Articles de revues : « Blue Nile River »

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Russo, Antonio, Getaneh Assefa et Balemwal Atnafu. « Sedimentary evolution of the Abay River (Blue Nile) Basin, Ethiopia ». Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1994, n^o 5 (1 mai 1994) : 291–308. http://dx.doi.org/10.1127/njgpm/1994/1994/291.

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Gelete, Gebre, Huseyin Gokcekus et Tagesse Gichamo. « Impact of climate change on the hydrology of Blue Nile basin, Ethiopia : a review ». Journal of Water and Climate Change 11, n^o 4 (3 octobre 2019) : 1539–50. http://dx.doi.org/10.2166/wcc.2019.014.

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Abstract Climate change alters the spacial and temporal availability of water resources by affecting the hydrologic cycle. The main objective of this paper is to review the climate change effect on the water resources of the Blue Nile River, Ethiopia. The impact of climate change on water resources is highly significant as all natural ecosystems and humans are heavily dependent on water. It alters precipitation, temperature, and streamflow of the Blue Nile river basin which is threatening the lives and livelihoods of people and life-supporting systems. Rainfall within the Blue Nile river basin is highly erratic and seasonal due to it being located in the inter-tropical convergent zone. The temperature and sediment load are shown to increase in the future while the rainfall and streamflow are decreasing. The Blue Nile basin is characterized by highly erosive rainfall, erodible soil, and shrinking forest cover. Therefore, mitigation and adaptation measures should be applied by considering these characteristics of the basin. Watershed management methods like afforestation and water conservation are recommended to reduce the impact on the Blue Nile basin.

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E.H., Osman, Gumaa Y.S.A. et Elhag A.M.H. « Land Cover/Land Use Trends along the Blue Nile River Blue Nile State – Sudan ». IRA-International Journal of Applied Sciences (ISSN 2455-4499) 13, n^o 1 (6 février 2019) : 1. http://dx.doi.org/10.21013/jas.v13.n1.p1.

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The study focused on quantifying the extent and sources of the deterioration of the vegetation cover of the study area at the Sudanese Blue Nile watershed in relation to agriculture extension policy, inefficient management and Lack of governmental policy. The Research was based on forest and vegetation inventory and soil analysis to determine the current situation using ground survey, forest inventory and remote sensing data as well as secondary information from other sources to cover historical records from 1990 to 2015.The results showed a significant change in natural ecosystems during the study period due to the change in the land use patterns. The Closed forests, open forests, and rural settlement areas were found to decrease by -90%, -43% and -32% respectively during the period (1990-2000). This negative trend was reflected in a positive trend showed by expansion in agriculture (+267%), horticulture (+73%), bare land (144%), and urban areas (12%). During the period (2010-2015), which was the civil war period, the area of closed forests, open forests and urban areas were increased, in comparison to that of 1990-2000) by 201,10, and 247% respectively, while that of agriculture, Rural areas, and bare lands is negative (-51, -54 and -68% respectively).The major factor for the change is mainly attributed to the migration of rural people towards urban areas due to civil war and economic crises. In addition, it is expected that there are other factors such as the absence of clear plans and coordination between concerned government authorities, at local and national levels, which may need further investigations and studies to clear the whole picture.

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SWAIN, ASHOK. « Ethiopia, the Sudan, and Egypt : The Nile River Dispute ». Journal of Modern African Studies 35, n^o 4 (décembre 1997) : 675–94. http://dx.doi.org/10.1017/s0022278x97002577.

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The Nile flows for 6,700 kilometres through ten countries in north-eastern Africa – Rwanda, Burundi, Zaïre/Congo, Tanzania, Kenya, Uganda, Eritrea, Ethiopia, the Sudan, and Egypt – before reaching the Mediterranean, and is the longest international river system in the world – see Map 1. Its two main tributaries converge at Khartoum: the White Nile, which originates from Burundi and flows through the Equatorial Lakes, provides a small but steady flow that is fed by the eternal snows of the Ruwenzori (the ‘rain giver’) mountains, while the Blue Nile, which suffers from high seasonal fluctuations, descends from the lofty Ethiopian ‘water tower’ highlands. They provide 86 per cent of the waters of the Nile – Blue Nile 59 per cent, Baro-Akobo (Sobat) 14 per cent, Tekesse (Atbara) 13 per cent – while the contribution from the Equatorial Lakes region is only 14 per cent.

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ALI, Yasir S. A., Alessandra CROSATO, Yasir A. MOHAMED, Seifeldin H. ABDALLA et Nigel G. WRIGHT. « Sediment balances in the Blue Nile River Basin ». International Journal of Sediment Research 29, n^o 3 (septembre 2014) : 316–28. http://dx.doi.org/10.1016/s1001-6279(14)60047-0.

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Mishra, Anil, Takeshi Hata, A. W. Abdelhadi, Akio Tada et Haruya Tanakamaru. « Recession flow analysis of the Blue Nile River ». Hydrological Processes 17, n^o 14 (2003) : 2825–35. http://dx.doi.org/10.1002/hyp.1436.

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Zaroug, M. A. H., E. A. B. Eltahir et F. Giorgi. « Droughts and floods over the upper catchment of the Blue Nile and their connections to the timing of El Niño and La Niña Events ». Hydrology and Earth System Sciences Discussions 10, n^o 8 (21 août 2013) : 10971–95. http://dx.doi.org/10.5194/hessd-10-10971-2013.

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Abstract. The Blue Nile originates from Lake Tana in the Ethiopian Highland and contributes about 67% of the discharge in the main Nile River. Previous studies investigated the relationship of sea surface temperature (SST) in the Pacific Ocean (Nino 3.4 region) to occurrence of floods and droughts in rainfall and river flow over the Nile basin. In this paper we focus on the dependence of occurrence of droughts and floods in the upper catchment of the Blue Nile on the timing of El Niño and La Niña events. Different events start in different times of the year and follow each other exhibiting different patterns and sequences. Here, we study the impact of this timing and temporal patterns on the Nile droughts and floods. We analyze discharge measurements (1965–2012) at the outlet of the upper catchment of the Blue Nile in relation to the El Niño index. When an El Niño event is followed by a La Niña event, there is a 67% chance for occurrence of an extreme flood. The association of start dates of El Niño with occurrence of droughts in the upper catchment of the Blue Nile is evaluated. An El Niño event that starts in (April–June) is associated with a significant drought occurrence in 83% of the cases. We propose that observations as well as global model forecasts of SST during this season could be used in seasonal forecasting of the Blue Nile flow.

