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Water pollution imperils the Neosho madtom (Noturus placidus), which is threatened federally and in Kansas. Within Kansas, madtom densities were historically lower in the Spring River compared to the Cottonwood and Neosho Rivers, especially within the Spring River below tributary inputs that delivered cadmium, copper, lead, and zinc pollution from the Tri-State Mining District of Missouri, Kansas, and Oklahoma. Neosho madtom are less numerous in waters containing elevated metal concentrations because of direct toxicity and lower benthic macroinvertebrate (i.e., food) availability. Long-term reductions in metal concentrations in the Spring River have occurred, but no study has examined whether madtom and macroinvertebrate densities have responded to improved water quality. We addressed this question by comparing madtom and macroinvertebrate abundances between the Neosho-Cottonwood system and the Spring River above and below metal pollution inputs. However, madtoms are influenced by environmental factors and anthropogenic stressors beyond mining-derived metal pollution, so we also examined if food availability, local habitat variables, and watershed characteristics were related to madtom densities. We found that madtom and macroinvertebrate population densities in the Spring River below metal pollution were similar to those in the Spring River above metal pollution and the Neosho-Cottonwood River system. Furthermore, macroinvertebrate availability and watershed characteristics were not associated with madtom abundance. However, two local habitat variables (turbidity and depth) were associated with madtom densities, such that an increase in turbidity or decrease in depth resulted in higher madtom densities. Our results highlight the benefits that water quality improvements can have on imperiled stream organisms. [ABSTRACT FROM AUTHOR]

Seepage flow through pervious media or formations is one of the causative factors for dam failure. In order to reduce and control this problem, seepage modeling and analysis are very important. The main aim of this article is to present the comprehensive review on various modeling approaches and methods available for seepage evaluation through or beneath dam. Furthermore, an attempt is also made to assess the application and effectiveness of these techniques in dam seepage modeling and analysis. Moreover, case studies of dam seepage analysis in Ethiopia were also reviewed. For a century, various techniques have been developed that can be used to study the seepage cases of hydraulic structures including dams. Broadly, these techniques can be categorized in to continuum and discontinuum seepage modeling approaches. Continuum approach includes pore-network model, whereas discontinuum approach includes equivalent continuum, discrete fracture network, dual-porosity, and triple-porosity models. Each of these approaches may consider different causative factors and utilizes various methods for seepage analysis. The experimental, analytical, and numerical methods are commonly used in the modeling approaches based on Darcian and non-Darcian laws. The selection of appropriate modeling approaches depends on various factors and considerations including the spatial and temporal scale of flow regime, material type and properties, dam width and height, water level, availability of data, and modeler's skill. In comparison, each of these models has its own advantages and disadvantages over the other. [ABSTRACT FROM AUTHOR]

Competition arises when species share a limited resource, but this can be avoided through niche partitioning. Despite the large body of literature on diadromous fishes, very few studies have focused on niche partitioning when competing for resources. Diadromous fishes are suffering a global decline throughout their range in part due to their peculiar life history traits as they migrate from the sea to freshwater to spawn or the reverse. They are particularly sensitive to river fragmentation induced by barriers. Dams for instance are expected to alter the spatial distribution and resource exploitation of diadromous fishes as well as other organisms. Here, we studied the ecological niche of six taxa of diadromous fishes, temporally co-occurring in the same land-sea continuum obstructed by two river dams. We used Bayesian mixing models run on C and N isotopes to infer the various habitats used and the origin of the trophic carbon in muscle and scale tissues of diadromous fishes. Results showed that the sub-adults of Anguilla anguilla, juveniles of Petromyzon marinus, and Salmo trutta exploit mainly the freshwater, or marine part for adults of Lampetra fluviatilis, whereas juveniles of Platichthys flesus and Mugilidae use all the habitats of the land-sea continuum. In the freshwater habitat, the microphytobenthos and biofilm are the main sources of carbon used, while in the marine habitat, the basal carbon sources are more diverse. The analyses of niche overlaps between diadromous fishes demonstrate that the widest isotopic niches, observed for A. anguilla and P. flesus, also have more impact within the community. Results are discussed in terms of intra- and interspecific competition between these diadromous fishes and their generalist/specialist strategies in an obstructed catchment. [ABSTRACT FROM AUTHOR]

