Search

Dam construction has some qualitative and quantitative effects on groundwater resources. This effect may be in the form of an increasing groundwater table or a changing groundwater system. In this paper, the effect of the Rodbal dam construction on the Darab aquifer was investigated. For this paper water table levels from observation wells and precipitation data was used. The study aims to analyse the behaviour of the water table during precipitation by employing a combination of the standardisation process, Fuzzy Inference System (FIS), and Root Mean Square Error (RMSE) calculations. Fuzzy logic involves the fuzzification of input data, transforming precise values into fuzzy sets. The effectiveness of the FIS is highlighted, particularly in determining the number of membership functions for inputs. The performance of the results is assessed using indicators such as RMSE and Coefficient of Determination (R2). The FIS showed a high level of effectiveness in performance assessment, exhibiting a 70% similarity between the fuzzy and Mann–Kendall methods. Nonetheless, the Fuzzy Purpose Method corresponded more closely with the observed data, indicating a more accurate reflection of reality. The findings indicate that for P3, P7, and P8, the results from the Mann–Kendall method do not show a discernible trend. Conversely, the proposed Fuzzy method accounts for changes in the behaviour of these piezometers. [ABSTRACT FROM AUTHOR]

The impact of reservoirs on downstream river hydrological characteristics is always a focal point in relevant studies exploring the relationship between rivers and dams. Anticipating river runoff patterns following the construction of new dams is crucial for the design of riverine engineering projects, particularly during dry periods. This paper presents a semi-theoretical estimation method based on the correlation between hydrological alterations and reservoir operation. The method incorporates differences in runoff increment distribution and the discrepancy between theoretical and practical results. It was validated and applied in the sub-basins of the upper reaches of the Yangtze River, namely the Jinsha River and Min River. The runoff increment during the driest month for the Jinsha River and the Min River is 817 m3/s and 434 m3/s, respectively. The estimated prediction biases were within 30% of the practical runoff increments observed in the Jinsha River and Min River, which is an acceptable range considering the inherent variability in such studies. Since the construction of the Wudongde and Baihetan dams in 2021, the average runoff during the driest month and the navigation assurance runoff at a 95% probability were predicted to be 2866 m3/s and 2174 m3/s, respectively. Therefore, the method developed in this paper provides a reasonable and straightforward tool for researchers, which can help prevent future engineering invalidation and minimize resource costs. Moreover, in the application process, this method requires careful consideration of the characteristics of the studied river section and the operation of the reservoir group. It relies on measured data to determine the differences between theoretical and actual runoff rather than simply generalizing to all watersheds. [ABSTRACT FROM AUTHOR]

Railway freight transport represents an advantageous way for regular transport of bulk substrates. As a result of changes within the industry and energy sectors as well as in the field of consumer behaviour, such business cases decline significantly. Nevertheless, transport such of the characteristic have being (and will be) still realized however, in addition, quantities of transported goods will be known in advance - as a part of major construction or environmental remediation projects. In the period of 2020-2021, the Department of Transporting Systems in the CTU in Prague, Faculty of Transportation Sciences prepared the study "Vlára, Vlachovice Hydraulic Structure, Logistic Study of Material Transport for the Dam Construction" for the state enterprise Povodí Moravy (the Morava River Basin). Among other things, the study dealt with transport of more than 2.5 million tonnes from two quarries to the construction site of the Vlachovice dam by goods trains (the Vlachovice dam will be built in Moravia - the eastern part of the Czech Republic). It was necessary to determine an optimal route of the goods trains, their parameters and general operating concept so that the transport costs would be minimised and, concurrently, the transport performance would be as high as possible. This paper sets itself a goal to present a general procedure and principles for proposal of freight trains for a business case characterized by long-term and regular transport of large quantities of goods. For the stated case study, transport technology in the railway station Bohuslavice nad Vláří is discussed in detail. [ABSTRACT FROM AUTHOR]

This paper, reflecting on the village and archaeological site of Jamalo located on the top of the Zayanderud dam, aims to explore the circumstances human settlements would have encounter with the construction of the dam and when its reservoirs were flooded. About 30 years ago, as the images from Google Map showed, the water strip emerging from the Zayanderud dam, wherein the left riverbank hosted the village and archaeological site of Jamalo. This site had been occupied for much of the sixth and fifth millennium BC until the beginning of the Early Bronze Age. In the Middle Bronze Age, it had been dominated by the Proto-literate, historic, and Islamic periods. Archaeological evidence from surface surveys also indicated that pottery shreds were similar to those of Sialk III and Bakun A. Now, Jamalo is exposed to the waters of the dam reservoir. Therefore, the main objective of this paper is to provide an overview of what would have happened to archaeological sites with the construction of the dam, its reservoirs were flooded, and when landscapes were radically altered. Another question was: "What would have happened to archeological sites as floods made it inaccessible?" Based on the excavation at Jamalo and the comparison of images taken from the region before and after the construction of the dam, it was observed that the reservoir had destroyed the village, and the slopes of the site, especially on the eastern and northeastern parts, had been covered with a layer of deposits. [ABSTRACT FROM AUTHOR]

A concrete production system (CPS) fault in dam engineering is one of the important factors influencing dam construction quality, which may directly affect the concrete-pouring construction progress and construction efficiency of the dam, and can even cause construction quality defects in the dam body. Reasonable classification and identification are of great significance to ensure the construction progress and quality of concrete dams. In this study, based on the concrete production logs of multiple concrete dams and literature reviews, a fault classification system for a CPS is proposed by comprehensively considering its mechanical structure characteristics and operating characteristics. The faults of the CPS are divided into 4 large categories and 22 subcategories. Additionally, the causes of CPS faults are summarized as human factors, environmental factors, mechanical component service life factors, and other factors. Based on the grey correlation analysis (GCA) method, a fault identification model of the CPS is established. With the actual production system fault statistical data of Shatuo hydropower station, the correlation coefficients for the four types of faults and the four influencing factors are calculated to determine the key faults of the CPS. The research results of the case study show that the service life factors of mechanical components have the greatest impact on batching metering system faults and mixer faults, with high grey correlation degrees of 84.66% and 76.85%, respectively. Environmental factors have the greatest impact on material delivery system faults and pneumatic system faults, with high grey correlation degrees of 90.81% and 94.9%, respectively. This paper provides theoretical support for the realization of fault pattern recognition of CPSs and provides a guiding reference for targeted fault handling. [ABSTRACT FROM AUTHOR]