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Mehari, Abrehet Kahsay, Shewit Gebremedhin et Belayneh Ayele. « Effects of Bahir Dar Textile Factory Effluents on the Water Quality of the Head Waters of Blue Nile River, Ethiopia ». International Journal of Analytical Chemistry 2015 (2015) : 1–7. http://dx.doi.org/10.1155/2015/905247.

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The study was conducted in 2013/14 with the objective of determining the effects of Bahir Dar textile factory effluents on the head of Blue Nile River water quality. Dissolve oxygen was higher at the upstream site of the river, whereas BOD5, TDS, and total alkalinity values were higher at wastewater outlet of the factory site. The mean values of dissolved oxygen, BOD5, and total alkalinity were above maximum permissible limits set by WHO for drinking water at head of Blue Nile River. The mean value of BOD5 was above permissible limit of IFC for textile effluents to be discharged to surface water. A total of 836 aquatic macroinvertebrate individuals belonging to 21 families were collected. The Shannon-Wiener Diversity Index, the Hilsenhoff family-level biotic index, family richness, and percent dipterans were calculated. Hilsenhoff family-level biotic index and percent dipterans metrics differed significantly among sampling sites(P<0.05). Hilsenhoff family-level biotic index was higher at the most downstream site but percent dipterans were higher at site of discharge of effluent to the head of Blue Nile River. Therefore, there is indication that effluent demands frequent control and proper treatment before being discharged to the environment.

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Berhane, Fisseha, Benjamin Zaitchik et Amin Dezfuli. « Subseasonal Analysis of Precipitation Variability in the Blue Nile River Basin ». Journal of Climate 27, n^o 1 (1 janvier 2014) : 325–44. http://dx.doi.org/10.1175/jcli-d-13-00094.1.

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Abstract The Ethiopian portion of the Blue Nile River basin is subject to significant interannual variability in precipitation. As this variability has implications for local food security and transboundary water resources, numerous studies have been directed at improved understanding and, potentially, predictability of the Blue Nile rainy season (June–September) precipitation. Taken collectively, these studies present a wide range of large-scale drivers associated with precipitation variability in the Blue Nile: El Niño–Southern Oscillation (ENSO), the Indian summer monsoon, sea level pressure (SLP) anomalies over the Arabian Peninsula and Gulf of Guinea, the quasi-biennial oscillation (QBO), and dynamics of the tropical easterly jet (TEJ) and African easterly jet (AEJ) have all been emphasized to varying degrees. This study aims to reconcile these diverse analyses by evaluating teleconnection patterns and potential mechanisms of association on the subseasonal scale. It is found that associations with the TEJ, Pacific modes of variability, and the Indian monsoon are strongest in the late rainy season. Mid–rainy season precipitation (July and August) shows mixed associations with Pacific/Indian Ocean variability and Atlantic Ocean indices, along with connections to regional pressure patterns and the AEJ. June precipitation is negatively correlated with SLP over the equatorial Atlantic and upper-tropospheric geopotential height. June and July precipitation show little significant correlation with the sea surface temperature over the equatorial Pacific Ocean. The observed intraseasonal evolution of teleconnections across the rainy season indicates that subseasonal analysis is required to advance understanding and prediction of Blue Nile precipitation variability.

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Abdelhadi, A. W., Takeshi Hata et O. E. Hamad. « A Recession-Forecast Model for the Blue Nile River ». Hydrology Research 31, n^o 1 (1 février 2000) : 41–56. http://dx.doi.org/10.2166/nh.2000.0004.

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An analytical model for the forecasting of the Blue Nile River low flow is developed and compared with the current modified similar year method. The model is based on the general non-linear reservoir equation and the historical flow of the river for the calibration period 1912-1961. The comparison is made after the year 1961 for 6 different years in terms of the temporal 10-day flows and for the period 1962-1996 in terms of the standard error of estimates (SEE). The model and the modified similar year forecasted 10-day flows were also compared with the actual temporal 10-day flows during the driest and the wettest year of the whole record between 1912-1998. Results showed that the model temporal distribution of flows is more close to the actual ones compared with the modified similar year method. The model has less SEE in 31 years out of 38 compared with the modified similar year method.

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Johnson, Peggy A., et P. Douglas Curtis. « Water Balance of Blue Nile River Basin in Ethiopia ». Journal of Irrigation and Drainage Engineering 120, n^o 3 (mai 1994) : 573–90. http://dx.doi.org/10.1061/(asce)0733-9437(1994)120:3(573).

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Shamseldin, Asaad Y., Gamal M. Abdo et Abderhman S. Elzein. « Real-Time Flood Forecasting on the Blue Nile River ». Water International 24, n^o 1 (mars 1999) : 39–45. http://dx.doi.org/10.1080/02508069908692132.

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Treszkai, Ákos. « The River Nile Conflict in the Aspects of Critical Infrastructure Protection ». Honvédségi Szemle 148, n^o 1 (7 septembre 2020) : 41–49. http://dx.doi.org/10.35926/hdr.2020.1.3.

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The aim of this paper is to present the River Nile conflict from the aspects of critical infrastructure protection. It is often stated that the next world war will be fought over water, and there are few regions as tense as the Nile Valley. Egypt and Ethiopia have a severe disagreement, Sudan is in the middle of it, and a big geopolitical shift is being played along the world’s longest river. The Grand Renaissance Dam has been un-der construction on the Blue Nile River in Ethiopia. This dam will be the greatest hydro-electric power plant in Africa. This critical infrastructure has both political and military importance.

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CONWAY, DECLAN. « The Climate and Hydrology of the Upper Blue Nile River ». Geographical Journal 166, n^o 1 (mars 2000) : 49–62. http://dx.doi.org/10.1111/j.1475-4959.2000.tb00006.x.

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Abu Sabah, Rasha Babiker Gurashi, Abubaker Haroun Mohamed Adam et Dawoud Mohamed Ali. « Assessment of Water Quality of Blue Nile River in Sudan ». Journal of Agronomy Research 1, n^o 3 (7 décembre 2018) : 1–14. http://dx.doi.org/10.14302/issn.2639-3166.jar-18-2457.