Numerous dams in North America are constructed on foundations and/or abutments consisting of unstable weak materials or low-friction pre-sheared surfaces such as the Oldman River Dam (ORD), in southern Alberta, Canada. The objective of this paper is to examine the performance of Interferometric Synthetic Aperture Radar (InSAR) on the slow-moving ORD site by comparing the mapped velocities obtained through InSAR analysis in 2015–2022 with velocities from previous investigations. Additionally, the study aims to determine the precision of estimated velocities by analyzing InSAR temporal decorrelation and incorporating the error of simplifying the assumption necessary to decompose line-of-sight velocities. The results indicate the spillway, covering an area of ~ 26 × 103 m2, has been moving at an average total velocity of 1.26 mm/year. On the slope of the embankment, measuring ~ 160 × 103 m2, an active area next to the left abutment is also experiencing a higher average velocity of 8.29 mm/year (both rates in millimeters per year). An analysis of the precision of the estimations showed an accuracy of 0.72 and 2.78 mm/year for the spillway and embankment, respectively. Overall, the spillway velocities have not deviated much from 1 mm/year in the study period but the embankment’s active area decelerated from > 20 to 5 mm/year toward the end of 2022. Eventually, a lagged spillway displacement in response to seasonal variation of the reservoir level was also observed. [ABSTRACT FROM AUTHOR]

The life cycles of potamodromous fishes are generally interrupted by the presence of a dam, and populations often display different life history traits between upstream and downstream. This study compared the age and growth rates of grass carp and silver carp above and below Changzhou Dam in the Pearl River. Standard length (SL) composition and back-calculated SL at ages one and two years were greater for grass carp upstream than for downstream individuals; and the length–weight relationship differed between upstream and downstream populations, while the sex ratio, age structure and growth were not significantly different. For silver carp, only SL compositions differed between upstream and downstream populations; sex ratio, age structure, SL-at-age and growth rates were similar. Mean SL-at-age and growth rates of both species were lower at high latitudes than at middle and low latitudes, and populations in the Yangtze River had greater mean SL-at-ages and faster growth relative to silver carp at low latitudes. There were no differences in mean SL or growth among populations at middle and low latitudes. For grass carp, age and growth varied with small-scale ecological processes and regions or latitude, while for silver carp, such variations were proportionate to latitude and the large-scale geographical range. This study provides not only guidelines for fisheries management and conservation of exploited potamodromous fishes, but also insights into the relationship between life history trait variation and adaptive capacity. Size composition, the relationship between SL and body weight, size-at-age of grass carp were different, and silver carp only had difference in size composition between upstream and downstream of Changzhou Dam in Pearl River, China. Grass and silver carp showed similar age structure, sex ratio and growth rate between upstream and downstream of Changzhou Dam in Pearl River, China. Size at age and growth rate varied with latitudes to some extent and showed variations among populations at middle and low latitudes in China. [ABSTRACT FROM AUTHOR]

Background: Klebsiella pneumoniae is an important opportunistic pathogen that frequently causes nosocomial infections. Notably, this bacterium has emerged as a major problem in hospital settings because of its acquisition of resistance to carbapenems. The majority of antibiotics act by targeting crucial pathways within bacterial cells. However, due to the development of resistance mechanisms, the efficiency of these antibiotics has decreased. Therefore, this study focused on a putative protein (DNA adenine methyltransferase; Dam) found in K. pneumoniae that encompasses a DNA methylation protein domain, indicating a novel potential target for pharmacological intervention. DNA methylation affects bacterial virulence attenuation. Methods: In the unavailability of a 3D structure for Dam protein in protein database, a 3D model was generated using SWISS-MODEL server and validated using computational tools. Following that, screening was performed against the Dam protein using a set of 2706 phytochemicals obtained from the ZINC database using PyRx0.8. ProTox-II platform was used to predict the physicochemical properties and various toxicity endpoints. Results: Among the screened compounds, ZINC4214775, ZINC4095704, and ZINC4136964 had higher binding affinity for the Dam and interacted with its active site residues. The computational analyses of these three identified hits indicate that their predicted properties were within an acceptable range for evaluating toxicity. In addition, a toxicity radar chart showed that these hits were within an acceptable range. Conclusions: These compounds have the potential to act as Dam inhibitors and could be investigated further for managing antimicrobial resistance in K. pneumoniae. [ABSTRACT FROM AUTHOR]