Gomal Zam Roller Compacted Concrete (RCC) Arch-Gravity Dam is up to now the only arch-type RCC dam in Pakistan. In the selection of dam axis and type, the local topographical and geological conditions were intelligently used to create the largest reservoir with the minimum dam volume. During the construction, several innovative technologies were applied. This paper highlights the notable structural features and innovative construction technologies. [ABSTRACT FROM AUTHOR]

A dynamic analysis of the Makhool dam using Geo-studio software is presented in this paper for the purpose of investigating the seismic behavior of earth dams. With emphasis on the dam's height, soil characteristics, and input motion, this study examines the effect of earthquake excitation on the dam's behavior. With input from the SEEP/W program, the analysis was conducted using the QUAKE/W program. In this study, the horizontal component of motion was taken at three different values: 0.04g, 0.06g, and 0.08g. In addition to total stress in x-direction and y-direction, pore water pressure, and x-displacement, the results were presented in figures. Study findings showed that the horizontal displacement and shear strain of the dam increased with dam height, with the maximum displacement of the dam equal to 94 cm at the end of the earthquake. Besides the type of dam soil, the acceleration of the dam was also affected by the strength of the soil, since weaker soil reduced the acceleration of the dam. The pore-water pressure at the dam's base was the highest, with the horizontal movement increasing with depth. In earthquake zones, seismic evaluation is vital for dam construction, and the research provides valuable advice for designing and building earth dams. [ABSTRACT FROM AUTHOR]

Cemented material dam (CMD) can fully utilize local sand, gravel, and rock materials for dam construction. It has many advantages such as flood overtopping without failure, environmental friendliness, economic savings, rapid construction, and so on. It has been rapidly popularised and applied to domestic and foreign projects since it was put forward by the first author. This paper illustrates the reasons for the proposal of CMDs, puts forward the stress–strain model of the cemented mixture and the intelligent system of production quality control, presents the model test results for CMD against flood overtopping, and introduces the practice of dam construction with low-strength soft rock and weathered materials. [ABSTRACT FROM AUTHOR]

Dams have proliferated along the Mekong, spurred by energy demands from economic development and capital from private companies. Swift dam evolution has rendered many databases outdated, in which mismatches arise from differing compilation methods. Without a comprehensive database, up-to-date spatial assessment of dam growth is unavailable. Looking at future development, hydropower potential specifically within the Mekong remains to be systematically evaluated. In this paper, we offer (1) an open-access and unified database of 1055 dams, (2) a spatiotemporal analysis of dams on a sub-basin and country level from the 1980s to the post-2020s, and (3) a grid-based assessment of the theoretical basin-wide hydropower potential using present-day discharge from the CaMa-Flood model (2011–2015, 0.05°) and future discharge from the WaterGAP2 model used for ISIMIP2b (2021–2040, 0.5°). The dam count of 1055 is more than twice the largest existing database, with 608 hydropower dams generating a boom in hydropower capacity from 1242 MW in the 1980s to 69 199 MW post-2020s. While China had the largest capacity increase from the 2000s to the 2010s (+ 16 854 MW), Laos has the most planned dams and the highest projected growth post-2020s (+ 18 223 MW). Based on present-day discharge, we estimate a basin-wide hydropower potential of 1 334 683 MW , where Laos is the highest at 514 887 MW. Based on future discharge modeled with climate change, hydropower potential could grow to over 2 000 000 MW. Laos and China are the highest at around 900 000 MW each, together forming over 80 % of the total potential. Our database facilitates research on dam-induced hydrological and ecological alterations, while spatiotemporal analysis of hydropower capacity could illuminate the complex transboundary electricity trade. Through both spatiotemporal and hydropower potential evaluation, we address the current and future vulnerability of countries to dam construction, highlighting the need for better planning and management in the future hydropower hotspot Laos. The Mekong dam database is publicly available at 10.21979/N9/ACZIJN (Ang et al., 2023). [ABSTRACT FROM AUTHOR]

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The compaction quality of embankment dams directly affects the safe operation of power stations. The traditional monitoring method has the shortcomings of limited sample and time consumption. Compaction quality can be reflected by the compression ratio (CR) of the filling material. A novel method based on unmanned aerial vehicle (UAV) photogrammetry technology, which can rapidly acquire the CR of the entire filling area, is proposed in the present paper. Specifically, the CR nephogram is obtained by processing the terra information of the compaction body collected by the UAV. Validation of the CR results is performed by comparing them with the results obtained via leveling measurements. Mean absolute error between CR results and leveling measurements results is less than 1%, and the corresponding settlement value error is millimeter-level, reflecting a fairly good agreement. Furthermore, the reduced-scale experiment shows that the UAV-based CR method is more stable than manual measurements, and the efficiency is increased by more than five times, which meets the requirements of compaction quality monitoring and quality control. The CR nephogram obtained can reflect the compaction quality information rapidly, comprehensively, and accurately, thereby guiding the quality control of embankment dam construction. [ABSTRACT FROM AUTHOR]

Industry 4.0 encompasses a range of ideas, technologies, and procedures that impact engineering education and other fields. Building information modeling (BIM) has become a widely adopted practice in Indonesia's construction industry, prompting polytechnic universities to incorporate BIM skills and concepts into their construction engineering and management degree programs. Nowdays, more than 50 dam construction works occurred in Indonesia from 2014-2024. Monitoring progress regularly is crucial to ensure a construction project's successful completion. This can be done by visually tracking the project's advancement, which enables the identification of any changes or deviations that occur. Accurate measurement data is essential for reliable progress management, as it allows for the prediction of future project success or failure. Image-based object detection is highly beneficial for retrieving site information and monitoring construction progress. To monitor the progress of a construction project, comparisons between the building's as-built and as-planned states are necessary. BIM is employed to establish the intended condition of a building by providing information regarding its geometric characteristics and construction schedule. In this paper, we present a novel method for producing a point cloud that accurately represents the dam building site using photogrammetry. To overcome the limitation of capturing photographs from every possible angle at a construction site, we employ a combination of structure from motion and control points. This approach allows us to generate a scaled point cloud in a standardized coordinate system. The building's as-built and as-planned states are then compared using this point cloud. Structure from Motion (SfM) disparity maps are fused to create dense point clouds, which are then compared to the goal state for updating 4D BIM. This makes it possible to identify missing building components. To validate the presence of building elements, a secondary examination is conducted using the positions in front of and behind the model planes constructed as per the original blueprint. The research paper explores potential approaches and presents empirical results obtained from an actual case study. [ABSTRACT FROM AUTHOR]

