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A theoretical study was conducted to investigate the cross-sectional configurations and the tensile forces of an air-inflated rubber dam anchored on the sidewall of the rigid base. A series of large-scale model tests were conducted using rubber dam models with a cross-sectional perimeter of 1.0 m and a length of 8.5 m. The results obtained from the analytical solutions agree well with those obtained from model tests. It is found that there is an optimum height of the rubber dam, especially for larger anchor depth with the increase of the inflated air pressure. The smaller the anchoring depth the higher the optimum inflated air pressure. The contact length between the rubber dam and the rigid base gradually decreases with the increasing inflated air pressure. The greater the anchor depth, the faster the contact length decreases to zero. Generally, the tensile force linearly increases with the increase of the normalized air pressure and the decrease of the anchor depth. • Theory was derived to calculate an air-inflated rubber dam anchored on the sidewall of rigid base. • A series of large-scale model tests were conducted to verify accuracy of the theoretical model. • Effects of upstream water levels, inflated air pressures and anchor depths were analyzed. [ABSTRACT FROM AUTHOR]

In this study, an automatic control technology for liquid-hydrogen zero boil-off was developed to improve the long-term storage capability of small-scale liquefaction systems. An innovative system capable of monitoring both the pressure within the heat pipe and the pressure within the LH 2 vessel was developed. This innovative approach ensures continuous efficiency and reduces downtime, significantly improving the overall performance of the hydrogen liquefaction process. The optimal conditions for automatic control were obtained through a cycle test in ON/OFF mode. In addition, experimental investigations were conducted sequentially to investigate the effect of the water level of liquid hydrogen such as 1st section, 2nd section and 3rd section of LH 2. As a result, these experiments successfully demonstrated zero boil-off of liquid hydrogen for long-term storage in the vessel, corresponding to a constant value in the liquid level meter in each section. The velocity of stabilization from the temperature and pressure perspectives in the vessel increased, and the entire cryocooler cycle time was significantly influenced by the amount of liquid hydrogen produced. • An automatic control technology for liquid-hydrogen zero boil-off was developed. • The pressure data on the liquid hydrogen vessel and heat exchanger were determined. • The effect of the water level of liquid hydrogen was investigated. • Experiments demonstrated zero boil-off of liquid hydrogen for long-term storage. • The entire cryocooler cycle time was influenced by the amount of liquid hydrogen. [ABSTRACT FROM AUTHOR]

• Spider community composition changed during the rice growing season. • The rice field development generally decreased the number of horizontal web-building spiders and captured detritivorous prey. • Species identity and species traits of spider as well as environmental factors affect prey capture by web-building spiders. Understanding the effects of microhabitat changes on arthropod predator communities and their prey in agroecosystems is essential for field management and biocontrol. Few studies have investigated the trait composition of web-building spider communities in rice ecosystems. Here, we examined how temporal changes during the rice field development affect the abundance and traits of orb-web spiders, and how these effects consequently influence captured prey number and prey composition in irrigated rice ecosystems in southern Thailand. We used structural equation models to evaluate direct and indirect, spider-mediated effects of rice field development on captured prey numbers in each different guild. We found that the number of horizontal web-building spiders decreased during the rice field development, whereas there was no significant change in number of vertical web-building spiders. The number of captured detritivorous insects was positively related to the numbers of horizontal and vertical web-building spiders, while phytophagous insects and others were positively related only to the numbers of vertical web-building spiders. Moreover, the prey number captured by vertical web-building spiders seems to be indirectly increased through the decreasing number of horizontal web-building spiders in the late rice season. A fourth-corner analysis showed that spider species identity, spider traits (web type, web height and web diameter), vegetation height, and water level generally influenced the prey captured by web-building spiders. Horizontal web-building spider species with lower web placement during the flooding phase captured high numbers of detritus-feeding insects, while vertical web-building spider species with higher web placement captured high numbers of rice pests, predators and others. Our results suggest that the field development acted as an environmental factor that determined the species identity and traits of web-building spider communities. The findings of this study can help to predict the ecosystem services provided by the web-building spider community in rice ecosystems. [ABSTRACT FROM AUTHOR]

Water-level reduction frequently occurs in deep reservoirs, but its effect on dissolved oxygen concentration is not well understood. In this study we used a well-established water quality model to illustrate effects of water level dynamics on oxygen concentration in Rappbode Reservoir, Germany. We then systematically elucidated the potential of selective withdrawal to control hypoxia under changing water levels. Our results documented a gradual decrease of hypolimnetic oxygen concentration under decreasing water level, and hypoxia occurred when the initial level was lower than 410 m a.s.l (71 m relative to the reservoir bottom). We also suggested that changes of hypoxic region, under increasing hypolimnetic withdrawal discharge, followed a unimodal trajectory with the maximum hypoxic area projected under the discharge between 3 m3/sec and 4 m3/sec. Besides, our results illustrated the extent of hypoxia was most effectively inhibited if the withdrawal strategy was applied at the end of stratification with the outlet elevation at the deepest part of the reservoir. Moreover, hypoxia can be totally avoided under a hybrid elevation withdrawal strategy using surface withdrawal during early and mid stratification, and deep withdrawal at the end of stratification. We further confirmed the decisive role of thermal structure in the formation of hypoxia under water-level reduction and withdrawal strategies. We believe the conclusions from this study can be applied to many deep waters in the temperate zone, and the results should guide stakeholders to mitigate negative impacts of hypoxia on aquatic ecosystems. [ABSTRACT FROM AUTHOR]

In recent decades, there have been individual cases of damage to geotextile filters due to clogging by flocculated ochre products. This process is defined as ochre clogging and has been extensively explained in recent theoretical studies (Tophoff et al., 2022). Several revetments of tidally influenced German North Sea estuaries have been damaged due to a severe reduction in the permeability of geotextiles. Therefore, experimental investigations of granular and geotextile filter constructions were carried out to better understand filter clogging. The investigations reproduce a revetment section at a scale of 1:1. For this purpose, the clogging process in the fluctuating water level or clogging zone was reproduced as a purely chemical iron precipitation. Ten short-term tests (10 h) and one long-term test (50 h) were carried out in total. The tests show that the process involves internal clogging and that the iron precipitates adhere immovably to the filter structure, reducing the pore space and permeability of the filter. This process is considered less problematic for granular filters. A reduction in permeability was measured in some cases for geotextile filter designs. Different geotextile material parameters appear to influence the iron ochre clogging tendency. • Ochre clogging has led to individual revetment damages in tidally influenced waterways. • Chemical iron precipitation in filters can be reproduced in the laboratory. • Iron precipitation is partly accompanied by a reduction in filter permeability. • Iron precipitates are physicochemically bound to the filter surface. • Ochre clogging products contain ultra-fine particles from the filter environment. [ABSTRACT FROM AUTHOR]

The importance of satellite altimetry for monitoring inland water bodies is increasing, with the increasing need for fresh water. With the addition of the Sentinel-6 Michael Freilich (MF) in 2020 to the satellite altimetry record, we have parallel high- and low-resolution inland water observations. In this study, we validate Sentinel-6MF low- and high-resolution lake water levels, as determined with a state-space model, with data from 124 gauges in 85 lakes (of size > 20 km2) from the United States, Canada, Sweden, and Australia. Furthermore, we estimate the scatter of the observations at 1330 globally distributed lakes. We address the difference in performance when using a physical (ocean) and empirical (OCOG) retracker. Using the 124 gauges as ground truth, we determine a best-case unbiased root mean squared error (u-RMSE) of 6.4 cm for Sentinel-6MF, when using the high-resolution mode and the OCOG retracker. The u-RMSE is between 6.4 and 12.3 cm when correcting for ice-covered lakes, and 15.6 to 31.3 cm for all data, depending on retracker and resolution mode. The corresponding median standard deviation of water surface elevations per transect from the 1330 lakes is 3.5 cm and 8.1 cm for high and low-resolution OCOG-based water levels, respectively. The corresponding median standard deviation of Sentinel-3A/B OCOG (enhanced measurement, 20 Hz mode, baseline-3/4) is 5.9 cm and 6.0 cm. We find a lower u-RMSE and standard deviation for high-resolution data, and the ability to observe more lakes, compared to the low-resolution mode. From this, we see that Sentinel-6MF yields valid estimates of the water surface elevation, including smaller lakes, and would provide additional value to future water level monitoring via remote sensing. [ABSTRACT FROM AUTHOR]

