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To date, seasonal dynamics of the denitrifying bacterial community in floodplain lakes is unknown. Here, we investigated the alpha diversity, abundance and composition of the sediment nirS-type denitrifying bacteria in Poyang Lake during the wet, mid-dry and dry seasons using Illumina MiSeq sequencing and quantitative polymerase chain reaction assay. The results showed that only a small part of the total operational taxonomic units (OTUs) were shared by the three seasons. OTU richness, Chao richness estimator and Shannon index exhibited higher values in the wet season than in the dry season. Some regular patterns of variation in the composition of the nirS-type denitrifying community at three classification levels (phylum, class and genus) were found among seasons. Community structures of nirS-type denitrifying bacteria were significantly different across seasons. In addition, the abundance of nirS gene showed no seasonal pattern. Total nitrogen, total phosphorous and pH were the most significant factors elucidating the compositional variation of the nirS-type denitrifying community. This study provided a new evidence for the ecological effects of seasonal water level fluctuations and improved our understanding of the nitrogen removal processes in floodplain lakes. [ABSTRACT FROM AUTHOR]

This article presents examples of the use of complex sheet metal in everyday life and the course of modeling a sheet bent simultaneously in two planes. The element selected to describe the modelling process is a fragment of the side wall of a lever hydroelectric power plant that operates on the Bystrzyca River in Lublin. The shape of the element is conditioned by the need to achieve a gentle change in the cross-section of the water stream during the flow between the steering system and the outflow area. The segment through which the water flows is clearly lower and wider than the other modules of the power plant, which is due to the average water level in the Bystrzyca River. Such a shape is necessary because the inflow and outflow parts of the power plant must be submerged under water all the time. This is due to the principle of operation of the power plant, which works by obtaining a vacuum created by pumping air from the inside. The article also presents the results of the strength analysis, which was performed for the segment exposed to the highest loads. The analysis and the entire design were performed in Autodesk Inventor, and the results obtained were as expected and even in the most critical places no values were reached that would require changes to the design. [ABSTRACT FROM AUTHOR]

Agricultural water consumption security is crucial for maintaining food production stability. Aiming to investigate water consumption efficiency and objectives in agricultural and non-agricultural sectors, we adopted a Budyko-analogous framework to establish an optimal water allocation model based on the maximum water utilization benefits principle. The proposed Budyko framework was verified through its application in Anhui Province, China, and the difference in water utilization efficiencies among different regions was discussed. The research findings can be concluded as follows: (1) during 2011–2020, the provincial agricultural productive loss caused by per-unit water shortage was lower compared to non-agricultural sectors, and this trend was adaptive in the south but totally opposite in the north; (2) the guaranteed level of agricultural water consumption was higher compared to non-agricultural sectors in the north due to the predominance of agricultural production but totally contrary in the south. Overall, the above findings are consistent with the actual industrial structure of Anhui Province. [ABSTRACT FROM AUTHOR]

We conducted a study to characterize the nutritional composition of the main aquatic herbaceous plants in two protected areas within the Central Amazon. Our investigation aimed to evaluate possible nutritional variations in these plant species between two floodplains contrasting in fertility throughout the annual hydrological cycle and to examine if such differences might influence Amazonian manatee migration patterns. Plant samples were collected during high water levels (2007), receding water levels (2013), and low water levels (2008). Bromatological analysis was employed to characterize various nutritional parameters including dry matter, moisture, crude protein, fat, mineral matter, non-nitrogenous extract, and digestible energy. Our findings revealed no significant variations in nutritional contents between herbaceous plants from várzea and igapó environments. However, nutrient compositions varied within each floodplain type across different hydrological periods. High levels of fat and crude fiber observed in both environments during high and receding water periods suggest an energetic contribution to the manatee's reproductive, migratory, and feeding restrictions. Nonetheless, irrespective of hydrological periods and environmental types, Amazonian manatees appear to have assess to aquatic plants with adequate nutritional requirements. Thus, migrations may be more closely associated with physical constraints of the environments rather than solely driven by the animal's feeding demands. [ABSTRACT FROM AUTHOR]

We use novel information about fixture-specific water lead levels (WLLs) in Portland, Oregon schools to explore inequalities in students' potential for exposure to lead in drinking water at school. We find that Black and Hispanic students were in classrooms with higher WLLs than white students primarily because they attended different schools. The elevated exposure of students with non-English first languages was also largely driven by sorting into different schools, although there were marginally significant differences between students within the same school. Our findings underscore the importance of broadly targeted remediation efforts like those implemented in Portland to address environmental injustices. [ABSTRACT FROM AUTHOR]

The preconcentration of uranium VI (U(VI)) at trace levels in some real water and wastewater samples and its determination by spectrophotometry using a homogeneous solvent-based microextraction method, specifically in-situ solvent formation microextraction, were investigated. This microextraction method uses a unique task-specific ionic liquid (IL) as the specific complexing agent and/or extracting phase. A pyrrolidinium-based IL modified with (E)-5-(bromomethyl)-2-(pyridin-2-yldiazenyl) phenol as a task-specific IL (E)-1-(3-hydroxy-4-(pyridin-2-yldiazenyl) benzyl)-1-methylpyrrolidinium bromide (TSIL/Br) was successfully synthesized and characterized by 1HNMR and FTIR analyses. TSIL/Br chelated with U(VI) ions in the aqueous phase to form a hydrophilic [U(VI)-TSIL/Br2] complex with high efficiency. It was then converted to a hydrophobic [U(VI)-TSIL/(NTf2)2] complex through a counter-ion agent, such as bis(trifluoromethanesulfonyl)imide ( NTF 2 - ) for separation from the aqueous solution phase. This process eliminates the need for a separate complexing agent, because TSIL/Br acts simultaneously as both a complexing agent and an extracting solvent. In brief, the conditions of the microextraction process must be optimized for the analysis of real water samples. Under the optimum conditions, a preconcentration factor, detection limit, quantification limit, linear dynamic range, and relative standard deviation of 218, 1.62 ng·mL−1, 5.42 ng·mL−1, 20.0–450.0 ng·mL−1, and 2.47% (n = 10, 20 ng·mL−1) were obtained, respectively. Finally, to assess the method's ability, it was successfully employed to determine the U(VI) ion content in various real water, wastewater and reference material samples. [ABSTRACT FROM AUTHOR]