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The objectives of this study were to quantify the fresh water quality of Blue Nile River before processing, identify the pollutants, and to determine the most polluted areas, and their impacts on living organisms as well as the surrounding environment. Thus, random water samples were collected and analyzed at the laboratory of the Ministry of Irrigation and Water Resources, Ground water and Wadis Directorates - Khartoum. The outcomes were compared with the World Health Organization standardization. The results revealed variations in the concentration of the studied elements taken from the different locations. But, the results indicated that the water quality is good, and it is within the permissible water use. However, further study is recommended to include seasonal variation as well as the biological analysis.

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Kendie, Daniel. « Egypt and the Hydro-Politics of the Blue Nile River ». Northeast African Studies 6, n^o 1 (1999) : 141–69. http://dx.doi.org/10.1353/nas.2002.0002.

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Mishra, A., T. Hata et A. W. Abdelhadi. « Models for recession flows in the upper Blue Nile River ». Hydrological Processes 18, n^o 15 (11 octobre 2004) : 2773–86. http://dx.doi.org/10.1002/hyp.1322.

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K.E., Bashar. « Rainfall-Runoff Model(s) Performance in the Blue Nile River ». FES Journal of Engineering Sciences 5, n^o 1 (6 octobre 2011) : 21. http://dx.doi.org/10.52981/fjes.v5i1.27.

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This paper presents the performance of some tested rainfall-runoff models to forecast river flows of the Blue Nile catchment up to Eddeim. Flow forecasting is an important step in river basin management in particular and water resources management in general. River flow models are used as components in actual flow forecasting schemes. They are also used in providing for efficient operation of storage reservoirs. Usually, flow forecasts are obtained in real time by transforming the input into a discharge using models. These forecasts may subsequently be modified or updated in accordance with the errors observed in the previous forecasts up to the time of making the new forecast. The system analysis or black box approach depends on a prior assumption of flexible linear and time invariant relationship the expression of which can be obtained by the application of systems analysis approach to records. The conceptual model provides an alternative approach in which the input-output transformation goes through a series of steps. In this study, systems and conceptual modelling techniques are applied to the Blue Nile catchment up to Eddeim of the Ethiopian high lands. The models were applied in non-parametric and parametric forms. Parameter optimisation is carried out by ordinary least squares, Rosenbrock, Simplex and genetic algorithm. The areal rainfall which is the main input to these models was estimated using arithmetic mean. However, attempts to estimate the areal rainfall by the Thiesen polygon method was made but the improvement in the model performance can not justify the amount of work involved in making Thiesen’s estimate. It is shown that the simple assumption of linearity is not adequate in modelling the rainfall runoff transformation. However, in the Blue Nile catchment, which exhibits a marked seasonal behaviour, good results were obtained with Linear Perturbation Model (LPM) which involves the assumption of linearity between the departures from seasonal expectations in input and output series. The application of the GFFS (collection of systems and conceptual models) software proved to be possible with variable efficiencies. The LPM in non-parametric or parametric form, the LVGF model, the ANN and the SMAR model can be used to forecast (reproduce) Ed-deim flows with high performance. Within the range of the tested models LPM was found to be the best candidate model that can forecast the flows under a wide range of conditions of marked seasonality by accounting for more than 90% of the initial variance.

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Abdellatif, M. « Water Balance Modelling for the Sudan's Four Basins of Blue Nile, White Nile, Atbara River, and Main Nile ». Egyptian Journal for Engineering Sciences and Technology 22, n^o 1 (1 février 2017) : 27–34. http://dx.doi.org/10.21608/eijest.2017.97190.

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Meresa, Hadush K., et Mulusew T. Gatachew. « Climate change impact on river flow extremes in the Upper Blue Nile River basin ». Journal of Water and Climate Change 10, n^o 4 (14 mai 2018) : 759–81. http://dx.doi.org/10.2166/wcc.2018.154.

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Abstract This paper aims to study climate change impact on the hydrological extremes and projected precipitation extremes in far future (2071–2100) period in the Upper Blue Nile River basin (UBNRB). The changes in precipitation extremes were derived from the most recent AFROCORDEX climate data base projection scenarios compared to the reference period (1971–2000). The climate change impacts on the hydrological extremes were evaluated using three conceptual hydrological models: GR4 J, HBV, and HMETS; and two objective functions: NSE and LogNSE. These hydrological models are calibrated and validated in the periods 1971–2000 and 2001–2010, respectively. The results indicate that the wet/dry spell will significantly decrease/increase due to climate change in some sites of the region, while in others, there is increase/decrease in wet/dry spell but not significantly, respectively. The extreme river flow will be less attenuated and more variable in terms of magnitude, and more irregular in terms of seasonal occurrence than at present. Low flows are projected to increase most prominently for lowland sites, due to the combined effects of projected decreases in Belg and Bega precipitation, and projected increases in evapotranspiration that will reduce residual soil moisture in Bega and Belg seasons.

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A.M.H., Elhag, Gumaa Y.S.A. et Osman E.H. « Monitoring, Predicting and Quantifying Soil Alkalinity, Sodicity and Salinity in Blue Nile State, Sudan, Using Soil Techniques, Remote Sensing and GIS Analysis ; Case Study : Blue Nile River ». IRA-International Journal of Applied Sciences (ISSN 2455-4499) 11, n^o 3 (1 août 2018) : 37. http://dx.doi.org/10.21013/jas.v11.n3.p2.

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This study focused on the assessment of land degradation on a transect of 20 km along the Blue Nile River (10 km at each side of the river) within the Blue Nile state, Blue Nile State, Sudan. Through mapping and monitoring the changes that occurred in the soil properties, due to Water Erosion, Vegetations degradation, mismanagement in addition to the Human activities and Climatic change The study attempted also to update some information in the study area such as chemical properties using different methods of data transformation and analysis such as: Soil analysis technique, GIS and remote sensing analysis. The research was based on the data and information deduced and extracted from soil survey data, soil analysis, and remote sensed data, in addition to fieldwork verification and other sources. The study covered an area about 346483.43 ha. Soil analysis and data compilation from other sources showed that the soil of the study area witnessed remarkable changes during the study Period (1990 – 2015). The degradations affected the Soil and Vegetations covers of the study area in both side around the Blue Nile River. The analysis indicated that soil degradation was taken place in the study area specially the top west and south east parts of the area which was affected by some buckets of salinity, northern part shown moderate level of acidity while the Part from the south East and South west area shown moderate level of Alkalinity. Assessment and evaluation of the soil of the study area in respect to soil texture revealed that 15% of the total area received some Sand deposits in the study area which it considered the beginning or indicator of soil degradation in the south west and northern part of the study area, while the SAR analysis indicated that all the soils of the study area fell within none sodic class. According to framework of the land suitability (FAO, 1976) revealed that the soil of the study area is moderately suitable (S2) for agriculture.