Therefore, the HT ht for GMDH is 42. Therefore, each neuron includes six parameters (i.e., { HT ht } in the first series of Table 4 of original paper that should be tuned through the training phase. [Extracted from the article]

The traditional quality gain-loss function(QGLF) considers the case that the primary term loss cannot be ignored, does not consider the cubic term loss, but in practice the cubic term loss should not be ignored. In this paper, based on the existing QGLF model, the Taylor expansion is reserved to the third order, the determination of the quality loss coefficient is discussed and analyzed under the condition that the compensation quantity is constant, and the asymmetric cubic QGLF model is established, and uses an example of concrete mixture out of the machine slump during the dam concrete construction to analyze and discuss the relationship between the proposed model and the traditional quadratic QGLF, which verifies the rationality of the proposed model. [ABSTRACT FROM AUTHOR]

Nowadays, more information is available about the activities of the Eurasian beaver (Castor fiber) as an ecosystem engineer species and the resulting ecosystem services. The environment-shaping activity of beavers not only affects the bed conditions of a given body of water but also affects the degree of diversity of the vegetation and fauna surrounding it. The research published in connection with this topic has only in recent years begun to deal more intensively with the condition characterisation and function analysis of the flooded areas under constant beaver influence, called beaver meadows. The focus of this paper is the investigation of beaver meadows directly connected to the dam system consisting of 19 beaver dams located along the Ablánc stream. The research examines the effect of the activity of the beaver colony, which has been continuously monitored for almost two years, on the soil moisture conditions of the beaver meadows in the Natura 2000 nature conservation area and to what extent this is reflected in the characteristics of the plant community. The focus of the analysis is the vertical distribution of soil moisture in the upper soil layer. During the vegetation mapping, 10 squares were designated to determine plant community parameters. High soil moisture values were detected in the examined quadrates, which varied between 39.0 φ% and a maximum of 50.0 φ%. A significant number of taxa could be identified - such as Myosoton aquaticum and Petasites hybridus - whose primary ecological requirements are a permanent wet environment and continuous water impact. [ABSTRACT FROM AUTHOR]

The grinding reinforcement of fine sand layers is a difficult problem in dam engineering construction. As a new type of grouting material, permeable polymer with excellent impermeability and high strength is widely used in dam engineering. In this paper, a series of compressive tests were designed considering different grouting pressures, curing days, moisture content, and porosity of fine sand. The influence of grouting parameters and sand layer conditions on the strength of fine sand layers reinforced by permeable polymers was analyzed. SEM and XDR tests were conducted to analyze the microscopic characteristics of the grouting stone. The functional calculation model of the strength and the influencing factors was established to explore the main factors influencing grouting stones. The compressive strength of grouted stones increases rapidly from the 7th to the 14th day, reaching about 96% of the maximum strength. The degree of influence of different factors is grouting pressure > moisture content > porosity. The compressive strength of the grouted stones increases with the increase of grouting pressure and the number of curing days. The compressive strength decreases with the sand layer's increasing moisture content and porosity. [ABSTRACT FROM AUTHOR]

Jordan is facing significant challenges related to water scarcity, including overexploitation of groundwater, increasing demand, and wasteful practices. Despite efforts to manage water resources, inadequate planning has resulted in ongoing water security concerns and deteriorating water quantity and quality. To address water stress, Jordan has implemented measures such as desalination, dam construction, and water conservation initiatives. However, water stress remains high, necessitating a comprehensive strategy that includes short-term demand-side interventions and long-term supply-side reforms. Financial and governance challenges hinder the implementation of these measures, requiring private investment and coordination among stakeholders. This paper provides a comprehensive review of Jordan's water resources, analyzing current trends, challenges, and opportunities. The aim is to offer insight into the current situation and propose sustainable management approaches. The findings will be valuable for policymakers, researchers, and stakeholders working towards addressing Jordan's complex water challenges and securing a sustainable water future for its citizens. [ABSTRACT FROM AUTHOR]

For the construction of dam substations in coastal or mountainous areas, inclined soft soil foundations are very common. The unique engineering characteristics of inclined soft soil foundations can bring great difficulties to the construction of dam substations. In this paper, a pile foundation reinforcement dam slope model on an inclined soft soil foundation is established; the influence of different pile spacings, the pile length, and the soft soil foundation angle on the slope safety factor is studied; and the failure mechanism and stability of pile-supported dam slope foundation are analyzed. The research results indicate that pile foundation reinforcement can reduce the deformation of the dam slope foundation and improve stability. The pile layout has an important impact on stability, but a change in the pile spacing has little effect on the settlement surface at the bottom of the dam slope. The pile length has a significant impact on the safety of the slope within a certain range. The main stress area of the pile is 0–2 m above the pile, and its main deformation is the lateral deformation of the upper part of the pile. The research results of this article can provide parameter support and theoretical guidance for the construction of dam substations. [ABSTRACT FROM AUTHOR]

The control of thermal cracks induced by the effect of early age are the main concerns in concrete dam during the construction stage. Despite its importance, detailed thermal analysis of concrete gravity dams during the construction period is relatively rarely in the literature, eventually because prediction the behavior of concrete gravity dam on early stage requires taking into account the several phenomena and interaction, demands a considerable computational effort. To overcome this drawback, the present paper proposes a numerical modeling strategy to predict the thermo-mechanical behavior of concrete gravity dams during construction periods considering the effect of early age and the construction schedule. The proposed strategy is also used to study the effect of precooling methods on the thermal-mechanical fields on concrete gravity dam during construction process. For this purpose, a Chemo- Thermo-Mechanical model is developed for predicting the behavior of a gravity dam at early stages. Firstly, temperature field model was established and verified with the results reported in the literature. Furthermore, the thermo-mechanical behavior of a concrete gravity dam is performed for two configurations: Early age state with pre-cooling and early age without pre-cooling. Thermal stress analysis was also conducted and results showed that the greatest tensile stresses after construction are developed at the heel of dams and resumption of concreting interface due to the internal restraint imposed by the concrete. The numerical results showed that the pre-cooling methods is an effective way to reduce both the hydration temperature and tensile stress induced by the effect of early age. [ABSTRACT FROM AUTHOR]

