Grand Ethiopian Renaissance Dam Analysis

The Integrated Human Futures Project provides a set of analytical and quantitative modeling and simulation tools that help explore the links among human social, economic, and ecological conditions, human resilience, conflict, and peace, and allows users to simulate tradeoffs and consequences associated with different future development and mitigation scenarios. In the current study, we integrate five distinct modeling platforms to simulate the potential risk of social unrest in Egypt resulting from the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia. The five platforms simulate hydrology, agriculture, economy, human ecology, and human psychology/behavior, and show how impacts derived from development initiatives in one sector (e.g., hydrology) might ripple through to affect other sectors and how development and security concerns may be triggered across the region. This approach evaluates potential consequences, intended and unintended, associated with strategic policy actions that span the development-security nexus at the national, regional, and international levels. Model results are not intended to provide explicit predictions, but rather to provide system-level insight for policy makers into the dynamics among these interacting sectors, and to demonstrate an approach to evaluating short- and long-term policy trade-offs across different policy domains and stakeholders. The GERD project is critical to government-planned development efforts in Ethiopia but is expected to reduce downstream freshwater availability in the Nile Basin, fueling fears of negative social and economic impacts that could threaten stability and security in Egypt. We tested these hypotheses and came to the following preliminary conclusions. First, the GERD will have an important short-term impact on water availability, food production, and hydropower production in Egypt, depending on the short- term reservoir fill rate. Second, the GERD will have a very small impact on water availability in the Nile Basin over the longer term. Depending on the GERD fill rate, short-term (e.g., within its first 5 years of operation) annual losses in Egyptian food production may peak briefly at 25 percent. Long-term (e.g., 15 to 30 year) cumulative losses in Egypt's food production may be less than 3 percent regardless of the fill rate, with the GERD having essentially no impact on projected annual food production in Egypt about 25 years after opening. For the quick fill rates, the short-term losses may be sufficient to create an important decrease in overall household health among the general population, which, along with other economic stressors and different strategies employed by the government, could lead to social unrest. Third, and perhaps most importantly, our modeling suggests that the GERD's effect on Egypt's food and water resources is small when compared to the effect of projected Egyptian population and economic growth (and the concomitant increase in water consumption). The latter dominating factors are exacerbated in the modeling by natural climate variability and may be further exacerbated by climate change. Our modeling suggests that these growth dynamics combine to create long-term water scarcity in Egypt, regardless of the Ethiopian project. All else being equal, filling strategies that employ slow fill rates for the GERD (e.g., 8 to 13 years) may mitigate the risks in future scenarios for Egypt somewhat, but no policy or action regarding the GERD is likely to significantly alleviate the projected water scarcity in Egypt's Nile Basin. However, general beliefs among the Egyptian populace regarding the GERD as a major contributing factor for scarcities in Egypt could make Ethiopia a scapegoat for Egyptian grievances -- contributing to social unrest in Egypt and generating undesirable (and unnecessary) tension between these two countries. Such tension could threaten the constructive relationships between Egypt and Ethiopia that are vital to maintaining stability and security within and between their respective regional spheres of influence, Middle East and North Africa, and the Horn of Africa.

Abstract. The filling of the Grand Ethiopian Renaissance Dam (GERD) started in 2020, posing additional challenges for downstream water management in the Blue Nile River in the Republic of the Sudan, which is already struggling to cope with the effects of climate change. This is also the case for many transboundary rivers that are affected by a lack of cooperation and transparency during the filling and operation of new dams. Without information about water supply from neighboring countries, it is risky to manage downstream dams as usual, but operational information is needed to apply modifications. This study aims to develop a novel approach/framework that utilizes hydrological modeling in conjunction with remote-sensing data to retrieve reservoir filling strategies under limited-data-availability conditions. Firstly, five rainfall products (i.e., ARC2, CHIRPS, ERA5, GPCC, and PERSIANN-CDR; see Sect. 2.3 for more information) were evaluated against historical measured rainfall at 10 stations. Secondly, to account for input uncertainty, the three best-performing rainfall products were forced in the conceptual hydrological model HBV-light with potential evapotranspiration and temperature data from ERA5. The model was calibrated during the period from 2006 to 2019 and validated during the period from 1991 to 1996. Thirdly, the parameter sets that obtained very good performance (Nash–Sutcliffe efficiency, NSE, greater than 0.75) were utilized to predict the inflow of GERD during the operation period (2020–2022). Then, from the water balance of GERD, the daily storage was estimated and compared with the storage derived from Landsat and Sentinel imageries to evaluate the performance of the selected rainfall products and the reliability of the framework. Finally, 3 years of GERD filling strategies was retrieved using the best-performing simulation of CHIRPS with an RMSE of 1.7 ×109 and 1.52 ×109m3 and an NSE of 0.77 and 0.86 when compared with Landsat- and Sentinel-derived reservoir storage, respectively. It was found that GERD stored 14 % of the monthly inflow of July 2020; 41 % of July 2021; and 37 % and 32 % of July and August 2022, respectively. Annually, GERD retained 5.2 % and 7.4 % of the annual inflow in the first two filling phases and between 12.9 % and 13.7 % in the third phase. The results also revealed that the retrieval of filling strategies is more influenced by input uncertainty than parameter uncertainty. The retrieved daily change in GERD storage with the measured outflow to the Republic of the Sudan allowed further interpretation of the downstream impacts of GERD. The findings of this study provide systematic steps to retrieve filling strategies, which can serve as a base for future development in the field, especially for data-scarce regions. Locally, the analysis contributes significantly to the future water management of the Roseires and Sennar dams in the Republic of the Sudan.