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Haile, A. T., T. H. M. Rientjes, E. Habib, V. Jetten et M. Gebremichael. « Rain event properties at the source of the Blue Nile River ». Hydrology and Earth System Sciences 15, n^o 3 (24 mars 2011) : 1023–34. http://dx.doi.org/10.5194/hess-15-1023-2011.

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Abstract. In the present study, spatial and temporal patterns of rain event properties are analysed. These event properties are rain event depth, event duration, mean event rain rate, peak rain rate and the time span between two consecutive rain events which is referred to as inter-event time (IET). In addition, we assessed how rain event properties change when the period over which rainfall data is aggregated changes from 1 to 6 min and when the minimum inter-event time (MIT) changes from 30 min to 8 h. Rainfall data is obtained from a field campaign in two wet seasons of June–August (JJA) of 2007 and 2008 in Gilgel Abbay watershed that is situated at the source basin of the Upper Blue Nile River in Ethiopia. The rainfall data was automatically recorded at eight stations. The results revealed that rain event depth is more related to peak rain rate than to event duration. At the start and towards the end of the wet season, the rain events have larger depth with longer duration and longer IET than those in mid-season. Event rain rate and IET are strongly related to terrain elevation. Sekela which is on a mountain area has the shortest IET while Bahir Dar which is at the south shore of Lake Tana has the longest IET. The period over which rainfall data is aggregated significantly affected the values of rain event properties that are estimated using relatively small value (30 min) of MIT but its effect diminished when the MIT is increased to 8 h. It is shown that increasing the value of MIT has the largest effect on rain event properties of mountain stations that are characterised by high rainfall intermittency.

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Tegegne, Getachew, Assefa M. Melesse, Dereje H. Asfaw et Abeyou W. Worqlul. « Flood Frequency Analyses over Different Basin Scales in the Blue Nile River Basin, Ethiopia ». Hydrology 7, n^o 3 (20 juillet 2020) : 44. http://dx.doi.org/10.3390/hydrology7030044.

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The frequency and intensity of flood quantiles and its attendant damage in agricultural establishments have generated a lot of issues in Ethiopia. Moreover, precise estimates of flood quantiles are needed for efficient design of hydraulic structures; however, quantification of these quantiles in data-scarce regions has been a continuing challenge in hydrologic design. Flood frequency analysis is thus essential to reduce possible flood damage by investigating the most suitable flood prediction model. The annual maximum discharges from six representative stations in the Upper Blue Nile River Basin were fitted to the commonly used nine statistical distributions. This study also assessed the performance evolution of the probability distributions with varying spatial scales, such that three different spatial scales of small-, medium-, and large-scale basins in the Blue Nile River Basin were considered. The performances of the candidate probability distributions were assessed using three goodness-of-fit test statistics, root mean square error, and graphical interpretation approaches to investigate the robust probability distribution for flood frequency analysis over different basin spatial scales. Based on the overall analyses, the generalized extreme value distribution was proven to be a robust model for flood frequency analysis in the study region. The generalized extreme value distribution significantly improved the performance of the flood prediction over different spatial scales. The generalized extreme value flood prediction performance improvement measured in root mean square error varied between 5.84 and 67.91% over other commonly used probability distribution models. Thus, the flood frequency analysis using the generalized extreme value distribution could be essential for the efficient planning and design of hydraulic structures in the Blue Nile River Basin. Furthermore, this study suggests that, in the future, significant efforts should be put to conduct similar flood frequency analyses over the other major river basins of Ethiopia.

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Osman, R., F. Alaily, A. Sayed et M. Kaupenjohan. « Investigations on the parent material of soils of two Nile Valleys with different river dynamics (White Nile and Blue Nile) ». CATENA 178 (juillet 2019) : 345–49. http://dx.doi.org/10.1016/j.catena.2019.03.022.

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Mulat, Asegdew G., et Semu A. Moges. « The impacts of Upper Blue Nile Dams construction on agricultural water availability of Sudan ». Water Practice and Technology 15, n^o 2 (23 avril 2020) : 437–49. http://dx.doi.org/10.2166/wpt.2020.031.

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Abstract The objective of this research is assessing water resource availability in the Blue Nile River for different development scenarios using Mike Hydro modeling. The long term Blue Nile total irrigation water demand will be more than 46.67 × 109m3, which is nearly similar to the naturalized flow (around 48 × 109m3). In the phase II irrigation, water shortfalls increase to 0.38 × 109m3/year. There is up to 2.172 × 109m3/year irrigation water deficit at the full development level in Ethiopia. Due to flow regulation, there are no shortfalls in irrigation in Sudan in either the medium or the long-term. Dams located in Ethiopia give more advantage to the Sudanese schemes than that of Ethiopian regarding irrigation development.

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Le, Justin A., Hesham M. El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota et Daniele C. Struppa. « Characterizing El Niño-Southern Oscillation Effects on the Blue Nile Yield and the Nile River Basin Precipitation using Empirical Mode Decomposition ». Earth Systems and Environment 4, n^o 4 (29 novembre 2020) : 699–711. http://dx.doi.org/10.1007/s41748-020-00192-4.

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AbstractUsing new mathematical and data-driven techniques, we propose new indices to measure and predict the strength of different El Niño events and how they affect regions like the Nile River Basin (NRB). Empirical Mode Decomposition (EMD), when applied to Southern Oscillation Index (SOI), yields three Intrinsic Mode Functions (IMF) tracking recognizable and physically significant non-stationary processes. The aim is to characterize underlying signals driving ENSO as reflected in SOI, and show that those signals also meaningfully affect other physical processes with scientific and predictive utility. In the end, signals are identified which have a strong statistical relationship with various physical factors driving ENSO variation. IMF 6 is argued to track El Niño and La Niña events occurrence, while IMFs 7 and 8 represent another signal, which reflects on variations in El Niño strength and variability between events. These we represent an underlying inter-annual variation between different El Niño events. Due to the importance of the latter, IMFs 7 and 8, are defined as Interannual ENSO Variability Indices (IEVI) and referred to as IEVI α and IEVI β. EMD when applied to the NRB precipitation, affecting the Blue Nile yield, identifying the IEVI-driven IMFs, with high correlations of up to ρ = 0.864, suggesting a decadal variability within NRB that is principally driven by interannual decadal-scale variability highlighting known geographical relationships. Significant hydrological processes, driving the Blue Nile yield, are accurately identified using the IEVI as a predictor. The IEVI-based model performed significantly at p = 0.038 with Blue Nile yield observations.