During the late 1960s, South Korean state engineers from construction agencies promoted large dam-building projects with the notion that their expertise would allow them to carve nature for the benefit of the nation. Hidden under this audacious declaration to manipulate nature was the precarious identitymaking of hydrological engineers from academia who contributed to rationalizing dam construction. This paper shows that the uncertain identity of hydrological engineers resonated with their position in a developing South Korea between the colonial legacy and the Cold War influx of Western knowledge. While working closely with state engineers, academic engineers had the distinct goal of establishing a unique Korean research program, overcoming both colonial river management and the Western methods on which it stood. This paper argues that carving nature ultimately concealed the haphazardness of the national water resources development plan as manifested in the tensions between state and academic engineers. [ABSTRACT FROM AUTHOR]

In the past, the optimization of engineering specifications primarily included the influence of quality loss terms on product quality; however, in actual production practice, compensation quantity inevitably affects the optimization quality of engineering specifications. In this paper, the quadratic exponential quality loss and gain function was first supplemented, and the quadratic exponential quality loss and gain function was constructed under the larger-the-better characteristic and the smaller-the-better characteristic; in order to accurately represent the change in compensation amount in the process of quality control, the optimization method of engineering specification under the calculation of quality loss and compensation was given in combination with the hyperbolic tangent function. Finally, with the support of the dam construction quality acceptance assessment, the engineering specification optimization model was tested. The optimal coefficient was obtained as 0.162, and the specification range was reduced from 0.744 to 0.648, achieving the optimization goal. [ABSTRACT FROM AUTHOR]

The construction of check dams is an important measure to prevent soil erosion on the Loess Plateau and reduce the amount of sediment entering the Yellow River. Based on an analysis of the current situation of soil and water conservation on the Loess Plateau and the three major problems faced by the traditional homogeneous soil check dam construction, the study of anti-scouring materials, hydrological calculation methods, dam design and construction technology and soil and water conservation monitoring are carried out in this paper. The results showed that the current soil and water conservation measures on the Loess Plateau have achieved remarkable outcomes. The new design and application concept of check dams with anti-burst and multi-sand interceptions is innovatively proposed in this paper. The new materials of solidified loess have good durability and anti-scouring characteristics and could meet the overflow and anti-scouring requirements of the new check dam. The small watershed high sand content of hydrological calculation can establish the upper limit of the flood sediment boundary for the anti-scouring protection layer of the check dam. The new technology of dam design and construction can achieve no collapse or slow collapse when encountering floods exceeding the standard. Intelligent monitoring systems can realize real-time dynamic monitoring for soil and water conservation on the Loess Plateau. The results will eventually contribute to the national strategy of the Ecological Protection and High Quality Development in the Yellow River basin. [ABSTRACT FROM AUTHOR]

The instability of dams will bring immeasurable personal and property losses to the downstream, so it has always been a trendy topic worthy of investigation. Currently, the rigid body limit equilibrium method is the most commonly used method for the dynamic stability analysis of dams. However, under the action of earthquakes, the instability of the integral dam-foundation system threatens the safety of the dams and is of great concern. In this paper, a stability analysis method that can reflect the complex geological structural forms of dam foundations is proposed in this paper. The advantages are that this method deals with the difficulty in assuming sliding surfaces and the lack of quantitative criteria for the dynamic instability analysis of dams with complex geological structural forms of dam foundations. In addition, through the method, the sliding channels that may appear in the dam foundations can be automatically searched under random earthquake action, and the safety factors of the dynamic instability of dams be quantitatively obtained. Taking a high RCC gravity dam under construction in China as an example, the proposed method is applied to the three-dimensional finite element model of the dam-foundation system of this dam, and then the dynamic stability calculation is carried out. Through this method, the formation process of the dam foundation's plastic zone and the failure of sliding channels with different strength reduction coefficients are studied on and analyzed detailedly, and the quantitative acquisition of the safety factors is realized. The results show that the method is reasonable and feasible, and helps provide a new idea and method for the dynamic stability analysis of dams. [ABSTRACT FROM AUTHOR]

The flood of the Senegal River is a resource for the populations of the Senegal valley, who practise agriculture, fishing and livestock farming in the annually flooded areas. The objective of this paper is to investigate the hydrological evolution of the Senegal River flood since the drought of the 1970s and the construction and management of the Manantali Dam. To this purpose, the paper analyses the evolution of several parameters of the flood hydrograph and defines the factors that determine the intensity of the flood. Also, a follow-up of the flooded areas in the valley is carried out using remote sensing. The results show that the flood hydrograph has been similar since the 1970s drought, due to the reduction in contributions from the Bafing after the construction of the Manantali Dam. As a result, the high floods depend now on the rainfall pattern in the Sudano-Sahelian zone of the watershed. [ABSTRACT FROM AUTHOR]

For several years, fragility curves have been used to assess the failure probability of flood defences when undertaking probabilistic flood risk assessments. When preparing an editorial, members of the Editorial Board sometimes discuss cases of floods that are topical at the time of writing. [Extracted from the article]

Social infrastructures such as dams are likely to be exposed to high risk of terrorist and military attacks, leading to increasing attentions on their vulnerability and catastrophic consequences under such events. This paper tries to develop advanced deep learning approaches for structural dynamic response prediction and dam health diagnosis. At first, the improved long short-term memory (LSTM) networks are proposed for data-driven structural dynamic response analysis with the data generated by a single degree of freedom (SDOF) and the finite numerical simulation, due to the unavailability of abundant practical structural response data of concrete gravity dam under blast events. Three kinds of LSTM-based models are discussed with the various cases of noise-contaminated signals, and the results prove that LSTM-based models have the potential for quick structural response estimation under blast loads. Furthermore, the damage indicators (i.e., peak vibration velocity and domain frequency) are extracted from the predicted velocity histories, and their relationship with the dam damage status from the numerical simulation is established. This study provides a deep-learning based structural health monitoring (SHM) framework for quick assessment of dam experienced underwater explosions through blastinduced monitoring data. [ABSTRACT FROM AUTHOR]

