil erosion.
18 Yimam, A. Y.; Bekele, A. M.; Nakawuka, Prossie; Schmitter, Petra; Tilahun, S. A. 2019. Rainfall-runoff process and groundwater recharge in the Upper Blue Nile Basin: the case of Dangishta Watershed. In Zimale, F. A.; Nigussie, T. E.; Fanta, S. W. (Eds.). Advances of science and technology. Proceedings of the 6th EAI International Conference on Advancement of Science and Technology (ICAST 2018), Bahir Dar, Ethiopia, 5-7 October 2018. Cham, Switzerland: Springer. pp.536-549. (Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering (LNICST) Volume 274) [doi: https://doi.org/10.1007/978-3-030-15357-1_43]
Groundwater recharge ; Rainfall-runoff relationships ; Watersheds ; Stream flow ; Groundwater table ; Infiltration ; Soil moisture ; Estimation ; Irrigation water ; Wells ; Land use / Ethiopia / Upper Blue Nile Basin / Dangishta Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050164)
(0.56 MB)
For planning, development and management of water resources, understanding runoff mechanism and groundwater recharge is useful especially to watershed management and groundwater use for domestic and irrigation water supply. During the period of the study, stream flow, groundwater levels, infiltration tests, rainfall and soil moisture measurements were conducted. The result from these measurement showed that saturation excess runoff were dominant in Dangishta watershed while infiltration excess runoff also contributes in some parts of the upslope area. This result was also corroborated by better correlation of (R2 = 0.82) at the main outlet than upstream sub watershed outlet (R2 = 0.56) using SCS runoff equation. The result from groundwater level measurement using water table fluctuations approach showed that the total annual groundwater recharge were found to be 400 mm (i.e. 24% of the total annual rainfall) which is a significant amount likely because of the interflow processes to each well.
19 Mengistu, D.; Bewket, W.; Dosio, A.; Panitz, H.-J. 2021. Climate change impacts on water resources in the Upper Blue Nile (Abay) River Basin, Ethiopia. Journal of Hydrology, 592:125614. [doi: https://doi.org/10.1016/j.jhydrol.2020.125614]
Climate change ; Water resources ; River basins ; Models ; Hydrology ; Stream flow ; Precipitation ; Evapotranspiration ; Temperature ; Forecasting ; Surface runoff ; Water yield ; Land use ; Land cover ; Uncertainty / Ethiopia / Upper Blue Nile Basin / Abay River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050183)
(6.16 MB)
This study assesses the impact of climate change on water resources in the Upper Blue Nile (Abay) River Basin using a regional climate model (RCM), COSMO Climate Limited-area Model (CCLM), coupled with a hydrological model, Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated and validated using measured streamflow data from four gauging stations. Climate change projections showed increases in mean annual temperature and decrease in precipitation in most parts of the Basin. Such changes are expected to affect the hydrologic regime of the Basin; these were assessed by running the SWAT model with the past (1981–2010) and future (2010–2039, 2040–2069 and 2070–2099) climate scenarios. The results show an increase of potential evapotranspiration (PET) by up to 27% by the end of the 21st century under RCP8.5 compared to the baseline period. Surface runoff is projected to increase by up to 14%. However, the increase in surface runoff could not increase the total water yield of the Basin. Instead, the total water yield of the Basin is estimated to decrease by -1.7 to -6.5% and -10.7 to -22.7%, for simulations forced by RCP4.5 and RCP8.5 scenarios, respectively. By the end of the 21st century, the contribution of baseflow to the total water yield of the Basin is also projected to decline to 11.4% from 41.3% during the baseline period. The decrease in baseflow partly explains the decline in the total water yield of the Basin. Such changes in the hydrologic balance will have significant implications for water management in the Basin.
20 Tarekegn, N.; Abate, B.; Muluneh, A.; Dile, Y. 2021. Modeling the impact of climate change on the hydrology of Andasa Watershed. Modeling Earth Systems and Environment, 17p. (Online first) [doi: https://doi.org/10.1007/s40808-020-01063-7]
Climate change ; Hydrology ; Watersheds ; Forecasting ; Temperature ; Rain ; Stream flow ; Soil moisture ; Land use ; Modelling ; Uncertainty / Ethiopia / Upper Blue Nile Basin / Andasa Watershed / Amhara
(Location: IWMI HQ Call no: e-copy only Record No: H050195)
https://link.springer.com/content/pdf/10.1007/s40808-020-01063-7.pdf
https://vlibrary.iwmi.org/pdf/H050195.pdf
https://vlibrary.iwmi.org/pdf/H050195.pdf
(2.93 MB) (2.93 MB)
This paper was aimed to study the impact of climate change on the hydrology of Andasa watershed for the period 2013–2099. The soil and water assessment tool (SWAT) was calibrated and validated, and thereby used to study the impact of climate change on the water balance. The future climate change scenarios were developed using future climate outputs from the Hadley Center Climate Model version 3 (HadCM3) A2 (high) and B2 (low) emission scenarios and Canadian Earth System Model version 2 (CanESM2) Representative concentration pathways (RCP) 4.5 and 8.5 scenarios. The large-scale maximum/minimum temperature and rainfall data were downscaled to fine-scale resolution using the Statistical Downscaling Model (SDSM). The mean monthly temperature projection of the four scenarios indicated an increase by a range of 0.4–8.5 °C while the mean monthly rainfall showed both a decrease of up to 97% and an increase of up to 109%. The long-term mean of all the scenarios indicated an increasing temperature and decreasing rainfall trends. Simulations showed that climate change may cause substantial impacts in the hydrology of the watershed by increasing the potential evapotranspiration (PET) by 4.4–17.3% and decreasing streamflow and soil water by 48.8–95.6% and 12.7–76.8%, respectively. The findings suggested that climate change may cause moisture-constrained environments in the watershed, which may impact agricultural activities in the watershed. Appropriate agricultural water management interventions should be implemented to mitigate and adapt to the plausible impacts of climate change by conserving soil moisture and reducing evapotranspiration.
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