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Nigussie, Getenet, Mamaru A. Moges, Michael M. Moges et Tammo S. Steenhuis. « Assessment of Suitable Land for Surface Irrigation in Ungauged Catchments : Blue Nile Basin, Ethiopia ». Water 11, n^o 7 (15 juillet 2019) : 1465. http://dx.doi.org/10.3390/w11071465.

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Planning and decision making for new irrigation development projects requires the systematic assessment of irrigable land together with available water resources. The data required are usually not available in developing countries, and therefore a method was developed for quantifying surface water resources and potentially irrigable land in ungauged watersheds in the Upper Blue Nile Basin using Soil and Water Assessment Tool (SWAT) model and Multi-Criterion Decision Evaluation (MCDE). The method was tested using the Lah river basin in the Jabitenan district and then applied in the whole area, including ungauged areas. In MCDE, soil type, slope, land use, and river proximity were considered. Onion, Cabbage and Tomato were grown on the identified irrigable areas. The predicted monthly stream discharge agreed well with observed values, with Nash and Sutcliffe efficiencies of 0.87 during calibration and 0.68 for validation. The SWAT model calibrated parameters from the gauged catchment were used to simulate the discharge of the ungauged catchments. The potential irrigable land was determined in Jabitenan woreda and included the Rivers like Birr, Tikurwuha, Gunagun, Leza Lah, Geray, Arara, Debolah, Guysa, and Silala, with an area of 460 km2. By evaluating gross irrigation demand of irrigable land with available flow in rivers (both observed and simulated), the actual surface irrigation potential was 47 km2. The main limitation for surface irrigation in all districts was the available water and not the land suitable for irrigation. Therefore, the study suggests that in order to irrigate a greater portion of the irrigable land, water should be stored during the monsoon rain phase for use in the last part of the dry phase.

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Muluneh, T., et W. Mamo. « Morphometric Analysis of Didessa River Catchment in Blue Nile Basin, Western Ethiopia ». Science, Technology and Arts Research Journal 3, n^o 3 (18 novembre 2014) : 191. http://dx.doi.org/10.4314/star.v3i3.31.

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Tabari, Hossein, Meron Teferi Taye et Patrick Willems. « Statistical assessment of precipitation trends in the upper Blue Nile River basin ». Stochastic Environmental Research and Risk Assessment 29, n^o 7 (18 février 2015) : 1751–61. http://dx.doi.org/10.1007/s00477-015-1046-0.

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Mengistu, D. T., et A. Sorteberg. « Validation of SWAT simulated streamflow in the Eastern Nile and sensitivity to climate change ». Hydrology and Earth System Sciences Discussions 8, n^o 5 (5 octobre 2011) : 9005–62. http://dx.doi.org/10.5194/hessd-8-9005-2011.

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Abstract. The hydrological model SWAT was calibrated with daily station based precipitation and temperature data for the whole Eastern Nile basin including the three subbasins: the Blue Nile, Baro Akobo and Tekeze. The daily and monthly streamflow was calibrated and validated at six outlets in the three different subbasins. The model performed very well in simulating the monthly variability of the Eastern Nile streamflow while comparison to daily data revealed a more diverse performance for the extreme events. Of the Eastern Nile average annual rainfall it was estimated that around 60% is lost through evaporation and estimated runoff coefficients were 0.24, 0.30 and 0.18 for Blue Nile, Baro Akobo and Tekeze subbasins, respectively. About half to two-thirds of the runoff could be attributed to surface runoff while the remaining contributions were from groundwater. The annual streamflow sensitivity to changes in precipitation and temperature differed among the basins and the dependence of the response on the strength of the changes was not linear. On average the annual streamflow responses to a change in precipitation with no temperature change was 19%, 17%, and 26% per 10% change in precipitation while the average annual streamflow responses to a change in temperature and no precipitation change was −4.4% K−1, −6.4% K−1, and −1.3% K−1 for Blue Nile, Baro Akobo and Tekeze river basin, respectively. While we show the Eastern Nile to be very sensitive to precipitation changes, using 47 temperature and precipitation scenarios from 19 AOGCMs participating in IPCC AR4 we estimated the future change in streamflow to be strongly dependent on the choice of climate model as the climate models disagree on both the strength and the direction of future precipitation changes. Thus, no clear conclusions can be made about the future changes in Eastern Nile streamflow.

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Betrie, G. D., Y. A. Mohamed, A. van Griensven et R. Srinivasan. « Sediment management modelling in the Blue Nile Basin using SWAT model ». Hydrology and Earth System Sciences 15, n^o 3 (8 mars 2011) : 807–18. http://dx.doi.org/10.5194/hess-15-807-2011.

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Abstract. Soil erosion/sedimentation is an immense problem that has threatened water resources development in the Nile river basin, particularly in the Eastern Nile (Ethiopia, Sudan and Egypt). An insight into soil erosion/sedimentation mechanisms and mitigation methods plays an imperative role for the sustainable water resources development in the region. This paper presents daily sediment yield simulations in the Upper Blue Nile under different Best Management Practice (BMP) scenarios. Scenarios applied in this paper are (i) maintaining existing conditions, (ii) introducing filter strips, (iii) applying stone bunds (parallel terraces), and (iv) reforestation. The Soil and Water Assessment Tool (SWAT) was used to model soil erosion, identify soil erosion prone areas and assess the impact of BMPs on sediment reduction. For the existing conditions scenario, the model results showed a satisfactory agreement between daily observed and simulated sediment concentrations as indicated by Nash-Sutcliffe efficiency greater than 0.83. The simulation results showed that applying filter strips, stone bunds and reforestation scenarios reduced the current sediment yields both at the subbasins and the basin outlets. However, a precise interpretation of the quantitative results may not be appropriate because some physical processes are not well represented in the SWAT model.