The Grand Ethiopian Renaissance Dam (GERD), formerly known as the Millennium Dam, has been filling at a fast rate. This project has created issues for the Nile Basin countries of Egypt, Sudan, and Ethiopia. The filling of GERD has an impact on the Nile Basin hydrology and specifically the water storages (lakes/reservoirs) and flow downstream. In this study, through the analysis of multi-source satellite imagery, we study the filling of the GERD reservoir. The time-series generated using Sentinel-1 SAR imagery displays the number of classified water pixels in the dam from early June 2017 to September 2020, indicating a contrasting trend in August and September 2020 for the upstream/downstream water bodies: upstream of the dam rises steeply, while downstream decreases. Our time-series analysis also shows the average monthly precipitation (derived using IMERG) in the Blue Nile Basin in Ethiopia has received an abnormally high amount of rainfall as well as a high amount of runoff (analyzed using GLDAS output). Simultaneously, the study also demonstrates the drying trend downstream at Lake Nasser in Southern Egypt before December 2020. From our results, we estimate that the volume of water at GERD has already increased by 3.584 billion cubic meters, which accounts for about 5.3% of its planned capacity (67.37 billion cubic meters) from 9 July–30 November 2020. Finally, we observed an increasing trend in GRACE anomalies for GERD, whereas, for the Lake Nasser, we observed a decreasing trend. In addition, our study discusses potential interactions between GERD and the rainfall and resulting flood in Sudan. Our study suggests that attention should be drawn to the connection between the GERD filling and potential drought in the downstream countries during the upcoming dry spells in the Blue Nile River Basin. This study provides an open-source technique using Google Earth Engine (GEE) to monitor the changes in water level during the filling of the GERD reservoir. GEE proves to be a powerful as well as an efficient way of analyzing computationally intensive SAR images.

About 98 percent of the annual sediments are carried by the Nile during the flood season. Most of these sediments are eroded from the Blue Nile high lands (about 82%). Since the grand Ethiopian renaissance dam (GERD) start to store the flooding water and sediment during this year, then sediment that will be stored by this dam will effect strongly on the life span of Aswan high dam reservoir (AHDR). The objective of this research is to determine the life span of AHDR with respect to the new regulation of the Nile Basin's water and sediment discharge, after the construction of GERD.Volume of sediment for the Blue Nile basin was determined by using remote sensing techniques and by the aid of hydrological model, watershed storm hydrograph model (WASHMO) that was established by Andy Ward 1986. Hydrological parameters for 15 sub basin were extracted from digital elevation model (DEM) of Shuttle Topographic Radar Mission. Other parameters that concerns rainfall, soil characteristics and land covers were collected from Atlas of the Blue Nile Basin (Yilma and Awulachew, 2009) and inserted in the mentioned model in order to determine sediment yield from the Blue Nile Watershed.Life Span of Aswan High Dam Reservoir (AHDR) was studied by many researchers during the last three decades of the last century. There results obtained on the basis of different studies and according to many approaches. It ranges from 362 years to 365 years (Shalash,1980, Makary;1982 and Moussa;1985). According to the volume of sediment that will be retained by grand Ethiopian renaissance dam and found to be 57.50 X 106 m3 for one storm/year .Then the life span of Aswan Reservoir can be estimated according to the establishment of this dam.

The knowledge of the behavior of any roller compacted concrete (RCC) dam and its foundation is gained by studying the service action of the dam and its foundation using measurements of an external and internal nature. The information by which a continuing assurance of structural safety of the RCC dam can be gauged is of primary importance. Similarly, the fact that the information on structural and thermal behavior and the properties of concrete that may be used to give added criteria for use in the design of future RCC dams is of secondary importance. Wide spread attention is now being given to the installation of more expensive instrumentation for studying the behavior of concrete dams and reservoirs and forecasting of any adverse trends. In view of this, the paper traces installation and need of the comprehensive instrumentation scheme implemented to monitor the structural and thermal behavior of 102.4 m high RCC dam constructed near Mumbai in India. An attempt is made in the present paper to emphasize the need to undertake an instrumentation program and evaluate their performance during construction and post construction stage of RCC structures. Few typical results, regarding the thermal and structural behavior of the dam, obtained through instrumentation installed at the dam site are presented and compared with the design considerations. The fair agreement is seen in the response observed through instrumentation with that governing the design criteria.

