Dam System Research Articles

Morphological and molecular analysis of Propanagrolaimus siweyae sp. n. (Nematoda: Panagrolaimidae) from Molepo dam, Limpopo Province, South Africa, and its relationship with water parameters

AbstractPanagrolaimidae members are bacterivorous with global distribution. There is no information on this species' morphology and molecular characterization in South Africa. During a survey of Molepo dam, Limpopo Province, a population of Propanagrolaimus nematodes belonging to the family Panagrolaimidae was recovered and determined utilizing conventional and molecular characters. Propanagrolaimus siweyae sp. n., was confirmed by morphological and molecular informations. Propanagrolaimus siweyae sp. n. is characterized by a body length 1026–1258 µm (a = 39.4–45.5, b = 5.4–6.5, c = 8.1–10.0, c’ = 6.9–7.8, V = 53–57), post vulval uterine sac 25–53 µm, and tail length 108–158 µm long. The scan electron microscopy (SEM) photographs revealed a tessellated cuticle and six slightly separated lips. The discriminant analysis placed populations of P. siweyae sp. n. close to P. hygrophilus with clear separation from the mentioned species. Partial sequences of the 18S and 28S regions of the ribosomal DNA gene were amplified for P. siweyae sp. n. The phylogenetic analysis grouped P. siweyae sp. n. in a clade with 1.00 and 0.87 posterior probability values together with other Propanagrolaimus and Halicephalobus based on 18S and 28S rDNA, respectively. Principal component analysis revealed no correlation between Propanagrolaimus and water parameters. However, the result showed a high correlation with diatoms (r = 0.937) in Molepo dam (site MD-6). In contrast, The PCA showed salinity, pH, and temperature with no significant effect on nematodes in Molepo dam, Limpopo Province, South Africa. In conclusion, the usefulness of free-living nematodes as bioindicators is an advantage to studying pollution in aquatic systems. Limpopo Province is facing pollution in the river and dam systems. Therefore, finding a bioindicator is critical to examine the ecological role of free-living nematodes such as Propanagrolaimus.

3D Modelling and Measuring Dam System of a Pellucid Tufa Lake Using UAV Digital Photogrammetry

The acquisition of the three-dimensional (3D) morphology of the complete tufa dam system is of great significance for analyzing the formation and development of a pellucid tufa lake in a fluvial tufa valley. The dam system is usually composed of the dams partially exposed above-water and the ones totally submerged underwater. This situation makes it difficult to directly obtain the real 3D scene of the dam system solely using an existing measurement technique. In recent years, unmanned aerial vehicle (UAV) digital photogrammetry has been increasingly used to acquire high-precision 3D models of various earth surface scenes. In this study, taking Wolong Lake and its neighborhood in Jiuzhaigou Valley, China as the study site, we employed a fixed-wing UAV equipped with a consumer-level digital camera to capture the overlapping images, and produced the initial Digital Surface Model (DSM) of the dam system. The refraction correction was applied to retrieving the underwater Digital Elevation Model (DEM) of the submerged dam or dam part, and the ground interpolation was adopted to eliminate vegetation obstruction to obtain the DEM of the dam parts above-water. Based on the complete 3D model of the dam system, the elevation profiles along the centerlines of Wolong Lake were derived, and the dimension data of those tufa dams on the section lines were accurately measured. In combination of local hydrodynamics, the implication of the morphological characteristics for analyzing the formation and development of the tufa dam system was also explored.

Prediction intervals for concrete face sandy gravel dam settlement using Kalman filter-based kernel extreme learning machine

Accurately predicting settlement of concrete face sandy gravel dams is a crucial yet challenging task. The conventional approach of point forecasting can hardly describe the uncertainties inherent in the complex dam system. Hence, a hybrid prediction interval (PI) method using Kalman filter-based kernel extreme learning machine (KELM) is proposed to quantify the uncertain information associated with dam settlement prediction. The Kalman Filter (KF) is integrated into the original KELM by incorporating real-time actual measurement. The wavelet multiresolution analysis is employed to eliminate irrelevant information from historical settlement time series for more accurate prediction. Additionally, a Bayesian method is used to detect change points in the KF modified-KELM model. The proposed method is demonstrated in the settlement monitoring of the Nazixia dam and is compared with three popular machine learning methods. Results indicate that the PI constructed by the proposed method can exhibit better interval coverage and a comprehensive index.