• The flow characteristics of vertical slot fishways at different slopes (1.5%, 3.0%, 4.5%, 6.0%) were systematically studied. • The turbulence and energy dissipation in a fishway increase with increasing slope. • The distribution of vorticity shows little variability with increasing slope but may interfere with the passage of fish through the vertical slot. • An increase in water depth has no significant effect on the flow characteristics in the pool. The effects of a vertical slot fishway slope (with slope values from 1.5% to 6%) on a flow field are numerically investigated, using a re-normalization group k – ε model. The distribution of the velocity, turbulence kinetic energy (TKE), average energy dissipation rate per unit volume (E), and vorticity for different slopes are systemically explored. The results indicate that, with an increase in slope, the appearance of downward flow in conjunction with an increase in vertical velocity results in three-dimensional flow characteristics. The recirculation region in H s , at a 6.0% slope, was 20.9% less than that at a 1.5% slope. Meanwhile, the flow velocity in the vertical slot region grew with increasing slope, which would limit the passage of fish with burst speed lower than the velocity in the vertical slot region. The TKE and E may locally exceed the threshold at larger slopes. Furthermore, vorticity distribution shows little variability with increasing slope, but may interfere with the equilibrium of the fish in the vertical slot region. In addition, the change in water level has little effect on the flow field, which is changed by the increase in slope. These findings can aid vertical slot fishway designs especially in terms of the efficiency of fish passage. [ABSTRACT FROM AUTHOR]

Water, a critical resource, suffers from significant losses due to leakages in Water Distribution Networks (WDN). These losses present financial, environmental, and public health challenges. With water utility companies amassing vast amounts of data from enterprise information systems, the opportunity for data-driven leakage detection arises. With the increased use of enterprise information systems, water utility companies are generating vast amounts of data that can be valuable for predicting or detecting water leaks early and also for the development of new, automatic, and effective data-driven leak detection techniques. The presented study utilizes this data, by applying anomaly detection methods to heterogeneous time-series data from various components of the WDN in Slovakia. Our results demonstrate that components of the network, such as measured power consumption, water source temperature, and water source levels show significant positive associations with faults in the Water Distribution Network. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop the method of using unmanned aerial vehicles (drones) to map fish fauna habitats in a large lowland river. The intention was to acquire and process spatial data to implement it in the Mesohabitat Simulation system (MesoHABSIM). At three different water levels, remote sensing data was acquired by unmanned aerial vehicles on the lower Vistula River section. In parallel, depths and velocities of flowing water were measured. Orthophotomosaics were created from the collected images, overlaid with depth and velocity observations to identify hydromorphological units. Maps of fish fauna habitats under different water levels were obtained. The application of the developed procedure algorithm proved successful in habitat mapping studies on a large, deep river with opaque water. The significance of using orthophotomosaics presenting the river under well-defined flow conditions was proven to achieve high accuracy in mapping habitat conditions and reduce errors in habitat usability analyses by fish community. The superiority of using unmanned aerial vehicles over other methods of collecting data on river habitats and depth and velocity measurements using the Acoustic Doppler Current Profiler (ADCP) method in large rivers with non-clarity water was confirmed. In addition, it was pointed out that drones provide high-resolution images under well-defined flow conditions, which are impossible to obtain using available cartographic materials. The validity of using the incomparably cheaper ADCP technology relative to laser technology, whose application in rivers with opaque water is very complicated, was also confirmed. [ABSTRACT FROM AUTHOR]

The natural environment of the Eemian Interglacial (MIS 5e) and Early Vistulian (MIS 5 d-a) in many areas in Central Europe is still insufficiently and fragmentarily known. Therefore, after the discovery of an almost complete skeleton of the Eemian Stephanorhinus kirchbergensis (Jäger, 1839) in outcrop of palaeolake sediments near Gorzów Wielkopolski (GW site, GS3 profile), a multi-proxy analysis was conducted for a precise recognition of the environmental and climate changes taking place before, during and after the life of this individual. Comprehensive palaeobotanical investigations of sediments of two palaeolakes lying above each other were performed palynological analysis including NPPs and algal analysis, plant macroremains studies (including wood fragments), as well as palaeozoological analyses of the Cladocera, Chironomidae and Coleoptera. The picture of changes in the environment and climate obtained thanks to the performed analyzes presented in a short way looks as follows. The end of the Wartanian Glaciation (MIS 6) was characterised by the dominance of herbaceous vegetation. Along with the gradually changing climatic conditions, the landscape of the Eemian Interglacial was dominated in sequence by birch, pine, oak (the so-called First Thermal Optimum), hazel forests with linden, hornbeam (Second Thermal Optimum) with a rarely recorded dry oscillation, then spruce with fir and again pine forests. The "older Eemian lake" during this time changed from deep, cold, oligotrophic and carbonate to shallower, cold waters with higher trophy, then deeper with lower trophy, again shallower with peats and dystrophic conditions and finally became terrestrial. The age of the post-Eemian part of the GS3 profile was reinterpreted, recognizing OSL dating as more reliable than radiocarbon dating, determining the age as Early Vistulian. Subsequent stages of this part of profile were characterised by significant cooling and intense development of heaths and peatbogs (MIS 5d), double return of pine and birch forests separated by intra-interstadial cooling (MIS 5c), recooling with dominant herbaceous plants (MIS 5b) and last warming with birch forests (MIS 5a). The "younger Early Vistulian lake" was formed with the rising of the water level. It was shallow, cold, low-trophic, with the water heating up in the summer, which caused trophic increases. Water levels fluctuated. With the progressing terrestrialization, oligotrophy appeared. Each of used proxies reconstructs a fragment of palaeoenvironmental changes on land and/or in the reservoir, registering climatic events on both regional and local scales. However, only the combination of all results allows for a full picture of natural changes. [ABSTRACT FROM AUTHOR]

This article presents the results of malacological and isotope studies on lacustrine sediments from the Eemian interglacial site in the Piła (north-western Poland). Twenty species of molluscs were found in the analysed sediments. Changes in the taxonomic composition and the quantitative structure of malacofauna in the profile allowed distinguishing five types of assemblages corresponding to different phases of the lake's evolution. Ratios of oxygen and carbon isotopes (δ18O and δ13C) reflecting changes in the lake water composition were measured in shells of two predominating snail species, Valvata piscinalis (Müller, 1774) and Bithynia tentaculata (Linnaeus, 1758), and in opercula of Bithynia tentaculata. Significant variability in isotope contents was noted for shells in individual profile sections and between analysed taxa. The results of malacological and isotope studies were supplemented with lithological, stratigraphical and palynological data. On this basis, the sediments age was determined (optimal and suboptimal phases of the Eemian interglacial). Environmental changes of paleolake have been also reconstructed. The analysed sediments were initially deposited in the coastal, periodically drained zone of the reservoir. The younger part of the sequence represents the shallow part of the littoral zone of the permanent water body. The malacological and isotope data also allowed distinguishing two phases of increased water level in the reservoir, and changes in its trophic state probably generated by climatic factors. [ABSTRACT FROM AUTHOR]

Farmers in a particular area of the Southern Philippines have confirmed that droughts have affected their rice farms, compelling them to lessen their cropping annually until enough water resources become available. This influenced them to seek alternative irrigation techniques. This study creates a system that implements an alternate wetting and drying technique-based irrigation scheduling to cover a whole rice cropping season through water level and soil moisture sensing. The system is available to three rice growth varieties; short, medium, and long. System development includes implementing SMS for notification, a low-power wide area network, and utilizing an IoT dashboard for data visualization. [ABSTRACT FROM AUTHOR]

Understanding and predicting water level rise is crucial for effective water resource management, flood control, disaster risk reduction, and adaptation to climate change. This study utilize the use of Support Vector Regression Machine (SVRM) models in predicting the water level of Mandulog River in the Philippines. To evaluate its predictive capability, two data architectures, various kernels, and parameters were examined to find the optimal configuration. Multiple kernels were compared for accurate pattern discovery, and parameter selection was performed to enhance predictive accuracy. The SVRM models achieved the lowest Mean Average Percentage Error (MAPE) of 2.186%, Root-Mean Squared Error (RMSE) of 0.00601 during the dry season, and MAPE of 2.226% and RMSE of 0.00602 during the rainy season. Both models were deemed suitable for watershed level forecasting. [ABSTRACT FROM AUTHOR]

To examine the performance of Artificial Neural Networks (ANNs) in predicting the water level of a watershed three days ahead of time, this study evaluated eighteen ANN models with different combinations of training algorithms and activation functions. The two best models corresponding to the two major climate seasons in the Philippines were: for the rainy season; it was the Resilient Propagation with Leaky ReLU which produced MAPE and RMSE of 6.731 and 0.0098, respectively; for the dry season, it was the Scale Conjugate Gradient with Leaky ReLU which produced MAPE and RMSE of 7.871 and 0.01045, respectively. [ABSTRACT FROM AUTHOR]