The surface area of Poyang Lake, the largest freshwater lake in China, has decreased substantially in recent decades due to multiple potential factors, including the change in inflow into the lake, flow rate regulation of the Three Gorges Reservoir (TGR), shifts in the Yangtze River stage-discharge relationship, and sand mining in the lake. Here, the daily surface area of Poyang Lake is estimated using Landsat image data and water-level measurements. Multiple regression models are then used to establish the relationship between the surface area and the predictor variables of inflow into the lake, Yangtze River water level, and cumulative sand mining. The contributions of each driving factor to the reduction of Poyang Lake's surface area are quantified by scenario comparison method. The results reveal that the mean annual surface area of Poyang Lake decreased by 388 km2 (approximately 15% of the total surface area), from 2,585 km2 in 1980–2002 to 2,197 km2 in 2003–2016. In terms of overall contribution, sand mining is identified as the most important factor in the surface area reduction, followed by the shift in the Yangtze River stage-discharge relationship and the TGR flow rate regulation. In terms of monthly scale impacts, sand mining reduced the surface area by more than 260 km2 each month. The shift in the Yangtze River stage-discharge relationship reduced the surface area by 16–156 km2 during the dry season (November–May) of the Yangtze River and increased the surface area by 33–84 km2 during the flood season (June–October). The TGR flow rate regulation has the opposite effects: it reduced the surface area by 109–172 km2 during the impoundment period from September to October and increased it by 19–68 km2 during the release period from December to June. [ABSTRACT FROM AUTHOR]

The river systems in the Himalayan region exhibit year-round flow due to precipitation during the rainy season and snow/glacier melt in summer. These rivers carry massive sediment loads, especially during monsoons. Hydraulic engineers face the challenge of designing infrastructure capable of managing this sediment. Breast wall spillways are recommended for their ability to handle floodwaters and sediment disposal. The hydraulics of breast wall/orifice spillways changes with the varying reservoir level. The flow is free flow for reservoir water levels below the top of the sluice, whereas for higher water levels the flow is orifice flow. Orifice spillways are designed to pass water through openings or gates, where the flow is primarily governed by the hydraulic head and the orifice size. The flatter bottom profile helps in smoothly directing the flow through the opening without causing significant turbulence or separation, especially when the gate is partially open. Hence, the crest profile is flatter as compared to the overflow crest profile to avoid flow separation and negative pressures on the crest for small gate openings. Kwar Hydro Electric Project is one such Himalayan region project planned across the Chenab River in which a breast wall spillway has been provided to serve the dual-purpose of flood and sediment disposal. The present paper describes the physical and numerical hydraulic model studies conducted for Kwar H.E. Project, Jammu and Kashmir, to evolve a breast wall spillway profile, ski jump type energy dissipator at the toe of the spillway. [ABSTRACT FROM AUTHOR]

Environmental impacts related to arsenic (As) contamination are a persistent issue of particular interest in Latin American countries with increasing mining activities. In Ecuador, the redefinition of public policies to promote the increase in mining since 2008 has led to a significant rise in the presence of this heavy metal in rivers and effluents, sometimes exceeding the 0.1 mg L−1, limit recommended by Ecuadorian Environmental Regulations. This study aimed to evaluate the sublethal effects through the detection of biochemical biomarker changes (Catalase, Antioxidant capacity by FRAP, and Glutathione S-transferase) generated in larvae of Nectopsyche sp following prolonged exposure to different concentrations of As (C1 = 0.05 mg L−1, C2 = 0.1 mg L−1, C3 = 0.8 mg L−1) in a controlled environment, emulating the maximum limits allowed by current Ecuadorian legislation. While As concentration levels in water increased, so did levels in the tissue of Nectopsyche sp specimens. On the other hand, behavioral parameters (mortality and mobility) did not show differences in either time or As concentrations. However, both Catalase and Antioxidant capacity by FRAP levels tended to decrease with increasing As concentration, and in both cases, the differences were significant. Additionally, Glutathione S-transferase activity did not increase significantly. These results preliminarily demonstrate that biochemical responses change with varying As concentrations in Nectopsyche sp and are affected at behavioral and biochemical levels produced by the As at chronic levels. [ABSTRACT FROM AUTHOR]

Twenty years of surface elevation table and marker horizon monitoring at three sites along the Fire Island (New York, USA) barrier island indicates that rates of marsh surface elevation change (Watch Hill, 4.4 mm year−1; Hospital Point, 3.5 mm year−1; Great Gun, − 0.3 mm year−1) were lower than the rate of monthly mean sea-level rise during the 2002–2022 monitoring period (5.1 mm year−1, NOAA Sandy Hook, NJ, water level station). The Great Gun monitoring site, with an elevation deficit relative to sea-level rise, shallow subsidence (surface accretion > marsh elevation rate), low elevation capital, prolonged marsh surface flooding, and declining vegetation cover, displays characteristics common to deteriorating marshes. The submergence trend was not as evident at the other monitoring sites, but with low tidal range (0.4 m) and projections of accelerated sea-level rise, sustainability is questioned if marsh elevation change continues to lag behind the local rate of relative sea-level rise. Hurricane Sandy occurred during the monitoring period (October 2012), creating a new inlet located about 300 m from one of the monitoring sites. Surprisingly, no immediate signals of deposition or erosion were noted from the marker horizon sampling. Overwash sand deposits on the marsh surface were extensive along Fire Island, although not reaching the monitoring sites, and will likely provide opportunities for future salt marsh growth, as will the flood-tide delta created by the inlet. Projecting the future of barrier island salt marshes under a regime of accelerated sea-level rise and episodic storms requires knowledge of marsh elevation and accretion processes and geomorphic dynamics. [ABSTRACT FROM AUTHOR]