Rockfill is a common irregular granular material used in most dam construction projects. The purpose of this paper is to investigate the distribution and size-dependent properties of the mechanical parameters describing the elastic properties and crushing strength of rockfill particles. These statistics can be used as a reference to calibrate the input parameters of numerical models when studying the macroscopic behavior of rockfill with particle breakage using the discrete element method. A series of limestone particles ranging in diameter from 20 to 240 mm were measured in this study using a single particle compression test. The elastic modulus, elastic contact stiffness, tensile stress and fracture force were then determined by characterizing each experimental force–displacement curve. Classical statistical methods were used. It has been shown that Weibull, lognormal and logistic functions can all represent the distributional features of the elastic modulus, tensile stress and fracture force, with the lognormal function being the optimal type here. As the grain size increases, the elastic modulus and tensile stress decrease, while the fracture force rises. Empirical models of power functions effectively reproduced these size-dependent laws. Meanwhile, the relationship between these parameters was also established. Finally, the lognormal function was adopted to express the randomness of the maximum elastic contact stiffness. Some suggestions were made after discussing the positive association between the maximum elastic contact stiffness and grain size. Moreover, the evaluation of the loading strain rates of individual particles tested shows that the present conclusions are applicable to quasi-static case. [ABSTRACT FROM AUTHOR]

Safety and environmental aspects are crucial beyond production goals in the hydropower industry. By monitoring landslides associated with the construction of a hydropower dam in the Santa Cruz River in Argentine Patagonia, this paper contributes to the assessment of the project structural integrity of the construction and safety risks. Ground deformation is monitored using synthetic aperture radar (SAR) satellite data and the persistent scatterer interferometry technique, and it is contrasted with optical imagery, geological and technical reports, and fieldwork. The results include maps of accumulated deformation and deformation time series for the locations of the anchorages of the dam, providing a new and independent dataset to assess the integrity of the construction. [ABSTRACT FROM AUTHOR]

The issue of dam type selection is a prevalent challenge in water resource allocation engineering. The site of the Y2 dam in China is suitable for building concrete arch dams and roller-compacted concrete (RCC) gravity dams. To determine which dam type is better in terms of construction progress, this paper proposes a multiattribute decision-making method based on construction simulation. First, the construction characteristics of concrete dams are analyzed, and the construction simulation systems for arch dams and gravity dams are developed based on construction simulation theory. Then, for each dam type, the initial construction schemes are used as the input of the simulation systems, and attribute values of construction progress are output. Secondly, a multiattribute decision-making method is used to select the typical scheme of each dam type from these initial schemes. Finally, the simulation results of the typical schemes for the arch dam and the RCC gravity dam are compared, to determine the optimal dam type for the Y2 dam. The results show that for the Y2 dam, the construction period of the arch dam is 34 months, and that of the RCC gravity dam is 28 months. From the perspective of construction progress, the Y2 dam type should select the RCC gravity dam. Compared with similar dams that have been built, it is concluded that the simulated progress result conforms to the current actual construction level, which also verifies the correctness of the calculation results and the reliability of the construction simulation. [ABSTRACT FROM AUTHOR]

In the absence of a transboundary water agreement between riparian states of Harirud River Basin, downstream states—Iran and Turkmenistan—have adopted a resource-capturing policy through the construction of Doosti Dam in the lower Harirud River Basin when the upstream state—Afghanistan—was engaged in social unrest during 1980s to the early 2000s. While Doosti Dam has a high potential of supplying water for major cities in Turkmenistan and Iran, its flow has declined due to climate changes and drought in the basin. The paper found that Iran accuses Afghanistan of blocking the flow of water through the construction of Salma Dam, whereas some Afghan and Iranian scholars critique Iran's water management approach for water shortages through construction of dams and employment of unsustainable irrigation approaches in the lower Harirud River Basin. Additionally, the hydro-hegemony theory was critiqued as the theory under-estimates the broader role of outside basin players in influencing and reshaping the hydro-politics of a shared watercourse. Finally, it was concluded that the rapid drawdown of the US forces from Afghanistan along with the establishment of a fragile, weak, and politically unrecognized government-Islamic Emirates of Afghanistan—under Taliban administration—helped Iran to reinforce its hydro-hegemonic potential in the basin. [ABSTRACT FROM AUTHOR]

In this paper potential dam sites were identified using remote sensing and GIS. Determinant factors viz., precipitation, slope, flow accumulation, soil texture, land use, and geology were analyzed in the GIS domain. Each factor was reclassified and assigned the suitable fuzzy membership values depending on their influence on the dam site potential. All the fuzzified layers were overlaid using the "Fuzzy Overlay" tool in the GIS platform. Initially, a total of 26 dam sites were proposed. Only seven sites were selected depending on their proximity to nearby dams, settlements, and flow accumulation. The selected dam sites with their flow accumulation, elevation, precipitation, slope, stream order, maximum storage capacity, and the time of concentration were calculated. The determinant factors of suitable dam sites were subjected to the ordinary least squared (OLS) regression to understand the relationship of factors and the potential dam sites. The OLS regression model statistics showed that all factors are positively correlated with potential dam sites except slope (as low slopes are more suitable for dam construction). The OLS regression diagnostics showed that the multiple R squares values and the adjusted R-square values were found to be 0.835894 and 0.872153, respectively. In this study, Koenker's (BP) statistic was found statistically insignificant (p > 0.01), proving that the relationship model is consistent. Jarque–Bera statistic was conducted and also found to be statistically insignificant (p > 0.01) indicating the Gaussian distribution of residuals. This proves that the fuzzy logic approach coupled with OLS regression is a powerful tool in deciphering the potential dam sites and can be applied at a regional and continental scale. [ABSTRACT FROM AUTHOR]