• A coupled model is proposed integrating a 2D double layer-averaged model for reservoir and a 1D model for bottom tunnel. • High water level, small cover layer thickness, short tunnel length and steep tunnel slope favour the occurrence of sediment flushing. • Low water level, large cover layer thickness, long tunnel length and gentle tunnel slope are more likely to cause tunnel blockage. Sediment flushing through a bottom tunnel is one of the most effective methods to alleviate reservoir sedimentation. However, the multi-physical hydro-sediment-morphological processes of reservoir sediment flushing through an initially covered bottom tunnel intake have remained poorly understood, and a physically enhanced and practically viable mathematical model is required. The present study uses an integrated model to resolve sediment flushing through an initially covered bottom tunnel intake. The proposed model couples a two-dimensional double layer-averaged model for the reservoir with a one-dimensional model for the bottom tunnel by means of numerical fluxes calculations at the inner boundary. The governing equations are solved synchronously using a well-balanced finite volume method. Several parameters related to boundary resistances and sediment exchange flux need to be determined for model closure. The model is tested against data from a series of physical experiments on reservoir sediment flushing, with sound agreement achieved between computed and measured scour hole geometries. Moreover, the present model successfully predicts the occurrence of tunnel blockage. The results prove that reservoir sediment flushing is best accomplished for high reservoir water level, small cover layer thickness, short tunnel length and steep tunnel slope. The present model facilitates reservoir design and operation to help preserve reservoir capacity. [ABSTRACT FROM AUTHOR]

Fish entrainment from reservoirs to downstream rivers by various water release structures may result in serious consequences for reservoir ecosystems. This study proposed an integrated modeling approach for determining fish entrainment risk zones and suitable reservoir regulations. The modeling approach combines hydrodynamic and fish risk assessment modeling with using fuzzy rules set defined by expert knowledge in fish ecology. We applied this modeling approach in the Maling Reservoir in China, where fish entrainment in the reservoir has been observed in the turbine, spillway, and irrigation system. Percocypris pingi (Tchang, 1930) and Onychostoma simum (Sauvage & Dabry de Thiersant, 1874), representing the main and protected fish species, were selected as target fish species. Five reservoir operation schemes were investigated under normal and designed water levels. The modeling results suggest that the fish entrainment risk for protected fish species (Onychostoma simum) is higher than that for the main fish species (Percocypris pingi). The results indicate a ranking of the fish entrainment risk from high to low in the following scenarios: with all spillways in operations, with one spillway in operation, with intakes in operation, with an irrigation system in operation, and with intakes and the irrigation system in combined operations. In addition, under normal and designed water levels, dead fish entrainment zone areas and percentages were extremely low compared to the entire forebay of the reservoir. These results indicate that the operation of the Maling Reservoir does not affect the ecological status of fish. These findings are generally applicable to any fish species in reservoirs that balance reservoir operations and ecological protection of fish, and could assist reservoir managers in making informed decisions on how to mitigate and compensate for fish entrainment. [ABSTRACT FROM AUTHOR]

• Water deficit exposed plants exhibited higher level of oxidative marker production. • Salicylic acid application help to revive stressed plants through triggered the antioxidative mechanism. • Salicylic acid influenced the Bacoside-A amount with integration of water deficit. Salicylic acid (SA), an eminent stress tolerance phytohormone, assists plants in dealing with abiotic stress. A pot experiment was carried out to substantiate the SA's ability to protect the medicinal herb Bacopa monnieri (L.) from exposure to water deficit. Diverse concentrations of SA (50, 75, 100, and 125 mg/l) were applied to plants as a foliar spray along with varied water levels based on reduced irrigation, WD1 (twice a week), and WD2 (once a week) against WW (once a day), with the first spray being applied after one week of water deficit treatment and the second one month later. The pool data for 2021 and 2022 demonstrated the resilience propensity of SA against water deficit in terms of oxidative markers detoxification (H 2 O 2 and MDA) via evoking the antioxidative mechanism of plants. The activity of antioxidants (SOD, CAT, GPOX, and APOX) and amount of non-enzymatic antioxidants (ascorbic acid, total phenolics and, flavonoid) including osmolytes (proline and total soluble sugar) was upsurged after SA (75 mg/l conc.) administration under both stressed and non-stressed plants. Additionally, stressed plants also revealed a recovery in their relative water content with intensifying the membrane stability index. Besides that positive repercussion in terms of medicinally bioactive compound (bacoside-A) content was also achieved with 75 mg/l conc. of SA foliar spray in addition to WD2. Conclusively, the present investigation unraveled the attainment of SA to ameliorate the B. monnieri (L.) under water deficit stress at moderate doses (up to 100 mg/l) by boosting their deterrence mechanisms through counterbalance of the physio-biochemical attributes. [ABSTRACT FROM AUTHOR]

Hyaluronic acid (HA) and chondroitin sulfate (CS) are polydisperse glycosaminoglycans (GAGs),which have important applications as health care products and drugs in skin beauty and arthritis prevention. Enzymatic synthesis is a significant strategy to obtain oligosaccharides and polysaccharides with uniform chain length and well-defined structure. However, the limitations of glycosyltransferase, such as low expression, poor stability, and difficulty in reuse, greatly restrict its application in large-scale commercial production. In this study, we constructed the expression system for hyaluronic acid synthase PmHAS and chondroitin synthase KfoC to obtain the enzyme with high expression level and good water solubility. Subsequently, we screened and optimized several highly biocompatible metal-organic frameworks (MOFs) to immobilize two glycosyltransferases efficiently. The resulting enzyme@MOF composite can catalyze the synthesis of hyaluronic acid and chondroitin oligosaccharides/polysaccharides in quantitative yield. Meanwhile, the supramolecular interactions between enzyme and hydrophilic MOFs confer satisfactory stability, durability, and reusability on immobilized PmHAS and KfoC. [Display omitted] • Immobilize glycosyltransferases in metal-organic framework. • One-step self-assembly method for constructing immobilized enzyme microreactors. • Efficient synthesis of glycosaminoglycan using enzyme@MOF composites. • The catalytic stability of glycosyltransferase was improved. [ABSTRACT FROM AUTHOR]

In Mongolia, overuse and degradation of groundwater is a serious issue. The authors have recently applied a process-based eco-hydrology model, NICE (National Integrated Catchment-based Eco-hydrology) to urban and mining hubs to explicitly quantify spatio-temporal variations in water availability. In this study, NICE was scaled up to the total of 29 river basins in the entire country. The model simulated the effect of past climatic change and human activity on water resources during 1980-2018 there. The model reasonably reproduced observed river discharge with a maximal value during summer rainfall seasons. The simulation also revealed heterogeneous distributions of hydrologic budget and its response to climatic and anthropogenic disturbances. In addition, the authors detected hot spots of groundwater degradation by anthropogenic activity in the national scale. Analysis of relative contribution of environmental factors further clarified the characteristics in these areas and quantified spatio-temporal trends in groundwater level due to the effects of changes in precipitation and various water uses. Generally, the result showed changes in precipitation had a large effect on changes in groundwater levels until 2000. In contrast, the model clarified human activities have recently had a large impact on groundwater level changes. This trend was particularly conspicuous in river basins with urbanization and mining development such as Orkhon, Kharaa, Tuul, Galba, Ongi, Altain Uvur Govi, and Taats River Basins. This methodology is powerful to resolve future competition for water resources in areas with fewer inventory data that could potentially trigger conflicts between urban, mining, industry, herders and local communities. [ABSTRACT FROM AUTHOR]