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Factors influencing the distribution and variations of abundance of phytoplankton of dams are yet to be accounted for in Southwest Nigeria. Therefore, the objective of this paper was to evaluate the seasonal distribution and variations of abundance of phytoplankton community in Ikere Gorge Dam, Oyo State, Southwest Nigeria using standard techniques. Data obtained show that a total of 494 microalgal taxa belonging to eight divisions were recorded. Zygnematophyceae comprised 360 taxa (64%), Bacillarophyceae 22 taxa (14%), Chlorophyceae 66 taxa (13%), Cyanophyceae 20 taxa (4%), Dinophyceae 8 taxa (1%), Trebouxiophyceae 13 taxa (2%), Ulvophyceae 3 taxa (0.02%), Xanthophyceae 2 taxa (0.01%). The observations and results confirm hypotheses that phytoplankton abundance varies more between season (wet and dry) than spatially in Ikere gorge dam. No single taxon or a combination of two or three taxa accounted for more than 80% of the phytoplankton abundance. Canonical correspondence analysis revealed DO, TDS, nitrate-nitrogen and water transparency as the major water quality variables driving variation in the composition of plankton communities in the dam. This study showed seasonality is the major factor influencing the diversity and abundance of phytoplankton community through changes in concentrations of DO, nitrates, and phosphate. Ikere Gorge dam showed a strong seasonal variation in physicochemical water quality variables owing to the size of the dam that is not well-mixed, and with long water residence times. This study contributes to understanding the water quality, determinant factors, and drivers of biological communities in dams of tropical regions that are being influenced by anthropogenic activities. [ABSTRACT FROM AUTHOR]

Pensacola Dam, operated by the Grand River Dam Authority (GRDA), is a multiple-arch buttress dam constructed in 1940. The dam has little or no existing geophysical reports on the integrity of the dam foundation rock and even less knowledge at depth. Visual inspection indicated evidence of seepage at some arches of the dam. As a pilot study, we conducted a suite of geophysical surveys inside two arches (Arch-16 and Arch-17) and a part of the downstream berm to characterize the dam foundation rock, delineate seepage zones, and identify the most appropriate geophysical methods for temporal monitoring of the dam's conditions. The geophysical methods included electrical resistivity tomography (ERT), self-potential (SP), multichannel analysis of surface waves (MASW), compressional (P)-wave refraction, and shear (S)-wave reflection. Water samples were collected for geochemical analysis to investigate the source of the seepage flow inside Arch-16. The geophysical results characterized the dam foundation rock into an unsaturated limestone and chert overlying a water-saturated limestone and chert. The ERT profiles indicated that groundwater is rising inside the arches and significantly dropping under the downstream berm, which can be due to the uplift pressure beneath the dam base. Zones of high seepage potential were detected near the buttress walls of the two surveyed arches, which may be related to previous blasting, excavation of the dam foundation, concrete placement, or improper grouting. The geochemical analysis of water samples taken from the artesian wells inside Arch-16 and the Grand Lake revealed different chemical compositions, suggesting that the source of water could be a mixture of groundwater and lake water or lake water interacting with rock and reaching the surface through fractures; however, more sampling and further analysis are required to ascertain the source of the seeps. This study showed that the ERT, SP, and S-wave reflection methods have effectively characterized the dam foundation rock and seepage zones beneath the arches. The study provided a better understanding of the conditions of the dam foundation rock, evaluated the utilized geophysical methods, and determined the optimum geophysical methods that can be used for the characterization and monitoring of the subsurface conditions along the entire length of the dam. In this study, we have demonstrated that the integration of effective geophysical surveys and geochemical analysis yielded optimum results in solving a complex dam safety problem. This strategy promotes the best practice for dam safety investigation. [ABSTRACT FROM AUTHOR]

This research aimed to investigate the effect of geological and geomorphological factors on the water quality of Gotvand Dam in Iran. Given the role of geomorphological parameters in water quality, the water quality indices were analyzed in the Excel and Chemistry applications. Water quality was evaluated by analyzing water samples obtained from the Statistical Data Center of Water and Power Organization of Khuzestan, and the total dissolved solids (TDS), electrical conductivity (EC), and pH of water were measured using the Mann-Kendall test. Then the effect of geomorphological factors on the physicochemical properties of the Karun River was assessed. The qualitative variables were pH, EC, and TDS in the statistical period of 2006–2021. The results of the Mann-Kendall test showed an insignificant decreasing trend in the TDS series in the Gotvand station. Meanwhile, August had a significant increasing trend in TDS, and considering the calculated Sen's slope, this parameter increased by 35% in the last 15 years (2006–2021). Like TDS, EC had both increasing and decreasing trends of changes. On the monthly scale, pH had a significant decreasing trend, meaning that the water is acidified, which severely affects the downstream fields and reservoirs. In the Gotvand station, the trend of changes in TDS and EC increased in 11 and 12 months of the year, respectively. [ABSTRACT FROM AUTHOR]