With the increasing height of rockfill dams, detailed and effective numerical simulation for the dam design and construction has become increasingly important. This paper develops a detailed and effective finite element simulation program for the construction and impoundment process of high large-scale earth rockfill dams and studies the influence of numerical simulation accuracy on dam deformation and crack analysis. By establishing the subdivision mode of conventional elements, the mesh generation of detailed finite element simulation is realized. Using the row compression storage method and the MPI parallel method, the calculation program of the total stiffness matrix is developed on the Linux operating system. On the basis of the detailed simulation program above, the filling and impoundment process of Pubugou high core wall rockfill dam is simulated, and it is found that the influence of simulation accuracy on the core wall zone is greater than that on the rockfill zone. Compared with the dam construction process, the detailed simulation of the impoundment process is more necessary. When simulating the impoundment process, there is a significant effect of simulation accuracy on the simulation result of the upstream side of the core wall and the upstream filtration zone. So, it is necessary to simulate the impoundment process of the earth rockfill dam in detail. Moreover, using the detailed method to simulate the impoundment process of earth rockfill dams can more accurately predict dam cracks. [ABSTRACT FROM AUTHOR]

Construction of the dam brings far-reaching changes in the economy and lifestyle of the dam command area. Palai dam is constructed some 16 km from Tangi town and 40 km north of Charsadda city on river Jindai in 2011. The main purpose of the dam is to irrigate 4600 acres of agricultural land in four villages of district Charsadda. This paper is aimed to study the socio-economic impact of Palai Dam on village Qilla and Palai Nasratzai located in tehsil Tangi, district Charsadda, falling in the command area of the dam. The study is based on both primary and secondary data. The primary data regarding household characteristics and socio-economic conditions was collected through a structured and pre-tested questionnaire and focus group discussions. Whereas the secondary data was acquired from the revenue office Tehsil Tangi. According to field survey and analysis of primary data, in Palai Nasrat Zai, the total revenue generated per household from both Kharif and Rabbi crops was PRs. 488511.68 in 2008-09 which incre sed to Rs.1089252.42 after the dam construction in 2016-17. In Village Qilla the net per household revenue from both Rabi and Kharif crops in2008-09 was PRs. 33796.05 which increased to PRs. 66541.74 in 2016-17 after the dam construction. The net income is almost doubled after the dam construction. Thus, this increase in net income is reflected in the socio-economic condition of both villages. Moreover, the area showed the growth of private schools. Also, people are availing the private medical facilities. Furthermore, the proportion of Pacca houses also increased after the dam construction. [ABSTRACT FROM AUTHOR]

This paper presents the water management during 1945-1989 in Romania, all through the communist and command economy period. It follows the investments, waterbeds management works, construction of dams and energy plants all around Romania. The extensive irrigation program as well as the forced industrial development were specific for this period. On the other hand, water supply for population and sewage network was developing strongly. Not all this development had positive follow-up, as conclusions point out in the end. [ABSTRACT FROM AUTHOR]

This paper reports the first account about dynamic changes on genetic diversity and population structure of Leptobotia microphthalma in the Yangtze River drainage due to dam constructions. The genetic diversity and population structure of twelve populations of L. microphthalma collected in 2010 and 2020 were estimated using 12 nuclear microsatellite markers. Reduction of genetic diversity between 2010 and 2020 was not significant in a paired t-test (p > 0.05), but population structure of L. microphthalma had a tendency to change: the genetic differentiation (Fst) among the five populations collected in 2010 were all insignificant (p > 0.05). However, differentiation (Fst) among some populations collected in 2020 were significant (p < 0.05), which indicated the population structure of L. microphthalma was changing. Correlation analysis indicated that negative correlations between the genetic diversities and geographical elevations among populations were significant for seven populations collected in 2020 (r = -0.819, p = 0.039), which means that populations of L. microphthalma in high elevation regions were more vulnerable than those in low elevation regions. Finally, some suggestions for conservation and restoration are proposed, such as artificial propagation, to prevent the further reduction of genetic diversity and population resources. [ABSTRACT FROM AUTHOR]

As the largest dam in the world, the impacts of the Three-Gorges Dam (TGD) on economy and agriculture in the counties along the Yangtze River in China have been subject to debates for a long time, but no conclusions have been made. This paper employs panel data with a wide variety of economic and agricultural variables for 751 counties over the period from 1997 to 2010, which covers the whole building period of the TGD. By calculating the distance of these counties to the dam site and applying the differences-in-differences (DID) method, the results generally imply that the TGD negatively affected economic growth in the downstream counties along the mainstream river. Conversely, counties located closer to the dam site in the upstream received economic benefits. Regarding its effects on agricultural productions, cotton yields of the upstream were negatively affected by building the TGD, while oil production planted in the upstream region were stimulated to grow since the functioning of the dam in 2003. This study proves both the economic and agricultural advantages/disadvantages of the dam in different construction periods for different locations of counties, and sheds light on policy implications for compensating the counties from economic and agricultural lenses due to the TGD construction. [ABSTRACT FROM AUTHOR]

Dams have proliferated along the Mekong, spurred by energy demands from economic development and capital from private companies. Swift dam evolution has rendered many databases outdated, in which mismatches arise from differing compilation methods. Without a comprehensive database, up-to-date spatial assessment of dam growth is unavailable. Looking at future development, hydropower potential specifically within the Mekong remains to be systematically evaluated. In this paper, we offer (1) an open-access and unified database of 1,055 dams, (2) a spatiotemporal analysis of dams on a sub-basin and country level from the 1980s to the post-2020s, and (3) a grid-based assessment of the theoretical basin-wide hydropower potential, using present-day discharge from the CaMa-Flood model (2011-2015, 0.05 degree), and future discharge from the WaterGAP2 model used for ISIMIP2b (2021-2030, 0.5 degree). The dam count of 1,055 is more than twice the largest existing database, with 608 hydropower dams generating a boom in hydropower capacity from 1,242 MW in the 1980s to 69,199 MW post-2020s. While China had the largest capacity increase from the 2000s to the 2010s (+16,854 MW), Laos has the most planned dams and the highest projected growth post-2020s (+18,223 MW). Based on present-day discharge, we estimate a basin-wide hydropower potential of 1,334,683 MW, where Laos is the highest at 514,887 MW. Based on future discharge modeled with climate change, hydropower potential could grow to over 2,000,000 MW. Laos and China are the highest at around 900,000 MW each, together forming over 80% of the total potential. Our database facilitates research on dam-induced hydrological and ecological alterations, while spatiotemporal analysis of hydropower capacity could illuminate the complex transboundary electricity trade. Through both spatiotemporal and hydropower potential evaluation, we address the current and future vulnerability of countries to dam construction, highlighting the need for better planning and management in the future hydropower hotspot Laos. The Mekong dam database is publicly available at https://doi.org/10.21979/N9/ACZIJN (Ang et al., 2023). [ABSTRACT FROM AUTHOR]