Arsenic is among the most critical environmental toxicants associated with many human disorders. However, its effect on type 2 diabetes mellitus (T2DM) is contradictory. This systematic review and dose-response meta-analysis aim to update information on the association between arsenic exposure and the risk of T2DM. The sample type (drinking water, urine, blood, and nails) conducted the subgroup analysis. Evaluation of the high vs. low arsenic concentrations showed a significant association between drinking water arsenic (OR: 1.58, 95% CI: 1.20–2.08) and urinary arsenic (OR: 1.37, 95% CI: 1.24–1.51) with the risk of T2DM. The linear dose-response meta-analysis showed that each 1 μg/L increase in levels of drinking water arsenic (OR: 1.01, 95% CI: 1.00–1.01) and urinary arsenic (OR: 1.01, 95% CI: 1.00–1.02) was associated with a 1% increased risk of T2DM. The non-linear dose-response analysis indicated that arsenic in urine was associated with the risk of T2DM (Pnon-linearity <0.001). However, this effect was not statistically significant for arsenic in drinking water (Pnon-linearity =0.941). Our findings suggest that blood arsenic was not significantly linked to the increased risk of T2DM in high vs. low (OR: 1.21, 95% CI: 0.85–1.71), linear (OR: 1.04, 95% CI: 0.99–1.09), and non-linear (P non-linearity =0.365) analysis. Also, nail arsenic was not associated with the risk of T2DM in this meta-analysis (OR: 1.33, 95% CI: 0.69–2.59). This updated dose-response meta-analysis indicated that arsenic exposure was significantly correlated with the risk of T2DM. • This meta-analysis evaluated the association between arsenic exposure and the risk of T2DM. • Drinking water and urinary arsenic were associated with the risk of T2DM in high vs. low analysis. • Drinking water and urinary arsenic were associated with T2DM in linear dose-response analysis. • Nonlinear dose-response analysis showed that arsenic in urine was associated with the T2DM risk. • Blood and nail arsenic levels were not significantly linked to the risk of T2DM. [ABSTRACT FROM AUTHOR]

Thermal stratification widely exists in large reservoirs, causing significant inflow-outflow temperature difference (IOTD), which goes against the downstream ecology. Reservoir optimal operation has recently been conducted to regulate the outflow temperature, while its effects for cascade reservoirs urgently needed to be illuminated. Taking the typical Xiluodu-Xiangjiaba cascade reservoirs (XXCR) as study case, this paper had built a multi-objective optimal operation model combing the non-dominated sorting genetic algorithm II (NSGA-II) and a hydrodynamic-temperature model, and the total power generation (TPG) and IOTD were simultaneously considered. The effects of different inflow discharge and global warming scenarios were analyzed. This paper showed the following: (1) The IOTD and TPG of XXCR showed a positively linear relationship with the water level of the superior Xiluodu Reservoir (XLD), instead of the inferior Xiangjiaba Reservoir (XJB). (2) The reservoir with larger water volume and depth (such as XLD) determined the thermal structure and hydropower generation in cascade reservoirs, compared with the inferior reservoir (such as XJB). (3) As the inflow discharge or air temperature increased, the slope between the IOTD and TPG in the Pareto front curve increased. The results of this paper could support the ecological operation for cascade reservoir to regulate the outflow temperature. [Display omitted] [ABSTRACT FROM AUTHOR]

• The risk of toxic metals in sediments were assessed at different depths. • Pb and cd binding to surface sediments is mainly mediated by organic functional groups. • Mineral components were mainly bound to toxic metals in the bottom sediments. • Mineral compounds (Fe, Mn), Pb, and c functional groups were unevenly distributed. • The type and sequence of toxic metal binding changed with sediment depth. The excessive accumulation of potentially toxic metals (Pb and Cd) in coastal wetlands is among the main factors threatening wetland ecosystems. However, the effects of water table depth (WTD) on the risk and binding mechanisms of potentially toxic metals in sediments remain unclear. Here, sediments from different WTD obtained from a typical coastal wetland were evaluated using a newly developed strategy based on chemical extraction methods coupled with high-resolution spectroscopy. Our findings indicated that the WTD of the coastal wetland fluctuates frequently and the average enrichment factor for Pb was categorized as minor, whereas Cd enrichment was categorized as moderate. High-resolution spectroscopy techniques also demonstrated that organic functional groups and partly inorganic compounds (e.g., Fe-O/Si-O) played a vital role in the binding of Pb and Cd to surface sediments. Additionally, mineral components rather than organic groups were mainly bound to these metals in the bottom sediments. Collectively, our findings provide key insights into the potential health effects and binding characteristics of potentially toxic metals in sediments, as well as their dynamic behavior under varying sediment depths at a microscale. [Display omitted] [ABSTRACT FROM AUTHOR]

Extremely high lead level in tap water caused by particulates has attracted increasing attention in recent years. Despite extensive research on the role of particulate Pb in water supply systems with lead service lines, little information is available on the role of particulate Pb in copper (Cu) water distribution systems. In this study, the dissolved, colloidal, and particulate lead and copper concentrations in representative prototype copper pipe water distribution systems with leaded solder joints and brass fixtures are measured. The effects of flow rate and stagnation time on metal fractionation are investigated. For each experimental scenario, all the water that stagnated inside the system is sampled to have a comprehensive understanding of lead contamination. Sampled at flow rates of 200–250 mL/s, the soluble lead and copper make up 60–96 % of the total concentration in the samples after hours of stagnation. More than half of the Pb and Cu particles are larger than 0.8 μm. Higher flow rates result in substantial increases in particulate metal concentrations but have no apparent effect on dissolved metals. The soluble and particulate copper concentrations (∼ 100–250 μg/L) both increase with stagnation time. For the case of Pb, while the particulate concentration increases (up to ∼ 40 μg/L after 12 h), the soluble concentration does not change significantly beyond 4 h; this can be attributed to the different solubilities of Pb (∼ 20 μg/L) and Cu (∼ 200 μg/L) in tap water. The results also show that particulates suspended by clean "once through" water (without prior stagnation) can lead to high levels of Pb contamination (> 10 μg/L). [ABSTRACT FROM AUTHOR]

• Floodplain conservation requires long-term knowledge of floodplain hydrology. • hyd1d provides interpolation algorithms for 1d hydraulics and gauging data. • hydflood provides extrapolation algorithms of hyd1d results into floodplains. • Together hyd1d and hydflood enable fast hydrological modelling on floodplains. • Input data, software and output are provided openly. Floodplains are environments characterized by fluctuating water levels. Spatial and temporal heterogeneity of habitat conditions driven by hydrology are the key factor for their high biodiversity because strong environmental filtering either creates favorable conditions for specialized organisms or eliminates competing generalists. hyd1d and hydflood are two R packages for simplified hydrological modelling in two large central European floodplains – along the rivers Rhine and Elbe in Germany – that enable users to simulate the dynamics of water level changes, flood extents and durations with high spatial and temporal resolution over long time periods and vast areas. They are simplified in the sense of not being based on physical equations, but they implement fast computing interpolation of 1d hydraulic data and GIS extrapolation algorithms. Annual and long-term products provide the possibility to predict the distribution of floodplain habitats. All input datasets are highly integrated into the packages and automatically updated. Computationally expensive products such as annual flood durations between 1960 and 2022 are provided as open data. The software itself is provided as open source software through CRAN and in public code repositories. With minimal efforts users can apply the software within the given conditions or integrate other river systems through data and source code contributions. [Display omitted] [ABSTRACT FROM AUTHOR]

Over the last few decades, satellite radar altimetry has developed enabling a wide range of applications, including the monitoring of lakes. As a method to measure lake water level time series, satellite radar altimetry contributes to gaps in data of in-situ networks in time and space, which is freely available, continuous, global, regular, and precise. However, depending on the location, shape, size, and surrounding environment of the lakes, the accuracy of water heights inferred from altimeters varies significantly. The accuracy of water heights also strongly depends on the quality of space-born instruments, with modern models having evolved from radar altimeters launched in the 1990 s. To determine the level of accuracy of radar altimeters, it is necessary to use ground observations of lake heights. However, the measurements performed onboard by altimeters and on the ground by water level gauges are not directly comparable because the physical properties and scaling of the measurements are completely different. In this study, we present an approach which permits realistic inter-comparison of water levels, in relation to a large lake with a large number of hydrological stations (at least 10) and the presence of at least 10 satellite measurements per month (on the example of lake Baikal), in order to provide diagnostics on the quality of the radar altimeter and statistics of the errors. [ABSTRACT FROM AUTHOR]

The momentum-conserving staggered grid (MCS) scheme to simulate shallow water flows in channels of varying width and topography is revisited in this article. Here, we modify the MCS scheme so that it can be applied to channels of arbitrary cross-section. The scheme is validated using steady analytical solutions for channels with rectangular and trapezoidal cross sections. We found that the method was capable of solving a wide variety of test cases; including subcritical, supercritical and transcritical steady flows and flows with hydraulic jumps. This MCS scheme could handle both steady and unsteady problems. In the implementation of a channel with arbitrary cross sections, the simulation depicts the time-lapse evolution of the water level toward the steady state. These results were consistent with previous findings in the literature. All numerical experiments carried out here demonstrate the merits of the numerical MCS scheme. • Steady and unsteady flows in prismatic channels are simulated using MCS scheme. • Validation is done using MacDonald's analytical steady solutions for various flows. • The MCS scheme is extended so that it can be used to handle non-prismatic channels. [ABSTRACT FROM AUTHOR]