The Grand Ethiopian Renaissance Dam (GERD) is estimated to cost close to 5 billion US dollars, about 7% of the of the 2016 Ethiopian gross national product. The lack of international finance for projects on the Blue Nile River have had long been alleged to Egypt’s persistent campaign to maintain presumed hegemony on the Nile water share. Ethiopia is forced to finance the GERD with crowd funding through internal fund raising in the form of selling bond and persuading employees to contribute a portion of their incomes. Despite the domestic success in fund raising, the contribution of Ethiopians and Ethiopian descent living abroad was met with scepticism due to the political environment in Ethiopia. The Chinese government is providing significant amount of international finance to the hydropower infrastructure. Gulf States were also claimed to contribute to the construction of the Dam along the Middle East political line with respect to their relationship with Egypt. Opposition to the government is intertwined with opposition to the fund raising for the dam. The dam is completed over 70% by the end of 2017 and strain of cash is being reported. The successful completion of GERD without explicit support from western financial institutions will have a significant impact on the perception and awareness of Nile water development. The parallels between the planning, construction and financing of High Aswan dam and GERD are stark reminders of critical role of international community to promote co-operation and avoid unintended and lasting ripples on the socio-economic and political landscape of the region.

The roller compacted concrete gravity dam is poured by thin layers and there are many horizontal layer surfaces and joint surfaces in the dam. The shear strength of these surfaces is obviously lower than that of the RCC concrete. These horizontal layer surfaces and joint surface are the key positions affecting the strength, stability and seepage of the dam. The height of the most RCC gravity dams is about 100m. The height is relatively low and the horizontal thrust is relatively small. So anti-sliding stability issue along the layer surfaces has not attracted enough attention. But for the dams 200m high, this problem is very prominent. In this study, using an isotropic damage model, based on the effective stress principle of porous media, taking the stress-seepage-damage coupling effect into account, the failure mechanism of Huangdeng RCC gravity dam is discussed. The results show that the failure mechanism of RCC gravity dam is the shear slipping along the layer surfaces and the foundation surface.

Increased demands for sustainable water and energy resources in densely populated basins have led to the construction of dams, which impound waters in artificial reservoirs. In many cases, scarce field data led to the development of models that underestimated the seepage losses from reservoirs and ignored the role of extensive fault networks as preferred pathways for groundwater flow. We adopt an integrated approach (remote sensing, hydrologic modeling, and field observations) to assess the magnitude and nature of seepage from such systems using the Grand Ethiopian Renaissance Dam (GERD), Africa's largest hydropower project, as a test site. The dam was constructed on the Blue Nile within steep, highly fractured, and weathered terrain in the western Ethiopian Highlands. The GERD Gravity Recovery and Climate Experiment Terrestrial Water Storage (GRACETWS), seasonal peak difference product, reveals significant mass accumulation (43 ± 5 BCM) in the reservoir and seepage in its surroundings with progressive south-southwest mass migration along mapped structures between 2019 and 2022. Seepage, but not a decrease in inflow or increase in outflow, could explain, at least in part, the observed drop in the reservoir's water level and volume following each of the three fillings. Using mass balance calculations and GRACETWS observations, we estimate significant seepage (19.8 ± 6 BCM) comparable to the reservoir's impounded waters (19.9 ± 1.2 BCM). Investigating and addressing the seepage from the GERD will ensure sustainable development and promote regional cooperation; overlooking the seepage would compromise hydrological modeling efforts on the Nile Basin and misinform ongoing negotiations on the Nile water management.