Space is a multidimensional, boundless realm in which the relative position of phenomena is reflected. During the last few decades, the water level of Lake Urmia has decreased drastically. Lake Urmia, as a geographical device and a complex system, has been affected by natural and anthropogenic factors, as visible and hidden layers. In order to check the water storage threshold of dams in reducing the water level of Lake Urmia, we first prepared the desired data bank: DEM of the basin, data from climatology stations, discharge of hydrometric stations and dam information. We estimated the linear relationships between altitude and Temperature and precipitation and altitude in SPSS software. Considering climatology stations and dams as output points, we extracted several sub-basins. We estimated the volume of water inflow into the basins without a hydrometric station using Justin's method; We also analyzed the percentage of annual discharge compared to annual precipitation and changes in the water storage volume of dams. The results indicate that the reservoir volume of 46 dams in 12 sub-basins (1628.68 million cubic meters) accounts for about 21% of the total volume of basin runoff; This number was 13% until 1996 and reached 21.8% in 2013. In 1970, with the construction of the Mahabad dam with a reservoir volume of 197.8 million cubic meters, the reservoir volume of the dams exceeded the environmental threshold; it caused the lake's water level to decrease irreversibly. Examining the volume of the dam reservoir according to the volume of water intake and the volume of rainfall in the basins of the dams shows that out of the 41 dams, the reservoirs of 28 dams are built according to the rainfall potential of the basin. The ratio of reservoir volume to rainfall volume of 33 dams has very favorable conditions, and 6 dams have favorable conditions. [ABSTRACT FROM AUTHOR]

Meninting Dam is located on the Meninting River, Meninting Watershed WS Lombok. Administratively, the location of this dam is located in Bukit Tinggi Village, Gunungsari District, and Gegerung Village, Lingsar District, West Lombok Regency. It is planned that Meninting Dam has a height of 79 m, the type of Urugan Zonal Random Dam with Upright Core, with a maximum storage capacity of 12.18 million m3 and an average storage capacity of 9.91 million m3. From the results of geological investigations during planning and pre-construction geological investigations, it is known that the body of the Meninting Dam will rest on a foundation in the form of volcanic breccia rock. Given that Meninting Dam has a reasonably high height, the foundation rock's quality is essential in terms of foundation permeability and the ability of the foundation rock to support the dam above it. On the left backrest, there is a volcanic breccia layer with a lousy level of cementation, which affects the high permeability value of the layer. In order to reduce the permeability value, it is necessary to conduct curtain grouting experiments to determine the extent of grouting effectiveness to reduce the permeability value and improve the overall foundation. The results of curtain grouting experiments and cement injection showed that the average incoming cement per meter was 21.43 kg / m or classified as efficient with a mixture change of 1 4. The effectiveness of grouting in poorly cemented volcanic breccia in Check Hole (CH) against Pilot Hole (G1) with an average of = 65% or classified as GOOD (Good) and seen semi-logarithmetically the significant decline of Lugeon towards target < 3 according to technical specifications. [ABSTRACT FROM AUTHOR]

The creep of fine soils is due to the viscous properties of the assembly of mineral particles accompanied of adsorbed water which forms intergranular skeleton. It is evident during the secondary consolidation that the effective stresses are constant, the deformation extends over time. Rock fill dams with clay sealing cores deformed during exploitation. During commissioning of the core, clay undergoes. Creep is a major characteristic of the nonlinear behaviour of materials, in which the material continues to become deformed under a constant load. It can cause considerable deformations of the works (two to three times instantaneous strain in three years). This study presents a prediction of the creep behavior of a clay core in a rock dam subjected to constant hydrostatic loading for 20000 h and describes a procedure for modeling the primary and secondary creep law simulation using ANSYS software APDL In this aims, we have applied the finite element method based on a model shown in equation 8 called (Strain Hardening Model) in order to simulate a creep behavior of clay core. [ABSTRACT FROM AUTHOR]

Abstract: Aim Monitoring altered environments is crucial to understand the impacts and the possible changes in the local fish fauna. Therefore, we aimed to compare the ichthyofauna within a 67-year-old small run-of-the-river reservoir with surveys carried out in 1986 and 2019-2021 and update the checklist of this reservoir. Methods We used the data provided by Alves et al. (1998) and sampled fish in two sites inside Itutinga reservoir using gill nets, seine nets and hand nets and at the one tributary of the area using only hand nets. Results We collected a total of 12,978 individuals belonging to 37 fish species, and the species accumulation curve showed a tendency to the asymptote. Five of the sampled species are non-native and five are migratory. Alves et al. (1998) sampled a total of 25 fish species, 17 genera, 9 families and 3 orders. We added 12 fish species to the checklist that were not recorded by Alves et al. (1998), including four non-native and two migratory. On the other hand, two migratory species and one rheophilic were registered only in the preview study. In addition, we observed important changes in the species abundance rank. Conclusions The differences in the fish assemblage structure comparing both studies indicate important changes in fish assemblages over more than 33 years. Our results highlighted the importance of long-term fish monitoring in altered environments to assess temporal variation in fish assemblages and their responses to the multiple possibilities of external stressors, such as the shift in abundance of non-native species in these environments.