Pressure and water level control are quite challenging in grate-fired boilers due to higher combustion lag. Fluctuation in the pressure and the water level is more evident in the coal-fired grate boilers due to the presence of lower volatile and higher char. This results in suboptimal operation and poor performance of the boiler. This paper presents a novel predictive and dynamic simulation model for the drum dynamics analysis of a grate-fired boiler by combining a data-driven model and a thermodynamic model. A data-driven methodology is employed for the estimation of combustion, heat transfers, and circulation performance of the boiler. A novel thermodynamic model is proposed for the boiler dynamics of a hybrid boiler. The proposed data-driven model has been integrated with the thermodynamic model to reduce the randomness and improve consistency. Pressure and water level errors are estimated by comparing the predicted value and experimental result and the multi-objective optimisation technique is employed for the minimisation of errors. The Stochastic Gradient Descent algorithm is proposed for its ability to quick learning and adaptation to variations in fuel and combustion characteristics. The model demonstrates good accuracy in predicting the combustion and boiler dynamics of a grate-fired boiler. The proposed model has good potential to be used for the reciprocating grate solid-fuel boiler control in fluctuating load conditions. • A model for the prediction of boiler pressure and water level for grate combustion. • Integration of a data driven combustion model and the boiler dynamics model. • Multi-objective optimisation to minimise the errors in pressure and water level. • Stochastic gradient descent method to adapt with the change in fuel and combustion. • Model can be used for the control of a grate boiler in fluctuating load condition. [ABSTRACT FROM AUTHOR]

In recent years, advances in information communications technology have proven their role in reducing water losses in water distribution systems. The geographic information system is a specialized set of Information Communication and Technology, which provides effective methods in the management of the water sector, in particular, non-revenue water. The Palestinian national strategic plan reported that reducing the non-revenue water from 38% to 35% will increase the revenue by US$40 million within 10 y. Similarly, the water sector regulatory council estimates that the non-revenue water rate is 33%. Surprisingly, water utilities have yet to implement extensive water loss management. Approximately 95% of the urban population in Khan Younis is served by a municipal water supply network. A high level of non-revenue water was recorded in Khan Younis in 2012 (about 40%). Many actions have been implemented to reduce the non-revenue water to 30% by 2020. This study aimed to quantify the non-revenue water of each water distribution zone and to classify the non-revenue water loss for distribution zone 20 (DZ20) per house connection. It was concluded that the adaptation of geographic information system made it possible to classify the highest loss rate of non-revenue water between 3% and 5% for DZ23. However, the distribution zone DZ20 showed a very high level of water loss (58.78%). The filed investigations illustrate that the developed map accuracy was presented as 83% accurate, whilst a strong positive correlation was revealed between non-revenue water and the age of the water meter and the number of populations occupying the house connection. [ABSTRACT FROM AUTHOR]

Harvesting of stormwater in the Gaza Strip is very important for the aquifer recharge since the stormwater infiltration is considered the sole replenishing source which reimburses the severe groundwater abstraction and protects the aquifer from unrecoverable deterioration. Gaza Strip experienced stormwater infiltration basins several years ago using different infiltration techniques. Waqf Basin is an existing stormwater infiltration basin located in Gaza City that used a surface natural infiltration technique, however, recently the basin was upgraded and augmented by drilling 18 boreholes (drywells) at zone 4 (western part of the basin). As a result, the basin has an improved infiltration capacity as revealed during the 2021–2022 wet season through field observation readings of water levels with a borehole infiltration capacity estimated as 111.0, 250, 316.7 m3 /d at 1.70, 3.40, 5.10 m ponded water depth, respectively. In addition, HYDRUS (2D/3D) software was used in this research to model/simulate Waqf Basin at ponded water depths 1.70, 3.40, and 5.10 m with the corresponding obtained borehole infiltration capacities as 289.0, 324.19, 250.39 m³ /d, respectively. The results emphasized that the single borehole infiltration capacity was in agreement with the field observed readings as the borehole infiltration capacity increases with the increase of basin ponded water depth. Nevertheless, the difference between HYDRUS and field observed results was attributed to the clogging effect which needs further studies in the future. Using the borehole infiltration technique is efficient when properly designed, implemented, and repaired at the end of each wet season to protect the system from permanent malfunctioning. [ABSTRACT FROM AUTHOR]

• The highest concentration of antibiotics was detected at the late aquaculture stage. • The concentration of antibiotics in natural water was related to aquaculture stages. • Antibiotics in coastal seawater mainly came from aquaculture ponds. • Correlation between antibiotics and water quality parameters was discovered. • The ecological risk caused by antibiotics increased with the aquaculture stages. The pollution of antibiotics commonly existed throughout the entire aquaculture process, but the residues of antibiotics at different aquaculture stages have rarely been studied. This study investigated the occurrence, distribution and risk assessment of antibiotics at different aquaculture stages (the non-aquaculture stage, the early aquaculture stage, the middle aquaculture stage, and the late aquaculture stage) in two typical marine aquaculture areas (Mahegang River and Dingzi Bay) surrounding the Yellow Sea. Fluoroquinolones and tetracyclines were commonly used antibiotics in the aquaculture of these areas with high detection frequencies (17% to 83%). Compared among four aquaculture stages, the highest concentration of antibiotics (9032.08 ng/L) in aquaculture ponds was detected at the late aquaculture stage. And the antibiotic pollution level of natural water was directly related to the aquaculture stages. Similarly, at the aquaculture stages, the detection frequency of antibiotics in sediments was higher than that at the non-aquaculture stage. Based on the correlation analysis, the concentration of main antibiotics in water showed a positive correlation with total nitrogen (p <0.05) and chlorophyll a (p <0.01), while it showed a negative correlation with salinity (p <0.01) in coastal water of the Dingzi Bay. According to the risk assessment, with the development of aquaculture stages, the selection pressure of fluoroquinolones and tetracyclines on resistant bacteria had increased. And the ecological risks caused by sulfonamides and tetracyclines to aquatic organisms had also increased markedly. Overall, this study may provide a reference for formulating regulatory policies regarding antibiotic use at different aquaculture stages. [Display omitted] [ABSTRACT FROM AUTHOR]

Water-level regulation can have significant impacts on coastal wetland ecosystems. In this study we sought to update marsh-bird-based ecological performance indicators (PIs) that support adaptive management of long-term outflow regulation for Lake Ontario. Previous PIs established in the mid-2000 s were based on single species and monitoring them required data not currently being collected at broad scales. We therefore focused on developing and validating community-level PIs using data from an ongoing, long-term, basin-wide monitoring program, the Coastal Wetland Monitoring Program (CWMP). After identifying species with documented responses to variation in water levels in the literature, we considered a suite of potential PIs by first examining correlations with both annual mean water levels and measures of interannual water-level fluctuations. We then used a mixed-modelling framework to determine which highly correlated PIs exhibited statistically significant relationships with water-level variables. Having established significant effects of water levels on the candidate PIs, we performed a power-sensitivity analysis to determine the degree of change in each PI that can be detected based on current CWMP sampling. From these analyses, we propose six potential marsh-bird based PIs: sum total abundance of sensitive marsh-obligate species, richness of sensitive marsh-obligate species, and abundance of each of red-winged blackbird (Agelaius phoeniceus), marsh wren (Cistothorus palustris), common gallinule (Gallinula galeata), and least bittern (Ixobrychus exilis). Of these, the community-based PIs of sum total abundance and richness of sensitive species appear most suitable for assessing the marsh-bird community response to outflow regulation on Lake Ontario. [ABSTRACT FROM AUTHOR]

Wetlands are amongst the world's most effective natural carbon sinks, and also have the potential to emit large quantities of stored carbon back into the atmosphere if disturbed. In the Murray-Darling Basin, high consumptive demand for water has led to widespread wetland loss and degradation. Remaining wetlands are commonly under additional pressure from grazing and trampling by feral herbivores or livestock and unseasonal flooding in summer to meet peak irrigation demand. Here, during a summer flood in Barmah National Park, we compared soil carbon and nitrogen and carbon emissions within, and outside of, a feral herbivore exclusion plot. The sustained global warming potential from the whole wetland (i.e., both within- and outside of the exclusion plot), totalled from both carbon dioxide (CO 2) and methane (CH 4) emissions, averaged 132.27 ± 9.88 g CO 2 -e m−2 d−1, an estimated 28- to 89-fold higher than the global average for natural wetlands. The high warming potential of the wetland was driven strongly by CH 4 emissions, which made up over 90% of total CO 2 -equivalents, with CO 2 contributing <10%. We expect these values represent peak CH 4 emissions from the site due to high water and soil temperatures, and low water levels, at the time of sampling. Soil carbon and nitrogen did not differ significantly within and outside of the exclusion plot, but surface soil samples indicated recent condition improvement in the absence of feral herbivores. We suggest that an emissions avoidance incentive could be developed around unseasonal, summer watering of forested floodplains where flood timing can be controlled. [ABSTRACT FROM AUTHOR]