Summary Platypus (Ornithorhynchus anatinus) are an endemic Australian freshwater mammal, impacted by synergistic threats across their range. During the extreme drought of 2017–2019, declining water levels threatened Platypus at Tidbinbilla Nature Reserve (TNR), Australian Capital Territory (ACT), Australia. TNR supports a population of Platypus, occupying interconnected ponds within a predator proof fence. During drought conditions in 2019, Platypuses could not move out of the fenced area to refugia as floodgates were closed due to low water levels. In winter of 2019, eight Platypuses were found deceased resulting from starvation. By December, water levels were extremely low and ponds were continuing to dry. Given these circumstances, a rescue intervention was undertaken to capture stranded Platypuses. They were temporarily relocated and housed at Taronga Zoo, Sydney, until they were returned when conditions at TNR improved. Seven Platypuses were rescued, with five successfully housed at Taronga for 5 months. One Platypus was lost after escaping from its enclosure and another Platypus died when trapped in a crevice. The Platypuses were returned after water levels increased at TNR and were monitored for 500 days post‐release, demonstrating successful repatriation. This case study outlines the key stages and considerations required for this intervention, providing critical information for rescue attempts on drought‐affected Platypus populations. There is a need to continue developing a decision framework for interventions of climate‐affected populations, including quantifying trigger thresholds and conservation prioritisation of populations. This will become increasingly necessary given the trajectories of habitat degradation, coupled with the increasingly frequent and severe droughts, expected under anticipated climate change scenarios. [ABSTRACT FROM AUTHOR]

Background and aims Methods Results Conclusion Low boron (B) availability is associated with strongly weathered, coarse‐textured, and low organic matter soils, widespread in sub‐Saharan Africa (SSA). It is unknown to what extent B fertilization can increase maize yields in SSA. This study aims to understand the soil properties controlling B availability to field‐grown maize.Boron fertilizer omission trials with maize were executed at 15 sites in Kenya, Zambia, and Zimbabwe. Yield, B uptake, and soil parameters potentially relevant for B availability, including extractable soil B (hot water, 0.01 M CaCl2, and 0.43 M HNO3), were determined.Soil B pools were strongly intercorrelated and were positively correlated with organic carbon, suggesting the relevance of organic matter for soil B availability. Soil parameters described limited variation in B uptake and the yield response to B fertilization. Boron fertilization did not increase yields in any of the 15 sites but increased uptake in 11 sites. Yields were reduced through B fertilization in five sites, likely because B application induced toxicity. No clear critical soil or plant B concentrations indicating deficiency could be derived, but positive yield responses to B fertilization were absent with hot water B levels above 0.69 mg kg−1.Assessing B fertilizer needs in maize grown in tropical soils based on soil or plant tissue concentrations remains challenging. Improving soil organic matter status could potentially alleviate B deficiency in crops when present. Recommendations are given to overcome the identified challenges associated with studying B availability in tropical soils. [ABSTRACT FROM AUTHOR]

Satellite altimetry water level measurements are valuable in episodic and climate change related hydrodynamic impact studies, despite their sparse temporal distribution over the global ocean. This study presents the spatiotemporal characteristics of the open-ocean satellite derived water level measurements globally for the period 31/12/1992-15/10/2019 and evaluates their efficacy to represent the water level even during intense atmospheric conditions. Water level measurements from 23 different satellite missions are compared with tide gauge records and hydrodynamic simulations. The satellite measurements reproduce the water-level variations with good to excellent skill for ~60% of the areas considered. Additionally, satellite measurements and local atmospheric conditions are utilized in order to examine whether statistical data driven models can contribute to decreasing the temporal sparseness of the water level data over the global ocean. The suitability of this low computational-cost method is demonstrated by deriving a 63-year hindcast of the daily maximum water level for the global ocean, and for a medium-term 15-day ensemble forecast. The publicly available long-term water-level hindcast and the parameters of the datadriven statistical model derived can serve as a tool for designing and facilitating local and global coastal risk-assessment studies. [ABSTRACT FROM AUTHOR]

Background: In recent years, studies have found small-to-medium positive effects of physical activity on academic achievement. Already acute bouts of exercise appear to improve certain cognitive functions. Spatial abilities are one aspect of cognition that is encountered frequently in daily life and that is closely related to success in science, technology, engineering, and mathematics (STEM)-subjects. However, little is known about the effects of an acute exercise session on spatial abilities. The aim of this study was therefore to evaluate the effect of a single session of coordinative motor training (CMT) on spatial ability performances in healthy children. Methods: Forty-nine children were assigned to either a single session of CMT (i.e., obstacle course with motor coordinative and spatial elements) (n = 25, 12 females, mean age: 10.7 ± 0.6 years) or a resting control group (n = 24, 12 females, mean age ± SD: 11.4 ± 0.5 years). Spatial abilities were evaluated in both groups using the Paper Folding Test (PFT), Mental Rotation Test (MRT), Water Level Task (WLT), Corsi Block Test (CBT), and Numbered Cones Run (NCR). Results: A statistical main effect for Test was observed for the majority of outcomes (i.e., all but the MRT). Test × Group interactions did not reach the level of significance. Conclusion: The results indicate that a single session of CMT does not improve spatial ability performances of healthy children. Future research should evaluate whether repeated longer-term interventions might be more suitable to generate significant improvements in spatial abilities. [ABSTRACT FROM AUTHOR]

Introduction: Drainage for agricultural purposes is one of the main drivers of peatland degradation, leading to significant greenhouse gas (GHG) emissions, biodiversity loss, and soil eutrophication. Rewetting is a potential solution to restore peatlands, but it generally requires a land-use shift to paludiculture or nature areas. Methods: This study explored whether three different water level management techniques (subsoil irrigation, furrow irrigation, and dynamic ditch water level regulation) could be implemented on dairy grasslands to yield increases in essential ecosystem services (vegetation diversity and soil biogeochemistry) without the need to change the current land use or intensity. We investigated vegetation diversity, soil biogeochemistry, and CO2 emission reduction in fourteen agricultural livestock pastures on drained peat soils in Friesland (Netherlands). Results: Across all pastures, Shannon-Wiener diversity was below 1, and the species richness was below 5. The plant-available phosphorus (P) was consistently higher than 3 mmol L-1. None of the water level management (WLM) techniques enhanced vegetation diversity or changed soil biogeochemistry despite a notable increase in water table levels. The potential for CO2 emission reduction remained small or even absent. Indicators of land-use intensity (i.e., grass harvest and fertilization intensity), however, showed a strong negative correlation with vegetation diversity. Furthermore, all sites' total and plant-available P and nitrate exceeded the upper threshold for species-rich grassland communities. Discussion: In conclusion, our research suggests that incomplete rewetting (i.e., higher water tables while maintaining drainage) while continuing the current land use does neither effectively mitigate GHG emissions nor benefit vegetation diversity. Therefore, we conclude that combining WLM and reducing land-use intensity is essential to limit the degradation of peat soils and restore more biodiverse vegetation. [ABSTRACT FROM AUTHOR]