Forecasting and uncertainty analysis of tailings dam system safety based on data mining techniques

Tailings dams, as critical infrastructure, play a vital role in ensuring the safety and reliability of tailings pond systems. Predicting the trend of tailings dam monitoring parameters helps monitor its operational status and support safety management and decision-making. The traditional time series prediction model focuses on point prediction while neglecting the nonlinear feature of data and the uncertainty of prediction results, which is far from meeting the requirements for risk monitoring and safety management of tailings dam systems. To address this, Deep Auto-Encoder is used to extract and optimize features of multi-dimensional time series; Whale Optimization Algorithm, Long Short Term Memory, and Kernel Density Estimation are used to build a monitoring parameters trend interval prediction model. It can effectively predict and analyze the uncertainty of tailings dam monitoring parameters. Time series data of monitoring parameters are collected from a tailings dam in Anhui, China and modeled to verify the effectiveness of the model. The results show that the hybrid prediction model performs the best in monitoring parameter prediction accuracy and trend. The Root Mean Square Error values of the Whale Optimization Algorithm and Long Short Term Memory prediction for reservoir water level, surface displacement, internal displacement, phreatic line, and beach width are 0.0160, 1.0405, 0.0389, 0.0176, and 0.7525, with errors reduced by 0.37 % to 17.92 % compared to other models. The uncertainty analysis confirms the high reliability of the model. The Kernel Density Estimation effectively forecasts the fluctuation range of predicted values, significantly improving the prediction effectiveness of the monitoring parameters.

Attitude of Dental Students Toward Rubber Dam Application: A Cross-Sectional Study.

Introduction The rubber dam (RD) system is globally recognized as an indispensable component of dental treatments, ensuring the highest standards of care. The use of RD isolation profoundly impacts the clinical aspects of dental procedures. The aim of this study was to assess the attitudes of dental students toward the use of RD, with an emphasis on evaluating the factors influencing its use among students at Umm Al-Qura University in Makkah city, Kingdom of Saudi Arabia. Methods An online questionnaire was distributed to a population sample of 203 undergraduate dental students in their clinical years at Umm Al-Qura University. Questions covered various aspects, including the frequency of RD use, perceptions of its effectiveness, and prospective intentions for its future use, as well as factors influencing these attitudes. Statistical analysis was performed using SPSS software Version 26 (IBM Corp., Armonk, NY, USA). In addition, the chi-square test and Fisher-Freeman-Halton exact test were used for the comparison of the data at a significance level of p<0.05. Results The questionnaire was completed by 191 participants, with a response rate of 95.5%. Of the students, 189 (99%) used RD during operative procedures for adhesive restorations. Furthermore, 157 (82.2%) students agreed that proper isolation cannot be achieved without RD application. All the advantages of RD application were recognized by 165 (85.9%) of the students. Notably, there was a significant association between the factors limiting the RD application and the students' academic year (p<0.05), with senior students reporting fewer limitations. Responses indicated that 163 (85.3%) of the students received satisfactory training for RD and 165 (86.4%) students had a high intention to continue using RD following graduation. Conclusion Within the limitations of this study, it can be concluded that the results presented a positive attitude toward RD use. However, there is a continued necessity to enhance education and advocate consistent RD application for improved patient care and clinical outcomes.