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Keshta, Eatemad, Mohamed A. Gad et Doaa Amin. « A Long–Term Response-Based Rainfall-Runoff Hydrologic Model : Case Study of The Upper Blue Nile ». Hydrology 6, n^o 3 (15 août 2019) : 69. http://dx.doi.org/10.3390/hydrology6030069.

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This study develops a response-based hydrologic model for long-term (continuous) rainfall-runoff simulations over the catchment areas of big rivers. The model overcomes the typical difficulties in estimating infiltration and evapotranspiration parameters using a modified version of the Soil Conservation Service curve number SCS-CN method. In addition, the model simulates the surface and groundwater hydrograph components using the response unit-hydrograph approach instead of using a linear reservoir routing approach for routing surface and groundwater to the basin outlet. The unit-responses are Geographic Information Systems (GIS)-pre-calculated on a semi-distributed short-term basis and applied in the simulation in every time step. The unit responses are based on the time-area technique that can better simulate the real routing behavior of the basin. The model is less sensitive to groundwater infiltration parameters since groundwater is actually controlled by the surface component and not the opposite. For that reason, the model is called the SCHydro model (Surface Controlled Hydrologic model). The model is tested on the upper Blue Nile catchment area using 28 years daily river flow data set for calibration and validation. The results show that SCHydro model can simulate the long-term transforming behavior of the upper Blue Nile basin. Our initial assessment of the model indicates that the model is a promising tool for long-term river flow simulations, especially for long-term forecasting purposes due to its stability in performing the water balance.

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Mekonnen, Dagnenet Fenta, Zheng Duan, Tom Rientjes et Markus Disse. « Analysis of combined and isolated effects of land-use and land-cover changes and climate change on the upper Blue Nile River basin's streamflow ». Hydrology and Earth System Sciences 22, n^o 12 (30 novembre 2018) : 6187–207. http://dx.doi.org/10.5194/hess-22-6187-2018.

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Abstract. Understanding responses by changes in land use and land cover (LULC) and climate over the past decades on streamflow in the upper Blue Nile River basin is important for water management and water resource planning in the Nile basin at large. This study assesses the long-term trends of rainfall and streamflow and analyses the responses of steamflow to changes in LULC and climate in the upper Blue Nile River basin. Findings of the Mann–Kendall (MK) test indicate statistically insignificant increasing trends for basin-wide annual, monthly, and long rainy-season rainfall but no trend for the daily, short rainy-season, and dry season rainfall. The Pettitt test did not detect any jump point in basin-wide rainfall series, except for daily time series rainfall. The findings of the MK test for daily, monthly, annual, and seasonal streamflow showed a statistically significant increasing trend. Landsat satellite images for 1973, 1985, 1995, and 2010 were used for LULC change-detection analysis. The LULC change-detection findings indicate increases in cultivated land and decreases in forest coverage prior to 1995, but forest area increases after 1995 with the area of cultivated land that decreased. Statistically, forest coverage changed from 17.4 % to 14.4%, by 12.2 %, and by 15.6 %, while cultivated land changed from 62.9 % to 65.6 %, by 67.5 %, and by 63.9 % from 1973 to 1985, in 1995, and in 2010, respectively. Results of hydrological modelling indicate that mean annual streamflow increased by 16.9 % between the 1970s and 2000s due to the combined effects of LULC and climate change. Findings on the effects of LULC change on only streamflow indicate that surface runoff and base flow are affected and are attributed to the 5.1 % reduction in forest coverage and a 4.6 % increase in cultivated land areas. The effects of climate change only revealed that the increased rainfall intensity and number of extreme rainfall events from 1971 to 2010 significantly affected the surface runoff and base flow. Hydrological impacts by climate change are more significant as compared to the impacts of LULC change for streamflow of the upper Blue Nile River basin.

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M. Abbas, Mohamed, Abdin M. A. Salih, Adil M. Elkider et Salih H. Hamid. « Hydrological Analysis and Trans-boundary Water Management of the Blue Nile River Basin ». Journal of Water Resource and Hydraulic Engineering 6, n^o 4 (30 décembre 2017) : 64–71. http://dx.doi.org/10.5963/jwrhe0604001.

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Elzeiny, Radwa, Mossad Khadr, Shreen Zahran et Ebrahim Rashwan. « Homogeneity Analysis of Rainfall Series in the Upper Blue Nile River Basin, Ethiopia ». Journal of Engineering Research 3, n^o 9 (1 septembre 2019) : 46–53. http://dx.doi.org/10.21608/erjeng.2019.125704.

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Bokke, Andualem Shigute, Meron Teferi Taye, Patrick Willems et Shimelis Asefu Siyoum. « Validation of General Climate Models (GCMs) over Upper Blue Nile River Basin, Ethiopia ». Atmospheric and Climate Sciences 07, n^o 01 (2017) : 65–75. http://dx.doi.org/10.4236/acs.2017.71006.

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Balthazar, Vincent, Veerle Vanacker, Atkilt Girma, Jean Poesen et Semunesh Golla. « Human impact on sediment fluxes within the Blue Nile and Atbara River basins ». Geomorphology 180-181 (janvier 2013) : 231–41. http://dx.doi.org/10.1016/j.geomorph.2012.10.013.

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Hussein Mohamed Ali, Ali, et Aws Zakaria Basheer Emam. « Rehabilitation of Blue Nile Steel Bridge Superstructure : Fatigue Assessment ». FES Journal of Engineering Sciences 9, n^o 1 (22 février 2021) : 20–29. http://dx.doi.org/10.52981/fjes.v9i1.653.

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The Blue Nile Steel Bridge over the Blue Nile River in Khartoum, Sudan, has been in service for 112 years. A riveted steel through-truss of Pettit Configuration with seven equal fixed spans of 65.53 m and a rolling lift span. The bridge currently accommodates approximately 61,000 vehicles per day along with insignificant pedestrian and railway traffic. Over the years from 1960 to 2014 several assessment studies were carried out by numerous parties have revealed that under cyclic loading of a long period time and effects of natural and man-made disasters, bridge deck was damaged severely and needed to be repaired and strengthened. A rehabilitation program was planned to extend the design life of the bridge for a more 50 years, which was carried out in period (2017 - 2018).This paper presents as a case study including a literature review on fatigue assessment of stringers on railway track. The rationale for selecting the rehabilitation strategy for the bridge is described, highlighting the challenging design aspects related to fatigue assessment, clarifying the methodology in which main members were identified for strengthening, using Midas Civil 2006 v7.01 and Midas FEA 2016 v1.1software to analyze the fatigue in the critical members by generating a model using Finite Element Method and estimating remaining fatigue life by adopting the classical approach (Stress-life method), the total damage accumulation was found greater than 1. Thus, it can be concluded that the stringers have no remaining fatigue life. Strengthening the stringers is considered the most favorable solution.