This study adds to knowledge by specifically focusing on the dam spillage-induced floods within a fast-urbanising city with weak law enforcement in a developing country. Employing a sequential mixed-method approach, we first selected and analysed data from 120 respondents through a survey and complemented it with key informants residing in the communities affected by flooding. The findings revealed that dramatic ramifications of dam spillage-induced floods disrupt the livelihoods of many individuals in the form of disruption to income-generating activities and substantial property loss. Notwithstanding the devastating effect of the dam spillage, residents lack advance and adequate preparedness. In coping with such challenges, most flood victims rely on support from nongovernmental sources. The challenge of flooding from the dam spillage is multifaceted and deeply rooted in complex factors which includes growing urbanisation, poor urban planning and weak law enforcement. Residents’ adaptive strategies remain limited, demonstrating a dearth of resilience against such shocks. Contribution: In light of these challenges, the authors advocate a close collaborative working partnerships among stakeholders to provide flood risk management interventions, strategic planned dam spillage that minimises the effect of dam spillage-induced floods on the local communities, early warning systems and planning and enforcement of building regulations.

Considering the overall behavior monitoring of an earth dam, the infiltration regime and the stability of slopes are the most important aspects to be considered, in order to permanently assess the technical status of the dam and its risk of collapse or breach. This paper presents the stability analysis for the upstream slope of Hălceni Dam, performed by the finite element stability method, using SLOPE-GeoStudio program, under the condition of the drawdown water level. Firstly, the infiltration curve in the dam was drawn with SEEP/W-GeoStudio program, according to the maximum level measured during the flood in June 2019. The effects of slow drawdown and rapid drawdown from the maximum water level in the reservoir were analyzed. Built-in finite element algorithms used in the SEEP/W and SLOPE/W solved the analysis and the results were obtained as a range of Factor of Safety (FS) values, that were later compared to the admissible Factor of Safety established in the legislation and the technical regulations in force in Romania. Both the measured parameters and the visual observations showed that the dam performed exceptionally well, in accordance with design specifications and predicted behavior for the evolution of the response parameters to external stresses.

The article discusses technological solutions for the renovation (reprofiling) of the outer layer of surface overflows, taking into account the size and shape of the Porąbka Dam. The history of its creation, the legitimacy of construction and basic construction parameters are presented. The issues of damage and destruction of concrete in damming structures of this type, techno logical aspects of the permanent connection of old and new concrete, the essence of shotcrete technology (shotcrete) and the results of durability and strength tests of selected building materials were discussed.

Multiple studies have recognized the involvement of the complement cascade during Alzheimer's disease pathogenesis. However, the specific role of C5a-C5aR1 signaling in the progression of this neurodegenerative disease is still not clear. Furthermore, its potential as a therapeutic target to treat AD still remains to be elucidated. Canonically, generation of the anaphylatoxin C5a as the result of complement activation and interaction with its receptor C5aR1 triggers a potent inflammatory response. Previously, genetic ablation of C5aR1 in a mouse model of Alzheimer's disease exerted a protective effect by preventing cognitive deficits. Here, using PMX205, a potent, specific C5aR1 antagonist, in the Tg2576 mouse model of Alzheimer's disease we show a striking reduction in dystrophic neurites in parallel with the reduced amyloid load, rescue of the excessive pre-synaptic loss associated with AD cognitive impairment and the polarization of microglial gene expression towards a DAM-like phenotype that are consistent with the neuroprotective effects seen. These data support the beneficial effect of a pharmacological inhibition of C5aR1 as a promising therapeutic approach to treat Alzheimer's disease. Supportive of the safety of this treatment is the recent FDA-approval of another other C5a receptor 1 antagonist, Avacopan, as a treatment for autoimmune inflammatory diseases.

The Chesapeake Logperch, Percina bimaculata, is a small fish endemic to the upper Chesapeake Bay drainage with a range significantly reduced by water quality and habitat degradation. It was described by Haldeman in 1842 and 1844 from the Susquehanna River, Pennsylvania, synonymized with the Logperch (Percina caprodes) by Jordan in 1877, and redescribed by Near in 2008. It is extirpated from the Potomac River drainage and extant in a portion of its historic range within the Susquehanna River drainage of Pennsylvania and Maryland in the United States of America. We reviewed available historic field survey information and defined the likely extent of the historic distribution of P. bimaculata and its change in response to historic environmental perturbations. We performed fisheries surveys during 2004–2023 to fill data gaps and to define the current distribution and abundance in the Susquehanna River drainage within Pennsylvania. Our surveys utilized electrofishing gears, electrified benthic trawls, and seines. Our surveys targeting P. bimaculata on the Susquehanna River and tributaries from York Haven to Holtwood, Pennsylvania, combined with available fisheries surveys conducted by others, confirm it was extirpated from that portion of the drainage. We documented the continued usage of Conowingo Pond, Susquehanna River, and tributaries below Holtwood by populations known to exist in historic field surveys. These populations appear to have been stable since at least the 1960s based on historic data and our current surveys. We documented previously unknown populations in the Octoraro Creek drainage, Octoraro Reservoir, and Muddy Run Pumped Storage Facility. Habitat utilization observations during our surveys indicate that clean sand, gravel, rubble, boulders, and large woody debris are preferred substrates. In the lower Susquehanna River and two tributaries, P. bimaculata has demonstrated a plasticity of habitat usage by continuing to occur in environments converted into impoundments by dams. In these impoundments, shorelines and connections with clean tributaries containing preferred substrates appear to be important given their utilization by P. bimaculata during our surveys. It is our opinion that the Susquehanna River and tributaries above Holtwood once again constitute suitable habitats. Conservation efforts focused on reintroductions, water quality, habitat, and connectivity have the potential to increase the extent of occurrence, abundance, and security of P. bimaculata.