Relationships between torrent check dam systems and shoreline dynamics in semi-arid Mediterranean area: A sub-regional focus in Calabria, Italy

The work reports the results of investigations on the historical evolution of the shoreline in relation to the presence of check dam systems along streams of the Mediterranean environment. To this end, a survey methodology specifically developed in a previous work, which provided initial indications worthy of more extensive evaluation, was integrated and applied to the watershed-coast system of eight Calabrian streams, six falling on the Ionian side and two on the Tyrrhenian side of the Aspromonte Massif, as the sides present significantly different climatic and geomorphological characteristics. The streams under investigation, with watershed areas ranging from 39.2 to 160.3 km2, have been affected by relevant restoration programmes with transverse control works carried out over four periods from 1954 to today. Overall, about 690 check dams were examined, distributed over the “mountain”, “intermediate” and “valley” reaches that were normalised for comparison purposes. Based on the intensity of intervention with check dams, five watersheds are included in the “medium-high” category and three in the “low” category. The volumes of sediment corresponding to shoreline movements (retreats or, less frequently, advances) and those retained upstream of the check dams, generally silted a few years after construction, were estimated and analysed. The overall results obtained highlight a relationship between the retirement tendency of the shoreline (with observed retreats up to 170 m and affected long shores up to 5 km) and the construction of transverse control works, suggesting that particular attention should be paid to the insertion of transverse works, as well as to their typology, in the valley reaches, in one effort to combine the requirements concerning with the hydrogeological safety and the stability of the shoreline asset, limiting the need of remediation measures for coastal protection, as it actually happens along the widespread urbanized strips.

Research and Development of an Embedded Multi-Channel Sensor Data Acquisition Device for Reservoir Dams

The embedded system of intelligent reservoir dam achieves the integration and efficient utilization of water conservancy dam system data through multi-channel data collection and analysis calculated by computer technology, CNC system, and neural network. Compared with traditional data collection and processing methods, both timeliness and accuracy have been greatly improved. This study aims to develop a multi-channel sensor data acquisition device for reservoir dams based on embedded system technology. This device can collect real-time and efficient data from sensors in various parts of the dam, ensuring the safe operation of the reservoir dam. By using advanced embedded system technology, this device has advantages such as low power consumption, high stability, and real-time data transmission. The Analytic Hierarchy Process (AHP) was used to study the embedded multi-channel sensor data acquisition device for reservoir dams in multiple directions and factors. The AHP method provides an effective means for problem decision-making in complex situations. Referring to the AHP method, the factors that affect reservoir dams can be divided into different levels. Compare the importance of two random factors in each level to obtain a specific quantitative expression of the relative important factors on a scale. Then repeat this step to obtain the weight ranking for different levels. At the same time, the device monitors key parameters such as temperature, humidity, displacement, and pressure in various parts of the dam through multiple sensors, providing strong support for early warning and decision-making of reservoir dams. The results of this study have important practical significance and application value for improving the safety and stability of reservoir dams.

Reduction of large vessel traffic improves water quality and alters fish habitat-use throughout a large river

Rivers are increasingly used as superhighways for the continental-scale transportation of freight goods, but the ecological impact of large vessel traffic on river ecosystems is difficult to study. Recently, the temporary maintenance closure of lock and dam systems on the Illinois Waterway (USA) brought commercial vessel traffic to a halt along the river's length, offering a rare opportunity to study the response of the ecosystem before, during, and after an extended pause of this persistent anthropogenic disturbance. We observed improvements in main- and side-channel water quality and a redistribution of fish habitat-use during a months-long, near-complete reduction of large vessel traffic. Over 3600 water quality and 1300 fish community samples indicate that large vessel traffic reduction coincided with a 33 % reduction in turbidity as well as increased use of sampling strata near vessel navigation corridors by sound-sensitive and rheophilic fishes. Gizzard shad (Dorosoma cepedianum), the most abundant species in the system, also expanded their use of these ‘impact’ areas. Though inland waterway transport is an economically- and climate-friendly alternative to trucking and rail for the shipment of freight, our data suggest that intense vessel traffic may have profound physical and biological impacts across a large river. Monitoring and mitigation of ecological impacts of the ongoing expansion of inland waterway transport around the world will be critical to balancing large rivers as both useful navigation corridors and functional ecosystems.

Phytoplankton species composition as bioindicator in the largest fragmented channel of the Pearl River, China.