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Mohieldeen, Yasir Elginiad. « More water flows from Western Sudan as virtual water than the flow of the River Nile in former Sudan ». Water Policy 18, n^o 3 (28 octobre 2015) : 533–44. http://dx.doi.org/10.2166/wp.2015.130.

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This study argues that by mobilising ‘social resources’, communities in water-scarce, semi-arid areas can not only successfully sustain a livelihood, but they can also play an important role in the water budget of their semi-arid regions. The pastoralist communities in the Darfur region of west Sudan utilise the limited volumes of green – root-zone – water in the soil to rear livestock. They have for centuries developed and adopted a very adaptive management system that has enabled them to utilise the green water of the Nile Basin. The embedded green water in livestock totals more than Sudan's annual share – 18.5 km3 – of the Nile River flow allocated to it by the 1959 Nile Waters Agreement. This study has revealed that this embedded ‘virtual water’ amounts to 37.6 km3. Results show that this silent, unrecognised, green water has been providing a solution to the water requirements of the Nile economies. It has been suggested that if Western Sudan's livestock were to be produced using fresh/blue water from the Nile, the national water balance of the Sudan would be very seriously impacted and the economy would be much less secure than it has been for the past half century.

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Wondimagegnehu, D., et K. Tadele. « Evaluation of climate change impact on Blue Nile Basin Cascade Reservoir operation – case study of proposed reservoirs in the Main Blue Nile River Basin, Ethiopia ». Proceedings of the International Association of Hydrological Sciences 366 (10 avril 2015) : 133. http://dx.doi.org/10.5194/piahs-366-133-2015.

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Abstract. This study mainly deals with evaluation of climate change impact on operation of the Blue Nile Basin Cascade Reservoir. To evaluate the impact of climate change, climate change scenarios of evapotranspiration and precipitation were developed for three periods. Output of ECHAM5 with RCM for the A1B emissions scenario were used to develop the future climate change scenarios. A hydrological model, HEC-HMS, was used to simulate current and future inflow volume to the reservoirs. The projected future climate shows an increasing trend in both maximum and minimum temperature and in evapotranspiration, but precipitation shows a fluctuating trend in the next century. Relative to the current condition, the average annual open water evaporation for the Beko-Abo and Mandaya reservoirs show increasing trend whereas the Border Reservoir shows a decreasing trend. Comparison of the base period and the future period average annual inflow volume shows an increase for Beko-Abo and Mandaya, but at Border Reservoir a decrease in volume is observed. The average annual power generation projected using HEC-ReSim also shows an increase at the Beko-Abo and Mandaya hydropower station, whereas a slight decrease occurs for Border hydropower station. On average, the time based and volumetric reliability of the reservoirs was estimated to be more than 90%. The resilience of the reservoirs is below 50% and their vulnerability is less than 50%. Therefore, these performance indices reveal good performance of the reservoirs except regarding the speed of recovery of the reservoirs from failure because the reservoirs will not able to recover rapidly from failure to a safe state.

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Eldaw, Elsiddig, Tao Huang, Adam Khalifa Mohammed et Yahaya Muhama. « Stochastic Time series analysis of Runoff data of the Blue Nile at Eldeim, Sudan ». E3S Web of Conferences 81 (2019) : 01005. http://dx.doi.org/10.1051/e3sconf/20198101005.

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To improve the management of operation system for the Roseires reservoir it is necessary to know the hydrological system of the Blue Nile river, which is the main water source of the reservoir. In this work, a Modified Thomas Fiering model for generating and forecasting monthly flow is used. The methodological procedure is applied on the data obtained at the gauging station of Eldeim in Blue Nile, Sudan. The study uses the monthly flows data for years 1965 to 2009. After estimation the model parameters, the synthetic time series of monthly flows are simulated. The results revealed that the model maintained most of the basic statistical descriptive parameters of historical data. Also, the Modified Thomas Fiering model is applied to predict the values of the next fifty-five years, with excellent results that conserved most basic statistical characteristics of runoff historical series. The Modified Thomas Fiering model is able to realistically reconstruct and predict the annual data and shows promising statistical indices.

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Bombelli, Giovanni, Stefano Tomiet, Alberto Bianchi et Daniele Bocchiola. « Impact of Prospective Climate Change Scenarios upon Hydropower Potential of Ethiopia in GERD and GIBE Dams ». Water 13, n^o 5 (6 mars 2021) : 716. http://dx.doi.org/10.3390/w13050716.

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Ethiopia is growing fast, and the country has a dire need of energy. To avoid environmental damages, however, Ethiopia is looking for green energy polices, including hydropower exploitation, with large water availability (i.e., the Blue Nile, the greatest tributary of Nile river). Besides other dams on the Omo river, the GIBE family, Ethiopia is now building the largest hydropower plant of Africa, the GERD (Grand Ethiopian Renaissance Dam), on the Blue Nile river, leading to tensions between Ethiopia, and Egypt, due to potentially conflictive water management. In addition, present and prospective climate change may affect reservoirs’ operation, and this thereby is relevant for downstream water users, population, and environment. Here, we evaluated water management for the GERD, and GIBE III dams, under present, and future hydrological conditions until 2100. We used two models, namely, Poli-Hydro and Poli-Power, to describe (i) hydrological budget, and flow routing and (ii) optimal/maximum hydropower production from the two dams, under unconstrained (i.e., no release downstream besides MIF) and constrained (i.e., with fair release downstream) simulation. We then used climate change scenarios from the reports CMIP5/6 of the Intergovernmental Panel on Climate Change (IPCC) until 2100, to assess future hydropower production. Our results demonstrate that the filling phase of the GERD, particularly critical, have optimal filling time of 5 years or so. Stream flows at GERD could be greater than the present ones (control run CR) at half century (2050–2059), but there could be large decrease at the end of century (2090–2099). Energy production at half century may increase, and then decrease until the end of century. In GIBE III discharges would increase both at half century, and at the end of century, and so would energy production. Constrained, and unconstrained simulation provide in practice similar results, suggesting potential for shared water management in both plants.