The microbial biomass in soil is an active and living constituent of organic matter. It is both a storage pool and a source of plant nutrients that can be used as required. In addition, each microbial indicator evaluates soil quality and health from different perspectives, which are not necessarily very different. This study was conducted to compare some physical, chemical, and biochemical characteristics of the soils of forest (SF) and deforested (SDE) areas located on the slopes of the Kirazlıköprü area, which was previously deforested due to dam construction in Bartın province in northwestern Turkey. Soil samples were taken from the topsoil surface (0–5 cm) to determine the microbial soil characteristics of the SF and SDE sites. The soil microbial biomass N (Nmic) was determined by chloroform fumigation extraction, and the Cmic/Nmic ratio and Nmic/Ntotal percentage were calculated using the original values. Total N, Nmic and Cmic/Nmic values are higher in the forest area. The lowest and highest total N (Ntotal) contents in the SF and SDE soils varied between 1.50 and 3.47 g kg−1 and 0.91 and 1.46 g kg−1, respectively. Similarly, the Nmic contents of the SF and SDE soils varied between 75.56 and 143.42 μg g−1 and 10.40 and 75.96 μg g−1, respectively. A statistical analysis revealed that the mean Ntotal and mean Nmic values differed (p < 0.05) in the SF and SDE soils. The mean Cmic/Nmic values in the SF and SDE soils were 8.79 (±1.65) and 5.64 (±1.09), respectively, and a statistical difference was found between the fields (p < 0.05). Our findings indicate that the soil microbial community structure varies according to the site. As a result, it can be concluded that deforestation and erosion due to dam construction in the area led to the removal of plant nutrients from the soil; deterioration in the amount and activity of microbial biomass; and, consequently, soil losses and degradation of soil quality.

Throughout history, the implementation of structural health monitoring systems has played a crucial role in evaluating the responses of dams to environmental and human-induced threats. By continuously monitoring structural integrity and analyzing dynamic characteristics, these systems offer a robust alternative to traditional visual inspection methods, ensuring the long-term safety of dams. This paper delves into the intricate process of operational modal analysis applied to dams, encompassing data collection, preprocessing, and the utilization of diverse modal identification techniques across both time and frequency domains. Moreover, it explores innovative approaches aimed at overcoming challenges encountered in previous methodologies. Also, the evolution of automated modal identification techniques and their application in dams are investigated. It explores the advancements in this field and their implications for enhancing the efficiency and accuracy of modal analysis processes. Furthermore, this paper evaluates the effectiveness of damage detection methods in dams based on operational modal identification.

Building Information Modelling (BIM) has emerged as a transformative force in the construction industry, gaining traction within the hydropower sector. This study critically examines the adoption and application of BIM throughout the entire lifecycle of hydropower projects, addressing a notable gap in existing research, to encompass a holistic approach to the management and resilience of these critical infrastructures. The objective is to delineate the comprehensive range of BIM applications, use cases, and adoption, integrating technologies including Digital Twin, UAV, GIS, and simulation tools, across components of hydropower projects. Employing a systematic search paired with a critical review of the selected literature, this study meticulously evaluates significant contributions in this domain. Through thematic analysis, the multifaceted utility of BIM in hydropower structures, including an in-depth evaluation of its current adoption within the industry, is presented. This encompasses an analysis of both benefits and challenges inherent in BIM implementation for hydropower infrastructures. This study is a significant contribution to understanding how BIM can be leveraged to enhance the resilience of hydropower infrastructures. It provides a comprehensive view of BIM’s applications, challenges, and future potential, guiding stakeholders in adopting strategies that ensure these structures withstand, adapt, and recover from disruptions while maintaining sustainable and efficient operations.

