Major Dams Research Articles

Turkey’s Hydropower Potential in the Near Future and the Possible Impacts of Climate Change—A Case Study of the Euphrates–Tigris Basin

Hydropower is becoming an important renewable energy source in Turkey, but the ever-changing atmospheric and climatic conditions of Turkey make it very difficult to be projected efficiently. Thus, an efficient estimation technique is crucial for it to be adopted as a reliable energy source in the future. This study evaluates Turkey’s hydropower potential in the Euphrates–Tigris Basin under changing climatic conditions. We adapted an empirical equation to model reservoir outflows, considering the site-specific characteristics of 14 major dams. Initial results from employing a model with a constant empirical coefficient, α, yielded moderate predictive accuracy, with R2 values ranging from 0.289 to 0.612. A polynomial regression identified optimal α values tailored to each dam’s surface area, significantly improving model performance. The adjusted α reduced predictive bias and increased R2 values, enhancing forecast reliability. Seasonal analysis revealed distinct hydropower trends: Ataturk Dam showed a notable decrease of 5.5% in hydropower generation up to 2050, while Birecik and Keban Dams exhibited increases of 2.5% and 2.2%, respectively. By putting these discoveries into practice, water resource management may become more robust and sustainable, which is essential for meeting Turkey’s rising energy needs and preparing for future climatic challenges. This study contributes valuable insights for optimizing reservoir operations, ensuring long-term hydropower sustainability, and enhancing the resilience of water resource management systems globally.

Quantitative impacts of hydroelectric dams on the trans‐Amazonian migrations of goliath catfish

AbstractHydropower expansion is increasingly responsible for connectivity and biodiversity loss in freshwater ecosystems. The Amazon basin, which supports the highest level of freshwater biodiversity globally, faces such unplanned expansion. Here, we demonstrate and quantify the impacts of two major hydroelectric dams on the Madeira River on the trans‐Amazonian movements of one apex predatory catfish (Brachyplatystoma rousseauxii) performing the longest migration known in freshwaters. Using otolith microchemistry, we show that above the dams, the former basin‐wide homing migration between the breeding grounds in the upper Madeira and the nursery in the Amazon estuary has now been replaced by residency. We found evidence suggesting downstream migration of juvenile fish past dams into the Amazon estuary and that some of them home back to the Madeira. However, we did not find evidence that the fish homing back from the estuary can access their breeding grounds in the upper Madeira; they remain blocked below the dams. Our results provide undisputable evidence that the conservation of the species primarily requires the reestablishment of connectivity with the construction of efficient fishways.

Causal relationship between project financing and overruns in major dam projects in Africa

PurposeCost and schedule overruns are rife in dam projects. Normative evidence espouses overruns as though they are inimical to development and prosperity aspirations of stakeholders. This study examines the causal relationship between project financing and overruns.Design/methodology/approachCausative data were extracted from completion reports of 28 major dam projects in Africa. Each of the projects was financed jointly by up to 10 international development lenders. Relationships between causes of overruns and project outcomes were analysed.FindingsAnalyses elicit indicators of remarkable correlations between finance procedures and project outcomes. Lenders’ disposition to risk attenuation was the main debacles to project success. Interests had mounted, whilst release of fund was erratic and ill-timed. Finance objectives and mechanisms were grossly inadequate for projects’ intense bifurcations. Projects had slowed or stalled because lenders’ risks attenuation processes were purposed to favour lenders’ objectives, and not projects’ interests. In addition, findings also show project owners’ own funds and the number of lenders to a single project correlate with overruns.Practical implicationsFindings imply commercial complexities around major projects. They also show transactions are shaped by subtle (mis)trust behaviours in project finance procedures. Thus, scholarly solutions to project performance issues should consider behavioural issues of stakeholding parties more broadly, beyond contractors and project owners. Project finance ecosystems are vulnerable to major actors’ self-interests, opportunism and predatory conducts. Borrowers would manage this by developing and improving their capacity to build resilience and trust. Evidence shows intense borrower nations in Africa have limited capacity and acuity for these.Originality/valueThis study contextualises megaprojects in complexity rather than cost. Its additionality is in how finance steers absolute control of project environment away from project owners and how finance administration triggers risks and overrun.