Inversion analysis is usually an efficient solution to process the monitoring data of earth-rockfill dams. However, it is still difficult to obtain calculation results that are consistent with monitoring data due to different construction statuses. To deal with this situation and to introduce a new solution to improve calculation accuracy, the general method of inversion analysis based on back-propagation neural networks and the original step-by-step inversion method assuming that the parameters of the constitutive model vary with construction periods are introduced and verified in this work. Then, both methods are applied in the inversion analysis of a high gravelly soil core rock-fill dam during construction periods. Moreover, the relationship between the inversed material parameters and the stress values of the core wall is discussed. The material parameters are further optimized to obtain more accurate displacement values. The results show that the step-by-step inversion method has a higher accuracy in vertical compression values compared with the conventional inversion method, the trend of material parameter K is more significant than other parameters, and the proposed variable parameter constitutive model has an accuracy between the step-by-step and conventional inversion methods. Conclusions can be drawn that the original step-by-step inversion method has more advantages than the conventional method and the variable parameter constitutive model proposed in this paper might be more suitable for the analysis of a high earth-rockfill dam during construction periods. [ABSTRACT FROM AUTHOR]

This paper uses a political ecology approach to unpack the experience of local governments and displaced communities in Sarawak, Malaysia, with Chinese dam construction at the Bakun Hydroelectric Dam. Data for the study was collected over 32 months from 2014 to 2016. The field site offered a unique insight into how recipient countries of aid are also often at the receiving end of domestic politics of donor countries. The paper finds that Chinese and Australian enterprises involved in the dam construction and resettlement of indigenous communities displayed different understandings with regards to social and environmental safeguards, resulting in a dysfunctional handover of the project from Australian to Chinese leadership. Consequently, indigenous communities were dispossessed from their land, affecting their ability to successfully reconstruct their livelihoods, with their attempts to do so causing further damage to the environment around the reservoir of the dam. [ABSTRACT FROM AUTHOR]

Due to its natural features, the Neretva River has been interesting throughout its stream for the construction of energy facilities, as well as its tributaries Rama, Trebišnica, Tihaljina, Lištica. Jablanica (1955), HPP Rama (1968), CHE Čapljina (1979), HPP Salakovac (1981), HPP Grabovica (1982), HPP Mostar (1987), HPP Peć Mlini, HPP Mostarsko blato have been built on the Neretva River and its tributaries. HPP. The aim of this paper is to determine the state of chemical and physical parameters of water in reservoirs and streams, as well as the parameters of the aquatic environment in which endemic salmonids previously lived and the possibility of revitalization of these watercourses. The ecological conditions of the Neretva reservoirs for the life of Neretva-endemic fish and the similarity to the conditions in the natural course of Neretva before the construction of the dam were examined. The research was conducted during 2017 and 2018 at several locations in the Neretva river basin (reservoirs and streams). [ABSTRACT FROM AUTHOR]

Knowledge of soil, which is an essential construction material, has great importance for dam construction. The level of density and carrying capacity of the soil is very important and should be taken into consideration in the planning and designing stages of civil construction, considering the soil functions as a means to withstand the load or structure built on it. Stabilization using sand soil material is one of the ways to meet the strength requirements of soil carrying capacity when there is no suitable soil material found in the nearby area. This paper aims to elucidate the physical properties of clay using a mixture of fine sand to reduce the risk of shrinkage when used for dam construction. Several analyses were carried out to find out the effect of the fine sand percentage in the clay mixture to decrease the swelling test value and permeability test of the soil carrying capacity for dam construction. The types of soil tested were silt clays taken from Tritisan subdistrict of East Lampung which were then stabilized using fine sand material from Central Lampung, Indonesia. This research was conducted using a mixture of sand, with percentages of 10%, 20%, 30%, and 40%. Subgrade tests such as CBR and permeability tests were also undertaken to investigate other soil properties from each sample. The results indicate that a higher percentage of sand causes decreasing water content. Thus, the value of the carrying capacity of the soil is increasing. The findings can be used to facilitate the increasing use of clay mixtures with the percentage of fine sand in case suitable clay material cannot be found around dam construction sites. The implications with suggestions for future research are also discussed. [ABSTRACT FROM AUTHOR]

The paper first presents a general overview of the problem of dam construction - the formation of reservoirs in karst terrains, followed by the overview of the karst terrains specificities, specificities of engineering geological problems, and the relevant influence factors of the karst process and its forms on dam construction in karst. The construction of dams in karst terrains is a special problem that requires additional conditions in relation to the conditions in other terrains, which is why special care is needed during engineering geological research, as well as construction and operation. There are numerous, complex, diverse and specific engineering geological problems in karst terrains, almost always somewhat different, at each new location, which must be taken into account when constructing dams. Typical examples of the engineering geological risk of constructing dams in karst terrains, from foreign and domestic practices, are presented at the end of this paper, including both, remediation works that have given positive solutions, and cases where extensive and long-term remediation works with high financial resources have not given satisfactory results. Special attention is given to the risk of water seepage from the accumulation. [ABSTRACT FROM AUTHOR]

The present paper aims itself as an investigation whether a historical graphic narrative with the help of its engaging representation of history might be able to induce a reader's empathy or not. It attempts to highlight and explore the empathic details in Orijit Sen's historical graphic text, The River of Stories. Though it is a debatable issue whether every work of art should have an objective or not, the reader finds Sen's social and political purpose of making people aware of the details of the protest and its horrific and crude consequences against the construction of a dam on the river Narmada and the consequent inducing of empathy into them. Hence, heartrending details of their protest and the adverse effects which induce readers' empathy are portrayed artistically and proficiently by Sen through the entire gamut of the story. [ABSTRACT FROM AUTHOR]