Previous research has demonstrated the value of the spirlin (Alburnoides bipunctatus), a small freshwater fish, as an indicator species for monitoring the ecological health of European rivers. In this study, we examine the temporal occurrence of spirlin in a lowland section of the River Drzewiczka, Poland, at the centre of the European distribution of the species. Using a mixed modelling approach, we show a significant interaction of freshwater fish species richness and time period on the probability of occurrence of spirlin across multiple microhabitats, with a strong positive relationship between the probability of occurrence and species richness at the end of the 20th Century, but an erosion in this relationship two decades later. This change in the predicted relationship of spirlin occurrence with freshwater fish species richness corresponds with a temporal decline in the water level of the River Drzewiczka. We discuss these findings in the context of the spirlin as an indicator species of the biotic integrity of European river environments. [ABSTRACT FROM AUTHOR]

Wave runup, the excess water level above mean sea level, has been measured using different techniques with varying degrees of precision and associated practical limitations. This critical parameter, typically included in coastal assessment studies, varies temporally and spatially and depends on variables that include beach characteristics and nearshore hydrodynamics. Access to continuous datasets, using efficient mechanisms can assist resource-limited regions, such as Caribbean small-island developing states (SIDS), in overcoming coastal resilience obstacles. Experiments were conducted at University College London (UCL) and the University of the West Indies (UWI), which were designed to explore the temporal behaviour of the water surface within the bed during runup events. The experiments encompassed linear waves impacting a static porous bed (UCL) and a moveable granular beach (UWI), with pressure sensors buried at the base of each beach. The analyses showed that the averaged values of the time-varying water elevations within the bed, when spatially presented, produced a quadratic or cubic polynomial fit, where the curves' stationary points were accurate indicators of the location of the maximum runup position at the surface of the bed. In this way, an arrangement of buried pressure sensors can be used as an efficient means to accurately produce a continuous time series of maximum runup positions. This article is part of the theme issue 'Celebrating the 15th anniversary of the Royal Society Newton International Fellowship'. [ABSTRACT FROM AUTHOR]

Horizontal wells have gained popularity as a technology for exploring water resources and remediating aquifers over the last decades, due to costs and numerous technical benefits compared to traditional vertical wells. This study presents a set of analytical solutions for drawdown distribution and various components of water budget contributing to flow toward a horizontal well in an aquifer-aquitard system interacting with a fully penetrating stream. It is assumed that the water level in the upper unconfined aquifer remains fixed at a specific elevation during the course of the pumping in the lower leaky aquifer. The water budget components account for inflows from aquifer storage, stream depletion, and leakage across the aquifer-aquitard interface. Analytical solutions to this three-dimensional, transient, non-axisymmetric Darcian flow model are given for both transient and steady-state flow conditions, relying on a four-fold integral transform technique that includes a Robin-type boundary condition at the aquifer-aquitard interface. It is shown how various components of water budget collectively counterbalance the effect of pumping discharge, confirming that the mass is conserved under both continuous and non-continuous pumping scenarios. Response maps are prepared to assess how different components of water budget react to changes in the well position. Furthermore, it is found that the components of water budget are most sensitive to the well-to-stream distance and anisotropy ratio of the leaky aquifer. [ABSTRACT FROM AUTHOR]

Introduction: The presence of water significantly reduces the mechanical strength of rocks and induces various engineering geological hazards. The water weakening coefficient Kp is used to quantify this effect, defined as the ratio of wet uniaxial compressive strength to the dry value. Methods: A comprehensive physico-mechanical test was conducted on fifteen sandstones under dry and saturated conditions to predict the water weakening coefficient using easily obtainable physical parameters. Multiple linear regression was employed to establish the relationship between these parameters and the saturated water weakening coefficient. Results: The saturated water weakening coefficient decreases with increasing porosity and increases with higher Primary wave velocity (P-wave velocity). Rocks with higher porosity but lower P-wave velocity typically absorb more water. The P-wave velocity and clay mineral content were identified as the best predictors of the saturated water weakening coefficient (R2 = 0.82). Unsaturated water weakening coefficients at any water saturation level were well estimated using a previous exponential function. Discussion: The roles of different clay minerals and P-wave velocity in the water weakening process of rocks are comprehensively discussed. This study enhances the understanding of the water weakening mechanism and provides an improved evaluation model for the water weakening coefficient of sandstones using physical parameters. [ABSTRACT FROM AUTHOR]

Introduction: With increasing drought stress due to climate change and water scarcity, the agricultural sector has sought innovative strategies to mitigate the detrimental effects on crop productivity. One approach that has received significant attention is the use of fertilizers and biostimulants as potential means of alleviating drought stress. Methods: In this study, five different irrigation levels including 100% (control), 80% (slight stress), 60% (mild stress), 40% (moderate stress), and 20% (severe stress) of field capacity (FC) and seaweed extract (SWE) at three concentrations (0, 5, and 10 g/L) were applied to the pots containing one-year-old licorice (Glycyrrhiza glabra L.) plants in a factorial completely randomized design experiment with three replications for eight weeks. Results and discussion: The glycyrrhizic acid content increased with water stress intensity without the application of SWE until severe (20% FC) water stress treatment. The application of 10 g/L SWE under 100% FC led to a significant increase in the glycyrrhizic acid value (32.5±0.889 mg/g DW) compared with non-SWE application (30.0±1.040 mg/g DW). The maximum glabridin content (0.270±0.010 mg/g DW) was obtained under irrigation of 20% field capacity with 10 g/L SWE application. In addition, the activity of the all studied enzymes such as APX (ascorbate peroxidase), CAT (catalase), POD (peroxidase), and SOD (superoxide dismutase) were boosted by increasing the water stress levels. The use of SWE further enhanced the increase of some of these metabolites and enzymes, which, in turn, helped the plant to tolerate stress conditions through the scavenging of more ROS (Reactive oxygen species), wherein for this purpose, the SWE 10 g/L was more effective than other concentration. The plants efficiently eliminated ROS driven from drought stress by both non-enzymatic and enzymatic systems. [ABSTRACT FROM AUTHOR]