Project procurement process and performance of major dam projects in Kenya

Project procurement process and performance of major dam projects in Kenya

Biochemical changes and bioaccumulation of manganese in Astyanax lacustris (Teleostei: Characidae).

Major tailings dam failures have occurred recently around the world and resulted in severe environmental impacts, such as metal contamination. Manganese is a metal highly associated with mining activities, largely detected in mining dam collapses. This metal is considered necessary for different organisms, but it can be toxic and cause oxidative stress and genetic damage in fishes. In this study, we investigated the toxic effects of manganese on Astyanax lacustris, by exposing the fish individually to different concentrations of this metal (2.11, 5.00, and 10.43 mg/L) for 96 h. To assess the effects of manganese, we used biochemical biomarkers (glutathione S-transferase, catalase, and acetylcholinesterase enzyme activity) and the manganese bioaccumulation in different tissues (liver and gills). The obtained data showed that only at concentrations of 5.00 mg/L and 10.43 mg/L the activity of glutathione S-transferase differed significantly. Additionally, the acetylcholinesterase activity in the brain tissue was inhibited. The highest level of manganese bioaccumulation was observed in the liver and branchial tissue. Overall, we concluded that high concentrations of manganese may cause physiological changes in Astyanax lacustris.

Predictive simulation of the water-energy-food nexus for the City of Cape Town

The City of Cape Town (CoCT), South Africa faced a critical situation between 2015 and 2018 in which the municipal water supply was almost completely exhausted. This situation, commonly referred to as Day Zero in South Africa emanated from a decline in rainfall, resulting in one of the most severe droughts in history. The crisis was also aggravated by rapid population growth and urbanization. CoCT was on the verge of becoming the first city in the past decade to experience a complete cessation of water supply for urban and agricultural purposes. In addition to the effects of low rainfall and population surge, urban energy consumption and increased food demand impacted directly the available water resources. To evaluate the interlinkages between water utilization, water production, energy supply and demand, and food production and demand, this study employed a system dynamics modeling (SDM) approach. The model was developed as a stock and flow diagram utilizing Stella Architect and encompassed five interconnected nodes: water, energy, food, land, and population. The findings revealed that by the end of the 20-year modeling period, the volume of accessible and stored water in all the major dams will be approximately 459 million cubic meters, with residential use accounting for about 85 % of urban water use and agriculture accounting for approximately30.37 % of total water demand. The model illustrates the impacts of precipitation rate, runoff, and evaporation on variables such as land-use change and population dynamics. It is anticipated that the outcomes of this study will serve as valuable inputs for decision-making processes, not only within the CoCT as it aims to mitigate or prevent the recurrence of Day Zero, but also for other cities facing similar challenges.

Health Risk Assessment Of Potentially Toxic Element Concentrations In Fish And Vegetables Obtained From Six Selected Dams In Osun State, Nigeria

This study aimed to assess the levels of certain heavy metals in tilapia fish (Oreochromis niloticus), as well as vegetables, and to evaluate the potential health risks associated with the presence of toxic elements from Dec. 2019 to June 2023. A total of 60 tilapia fish, 12 okra (Abelmoschus esculentus) and 12 bitter leaf (Vernonia amygdalina) from six major dams in Osun State were prepared for analysis using wet digestion with aqua-regia. The concentrations of heavy metals were measured using an Atomic Absorption Spectrophotometer (Shimadzu AA-630). The health risk associated with fish consumption was estimated using various parameters. Statistical analysis was conducted using the Statistical Package for Social Sciences (SPSS) version 16.0. The concentrations of micro elements followed the order of Fe > Zn > Cu > Mn in decreasing concentrations. These concentrations exceeded the permissible limits set by the World Health Organization (WHO) for Ni, Cd, Pb, and Cr, which are 0.6, 0.3, 0.3, and 0.7 mg L-1, respectively. The results obtained for okra and bitter leaf were within the limits established by the World Health Organization (WHO). Therefore, the presence of these metals indicates the need for close environmental monitoring of the six selected dams.