To test the serial discontinuity concept (SDC) predictions in a regulated river ecosystem, environmental parameters and phytoplankton community structure were determined in a subtropical river (China) which was regulated by 11 cascade dams. Our results showed that total phosphorus (TP) and silicate during the wet period in several dams supported the SDC predictions. Variations of phytoplankton species composition in several cascade dams, such as Datengxia (DTX) and Changzhou (CZ), also supported the SDC predictions. Moreover, the stations near the dams showed the maximum or minimum values of total species numbers in each cascade segment. Predictive model indicated that the types of phytoplankton decreased in the middle reaches, conforming to SDC predictions. In the whole system of cascading dams, an increase in silicate concentration and phytoplankton communities in the downstream was also consistent with SDC predictions. Therefore, these findings aligned with the SDC predictions in the aspects of both single dam and whole cascade dam system to some extent. In future research, our aim is to further investigate the effects of cascade damming on additional phytoplankton-related indices in this aquatic ecosystem. We hope to gather more comprehensive data to fully validate the SDC predictions.

Comparison of Functional Outcomes of Two Different Rubber Dam Systems in Dental Practices

&lt;p&gt;&lt;strong&gt;Background and Objective:&lt;/strong&gt; The rubber dam is the only method that can ensure complete isolation during dental procedures. During endodontic and restorative procedures, it improves patient protection, treatment efficacy, and infection control. A novel rubber dam system called Optradam has introduced a remarkably comfortable, user-friendly clamp-free technique. Therefore, this study was conducted to compare conventional rubber and OptraDam&amp;reg;Plus (Ivoclar Vivadent) based on patients&amp;rsquo; and dentist preferences.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;After receiving ethics board clearance, this trial was carried out at the Department of Operative Dentistry at a tertiary care hospital in Islamabad from June to December 2022. A total of 30 participants were assigned to each group; conventional rubber dam (Group-1) and OptraDam&amp;reg;Plus (Group-2). Two questionnaires were designed and validated one to be completed by dental practitioners and the other by patients. The gathered information was analyzed using statistical tests of significance.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; A total of 60 patients were treated; 31 (52%) males and 29 (28%) females with a mean age of 32.35 years (SD = 4.59). Both the dentists (80% ) and the patients (73.3%) favored the conventional rubber dam system (Group-1). Concerning patient comfort, the conventional rubber dam (96.7%) was considered more comfortable than the OptraDam&amp;reg;Plus (Group-2) (86.7%). More effective moisture management was seen in Group-1 patients (90%). Other factors, such as time, convenience of application, and imaging radiography, had statistically insignificant results among both groups.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; The results indicate that both patients as well as operators, preferred the use of conventional rubber dams over OptraDam&amp;reg;Plus during an endodontic and restorative procedure.&lt;/p&gt;

Study of irrigation aspect in the interconnection system of Telaga Tanjung and Singin Ponds in Tabanan Regency

Interconnection is a channel that links multiple water channel systems with those downstream of a river area. The proposed system will utilize existing canals in Gadungan, Matan, and Unun Irrigation Areas, extending to the Lambuk Reservoir dam system. The problem is that irrigation areas downstream of the Lambuk Reservoir are Lambuk (726 ha), Babakan Anyar (42 ha), and Lanyah (281 ha) experience water shortages (planting intensity of 170% to 200%) during the dry season. The study utilized water balance methods in rice fields, the basic year method for main discharge at weirs, and interconnection channel analysis for water needs calculation. From the water balance analysis, the Singin System cannot make a new interconnection channel to the Lambuk Reservoir because the available water in each reservoir can only irrigate the Matan and Unun Irrigation Areas. From the Telaga Tunjung System, there is still a lot of water available, especially during the rainy season, so that it can supply the reservoir for the Lambuk Reservoir. This means that the interconnection system from this reservoir still needs to be created from the primary channel of the Gadungan Irrigation Area.