The Nile River stretches from south to north throughout the Nile River Basin (NRB) in Northeast Africa. Ethiopia, where the Blue Nile originates, has begun the construction of the Grand Ethiopian Renaissance Dam (GERD), which will be used to generate electricity. However, the impact of the GERD on land deformation caused by significant water relocation has not been rigorously considered in the scientific research. In this study, we develop a novel approach for predicting large-scale land deformation induced by the construction of the GERD reservoir. We also investigate the limitations of using the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) mission to detect GERD-induced land deformation. We simulated three land deformation scenarios related to filling the expected reservoir volume, 70 km3, using 5-, 10-, and 15-year filling scenarios. The results indicated: (i) trends in downward vertical displacement estimated at −17.79 ± 0.02, −8.90 ± 0.09, and −5.94 ± 0.05 mm/year, for the 5-, 10-, and 15-year filling scenarios, respectively; (ii) the western (eastern) parts of the GERD reservoir are estimated to move toward the reservoir’s center by +0.98 ± 0.01 (−0.98 ± 0.01), +0.48 ± 0.00 (−0.48 ± 0.00), and +0.33 ± 0.00 (−0.33 ± 0.00) mm/year, under the 5-, 10- and 15-year filling strategies, respectively; (iii) the northern part of the GERD reservoir is moving southward by +1.28 ± 0.02, +0.64 ± 0.01, and +0.43 ± 0.00 mm/year, while the southern part is moving northward by −3.75 ± 0.04, −1.87 ± 0.02, and −1.25 ± 0.01 mm/year, during the three examined scenarios, respectively; and (iv) the GRACE-FO mission can only detect 15% of the large-scale land deformation produced by the GERD reservoir. Methods and results demonstrated in this study provide insights into possible impacts of reservoir impoundment on land surface deformation, which can be adopted into the GERD project or similar future dam construction plans.

It was in June 2013 when the wider international public became fully aware of the dramatic changes currently transforming the hydropolitics of the Nile: a high-level meeting of Egyptian politicians, chaired by then President Mohammed Mursi, discussing strategies to prevent Ethiopia from building a major dam upstream on the Blue Nile.

The unexpected drop of the Blue Nile water in July 2020, attributed to the sudden closure of the Grand Ethiopian Renaissance Dam (GERD) during the first filling in 2020, significantly interrupted the water supply for Khartoum, Sudan. This incident pursued using satellites and hydrological models to estimate inflows into Roseires dam. A hydrological model was developed to predict GERD inflows, while reservoir levels were extracted from Sentinel-1, -2 and Jason-3. A water balance model was developed to predict GERD releases and the dates of overtopping during subsequent fillings events. The study demonstrates the effectiveness of satellite data and models for transboundary reservoir management.

The response surface approach is cooperated with the finite step method for the fitting of explicit performance function and reliability index calculation, which can make the system reliability analysis and failure path analysis of complex structures very easy. The failure path, functionality failure mode and corresponding reliability system index of Longkaikou roller compacted concrete gravity dam is studied. Different failure paths for dam, rock and roller compacted concrete layers are searched, and the corresponding explicit failure mode or performance functions for different function such as limit loads state are obtained with Response Surface Method for the subsequent reliability index calculation with Finite Step Method. And based on the theory of system reliability, the failure probability and reliability of the whole dam are obtained. The validity of proposed method is verified.

The main objective of this study is to present a method of determining viscoelastic deformation monitoring index of a Roller-compacted concrete (RCC) gravity dam in an alpine region. By focusing on a modified deformation monitoring model considering frost heave and back analyzed mechanical parameters of the dam, the working state of viscoelasticity for the dam is illustrated followed by an investigation and designation of adverse load cases using orthogonal test method. Water pressure component is then calculated by finite element method, while temperature, time effect, and frost heave components are obtained through deformation statistical model considering frost heave. The viscoelastic deformation monitoring index is eventually determined by small probability and maximum entropy methods. The results show that (a) with the abnormal probability 1% the dam deformation monitoring index for small probability and maximum entropy methods is 23.703 mm and 22.981 mm, respectively; thus the maximum measured displacement of the dam is less than deformation monitoring index, which indicates that the dam is currently in a state of safety operation and (b) the obtained deformation monitoring index using orthogonal test method is more accurate due to the full consideration of more random factors; the method gained from this study will likely be of use to diagnose the working state for those RCC dams in alpine regions.

This paper presents a mathematical model about the temperature regime and thermal stress state of Ban Lai roller-compacted concrete gravity dam, built in the climatic conditions of northern Vietnam. The model is made on the basis of the finite element method using the software complex Midas Civil. The three cases of dam construction were considered: The first was construction progress with 0.3 m/day, the second was construction process with 0.4 m/day and the last was actual construction progress. The results obtained from the mathematical model compared to the field measurements are reliable. This allows us to recommend the use of the proposed methodology with similar objects. The obtained values of maximum temperatures and thermal stresses indicate a low probability of temperature cracks.

A coupled thermal-structural analysis is carried out using both a two- and a three-dimensional finite-element method. The computer program ANSYS is used and simulates the construction process of a roller compacted concrete (RCC) dam. Thermally induced stresses are computed for the 60 m high RCC Tannur Dam in Jordan. The actual temperature distribution in the body of the dam measured by thermocouples is compared with that obtained by ANSYS; generally, a good agreement is obtained. The study demonstrates that detailed thermal stress analysis should be performed for large RCC dams to provide a basis to minimize and control the occurrence of thermal cracking.