This work presents a macroseismic analysis of the AD 1755 Lisbon Earthquake-Tsunami event by means of the combination of intensity data derived from the EMS-98 scale and the ESI-07 scale (Environmental damage). About 600 records of secondary earthquake environmental effects (EEEs) for the whole Spain have been used to define intensities, focused on the SW portion of the Iberian Peninsula. The Spanish data have been complemented with 308 EEEs records from Portugal. The analyses indicate maximum intensities of X EMS-ESI along the Atlantic margin of the Iberian Peninsula with 76 records of Tsunami environmental effects (TEEs). An important amplification (VIII – VII) occurred all along the Guadalquivir basin and the adjacent Betic front at epicentral distances of 300–700 km. In these zones 55 records of ground effects (ground cracks, Liquefactions and slope movements) are catalogued. In the rest of the territory of the Peninsula the most widespread effects were hydrogeological changes with 505 records in Spain and 196 in Portugal (total 701 records) covering all the intensity levels. Increase of flow discharges in springs and elevation of water level in wells was the common groundwater response to seismic shacking, especially in SW Iberia. In this zone water elevation in wells was between 5 and 3 m and persistent increases of discharges long-lasting (several days to two months). Persistent discharges on springs were linked in 143 cases to important SW-NE crustal faults (e.g., Alentejo-Plasencia Fault). From the Intensity distribution the historic seismic scenarios are explored by means of the development of empirical ShakeMaps. These consider the three classical seismic sources proposed for this earthquake: Gorringe Bank (G); Marques de Pombal Fault (M) and Atlantic delamination beneath the Gulf of Cadiz (C). However, individually these seismic sources are too small and unable to generate the resulting seismic scenario depicted by the intensity map developed in this work, with onshore seismic accelerations (PGA) up to 0.82 g. These acceleration values and the great amplification experienced throughout the Guadalquivir basin (0.34–0.52 g) are only possible considering a combination of the three seismic sources (GMC Source) probably related to shallow subduction or lithospheric delamination beneath SW Iberia and the Gulf of Cadiz. This will suggest an NNE-SSW offshore rupture length of 350–360 km with an overall rupture area of c. 84,500 km2 resulting in an event magnitude 8.6 Mw calculated from empirical relationships. The results demonstrate the efficacy of these kind of approaches for better identifying and modelling seismic sources for historical events. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigated photocatalytic property of two dimensional heterostructure MoS 2 /WS 2 by a first principles calculation. Firstly, we evaluated the energetic stability of different heterostructures by comparing combination energies of heterojunctions with those between adjacent layers in multilayer MoS 2 or WS 2 system after constructing nine heterostructures (MoS 2) n /(WS 2) m (n, m = 1, 2, 3). The subscripts n and m are the numbers of MoS 2 or WS 2 layers that are contained in the above heterostructures, respectively. The investigated heterostructures have all stable binding energy of about 0.2 eV. Secondly, we calculated band gap of every heterostructure in order to compare it with the oxidation/reduction level for water splitting. Among the considered nine structures, the heterostructure (MoS 2) 1 /(WS 2) 1 is suitable for overall water splitting because it has a band gap of 1.70 eV and energy barrier of 0.21 eV for preventing recombination of electrons and holes generated by light irradiation. In addition, the heterostructure is also favorable to the evolution of hydrogen, as it has a low hydrogen desorption energy of 0.035 eV. • The considered heterojunctions are all stable energetically. • Monolayer WS 2 contributes to overall water-splitting. • Multilayer WS 2 contributes to half water-splitting. • (MoS 2) 1 /(WS 2) 1 is favorable to separating electrons and holes. • (MoS 2) 1 /(WS 2) 1 has a good hydrogen desorption property. [ABSTRACT FROM AUTHOR]

High density polyethylene(HDPE) material is excellent, often made into bellows, and is an important part of the urban drainage system. The blasting seismic dynamic load is one of the key problems affecting the safety of buried pipeline structures. As a commonly used artificial source excitation method, blasting is often used to study the seismic structural response test. Combined with the characteristics of the buried typical stratum of pipelines in urban areas, full-scale blasting tests of embedded HDPE bellows are conducted. The characteristics of vibration acceleration and strain in the empty pipe under blasting vibration are monitored and analyzed. LS-DYNA is used to establish the model based on the field test conditions and verify the rationality of the model. Then, the models of different water levels are added and the dynamic response characteristics of the pipeline are calculated and analyzed. Finally, according to the max allowable stress criterion, the safety of the pipeline is evaluated. [ABSTRACT FROM AUTHOR]

Waste energy recovery is crucial to improving the overall energy efficiency of any industry. Industrial wastewater discharge contains a considerable amount of hydraulic energy, a waste that can recover using micro-hydropower concepts. Gravitational water vortex power (GWVP) is considered one of the most suitable micro-hydro extraction methods for such applications. Therefore, this study mainly focused on the numerical and experimental investigation of the GWVP plant, which was designed based on discharge water flow from an industrial fish farm located on the south coast of the Republic of Korea. The initial prototype model was investigated by simulations and experiments evaluating performance under three conditions: different rotational speeds, flow rates and water levels. The maximum hydraulic efficiency was recorded as 61.3% in simulation while 60.5% in the experiment for the prototype model. Then the actual scale simulation is also conducted to compare the performance with Froud similarity prediction. Actual scale simulation yields 6 kW of extracted power having 63.3% efficiency, whereas the deviation of efficiencies occurs due to the scaling effects. Thus, the flow field of each case was analysed considering the water-air interface, pressure contours and velocity vectors while justifying the variation of performance. Since the target power output was reached in the designed GWVP plant, an actual site application was proposed to recover the industrial waste energy as a sustainable solution. • Numerical and experimental investigation of vortex power plant. • Energy recovery from industrial wastewater. • Performance comparison between prototype and actual scale models. • Flow analysis considering water-air interface, pressure and velocity. • 61.3% maximum efficiency in simulation and 60.5% in experiment study. [ABSTRACT FROM AUTHOR]

• Water physicochemical parameters gradient is higher in the north than the south lake. • Causeway changed lake current direction from a clockwise to an anti-clockwise. • Causeway is an obstacle complete water balance between northern and southern lakes. The Urmia Lake in NW Iran, the world's second-largest hypersaline lake, has been exposed to rapid water level fall in the last two decades due to water resources mismanagement, building up of dams on inlet rivers, and the causeway construction in the lake. This human intervention has divided the lake into northern and southern parts and caused an extreme disturbance in the hydro-chemical and hydrodynamic systems, namely current direction reversal. To fully understand the current situation, water depth and lake surface and deepwater physico-chemical parameters (i.e. density, temperature, acidity, electrical conductivity, and total dissolved solids) are analysed in the wet and dry seasons of 2019. In the wet season, deepwaters have a higher density than surface waters, and the northern part of the lake contains denser water compared to its southern counterpart. The formation of density gradients creates an anticlockwise direction lake current. Deepwaters show higher electrical conductivity and total dissolved solids than surface waters in the wet season. Unlike the wet season, the lake water becomes more homogenised due to wave action and evaporation in the dry season. Our study clearly demonstrates that the water passageway of the causeway does not allow for a complete yearly balance between water and sediment exchange. Results suggest that the northern and southern parts of the lake have almost independent hydro-chemical and hydrodynamic systems. In the undeniable reality of global warming trends, anthropogenic interventions into sensible ecologic systems need to be better planned if we were to prevent the ecological disasters we now have to face. [ABSTRACT FROM AUTHOR]

Affected by the reservoir water and rainfall and other factors, the stability of the landslide changes with the different reservoir water level decline rate. Using the Baota landslide in Yunyang County in Three Gorges Reservoir region as an example, and applying the saturated-unsaturated numerical simulation method, the groundwater seepage field is calculated when the reservoir water level rises and declines. The calculated pore water pressure is used for the ultimate equilibrium analysis of landslide, and the effect of reservoir water level drop on landslide stability was discussed. The calculation results show that with the water level falling from 159 m to 145 m, and the increase of the rate of decline in the reservoir water level, the decline in groundwater seepage lines has increased somewhat. The landslide stability coefficient calculated under each working condition is larger than that in the original design, and the decrease rate of reservoir water has a qualitative effect on the stability of the landslide, but the influence is very small. Through the SBAS-InSAR time series monitoring of Sentinel-1 data in the 13th period and field verification, it is found that the cumulative deformation of the slope is small, which prove the stability of the landslide. [ABSTRACT FROM AUTHOR]