Modeling Variability in Seismic Analysis of Concrete Gravity Dams: A Parametric Analysis of Koyna and Pine Flat Dams

This study addresses the vital issue of the variability associated with modeling decisions in dam seismic analysis. Traditionally, structural modeling and simulations employ a progressive approach, where more complex models are gradually incorporated. For example, if previous levels indicate insufficient seismic safety margins, a more advanced analysis is then undertaken. Recognizing the constraints and evaluating the influence of various methods is essential for improving the comprehension and effectiveness of dam safety assessments. To this end, an extensive parametric study is carried out to evaluate the seismic response variability of the Koyna and Pine Flat dams using various solution approaches and model complexities. Numerical simulations are conducted in a 2D framework across three software programs, encompassing different dam system configurations. Additional complexity is introduced by simulating reservoir dynamics with Westergaard-added mass or acoustic elements. Linear and nonlinear analyses are performed, incorporating pertinent material properties, employing the concrete damage plasticity model in the latter. Modal parameters and crest displacement time histories are used to highlight variability among the selected solution procedures and model complexities. Finally, recommendations are made regarding the adequacy and robustness of each method, specifying the scenarios in which they are most effectively applied.

Solution of Subsurface dam for water supply

Subsurface dam is a dam system that built in earth’s worb to reserve water and to increase levels of aquifer ground. Region with harsh climate conditions, low rainfall, land is uncultivated, low level of ground water then capacity to provide water is limited. Therefore, subsurface dam is a solution to help to improve the groundwater table, provide water during dry season. At coastal land, beside the advantage of reserve water, the subsurface dam also helps to present infiltration of salt water. This article discusses about subsurface dam, solutions to build the subsurface dam and its application scale, advantages and disadvantages of applying subsurface dams in Vietnam. Moreover, the author proposes solutions for water supply to areas which are shortage of water in Ninh Thuan province, Vietnam.

Securitization of Water in Central Asia: Insights from the Regional Water Security Complex

Central Asia is revealing itself as an area where the problem of access to water and its current regional dynamics are almost at a radically critical level, where the potential risk of water disputes is still one of the highest in the world. Therefore, water scarcity issues and challenges triggered by the Aral Sea syndrome, the existing water mismanagement system, infrastructural and investment projects of dams and water reservoirs (Rogun, Naryn, Kambarata, Toktogul, etc.) and their transformation towards an existential threat will be analyzed within the securitization prism through the selected speech acts. This article will contribute to developing a new analytical framework of Regional Security Complex Theory (RSCT) and the securitization theory in water stress. The efforts undertaken in this article will ultimately lead to the development of a new approach to issues of water security and hydro politics within the concept of the Regional Water Security Complex (RWSC) on the example of the Central Asian region. The main research question will be to what extent water, as an immanent feature of this complex, is politicized and securitized. An important question will also be how the formulated security language indicates the existential nature of water as a security problem in the region.

Stosunki węgiersko-czechosłowackie z węgierskiej perspektywy (1990–1992)

As a result of the first free and democratic elections in Hungary, in May 1990, József Antall formed a government, whose foreign goal was the restoration of the sovereignty of Hungary and the support and representation of the Euro-Atlantic integration and of the Hungarians across the border. In the Hungarian-Czechoslovak bilateral relations, the new Hungarian government’s aim was to expand the political relations in both federal and republican levels. It was Hungary’s interest that serious legacies, such as the issue of the Bős-Nagymaros Dam system, should not hold back the general advance, therefore, a solution appropriate for both parties had to be found. The paper presents the Hungarian-Czechoslovak relations from the Hungarian perspective in the years 1990–1992.

Distribution of the riverine benthic macroinvertebrate community along the citarum cascading dam system in West Java, Indonesia

Distribution of the riverine benthic macroinvertebrate community along the citarum cascading dam system in West Java, Indonesia