Complex drivers of geomorphic response and habitat formation revealed in multiyear monitoring of Cosumnes River experimental floodplain reconnection

In this study, we examine a novel levee breach experiment that reconnected a floodplain along the Cosumnes River, California to determine the decadal impact of removing 250 meters of levee and assess the recruitment of large wood. This is the latest study in an ongoing series of investigations 40 years in the making along the largest river on the western slope of the Sierra Nevada without a major dam. We present the findings of this multi-modal investigation here by first measuring the geomorphic alteration of the floodplain surface to quantify the depletion and accretion of sediment across the excavated site. We then identify and quantify the deposition of large wood. Results indicate initiation of anastomosing channel formation and distinct areas of large wood recruitment supporting a naturally evolving lateral levee. Accretion resulted in more than 25,000 m3 of sediment deposition within the original excavation site, the development of multiple sand splays, and natural recruitment of native riparian tree species. We conclude by discussing implications following other approaches to floodplain restoration as a Nature-based Solution. In episodic flow regimes, like in California’s Mediterranean-montane hydroclimatic regime, restoring lateral hydrologic connectivity facilitates ecosystem function. Large flood pulse events drive sediment dynamics and geomorphic heterogeneity while enriching biodiversity through biogeochemical fluxes and habitat creation on reconnected floodplains that store floodwaters and reduce peak discharge. These findings support the importance of long-term monitoring efforts of floodplain restoration.

Morphometric Analysis Using Geographical Information System and the Relationship with Precipitation Quantiles of Major Dam Basins in South Korea

Geographic information system (GIS) and remote sensing (RS) technologies are potent tools for evaluating various aspects of basin hydrology. This study conducted a morphological analysis using GIS tools on seven major dam basins in Korea. Additionally, long-term RS-based precipitation data were obtained, the probability of precipitation was estimated, and their relationship was examined. The findings are summarized as follows. It was observed that most major dam basins in Korea, which were the focus of this study, had a broad radial shape, and due to the mountainous topography, there was a notable presence of numerous river branches. Through the estimation of probability precipitation and its comparison with morphological indices, it was noted that wider basins tend to have higher rainfall amounts and a relatively uniform spatial distribution. Furthermore, it was found that the more uniform the spatial distribution, the simpler the river network. This trend becomes more pronounced in relation to basin size for longer durations, and in spatial dispersion for shorter durations. However, it is crucial to acknowledge that the complexity of these relationships is also affected by other factors such as climate, altitude, and local geographical conditions.

A Half-Century of Human Impact on Nan River Runoff and Sediment Load Supplied to the Chao Phraya River

The construction of large dams in the upper tributary basin of the Chao Phraya River (CPR) has been linked to a significant decrease in sediment load in the CPR system, estimated between 75–85%. This study, utilizing historical and recent river flow and sediment data from 1922 to 2019, examines the impact of three major dams constructed in the Nan River basin (the Sirikit, Naresuan, and Khwae Noi dams) on river runoff and sediment loads in the CPR. The investigation employed the Mann–Kendall (MK) test and the double mass curve (DMC) for analysis. Findings indicate that the Nan River is a major contributor to the CPR, accounting for around 40% of the runoff and 57% of the total sediment load (TSL). The Naresuan diversion dam’s water regulation was found to significantly reduce annual runoff and TSL downstream of the dam. Despite an initial increase in sediment load at the CPR headwater (C.2) post the construction of the Sirikit dam, attributed to expanded irrigation downstream and channel improvements in the lower Nan River, the operation of the three dams eventually led to a 31% reduction in sediment load at C.2 compared to pre-construction levels.