This work developed a numeric-based kinematic approach for evaluating the required strength of three-dimensional (3D) geosynthetic-reinforced soil structures (GRSSs) with different water levels. Instead of directly employing the pore-water pressure coefficient r u , this work utilizes numerical simulations to obtain the distribution of pore-water pressures. The presented method avoids to determine the value of r u , which is uncertain as the variation of water tables. A 3D horn-like failure mechanism is discretized to describe the collapse of GRSSs. On this basis, the seepage forces acting on each element of the discretized mechanism are determined by using an interpolation technique. Thanks to the principle of work rate balance, the required reinforcement of geosynthetics is determined through optimization. Sets of design charts are provided for simplicity of practical use, followed by a sensitivity analysis. Results of this paper indicate that the presence of a seepage flow increases the required strength of reinforcements, whereas the inclusion of 3D effects has an opposite effect. The variation of water levels significantly impacts the required strength and the failure pattern of GRSSs. The proposed method in this paper can provide an insight into the design of GRSSs subjected to seepage forces. • A numeric-based kinematic method is developed to evaluate the required geosynthetic strength for 3D GRSSs. • This work utilizes numerical simulations to obtain the distribution of pore-water pressure. • The presence of seepage forces significantly increases the required geosynthetic strength. [ABSTRACT FROM AUTHOR]

Groundwater is best portrayed as the world's truly covered up treasure. It has had an effect in giving safe drinking water during dry season. It is the world's biggest open store of fresh water (barring ice sheets and icy masses) and comprises around 94% of all fresh water. Rajasthan witnesses water scarcity problem therefor, it aims at forecasting the rainfall in the state, based on different features provided by the state government. The motivation of the paper is to predict the groundwater level so that proper conservative methods can be applied to raise the level of ground water. In this paper, a comparative analysis of different individual models is used on the derived dataset and two new hybrid models are added to increase the efficiency and accuracy of the prediction. [ABSTRACT FROM AUTHOR]

This study presents the results of lithological, diatom, geochemical analyses and radiocarbon chronology of the bottom lake sediments and peat bogs in the central part of the Onega Peninsula (the southern coast of the White Sea): Lake Maloye Murakanskoye (11.0 m a.s.l.), Lake Zhirovskoye (9.5 m a.s.l.), Lake Murakanskoye (7 m a.s.l.), and the Gorbovatiy Mokh bog (6.5 m a.s.l.). The bottom topography and sediments of Lake Murakanskoye were examined using sonar and ground penetration radar (GPR) survey, whereas in the other locations only the water depth was measured. Then, the digital models of the lake bottom topography were created. As an additional indicator of the relative sea-level (RSL) position, we used data on the altitude of the coastal terraces. Evidences of two transgressions in the White Sea (late glacial and Middle Holocene) are revealed. The transgressions were interrupted by two regressions (Early and Late Holocene). Our studies do not allow us to make a clear conclusion about the time and maximum level of the late glacial transgression. However, we may suggest that its level was above 11 m a.s.l. The regression of the Early Holocene started before 10.6–10.2 ka cal BP when the water level in the study area dropped below the altitude of 11m. At 9.4–9.1 ka cal BP the RSL was at an altitude of ca 7m. The Middle Holocene transgression (Tapes) started after 8.4 ka cal BP. The maximum level was reached before 7.4 ka cal BP and did not exceed an altitude of 9.5 m. The RSL stabilized at an altitude about 8.5–8 m during 7.4–6.0 ka cal BP. During 6.0–3.9 ka cal BP RSL very slowly decreased or fluctuated by the level of 8–7 m. RSL began to fall from the 7 m altitude about 4.0–3.9 ka cal BP and by 2.7–2.3 ka cal BP the sea-level reached 4.5 m. After that RSL dropped to its modern position. During the last 4.0 ka cal BP the rate of RSL fall was approximately 0.17–0.18 cm/year. [ABSTRACT FROM AUTHOR]

The high-resolution biochemical records (SRXRF, ICP-MS and FTIR analyses) of bottom sediments were used for the reconstruction of clastic flux into Lake Baikal via the Barguzin River as moisture and glacier indexes from 1631 ka BP. According to the obtained data, proxies of a high supply of clastic flux by the river are high: the content of feldspar and LREE/HREE, Rb/Sr and Th/Mo ratios. We sampled a sediment core extremely close to the estuary of the Barguzin River. It seems that the water budget of the Baikal tributaries dramatically reduced ca. 34–30 ka BP, and the lake water level was minimum (less than 35–40 m compared to the present) for the last 34 ka. The lake water level has gradually increased from ca. 30 to 25–23 ka BP, and it was likely linked with the activity of the East Asia Monsoon. The very contrasting changes in chemical and mineralogical records were ca. 29.5 ka BP, and these changes were very likely associated with the Heinrich-3; however, there were no significant changes in the records around the Heinrich-2. Our records revealed some intensification of the clastic flux of the Barguzin River into the Barguzin Bay ca. 25–23 ka BP. The Baikal event ca. 21.5–22.5 ka BP was characterized by a sharp reduction of the influx of clastic material into the Barguzin Bay. The time span of 19.5–18 ka BP was the last time that the Barguzin River inflow increased during the Late Pleistocene. This increase in the water budget was at arid regional conditions, and we assumed it could occur due to the contribution of meltwater from glaciers of the Barguzin Ridge. It is most likely that at the regional Late Pleistocene/Holocene transition (around 12–13 ka BP), a rapid rise of the water budget of the Barguzin River occurred, while the lake level was not high, and the sediments deposited from 12(13)–16.5 ka BP could be directly eroded by a kill of the Barguzin River. In general, the obtained records show that an increase in the water budget of the Barguzin River was gradual. The duration of high inflow into the Barguzin Bay was ca. 1.5 ka, while the reductions of this inflow were dramatic. [ABSTRACT FROM AUTHOR]

This paper studies the stability and dynamic response of two-stage hydropower stations cascaded by regulating reservoir. Firstly, the model of the two-stage hydropower stations cascaded by regulating reservoir is established. Then, the stability and dynamic response of two-stage hydropower stations are analyzed. Finally, the effects of sectional area of regulating reservoir on the stability and dynamic response based on the first-stage and second-stage hydropower stations are analyzed. The critical stable sectional area of regulating reservoir is determined. The results show that, the stable domain of the first-stage hydropower station is smaller than that of the second-stage hydropower station because of the feedback mode of water level of regulating reservoir and parameters of two-stage hydropower stations. The sectional area of regulating reservoir has a remarkable influence on stable domains and dynamic response processes. Under different combinations of proportional gain and integral gain of governor, the critical stable sectional area of regulating reservoir has two positive solutions. The intersection, curves of the critical stable sectional area of regulating reservoir and integral gain of governor, divides the parameter plane into stable domain and unstable domain. The stability of two-stage hydropower stations becomes better with the decrease of integral gain of governor. • Model of two-stage hydropower stations cascaded by regulating reservoir is built. • Stability and dynamic response of two-stage hydropower stations are studied. • Effects of sectional area of regulating reservoir on stability are revealed. • Critical stable sectional area of regulating reservoir is determined and analyzed. [ABSTRACT FROM AUTHOR]

The complementary operation of cascade hydropower (CHP) and photovoltaic (PV) can increase the integration of PV power and has become a trend in modern power systems. However, the randomness and variability of PV power output might cause challenges in precisely tracking the submitted generation plan of the CHP-PV complementary system. The safety and stability of the receiving-end power grid might deteriorate. In this paper, a multi-time scale dispatch framework with day-ahead and intra-day dispatch is established for the CHP-PV complementary system to address the PV uncertainties. The day-ahead dispatch is employed to provide reliable reference results and sufficient adjustment reservations for the intra-day dispatch. An Itô-theory-based stochastic optimization (ITB-SO) approach is proposed for the intra-day dispatch by modeling the PV prediction error with stochastic differential equations (SDE). The SDE model can be embedded into the ITB-SO approach without scenario generation, and thus computational burden can be significantly reduced compared with scenario-based methods. A complementary system in southwest China is chosen as a detailed case study. The simulation results demonstrate that real-time random PV fluctuations could be compensated by adjusting CHPs. Meanwhile, the target water level of cascade reservoirs can be tracked under the proposed approach. [ABSTRACT FROM AUTHOR]