This paper addresses the problem of removing 3D effects as one of the most challenging problems related to 2D electrical resistivity tomography (ERT) monitoring of embankment structures. When processing 2D ERT monitoring data measured along linear profiles, it is fundamental to estimate and correct the distortions introduced by the non-uniform 3D geometry of the embankment. Here, I adopt an iterative 3D correction plus 2D inversion procedure to correct the 3D effects and I test the validity of the proposed algorithm using both synthetic and real data. The modelled embankment is inspired by a critical section of the Parma River levee in Colorno (PR), Italy, where a permanent ERT monitoring system has been in operation since November 2018. For each model of the embankment, reference synthetic data were produced in Res2dmod and Res3dmod for the corresponding 2D and 3D models. Using the reference synthetic data, reference 3D effects were calculated to be compared with 3D effects estimated by the proposed algorithm at each iteration. The results of the synthetic tests showed that even in the absence of a priori information, the proposed algorithm for correcting 3D effects converges rapidly to ideal corrections. Having validated the proposed algorithm through synthetic tests, the method was applied to the ERT monitoring data in the study site to remove 3D effects. Two real datasets from the study site, taken after dry and rainy periods, are discussed here. The results showed that 3D effects cause about ±50% changes in the inverted resistivity images for both periods. This is a critical artifact considering that the final objective of ERT monitoring data for such studies is to produce water content maps to be integrated in alarm systems for hydrogeological risk mitigation. The proposed algorithm to remove 3D effects is thus a rapid and validated solution to satisfy near-real-time data processing and to produce reliable results.

Dams play a vital role as a primary water supply for irrigation in Jordan, necessitating an assessment of their water quality. This study aimed to evaluate the suitability of irrigation water in a key number of Jordanian dams, namely Al Kafrain, Al Waala, King Talal (KTD), Mujib, Shuaib, and Sharhabil. Monthly readings of major water parameters (EC, Cl−, SO42−, HCO3−, Na+, Ca2+, and Mg2+) were recorded for seven years (2015–2021) for each dam. The assessment criteria included the sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC), magnesium adsorption ratio (MAR), kelley ratio (KR), total hardness (TH), and water quality index (WQI) using both average (APL) and maximum permissible limits (MPL). Additionally, USSL, Wilcox, Doneen, Piper, and Gibbs diagrams were applied. The findings indicate that all the dams demonstrated suitability for irrigation based on the SAR, SSP, RSC, MAR, and KR values. The USSL diagrams showed most samples falling under C2S1 and C3S1, except KTD, which fell under C3S2. According to the Wilcox diagram, the water was either Excellent to Good or Good to Permissible, while the KTD water was classified as Permissible to Doubtful. Furthermore, the water chemistry was found to be mainly influenced by rock weathering, as revealed in the Gibbs diagram, and has no restriction on permeability, according to the Doneen diagram. The WQI showed that all the dams fall in the Good and Excellent category for irrigation using APL, while applying MPL, all the dams were in the Excellent category, which demonstrates the necessity of considering extreme events and regulatory thresholds.

Purpose: to develop the technology for accumulating groundwater flow, taking into account the rheological soil properties in the system of accumulating precipitation for expanding reclamation systems. Materials and methods. With the help of an underground dam, the conditions for accumulating groundwater flow are created, taking into account the rheological soil properties in the system of accumulating precipitation for expanding reclamation systems. The studies were performed using the midas GTS NX software package. Mathematical modeling was performed in the wxMaxima software package. Results. A set of technical devices combined into a technological system, intended for ensuring reliable accumulation of precipitation flow in the autumn-winter period and water withdrawal in the required volume, including dry periods of the year, in mountain river valleys with periodically intermittent watercourse has been developed. The technological scheme includes the construction of an impermeable underground dam in the cross section of the river valley, completely covering the aquifer in terms of power and width and forming the main underground reservoir. The regularities of the stress-strain state of the soil mass in time under the loads, including hydrostatic ones, are obtained at upstream water levels in the range from minus 8.19 to minus 1.18 m and downstream water levels from minus 7.93 to minus 6.68 m. It has been determined that the displacement of the underground dam foundation depends on pressure in the upstream of dam: the greater the pressure, the greater the displacement of its foundation, and with an increase in pressure by 4 times, the displacement of the foundation increases by 5.5 times. Conclusions. The proposed technology of groundwater flow accumulation under conditions of water resources deficit, based on the system of regulation of an underground dam with lifting and transport equipment, is designed to guarantee the accumulation of natural waters and their use in irrigation systems.