The contribution of this paper is twofold: 1) it develops a replicable socio-hydrology-inspired model that elicits agents' preferences while accounting for the two-way feedbacks between complex human and water systems; and 2) it integrates the resultant socio-hydrology model into robustness-based frameworks to inform the adoption of policies that show a satisfactory performance under most plausible futures. The socio-hydrology model is used to produce a database representing multiple plausible futures that quantifies uncertainty regarding scenario assumptions under alternative adaptation strategies. Using a robust decision-making framework, the mechanistic outputs from the database of plausible futures are combined with heuristic methods through experts' knowledge and opinion to co-design scenarios, identify vulnerabilities and quantify tradeoffs of proposed strategies, and subjectively propose new scenarios and choose the preferred adaptation strategy. Methods are illustrated with an application to the Cega Catchment in central Spain, one of the few major catchments in central Spain that remains non-regulated, and where the construction of a major dam has been projected. Following a robust decision-making process informed by our socio-hydrology model and involving all key parties to the decision, the status quo strategy (no dam construction) was revealed preferred. • We mainstream socio-hydrology modeling into robustness-based decision-making frameworks. • Socio-hydrology modeling quantifies impacts and uncertainties for selected strategies. • Models are combined with experts' knowledge and opinion to identify robust strategies. • Methods are illustrated with an application to dam construction in the Cega Catchment (Spain). • The status quo strategy (no dam construction) was revealed preferred. [ABSTRACT FROM AUTHOR]

Accurate determination of rock mass deformation modulus is very important in rock engineering projects. The plate loading test (PLT) is a method that is generally used in dam construction projects to determine rock mass modulus. Numerical simulation was used to investigate the mechanisms involved in this test. The first objective of the paper was to employ 3D modeling in the interpretation of plate load tests conducted at the Bazoft dam site in Iran. Additionally, a parametric study of the effects of key parameters such as displacement measuring depth and loading plate diameter on the test results was another objective of the study. The moduli values determined numerically were compared against actual filed testing data determined from in-situ test data conducted at the Bazoft dam site, and the values determined from the ISRM suggested formula. The analysis showed that the optimum measurement depth for rock mass modulus calculation is approximately equal to the loading plate diameter and the data determined from measurement depths beyond one plate diameter can be unrealistic. Moreover, the plate diameter can have a significant effect on test results. As the measurement depth increases, the determined modulus values increase at a much more rapid pace when employing smaller size loading plates. [ABSTRACT FROM AUTHOR]

This paper comprises the search of the optimal geometric parameters (area and volume) for double-arch dams. The approach is structured in several consecutive stages. The process begins with a definition of the problem about Bayesian estimators, to define the dam-shape design values. After that, an iterative sequence of equations calculation was developed until reaching a solution that satisfies the a priori established constraints. A modeling of the optimized dam has been carried out to estimate static and dynamic internal stresses. Data were retrieved from inventories of existing dams, whereas to obtain the unknown data, a Gaussian distribution under hypotheses of the Bayes' theorem has been employed. This theorem converts the a priori distribution, through unknown parameters, into the a posteriori distribution providing expected estimators. The design of the dam shape is strongly based on the experience, therefore by collecting real information about existing dams a more accurate analysis is possible. [ABSTRACT FROM AUTHOR]

This paper applies the boundary face method (BFM) to solve both steady-state and unsteady-state heat conduction problems in the dam construction. Instead of employing the isoparametric elements as in the boundary and finite element methods, the BFM uses directly geometric models from CAD packages to avoid geometric errors for any complex structures. Moreover, the variable approximations and the boundary integration are all performed in the parametric space of the boundary surfaces, which means that the elements and integral patches are defined in the parametric space. A numerical example of steady-state analysis presented in this paper is a concrete dam structure which consists of several blocks. The example of unsteady-state analysis, which concerns a single block with several holes in it, has also been presented to illustrate the validity and the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

This paper describes an earth-rock dam whose filters' characteristics did not comply with the design criterion. In addition, the degree of compaction and the water content in the impervious core consisted of highly plastic residual clay. Although Terzaghi's filter design criterion was used, the as-built grain size distribution did not comply with such criterion. Several problems arose right after the first filling of the dam, including the following: (1) water leak at a rate of 200 L/s was observed along the downstream slope, in the vicinity of the outlet pipeline; the dark color of the observed water implied that the core material was being eroded; (2) two sinkholes near the crest (20 m apart) were observed along the outlet axis, one on the upstream and the other on the downstream slopes; right after the occurrence of these two sinkholes, the water leakage decreases significantly, noticing a plugged effect of the material that falls down through the sinkholes. To avoid piping, a notch was installed on the spillway to quickly reduce the reservoir level. A site investigation around the affected zone was performed to find the causes of the observed seepage through the dam. The paper presents a detailed description of the site investigation. In addition, the paper presents the instrumentation, laboratory, and field tests employed as part of the site investigation. After analyzing the information produced in the site investigation, the following conclusions were derived: (1) large variation in the water content was used during the compaction of each lift of the impervious core which resulted in a highly heterogeneous core of the dam; (2) stress analysis of the zones around the outlet pipe demonstrated that the hydrostatic pressure in such zones exceeded the sum of the transverse normal and tensile stresses, inducing hydraulic fracturing; and (3) because of the grain size segregation during the placement of the filter material, the upstream and downstream filters did not satisfy the design criterion. Description of the stabilization of the damage zones through a grouting process, together with the construction of a diaphragm wall and an interface grouting, is presented. Finally, this paper reviews existing criteria for designing filters to protect earth and rockfill dams against internal erosion or piping and applies these criteria to the described dam. A special discussion on this topic is also presented. [ABSTRACT FROM AUTHOR]

Based on the research project entitled ‘Data Collection and Decision Support System for Hydropower Dam Construction’ sponsored by the National Development and Reform Commission of China, this paper puts forward a multilayer architecture and a support system for the knowledge portal utilizing web services and J2EE while offering a method for integrating existing resources. The purpose for this system is to help the China Gezhouba Group Corporation (CGGC) manage the construction of a large-scale hydropower dam. Through the interoperability in distributed environment, software integration technology and heterogeneous system integration, the interoperability of heterogeneous systems is realized by the enterprise application integration (EAI). In this project, an open and unified integration environment is provided by the analytic system (AS), making it possible for all kinds of software resources to be made readily accessible. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]