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Tan, Cho, Tohid Erfani et Rasool Erfani. « Water for Energy and Food : A System Modelling Approach for Blue Nile River Basin ». Environments 4, n^o 1 (9 février 2017) : 15. http://dx.doi.org/10.3390/environments4010015.

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Koukoula, Marika, Efthymios I. Nikolopoulos, Zoi Dokou et Emmanouil N. Anagnostou. « Evaluation of Global Water Resources Reanalysis Products in the Upper Blue Nile River Basin ». Journal of Hydrometeorology 21, n^o 5 (mai 2020) : 935–52. http://dx.doi.org/10.1175/jhm-d-19-0233.1.

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AbstractWater resources reanalysis (WRR) can be used as a numerical tool to advance our understanding of hydrological processes where in situ observations are limited. However, WRR products are associated with uncertainty that needs to be quantified to improve usability of such products in water resources applications. In this study, we evaluate estimates of water cycle components from 18 state-of-the-art WRR datasets derived from different land surface/hydrological models, meteorological forcing, and precipitation datasets. The evaluation was conducted at three spatial scales in the upper Blue Nile basin in Ethiopia. Precipitation, streamflow, evapotranspiration (ET), and terrestrial water storage (TWS) were evaluated against in situ daily precipitation and streamflow measurements, remote sensing–derived ET, and the NASA Gravity Recovery and Climate Experiment (GRACE) product, respectively. Our results highlight the current strengths and limitations of the available WRR datasets in analyzing the hydrological cycle and dynamics of the study basins, showing an overall underestimation of ET and TWS and overestimation of streamflow. While calibration improves streamflow simulation, it results in a relatively poorer performance in terms of ET. In addition, we show that the differences in the schemes used in the various land surface models resulted in significant differences in the estimation of the water cycle components from the respective WRR products, while we noted small differences among the products related to precipitation forcing. We did not identify a single product that consistently outperformed others; however, we found that there are specific WRR products that provided accurate representation of a single component of the water cycle (e.g., only runoff) in the area.

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Abate, Mengiste, Jan Nyssen, Tammo S. Steenhuis, Michael M. Moges, Seifu A. Tilahun, Temesgen Enku et Enyew Adgo. « Morphological changes of Gumara River channel over 50 years, upper Blue Nile basin, Ethiopia ». Journal of Hydrology 525 (juin 2015) : 152–64. http://dx.doi.org/10.1016/j.jhydrol.2015.03.044.

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Mortazavi, S. S., R. Sahraei et A. Farmany. « Silver nanoparticle-based spectrophotometric method for quantification of nile blue A in river water ». Journal of Industrial and Engineering Chemistry 20, n^o 4 (juillet 2014) : 1581–83. http://dx.doi.org/10.1016/j.jiec.2013.08.001.

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Kim, Ungtae, et Jagath J. Kaluarachchi. « Climate Change Impacts on Water Resources in the Upper Blue Nile River Basin, Ethiopia1 ». JAWRA Journal of the American Water Resources Association 45, n^o 6 (29 septembre 2009) : 1361–78. http://dx.doi.org/10.1111/j.1752-1688.2009.00369.x.

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Abdel-Aziz, Osama R. « Flood forecasting in Blue Nile basin using a process-based hydrological model ». International Journal of Environment 3, n^o 1 (28 février 2014) : 10–21. http://dx.doi.org/10.3126/ije.v3i1.9938.

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Predictions of variations in global and regional hydrological cycles and their response to changes in climate and the environment are key problems for future human life. Therefore, basin-scale hydrological forecasts, along with predictions regarding future climate change, are needed in areas with high flood potential. This study forecasts hydrological process scenarios in Blue Nile basin using a distributed hydrological model (DHM) and predicted scenarios of precipitation from two general circulation models, CCSM3 model and Miroc3.2-hires. Firstly, river discharge was simulated by the DHM using the observed rainfall from 1976 to 1979 and then, simulating future precipitations from 2011 to 2040, discharge scenarios were predicted. DOI: http://dx.doi.org/10.3126/ije.v3i1.9938 International Journal of Environment Vol.3(1) 2014: 10-21

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Mohamed, Y. A., B. J. J. M. van den Hurk, H. H. G. Savenije et W. G. M. Bastiaanssen. « Hydroclimatology of the Nile : results from a regional climate model ». Hydrology and Earth System Sciences Discussions 2, n^o 1 (10 février 2005) : 319–64. http://dx.doi.org/10.5194/hessd-2-319-2005.

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Abstract. This paper is the result of the first regional coupled climatic and hydrologic model of the Nile. For the first time the interaction between the climatic processes and the hydrological processes on the land surface have been fully coupled. The hydrological model is driven by the rainfall and the energy available for evaporation generated in the climate model, and the runoff generated in the catchment is again routed over the wetlands of the Nile to supply moisture for atmospheric feedback. The results obtained are surprisingly accurate given the extremely low runoff coefficients in the catchment. The paper presents model results over the sub-basins: Blue Nile, White Nile, Atbara river and the Main Nile for the period 1995 to 2000, but focuses on the Sudd swamp. Limitations in both the observational data and the model are discussed. It is concluded that the model provides a sound representation of the regional water cycle over the Nile. The model is used to describe the regional water cycle in the Nile basin in terms of atmospheric fluxes, land surface fluxes and land surface-climate feedbacks. The monthly moisture recycling ratio (i.e. locally generated/total precipitation) over the Nile varies between 8 and 14%, with an annual mean of 11%, which implies that 89% of the Nile water resources originates from outside the basin physical boundaries. The monthly precipitation efficiency varies between 12 and 53%, and the annual mean is 28%. The mean annual result of the Nile regional water cycle is compared to that of the Amazon and the Mississippi basins.

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Dessie, M., N. E. C. Verhoest, V. R. N. Pauwels, T. Admasu, J. Poesen, E. Adgo, J. Deckers et J. Nyssen. « Analyzing runoff processes through conceptual hydrological modeling in the Upper Blue Nile Basin, Ethiopia ». Hydrology and Earth System Sciences 18, n^o 12 (12 décembre 2014) : 5149–67. http://dx.doi.org/10.5194/hess-18-5149-2014.

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Abstract. Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data-scarce regions such as the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall–runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile Basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall–runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile Basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44–48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18–19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics the rainfall–runoff process in the Upper Blue Nile Basin well and yields a useful result for operational management of water resources in this data-scarce region.

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