Estimation of the potential consequences from events occurring downstream of a dam is part of the risk assessment needed during the installation phase of a new dam. In the case of specific natural or man-made ongoing or prospected events, it may also be important to carry out fast computations that can provide information on the areas at risk either because the original design analyses are not available or because the parameters needed are different. This study aimed to develop a procedure that strongly facilitates the preparation of the input deck and the derivation of the output quantities to allow a fast analysis of a dam break event using a shallow water model, NAMI DANCE, as the analysis tool. The analysis shows that in a few minutes, it is possible to obtain the input deck for a new case. This makes it possible to include the prospected methods into automatic routines in analytical tools such as the Global Disasters Alerts and Coordination System (GDACS) to have a quick overview of the expected flood due to a dam break event.

One of the projects currently being undertaken by PT. XYZ is Dam “X”. Based on project management data obtained from PT. XYZ, the actual project construction process experienced a significant delay from the planned schedule, with a delay duration of approximately 30 days. The delay will have an impact on the duration of the final completion of the project, including the process of delivering project results to consumers. The purpose of this study is to determine the critical path in project implementation and identify activities that do not have slack time because it will affect the duration of the overall project completion. The method used in this study is the Critical Path Method (CPM), which is a network method consisting of a series of activity components with the longest total time and showing the fastest duration of project completion. The results showed that the Manufacturing Project has a total of 11 critical activities out of 37 activities (work packages), with a total critical time of 75 days. The total critical time from the calculation of the CPM method also shows the optimal total project duration which can be used as a reference for the project team for the completion of a fabrication project or a hydromechanical component installation project on Dam "X".

Infrastructure projects, encompassing the construction of roads, railways, power facilities, and other structures, have a tangible impact on the physical landscape. When implemented within or through a settlement, these projects also influence cultural and social aspects of life. Despite their intention to enhance citizens' well-being as part of modernization endeavours, infrastructure initiatives often produce uneven effects on different social groups. This study focuses on the transformative processes that unfolded in the village of Mrzla Vodica, located in Gorski Kotar, Croatia, following the construction of the Lujzijana Road in the early 19th century and a dam in the mid-20th century, and all the way to the present day. Employing a classic ethnographic approach and a literature review, this research aims to demonstrate how infrastructure can generate both prosperity and significant disruptions to space, potentially leading to the decline or even disappearance of a certain community. By shedding light on the inequality produced by infrastructural development, this study tries to contribute to a deeper understanding of the modernization processes in rural areas.

Factors influencing the distribution and variations of abundance of phytoplankton of dams are yet to be accounted for in Southwest Nigeria. Therefore, the objective of this paper was to evaluate the seasonal distribution and variations of abundance of phytoplankton community in Ikere Gorge Dam, Oyo State, Southwest Nigeria using standard techniques. Data obtained show that a total of 494 microalgal taxa belonging to eight divisions were recorded. Zygnematophyceae comprised 360 taxa (64%), Bacillarophyceae 22 taxa (14%), Chlorophyceae 66 taxa (13%), Cyanophyceae 20 taxa (4%), Dinophyceae 8 taxa (1%), Trebouxiophyceae 13 taxa (2%), Ulvophyceae 3 taxa (0.02%), Xanthophyceae 2 taxa (0.01%). The observations and results confirm hypotheses that phytoplankton abundance varies more between season (wet and dry) than spatially in Ikere gorge dam. No single taxon or a combination of two or three taxa accounted for more than 80% of the phytoplankton abundance. Canonical correspondence analysis revealed DO, TDS, nitrate-nitrogen and water transparency as the major water quality variables driving variation in the composition of plankton communities in the dam. This study showed seasonality is the major factor influencing the diversity and abundance of phytoplankton community through changes in concentrations of DO, nitrates, and phosphate. Ikere Gorge dam showed a strong seasonal variation in physico-chemical water quality variables owing to the size of the dam that is not well-mixed, and with long water residence times. This study contributes to understanding the water quality, determinant factors, and drivers of biological communities in dams of tropical regions that are being influenced by anthropogenic activities.

The damming in a watershed alters all its fluvial dynamics, affecting the patterns of occurrence and distribution of the fish community. Despite being an important refuge for fish communities in tropical Brazil, the river–estuarine continuum is strongly affected by human activities that have considerably disturbed the natural dynamics. In this study, our objective was to evaluate the spatial and seasonal composition of the fish community in three distinct regions along the river–estuarine continuum of the São Francisco River, raising the hypothesis that the seasonal effect does not interfere in the structuring of the fish assemblage. Our results demonstrate that seasonality does not influence the composition and distribution of fish species in the lower São Francisco, this differentiation is due to the spatial effect of the regions studied. These findings add to the available knowledge about the absence of the seasonal effect in highly dammed environments. [ABSTRACT FROM AUTHOR]

The article provides information about the natural conditions of the Mullalaq HPP construction area, as well as the main layout solutions and parameters of this hydroelectric complex. [ABSTRACT FROM AUTHOR]