Dam System and Reservoir Operational Safety: A Meta-Research

Dams are critical infrastructure necessary for water security, agriculture, flood risk management, river navigation, and clean energy generation. However, these multiple, and often conflicting, objectives introduce complexity in managing dam operations. In addition, dam infrastructure has been evolving as complex systems-of-systems with multiple interacting components and subsystems, all susceptible to a wide range of uncertainties. Such complexities and uncertainties have triggered extensive research initiatives focused on dam systems and reservoir operational safety. Focusing on the latter, this paper meta-researches (conducts research-on-research) previously published studies to identify the critical research gaps and propose future research directions. In this respect, this paper first performs a quantitative analysis of the pertinent literature, using text mining and subsequent topic modeling, to identify and classify major and uncover latent topics in the field. Subsequently, qualitative analysis is conducted to critically review the identified topics, exploring the concepts, definitions, modeling tools, and major research trends. Specifically, the study identified seven topics: optimization models; climate change; flood risk; inflow forecasting; hydropower generation; water supply management; and risk-based assessment and management. The study also presents three main research gaps associated with the limitations in modeling concepts, modeling tools capabilities, and the lack of resilience-guided management of dam operational safety. Overall, this study presents a road map of the currently available dam and reservoir operational safety research and associated knowledge gaps, as well as potential future research directions to ensure the resilience of such critically important infrastructure, especially in the age of climate change.

Raising of Embankment of an Ore Tailings Pond and an Analysis of its Stability

Abstract The article presents a method for the intensification of a tailings pond. A tailings pond serves for the hydraulic storage of silt-sand waste arising during a flotation treatment and the processing of polymetallic ores. The intensification of the tailings pond consisted of raising its dam system to increase its accumulation space. The total proposed height of the tailings pond dam system after its elevation will be 60 m. The structural and shape arrangement of the dam in the dam system of the tailings pond was the result of a stability analysis of the state of the tailings pond before and after the dam system was raised. The article presents the results of experimental verifications of the geomaterial properties that form quasi-homogeneous units of the tailings pond (subsoil, dam system, and sediment) that serve as the inputs for stability analyses. New limiting and critical water levels are modelled based on the stability analysis for the intensified dam system of the tailings pond, taking into account the standard requirements for its overall stability.

Climate stress impacts on the reservoir inflows: a decision-scaling and IHACRES modeling approach in South Korean basins

Abstract This study employed the Decision-Scaling (DS) approach and the IHACRES (Identification of unit Hydrographs And Component flows from Rainfall) long-term runoff model to investigate the impact of composite changes in rainfall and temperature on dam inflows at Chungju dam, Yongdam dam, Hapcheon dam, and Seomjingang dam basins. By analyzing flow regimes, rainfall scenarios, and temperature scenarios, the study revealed crucial insights into dam inflow and its response to climate stressors. The findings demonstrated that the rate of inflow increase in the study basins exceeded the rate of rainfall increase, indicating the significance of basin storage effects in contributing to runoff generation. The analysis of rainfall changes by quantile highlighted the dominant influence of the upper-high (UH) rainfall quantile, which led to higher flood inflow compared to other quantiles. Furthermore, scenarios with different rainfall patterns were compared, showcasing the predominant impact of UH quartile rainfall on the total inflow variation. The study also analyzed the runoff ratio, finding that changes in precipitation proportionally affected the runoff ratio. Overall, these insights contribute to understanding the sensitivity of dams to changes in rainfall and temperature, facilitating the development of strategies for sustainable water supply and flood management in dam systems.

Guide curves in stochastic dynamic programming to optimize operation policies in sequential hydropower dams

The guide curves are tools that specify rules for dam operation that allow reducing the chances of unwanted spill or deficit events. In this research, we analyzed the importance of using guide curves and penalizing the deviation of such curves by the occurrence of surplus volume, or deficit, using optimization tools on an objective function that apply stochastic dynamic programming (SDP), guide curves and reservoir operation simulation all together, to obtain and evaluate biweekly operation policies for hydropower generation purposes. The main dams of the Grijalva River were taken as a case study. The optimization tool is based on sequential decision stages (time intervals) to operate a dam system that considers the restrictions on storage volumes, defined by high and low guide curves. An objective function was considered which maximizes energy generation, it uses coefficients to penalize unwanted events of spills, deficits, and operation conditions outside the limits of the guide curves. In conjunction with the agencies that manage the system, three tests with different guide curves were defined. To analyze their sensitivity in the results (mainly events of spillage) one more test was defined for an operation rule without considering guide curves. The system behavior was simulated with the historical record, where five variables were analyzed: total spills and deficit, minimum and maximum storage, as well as the average energy generated. By using the guide curves, the occurrence of spills and deficits was avoided.