Assessment of Elemental Contamination of Selected Major Dams from Osun State, Nigeria by Multivariate and Hazard Index Analyses

Dams and their environment, interrelate with a degree of complexity that often affects the availability of potable water. In Nigeria, dams are an important source of drinking water in many communities but are vulnerable to contamination from different sources. This study assessed the possible elemental (Cd, Cr, Cu, Fe, Ni, Pb, Mn, and Zn) contamination sources of selected dams in a total of 126 samples comprising 54 surface water, and 72 sediment samples collected from six main dams in Osun State using multivariate analyses like Principal Component Analysis (PCA) and Cluster Analysis (CA). Generally, the average elemental concentration was in the decreasing order of Cr > Ni > Cd > Pb > Cu > Fe > Zn > Mn and Pb > Cr > Ni > Cd > Zn > Mn > Fe > Cu for surface water and sediment samples respectively. Furthermore, statistical analysis showed that the average concentrations of the potentially toxic elements (PTEs) did not differ significantly (p < 0.05) across the sampling sites, indicating similar PTEs profiles. The PCA and CA revealed possible sources of elemental contamination to the dam quality as weathering of bedrocks, uncontrolled farming activities, abandoned equipment, boat fueling, maintenance, and repairs. Although only 13.9% of the hazard quotients (HQ) were higher than one for all the studied heavy metals in surface water, 91.7% of the hazard index (HI) were higher than one. This suggests an unacceptable risk of non-carcinogenic effects from the direct consumption of dam water. Furthermore, the oral target cancer risk, TCRoral in children > adults and > 1 × 10−4 for cancer risk set by USEPA, however, the % contribution of Cr to ∑TCRoral in adults which is > 1 × 10−4 ranged between 98.9 to 99.5%, indicating that Cr is the most dominant carcinogens in the overall cancer risk in adults.

Geotechnical Evaluation of Basalt Rocks: A Review in the Context of the Construction of Civil Engineering Structures

Basalt rocks are a common geological formation that plays a crucial role in various engineering applications, such as construction, infrastructure development, and geotechnical engineering. Understanding the physical and geotechnical properties of basalt rocks is essential for ensuring the stability and safety of structures built on or within these formations. It is crucial to understand how basalt rocks deform and fail under applied loads for geotechnical assessments. Deformation and failure mechanisms are influenced by factors such as jointing, weathering, and stress conditions. Therefore, a comprehensive analysis is necessary to ensure reliable engineering designs. Proper site investigations and geotechnical assessments are essential to address these challenges effectively and ensure reliable engineering designs. This paper provides a comprehensive review of the geotechnical properties of basalt rocks, including their origin, mineralogy, physical characteristics, and engineering behavior. The paper also includes case studies of the Sardar Sarovar (Narmada) dam Project and Karjan dam, Gujarat, India, highlighting the successful utilization of basalt rocks in the construction of major dams and underground powerhouse. These case studies provide insights into potential challenges posed by basalt rocks and associated features in the construction of structures and their adequate solutions.

Effects of mine tailings on aquatic macroinvertebrate structure within the first year after a major dam collapse

Context The collapse of a tailings dam in Brumadinho (Brazil) is considered one of the largest mining disasters worldwide. The mine tailings polluted the water and sediment of the Paraopeba River downstream of the collapsed dam. The effects of the tailings on biological communities remain unknown. Aims We evaluated the effects of the tailings dam collapse on aquatic macroinvertebrate assemblages in the Paraopeba River and highlighted a potential bioindicator for the cumulative effects of the mine tailings spill. Methods We sampled the macroinvertebrates upstream and downstream of the collapsed dam during the first dry and wet seasons following the collapse. Key results We found that turbidity (likely non-related to the tailings) negatively affected the macroinvertebrates’ abundance, but the richness was negatively affected by the presence of the mine tailings. The riparian land use negatively affected the macroinvertebrate richness and composition. We identified Helicopsyche spp. as a bioindicator. Conclusions We provide circumstantial evidence of the effects of mine tailings on aquatic macroinvertebrates, suggesting that it may have affected their richness and caused the loss of Helicopsyche spp. in the most affected sites. Implications We suggest that the richness and Helicopsyche spp. are potential biomonitoring tools for evaluating the effects of the tailings dam collapse on the macroinvertebrate assemblages.