Sustainability in a holistic form encompassing environmental, social and economic factors is of utmost importance. Yet, renewable energy's dependence on wind, solar radiation or water levels leads to energy price fluctuations. Companies are increasingly recognizing the economic importance of social sustainability, and this requires production planning to unite economical and sustainable production. In addition, there are challenges resulting from increasing variability in demand in complex markets and supply networks. This paper introduces a nonlinear aggregate production planning (APP) model that recognizes fluctuating energy costs and social sustainability. The model is solved using model predictive control (MPC) in two exemplary case studies. [ABSTRACT FROM AUTHOR]

This study investigates the determination of compound risk under the co-existence of heavy rainfall and water level rise at Alappuzha, a coastal district in Southern Kerala, India using Copulas. In the case of Alappuzha, when the combined action of rainfall and water level rise occurs, the chances of compound flooding is more in and around Vembanad Lake and lower Kuttanad regions. So, the water level and rainfall of three different locations viz. Punnmada, Cherthala, Arookutty are considered for compound flood risk analysis. A joint probability model based on Copula is used to determine the combined risk of flooding. First the marginal distributions of daily rainfall and water level data are developed for each locations and the best fit distribution is used for finding the joint probability. The three most common Archimedean copulas Gumbel–Hougaard (GH), Clayton and Frank are used to find the joint probability of rainfall and water level and the best copula for each location is also identified. Subsequently, the joint and conditional return periods of rainfall and water level are also obtained in an exercise of risk modeling. By using the digital elevation model (DEM) in a Geographic Information System (GIS) platform, the flood prone areas are calculated and represented them graphically, for specific cases of joint return period-water level combinations. This helps as an aid for administrators or policy makers to effectively perform the disaster management at Alappuzha. [ABSTRACT FROM AUTHOR]

River channel deflectors are environmentally friendly low head hydraulic structures constructed from wood, stones and coarse gravel Their aim is to protect river banks against erosion, to change the direction of river flow making the river course naturally meandrous instead of artificially straight, to provide natural refugia for fish and invertebrates and finally to improve hydraulic discharge conditions. However, from the designing point of view they are difficult to represent in hydrodynamic models since they are constructed and fixed in the river bed differently. For this reason, in hydraulic models' deflectors may be treated as modifications to the value of the watercourse bed roughness or reduction in the active part of the cross-section. Thus, to test the suitability of one-dimensional models for river restoration involving river deflectors, a 1-D numerical model of the lower section of the Flinta river (Wielkopolska Province, Poland) was prepared. To do that, firstly three channel flow deflectors were constructed and installed in the lower section of the Flinta river. Secondly, hydrometric measurements were continued systematically over three years. Next, based on field studies and field data, calculations were made using the HEC-RAS 1-D software. Several variants of the shape and the effect of deflectors were tested. On this basis, the variability of the roughness coefficient value for the Flinta riverbed after the implementation of deflectors was analyzed. The novelty of the research is that the obtained results show that river channel deflectors have a significant influence on the processes of morphological changes (such as: velocity distribution, grain size changes, tendency towards channel meandering, channel slope) of the riverbed and thus also on changes in hydromorphological parameters of river flow. The presented case study confirmed the potential for effective deflector operation for the velocity range of 0.10 – 0.30 m·s−1. The maximum changes of the river bed elevation after the deflectors had been introduced reached 0.10 m. It was also found that the effect of deflectors on roughness at high water levels was non-significant and did not increase the risk of flooding. For Q1% flow, the implementation of flow deflectors had no significant effect on the capacity of the studied river section. Only slight subduction of 0.02 – 0.03 m of the water surface in the vicinity of the deflectors could be observed compared to the model from before the restoration activities. The greatest impact of the channel deflectors is seen at low water levels and low flows that do not exceed average flow values. Finally, it was shown that the best solution to implement deflectors into a one-dimensional model is to consider their influence as a change in the value of Manning's coefficient. The obtained results can be considered universal in relation to typical transformed small lowland watercourses that have been straightened and regulated and are to be subjectedto the process of river restoration. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting, and carbon dioxide (CO 2) utilization devices have attracted immense attention as sustainable technologies for the generation of hydrogen (H 2) fuel and value-added chemicals feedstock. Among numerous semiconductors, bismuth vanadate (BiVO 4) has emerged as a promising photoanode owing to its fascinating features such as high chemical stability, straddling band alignment with water redox levels, eco-friendly, and cost-effectiveness. However, sluggish oxidation kinetics, photo-corrosive nature, low electronic conductivity, and short carrier diffusion length limit its commercialization on the PEC horizon. To mitigate these inadequacies, several strategies have emerged such as novel heterojunctions, doping with unique materials, interface modulation, morphology, facet orientation, co-catalyst loading for surface engineering, etc. to realize the outstanding cost-to-efficiency ratios and long-term stability of PEC devices. The review highlights the recent advancement in BiVO 4 -based photoanodes in last five years (2018–2022) and their utilization in the single absorber and unexplored tandem PEC systems towards boosted water splitting and CO 2 reduction. A discussion on theoretical studies of BiVO 4 -based PEC systems elucidates the microscopic mechanism of promotion effect of the bulk/interface/surface strategies on surface catalysis as well as interfacial charge transfer in boosting oxidation kinetics. Moreover, this review addresses the versatility of the BiVO 4 -based photoanode for the novel yet commercially viable PEC applications. This review will provide a broad avenue in designing highly durable, and scalable BiVO 4 -based systems toward various PEC energy conversion devices. [Display omitted] • BiVO 4 is a promising photoanode for PEC water splitting and CO 2 reduction. • Recent progress in the various strategies to improve PEC performance is reviewed. • BiVO 4 -based tandem water splitting and CO 2 reduction systems are emphasized. • Future outlooks are addressed with associated challenges. [ABSTRACT FROM AUTHOR]

Population growth and increased agricultural activities in Karaman and its surrounding region, located in the southwest of the Konya Closed Basin, have led to increasing water demand in recent years. Karaman's drinking and irrigation water needs are also almost entirely met from groundwater. Accordingly, excessive groundwater extraction deepens the water level inside the aquifers, resulting in land subsidence. In this study, the spatio-temporal evolution of surface deformation in and around the city of Karaman was investigated using Sentinel-1/A SAR data, Global Navigation Satellite System (GNSS), and groundwater levels over a period from 2016 to 2021. Sentinel-1 images obtained from ascending satellite orbits were evaluated using the persistent scatter interferometry (PS-InSAR) approach. Mean velocity maps and line-of-sight displacement time series were obtained and compared with GNSS data and groundwater levels. In all three datasets, a significant level of subsidence was obtained in the study region. The land subsidence values were found to be 25 mm/yr in the city center of Karaman and reached values of 50 mm/yr toward the northern part of the province. According to the results, there is a strong correlation between subsidence rates and groundwater levels over the analyzed period, indicating that subsidence in the area is most likely driven by excessive groundwater withdrawal. [ABSTRACT FROM AUTHOR]

Reliance on groundwater in Sub-Saharan Africa is growing and expected to rise as surface water resource variability increases under climate change. Major questions remain about how groundwater will be used, and who informs these decisions. We represent different visions of groundwater use by 'pathways': politically and environmentally embedded socio-technological regimes for governing and managing groundwater systems. We presented policy actors (9 sets), development and research stakeholders (4 sets), and water users (6 sets) in three river basins in Ethiopia, Niger and Tanzania with information on the social and environmental impacts of six 'Groundwater Development Pathways', before gathering their opinions on each, through Multicriteria Mapping (MCM). Participants preferred pathways of low-intensity use, incorporating multiple agricultural, pastoral and domestic purposes, to high-intensity single-use pathways. Water availability and environmental sustainability, including water quality, were central concerns. Participants recognised that all groundwater uses potentially impinge upon one another affecting both the quantity and quality of abstracted water. Across participant groups there was ambiguity about what the most important water use was; each expressed demands for more detailed, certain modelling data. Water users preferred community or municipal-scale management regimes, perceiving that water quality was more likely to be safeguarded by institutions at these levels, whereas policy and development actors preferred individual-scale management, viewed as more efficient in terms of operation and maintenance. We conclude that MCM, combined with more detailed modelling, can provide an effective framework for policy actors to understand other stakeholders' perspectives on groundwater development futures, enabling equitable, inclusive decision-making and governance. • Stakeholders prefer low-abstraction, multi-use groundwater development trajectories. • The cluster of policy actors consulted preferred individual level water management. • The cluster of water users preferred municipal level management. • Multicriteria Mapping and Participatory Modelling show actors' policy preferences. [ABSTRACT FROM AUTHOR]