A method for the determination of phthalates in water is validated. It includes the sorption of hydrophobic components of a sample on a liquid chromatography column and the separation of analyte concentrated by online reversed-phase HPLC: for the quantitative determination of priority phthalates (PPhs) in surface waters at a trace level; qualitative assessment of the ratio of stable carbon isotopes 13C/12C in the PPh composition. It is shown that there is no contribution of PPhs from the laboratory background to the measurement results. The limits of determination (0.15−0.22 μg/L) and the accuracy of the determination (±δ = 10−20%) are found using online reversed-phase HPLC and the UV detection of the analytes. The boundary values for the 13C/12C isotope ratio are substantiated for a qualitative assessment of the results of measuring the Δ13C value in the structure of di(2-ethylhexyl) phthalate and its ingress into waters of Lake Baikal from biogenic and abiogenic sources is revealed. A procedure for determining PPhs by reversed-phase HPLC with online UV detection is tested in the field using a portable liquid chromatograph; the concentration ranges for di-n-butyl phthalate (from <0.15 to 1.6 μg/L) and di(2-ethylhexyl) phthalate (from <0.22 to 1.6 µg/L) in the coastal zone of Lake Baikal are evaluated. [ABSTRACT FROM AUTHOR]

AbstractChanges in reservoir water level often trigger landslides along the reservoir banks, which are common geological hazards that significantly affect the construction and operation of hydropower projects. In this paper, the stability of the RS reservoir landslide in the southwestern region of China is investigated. A discrete element seepage analysis model is constructed based on the theory of changes in the infiltration surface of the deposit caused by water level drawdown. The model is then embedded into a continuous-discontinuous three-dimensional numerical simulation method to systematically investigate the influence of reservoir water level decrease on the stability of the RS deposit. The results indicate that, under the condition of a sudden drop in reservoir water level decrease, the deposit experiences destabilization failure. Its sliding velocities are mainly influenced by seepage forces and gravity, while sliding displacements are influenced by seepage forces and topographic conditions. The landslide process shows distinct stratification characteristics. The portion of the deposit that slides into the river channel is mainly distributed between an altitude of 2655 m and 2870 m. The research results provide a scientific basis for studying the mechanism of slope failure and landslide disaster chain under the condition of reservoir water level lowering. [ABSTRACT FROM AUTHOR]

Marsh terraces, constructed as a restoration and protection strategy, consist of a series of earthen berms in open water areas of the coastal wetland landscape and are being implemented across the Louisiana coast. To assess the efficacy of the marsh terraces as a nature-based solution, a small-scale, high-resolution hydrodynamic model was developed based on field sampling of vegetation and physical parameters (water level, waves, sediment, turbidity, and terrace elevation). This study tested common marsh terrace designs (e.g., chevron, linear, box, T-shape, etc.), ultimately selecting a preferred design based on the evaluation of factors such as vegetation, water depth, and sediment type on terrace stability and sediment retention under calm and storm conditions. The model results revealed that the 100 m box and the chevron designs exhibited greatest terrace stability and sediment trapping, particularly when installed perpendicular to prevailing wind and waves. The preferred terrace design was the box design due to its higher modeled resilience to wind and waves from multiple directions. Vegetation presence enhanced terrace resistance to erosion, with variations depending on vegetation type. Higher vegetation biomass, especially during the summer, contributed to the greatest stability of terraces. Greater water depth between terraces led to increased sediment retention, and terraces predominantly composed of organic-rich mud demonstrated greater stability than those with higher proportions of sand. Overall, vegetation had the greatest impact on sediment retention in the terrace field compared to water depth and sediment type. However, the potential habitat for submerged aquatic vegetation (SAV) was more influenced by water depth (i.e., 0.1 m < depth <1 m) than shear stress (<0.5 Pa). Even under storm conditions, shear stress rarely determined potential habitat for SAV, as shear stress remained relatively low within the terrace field. Potential SAV habitat was most abundant in shallow areas and increased where sediment stability was lowest (i.e., no vegetation and sand), primarily due to eroded sediment increasing the shallow area. While this model was developed using field data specific to Louisiana marshes, it can be adapted as a tool for terrace restoration project design and planning in most coastal wetlands. [ABSTRACT FROM AUTHOR]

The release rate of CO2 gas can be influenced by peatlands' physical properties, such as water level and soil moisture, and rainfall. To anticipate the unstable condition which is when the peatland emit more carbon, we developed the Generalized Space Time Autoregressive (GSTAR) model in predicting these physical properties for the following weeks. As the innovation in modelling, the spatial weight matrix was based on three-dimensional coordinates with a modification on the height factor. The data we used are real-time data of water level on the peatlands in Pulang Pisau Regency, Central Kalimantan Province from 20 February 2021 to 18 March 2023. We then used Ordinary Kriging interpolation on the prediction results to create contour maps on different dates. There were empty data on several dates, especially from 24 March until 3 August 2022. To fill the empty data, we used linear interpolation and then we added white noise to the interpolation results. From the data, the water level has a downward trend pattern from around November to September and an upward trend pattern from October to November. Furthermore, we found that the best model for water level was GSTAR (2;0.1) with a modified matrix a = 0.1 and b = 1.1 . Based on the predicted water level, there is a risk of changes in the properties of the peatlands in several areas in Pulang Pisau Regency. [ABSTRACT FROM AUTHOR]

Currently, the alarm functions of existing levee seepage monitoring systems are limited to single-parameter monitoring and lack rate-of-change alarms and correlation alarms. This can lead to false alarms, missed alarms, equipment failures, or unnecessary downtime. To enhance the intelligence of levee safety monitoring and seepage alarms, a levee seepage intelligent alarm system based on a Bidirectional Long Short-Term Memory (BILSTM) network model was designed and implemented. Firstly, data cleaning and preprocessing are carried out on the engineering safety monitoring operation data to reduce the influence of dirty data such as outliers and repetitive values on the accuracy of alarms. Secondly, for the correlation between the piezometric tube water levels of the levee and the Yangtze River water levels, a correlation analysis based on Mutual Information (MI) theory was conducted to minimize the effect of piezometric tube water level change delays on correlation. Finally, the BILSTM model was used to predict trends in these potentially abnormal data intervals. Based on engineering application requirements, alarm thresholds were established, and a multi-level alarm module was developed. Field operation test results show that the proposed method can accurately predict the piezometric tube water levels of levees, achieving intelligent alarms within the engineering safety monitoring system. [ABSTRACT FROM AUTHOR]