Insularization drives physiological condition of Amazonian dung beetles.

The fragmentation and degradation of otherwise continuous natural landscapes pose serious threats to the health of animal populations, consequently impairing their fitness and survival. While most fragmentation ecology studies focus on habitat remnants embedded withinn terrestrial matrices, the effects of true insularization remains poorly understood. Land-bridge islands created by major dams leads to habitat loss and fragmentation, negatively affecting terrestrial biodiversity. To assess the effects of insularization, we conducted a study on the key aspects of dung beetle physiological condition and body size throughout the Balbina Hydroelectric Reservoir located in the Central Amazon. We assessed these traits at the population and assemblage levels, collecting dung beetles from both forest islands and continuous forest areas while analyzing various landscape variables. We show that landscapes with higher forest cover positively affected dung beetle body size. Interestingly, dung beetle responses to insularization were species-dependent; larger islands tended to host larger individuals of Deltochilum aspericole, while in Canthon triangularis, smaller islands showed larger body sizes. However, individuals from the mainland were larger than those from the islands. Moreover, the proportion of closed-canopy forest in the landscapes also impacted physiological attributes. It negatively affected the body size of Deltochilum aspericole and the lipid mass of Dichotomius boreus, but positively affected the lipid mass of Canthon triangularis. These findings contribute to a better understanding of how habitat fragmentation in aquatic matrices affects the size structure and physiology of insect assemblages. This is essential in formulating effective conservation strategies for preserving biodiversity loss in tropical forest regions and mitigating the consequences of hydropower infrastructure.

International law and transboundary dams: lessons learned from the Binational Entity ITAIPU (Brazil and Paraguay)

The international river Paraná flows through Brazil, Paraguay and Argentina, and holds two major binational dams: the upstream ITAIPU dam (Brazil-Paraguay) and the downstream Yacyreta dam (Argentina-Paraguay). In the past years, the South American region was strongly affected by adverse environmental challenges exacerbated by climate change, like wildfires and severe droughts, which in turn drastically affected the water flow of the Paraná river, a river used for multiple purposes, inter alia the production of energy. The hydropower obtained from ITAIPU is one of the main sources of energy for Paraguay and the Southern part of Brazil. At the same time, the downstream parts of the river is used for navigation purposes, which is crucial for land-locked Paraguay to export its agricultural products, and for water consumption, as is the case for Argentina. The present case study will show how in spite of these challenges, South America has been an successful example of transboundary water cooperation, especially by using the international water law guidelines aimed at achieving reasonable and equitable utilization of an international river.

Development of maps for assessment of landslide risk in reservoirs of major Italian dams

Development of maps for assessment of landslide risk in reservoirs of major Italian dams

EFFECT OF RESERVOIR UTILIZATION AND OTHER ANTHROPOGENIC ACTIVITIES ON THE HADEJIA RIVER VALLEY FLOODS: A REVIEW

The unceasing risk perception and socio-economic damages caused by flood disasters have been persistent in Hadejia River Valley (HRV). There is, however, a need to review upstream factors that could exacerbate downstream floods in the valley. The review tends to gain insight from the local and global flood occurrences due to the interplay between upstream reservoir management and other anthropogenic activities and downstream floods. The review underscores the impact of poor upstream reservoir operation, agriculture and other anthropogenic activities in exacerbating the occurrence of floods. These activities alter natural drainage patterns, reduce water absorption, and frequent spills from the major dams and hence, amplify runoff resulting in heightened flood risks. It was observed that reservoirs can serve as flood control facilities (if well-managed) and also exacerbate flooding by releasing large volumes of water too quickly or reaching capacity during intense rainfall events. It is, therefore, essential to consider the location, design, and operation of reservoirs, as well as their role within the HRV management context. In conclusion, the Hadejia-Jama’are River Basin Development Authority (HJRBDA) should adopt the Integrated Water Resource Management (IWRM) approach that combines reservoir management, land use, flood forecasting, and emergency response strategies for minimizing downstream flood risks and maximizing the utilization of the upstream reservoirs.