The recent surge in reservoir construction has increased global surface water storage, with Mainland Southeast Asia (MSEA) being a significant hotspot. Such infrastructural evolution demands updates in water management strategies and hydrological models. However, information on actual reservoir storage is hard to acquire, especially for transboundary river basins. To date, no high spatio-temporal dataset on absolute storage time series is available for reservoirs in MSEA. To address this gap, we present (1) a comprehensive, open-access database of absolute storage time series (sub-monthly) for 185 reservoirs (larger than 0.1 km3) in MSEA spanning the period 1985–2023, and (2) an analysis of the reservoir storage dynamics. The MSEA-Res database includes static (Area-Elevation-Storage curves, water frequency, reservoir extent) and dynamic (area, water level, and absolute storage time series) components for each reservoir. The 185 reservoirs collectively store around 175 km³ (140 km³ – 210 km³) of water, covering an aggregated area of 8,700 km² (6,500 km² – 10,000 km²). We show that the combined average reservoir storage has increased from 70 km³ to 160 km³ (+130 %) from 2008 to 2017, primarily contributed by dams in the Irrawaddy, Red, Upper Mekong, and Lower Mekong basins. Our in-situ validation provides a good match between estimated storage and in-situ observations, with 60 % of the validation sites (12 out of 20) showing an R² > 0.65 and an average nRMSE < 15 %. The indirect validation (based on altimetry-converted storage) shows even better results, with an R² > 0.7 and an average nRMSE < 12 % for 70 % (14 out of 20) of the reservoirs. Furthermore, the analysis of the 2019–2020 drought event reveals that nearly 30–40 % of the MSEA region experienced more than five months of drought, with the most significant impact on reservoirs in Cambodia and Thailand. As a result, storage departures ranged up to -40 % in some reservoirs, highlighting significant impacts on water availability. Overall, this analysis demonstrates the potential of the inferred storage time series for assessing real-life water-related problems in Mainland Southeast Asia, with the possibility of applications in other parts of the world. The MSEA-Res database and associated Python code are publicly available on Zenodo at https://doi.org/10.5281/zenodo.12787699 (Mahto et al., 2024). [ABSTRACT FROM AUTHOR]

During the operation of a turbine, the water level drop can cause vibration and damage to the flow components, severely threatening its stability and reliability. Investigating the impact of operational parameters on the internal flow field and flow structures of tidal turbines under low flow conditions is crucial for peak shaving and deployment of tidal power stations. This paper takes a 24MW turbine as the research object, using numerical calculations to analyze the effects of tailwater height on the flow characteristics and structural properties of the unit under low flow conditions. It studies the hydraulic impact on the flow component walls under different operating parameters and verifies the reliability of numerical calculations through vibration and stress tests. The results show that the increase in tailwater level affects the turbine’s flow characteristics, forming large-scale, high-intensity vortices in the internal flow field and causing pressure pulsations near the wall surface. Modal analysis reveals that under different tailwater heights, the maximum modal effective mass exists along the axis of the impeller, with modal frequencies higher than the main frequencies of pressure pulsations. The impeller region corresponds to the turbine chamber wall bearing significant stress, which induces strain. The magnitude of stress and the degree of strain are positively correlated with the tailwater height. The research findings provide guidance for tailwater regulation and stable operation of tidal power stations. [ABSTRACT FROM AUTHOR]

This paper presents a new approach to the spatiotemporal design of groundwater quality monitoring networks for coastal aquifers. A fusion model combines the outputs of several developed simulation models to make estimates more accurate. A modified GALDIT method is used to incorporate the aquifer vulnerability to saltwater intrusion. The value of information (VOI) theory is applied to determine sufficient monitoring wells. The groundwater quality monitoring network is designed by employing a robust decision-making (RDM) approach under different management strategies and economic considerations. This approach incorporates the deep uncertainties of some critical variables, including water level and total dissolved solids (TDS) concentration at the coastline and pumping flow rates of agricultural wells. The new methodology is implemented in the coastal Qom-Kahak aquifer, Iran. The results illustrate that the combination model has significantly improved evaluation criteria compared to individual prediction models. The fusion model results indicate that thirty monitoring wells would be ideal. The RDM-based analyses in the Qom-Kahak aquifer showed that an optimal network with 30 monitoring wells outperforms the current network regarding various criteria, such as VOI and variance of estimation error. The new well configuration also demonstrates a suitable spatial distribution. Given that the current sampling frequencies are unsuitable for areas with varying vulnerabilities, we recommend sampling every 3 months in areas with moderate vulnerabilities and once every three seasons in areas with low vulnerabilities, based on the information transfer index. Finally, a management strategy in which the pumping rate should be less than 60% of the current rate is suggested to prevent saltwater intrusion into the aquifer. [ABSTRACT FROM AUTHOR]

By considering that the predators have some additional foods apart from the focal prey and the prey take refuge, a predator–prey model with the effect of seasonality in a fluctuating environment is investigated in this study. Gaussian white noises, created by random fluctuation of water level, are introduced on the prey’s growth rate and predator’s mortality rate. Both the deterministic and stochastic systems are analyzed mathematically as well as numerically. Our analytical findings show that the intensity of environmental noise, additional foods and prey refuge play significant roles in survival as well as extinction of both prey and predator populations in the aquatic system. Our numerical results show that the effectual level of additional foods, depending on water level, has positive as well as negative effects on the predator and prey populations. We find that both species strongly persist at certain water level and for the low intensity of noise. However, for an increased value of noise intensity, they persist weakly and then go to extinction. Overall, our findings show that the variations of water level together with additional food and white noise plays crucial roles in persistence and extinction of species in the ecosystem. [ABSTRACT FROM AUTHOR]

Dike failures often induce highly damaging floods. Improved understanding of the inherent mechanisms is important to predict and prevent dike failures. This research focuses on sand dike failure by overtopping. During the experiments, the evolution of nine sections was monitored using laser-sheet while the water level in the upstream reservoir was captured using ultrasonic gauges. The impact of the grain size was studied by comparing a fine and a coarser sand. Even though the failure mechanisms look similar in both cases, some differences could be observed in the evolution of the geometry of the dike. Finally, the failure was simulated with 1D and 2D models. The 1D model shows good results for the initial stage of the dike evolution and in predicting the evolution of the width of the breach. The 2D model predicts the morphological evolution of the dike more accurately but slightly overestimates the widening of the breach. [ABSTRACT FROM AUTHOR]

This study presents an improved data-centric approach to short-term water demand forecasting using univariate time series from water reservoir levels. The dataset comprises water level recordings from 21 reservoirs in Eastern Thessaloniki collected over 15 months via a SCADA system provided by the water company EYATH S.A. The methodology involves data preprocessing, anomaly detection, data imputation, and the application of predictive models. Techniques such as the Interquartile Range method and moving standard deviation are employed to identify and handle anomalies. Missing values are imputed using LSTM networks optimized through the Optuna framework. This study emphasizes a data-centric approach in deep learning, focusing on improving data quality before model application, which has proven to enhance prediction accuracy. This strategy is crucial, especially in regions where reservoirs are the primary water source, and demand distribution cannot be solely determined by flow meter readings. LSTM, Random Forest Regressor, ARIMA, and SARIMA models are utilized to extract and analyze water level trends, enabling more accurate future water demand predictions. Results indicate that combining deep learning techniques with traditional statistical models significantly improves the accuracy and reliability of water demand predictions, providing a robust framework for optimizing water resource management. [ABSTRACT FROM AUTHOR]

In order to further alleviate the navigation pressure of the Xiazhimen Channel, avoid extreme situations such as the Suez Canal blockage incident, and ensure the "dual circulation" of the core port area of Zhoushan Port in Ningbo, it is urgent to improve the navigation capacity of the Tiaozhoumen Channel. In response to the special natural conditions and mixed navigation requirements of multiple ship types in the island and reef waters, a plan layout and design scale scheme for the Tiaozhoumen Channel were proposed through research methods such as tidal sediment mathematical models, ship model simulation. experiments, and traffic flow analysis. The use of a long channel and multi station combined tidal method to reasonably determine the tidal water level in each section effectively reduces dredging elevation, construction costs, and maintenance difficulties. The design concept, research methods, and achievements of this project can be used as a reference for similar engineering projects. [ABSTRACT FROM AUTHOR]

The standard reconstruction of river-crossing bridges is an important component of waterway regulation projects, which has high investment and significant social impact. In waterway regulation projects, it is necessary to conduct a preliminary evaluation of the impact of navigation conditions on existing bridges. There are numerous river-crossing bridges along the Sushen Inner Port Line waterway, in the evaluation process, for bridges with significant difficulty in renovation due to insufficient clearance dimensions, the method of calculating the navigation capacity of the bridge area waterway is adopted to quantitatively analyze the degree of obstruction to navigation of the bridge. Theoretical analysis can be used to calculate the navigation capacity of the bridge area waterway. On the basis of the conventional channel capacity calculation method for the tidal section outside the gate, the navigation guarantee rate of each water level can be inferred using the cumulative frequency curve of tide level. The navigation guarantee rate is used as a correction coefficient to calculate the navigation capacity of the bridge area waterway. By comparing the calculated capacity of the waterway with the planned and designed freight volume, the necessity and urgency of bridge reconstruction can be preliminarily judged. [ABSTRACT FROM AUTHOR]

In response to the complex and variable water flow patterns in the estuary section, which are not conducive to organizing river dredging construction, taking the New Western Land-sea Corridor Channel (Pinglu Canal) as an example, the HEC-RAS one-dimensional unsteady flow mechanics calculation module is applied to construct a hydrodynamic model for the canal estuary section, and the roughness of the model is calibrated and the accuracy of the model is verified. On this basis, based on the water level and flow characteristics of the Youth Sluice (under the sluice), four flow (water level) conditions are set under the sluice to simulate and analyze the changes in river flow velocity. The results show that the HEC-RAS model has high simulation accuracy and good applicability in tidal river sections; With the increase of cross-sectional flow, the flow velocity response of the section from $26 to $32 near Shijiangdun is rapid, and the flow velocity is about 34.0% higher than other sections. The research results can provide technical support for the construction of dredging projects in the estuary of the canal. [ABSTRACT FROM AUTHOR]

To develop an insect-scale aerial/aquatic robot, we analyzed takeoff mechanisms to counteract surface tension, such as paddling, slapping, and clap-and-fling. Because a diving beetle, Eretes griseus, takes off directly from the water surface, a flapping-wing robot is promising as an alternative to a drone with multiple rotary wings. In this study, we first investigated diving beetle flight with a three-dimensional high-speed camera system and analyzed the motion characteristics. Subsequently, we developed a computational fluid dynamics method that tracked the water surface using a volume of fluid method, reproduced the motion with a multibody model, treated the deformation of the elastic membrane wing with the phase delay of the joint angle functions, and simulated takeoff, that is, the transition from water to air, and hovering near the water surface. The simulation result showed that during the transition, the slapping motion exerted the maximum and average lift per unit of body weight of 18 and 9.2, respectively, while those of paddling produced 0.46 and 0.23, respectively. The water surface effect improved the lift by 25% at the normalized height of less than 0.44 and disappeared at a height greater than 0.7. During hovering, while the clap-and-fling motion improved lift by 2.6% and the water surface effect was 9.8%, the synergy effect was 22%. In addition, the former enhanced it significantly after the fling, while the latter was remarkable during the wing acceleration phase. In contrast to ground effects, flapping reduced the water level and caused the ripples, dynamically changing the water surface effect. [ABSTRACT FROM AUTHOR]

This paper presents deep learning using LSTM, machine learning employing RF and GB algorithms, and the rating curve (RC) that can be used for estimating daily streamflow at the outlet of river basins. The Kone River basin in Vietnam is selected as an example for demonstrating the ability of these approaches. Hydro-meteorological data, including rainfall at Vinh Kim as well as water level and streamflow at Binh Tuong, were collected in the long period from 1/1/1979 to 31/12/2018. Multiple approaches mentioned above are implemented and applied for estimating daily streamflow at Binh Tuong in the Kone River basin. Firstly, coefficients and hyper-parameters in each approach are carefully determined using available hydro-meteorological data from 1/1/1979 to 31/12/2009 and dimensional and dimensionless error indexes. The results revealed that deep learning using LSTM presents the most suitable performance of the observed streamflow, with correlation coefficient r and NSE being close unity, while RMSE and MAE are less than 1.5% of the observed magnitude of streamflow. The RC and machine learning employing RF and GB algorithms procedures acceptably the observed streamflow, with r and NSE varying between 0.77 and 0.98, and RMSE and MAE ranging from 0.4 to 6.0% of the observed magnitude of streamflow. Secondly, multiple approaches are also applied for estimating daily streamflow from 1/1/2010 to 31/12/2018, revealing consistent statistical characteristics of streamflow in the river basin. Finally, the impacts of input data on output streamflow are discussed. [ABSTRACT FROM AUTHOR]