Comparative Study of Water Quality from Two Major Dam Reservoirs of Thiruvananthapuram District, Kerala

Neyyar Dam and Aruvikkara Dam are two major dam reservoirs located at Thiruvananthapuram District of Kerala State. Physicochemical parameters of water from these two dam reservoirs were studied and compared during pre-monsoon and monsoon period from April 2018 to July2018.Water samples were collected from different sampling stations of the reservoirs and analyzed as per standard methods of APHA (2012). Water from Neyyar dam shows maximum value of all physicochemical parameters compared to water from Aruvikkara dam in the present study period. Water temperature, Total Dissolved Solids, Total Suspended Solids, pH, free CO2, Biological Oxygen Demand and Total hardness were maximumin pre monsoon season and Turbidity, Productivity and Dissolved Oxygen were maximum in monsoon season at both sites. Present study reveal that water from Neyyar dam is more polluted than water from Aruvikkara.

GIS-assisted Flood-risk Potential Mapping of Ilorin and its Environs, Kwara State, Nigeria

The incessant reoccurrence of flooding disasters across Nigeria has mandated an urgent outlook on flood-risk management techniques. Ilorin and its environs have suffered immensely from annual flood reoccurrence. This study aims to assess flood risk within Ilorin and its environs and proffer adequate flood mitigation strategies that governments and policymakers can adopt to placate future flooding events within the state. Satellite imagery data were acquired and analyzed for flood-risk assessment of the area. Ten highly influential flood causative factors were synergized using Multi-Criteria Decision-Making techniques in this research; they are Land Surface Temperature, Elevation, Soil Moisture Index, and Distance to Stream, Drainage Density, Stream Power Index, Normalized Difference Vegetation Index, Land Use Land Cover, Slope, and Topographic Wetness Index. Findings showed that approximately 47.2% of the study area had low flood risk, while moderate and high flood-risk zones occupied 33.5% and 19.29%, respectively. Most parts of Ilorin and its environs are safe from flood disasters; only about one-quarter of the total area under investigation lies in the high flood-risk zones; these areas mostly fall within the shores of major streams, rivers, and dams within the state. A plot of previous flood cases in the state placed the affected areas in the high and moderate zones of flood risk, confirming the efficacy of geospatial techniques in flood-risk assessment. It is hoped that this study's findings and recommendations can be implemented to prevent future devastating flooding occurrences within the state.

The political economy of the climate crisis in Southern Africa

ABSTRACT This article maps out the dynamics of the climate crisis that is unfolding globally, but whose consequences have a disproportionate impact on countries in sub-Saharan Africa and the wider global South. Although these countries have contributed insignificant amounts of greenhouse gas emissions (compared to their industrialised counterparts), their populations are the major victims of climate change, whose disastrous impacts were recently witnessed in Zimbabwe during Cyclone Idai and in South Africa during the Durban floods. In addition, Southern Africa is experiencing climate change-induced droughts, depleting water in major dams and undermining hydroelectric power generation, especially in Zambia and Zimbabwe. As a result, the region is experiencing dangerous power outages affecting agriculture and other key industries. This article adopts a novel decolonial perspective to make sense of these extreme weather events, arguing that the climate crisis is already affecting the livelihoods of many people in Southern Africa and that it is often the poor and vulnerable who suffer most from the impacts of climate change. There is thus a need for industrialised countries to contribute towards the costs of climate change mitigation since they are historically responsible for most of the carbon emissions.