A heated junction thermocouple (HJTC) is a device designed to monitor the water level of nuclear reactors to prevent explosions due to overheating. This device consists of heated and non-heated thermocouples. When heat is applied, the temperature rise in HJTC varies depending on whether the device is submerged in water or exposed to air. In this study, we analyzed the thermal characteristics of HJTC through 3D COMSOL simulation. The temperature profile of the cross-section was extracted based on three design parameters: applied heat, heating length of the wound coil, and diameter of the HJTC. The temperature difference between the two thermocouples was more pronounced upon exposure to air. Meanwhile, high applied heat, short coil heating length, and small diameter of the HJTC contributed to a more pronounced temperature difference based on the surrounding environment. These results can aid in the appropriate HJTC design to achieve the desired detection sensitivity. [ABSTRACT FROM AUTHOR]

Accurate monitoring of soil moisture and the development of timely interventions are important to reduce the social and economic losses caused by drought. Compared to short-wave infrared (SWIR) and thermal infrared (TIR), near-infrared (NIR) and visible bands are widely used in almost all optical satellites. Drought monitoring using NIR and visible bands is therefore more relevant for optical satellites. Among the visible bands, the red band is often used in combination with the NIR band for drought monitoring due to its sensitivity to vegetation. However, current drought indexes based on the NIR and the red band applied to areas of high vegetation suffer from insufficient accuracy or tedious calculations. In this study, the ratio drought index (RDI) was developed after constructing a new feature space by examining the spectral properties of soil and vegetation at different water levels in the NIR and red bands. The accuracy of soil moisture inversion under two types of bare soil and vegetation was evaluated using in situ data from Tai'an City, Shandong Province. The perpendicular drought index (PDI) and modified perpendicular drought index (MPDI) were also used to compare for the RDI. The results showed that the RDI correlation coefficients (R2) of 0.653 and 0.641 were better than the MPDI of 0.616 and 0.594 and the PDI of 0.602 and 0.546 for soil moisture measurements from vegetation and bare soil cover. The RDI attenuates the effect of vegetation on soil moisture inversion, as its root mean square error (RMSE) in vegetated areas is lower than that of the PDI and MPDI. The RDI calculation can be used as a theoretical guide for large-scale soil moisture estimation because it is fast, accurate and does not require additional quantitative remote sensing inversion factors. [ABSTRACT FROM AUTHOR]

High-accuracy deformation monitoring is crucial for investigating landslide–pipeline interaction problems, in which the fiber optic nerve system (FONS) holds enormous potential. This paper presents a theoretical framework for interpreting landslide–pipeline interactions using the FONS and proposes a novel method for calculating characteristic parameters of pipe–soil interfaces based on distributed strain measurements. The feasibility of this method is validated through a full-scale model test, and its application for studying pipeline behaviors is demonstrated in the Xinpu landslide, situated in the Three Gorges Reservoir region, China. The field monitoring results reveal that short-duration, high-intensity rainfall events triggered immediate acceleration of landslide movements, leading to pipeline elongation and flexure. Strain measurements of the underground pipeline allow for the identification of the local slipping interface of the landslide. Furthermore, the relationships between reservoir water level (RWL) fluctuations, rainfall events, landslide deformation, and the structural response of the pipe are analyzed. The findings suggest that the deformation of the landslide in the leading and middle parts exhibits high correlations with the combined effect of rainfall and RWL drawdown. [ABSTRACT FROM AUTHOR]

Understanding regional sea level variations is crucial for assessing coastal vulnerability, with accurate sea level data playing a pivotal role. Utilizing historical sea level marigrams can enhance datasets, but current digitization techniques face challenges such as bends and skews in paper charts, impacting sea level values. This study explores often‐overlooked issues during marigram digitization, focusing on the case study of Dún Laoghaire in Ireland (1925–1931). The methodology involves digitizing the original marigram trace and underlying grid to assess offsets at the nearest ft (foot) interval on the paper chart, corresponding to changes in the water level trace for each hour interval. Subtracting the digitized value from the known value (the actual measurement) allows for the determination of differences, which are then subtracted from each hourly trace value. After adjusting for offsets ranging from −3.962 to 13.716 mm (millimetres), the study improves the final accuracy of sea level data to approximately the 10 mm level. Notably, data from 1926 and 1931 exhibit modest offsets (<7 mm), while other years show more substantial offsets (>9–14 mm), emphasizing the importance of adjustments for accuracy. Such 10 mm accuracy is compatible with requirements of the Global Sea Level Observing System. Comparing the adjusted digitized data with other survey data shows similar amplitudes and phases for Dún Laoghaire in both the historical and modern datasets, and there is an overall mean sea level rise of 1.5 mm/year when combined with the available data from the Dublin region. [ABSTRACT FROM AUTHOR]

Remote sensing is now a valued solution for more accurately budgeting water supply by identifying spectral and spatial information. A study was put in place in a Vitis vinifera L. cv. Cabernet-Sauvignon vineyard in the San Joaquin Valley, CA, USA, where a variable rate automated irrigation system was installed to irrigate vines with twelve different water regimes in four randomized replicates, totaling 48 experimental zones. The purpose of this experimental design was to create variability in grapevine water status, in order to produce a robust dataset for modeling purposes. Throughout the growing season, spectral data within these zones was gathered using a Near InfraRed (NIR) - Short Wavelength Infrared (SWIR) hyperspectral camera (900 to 1700 nm) mounted on an Unmanned Aircraft Vehicle (UAV). Given the high water-absorption in this spectral domain, this sensor was deployed to assess grapevine stem water potential, Ψstem, a standard reference for water status assessment in plants, from pure grapevine pixels in hyperspectral images. The Ψstem was acquired simultaneously in the field from bunch closure to harvest and modeled via machine-learning methods using the remotely sensed NIR-SWIR data as predictors in regression and classification modes (classes consisted of physiologically different water stress levels). Hyperspectral images were converted to bottom of atmosphere reflectance using standard panels on the ground and through the Quick Atmospheric Correction Method (QUAC) and the results were compared. The best models used data obtained with standard panels on the ground and allowed predicting Ψstem values with an R2 of 0.54 and an RMSE of 0.11 MPa as estimated in cross-validation, and the best classification reached an accuracy of 74%. This project aims to develop new methods for precisely monitoring and managing irrigation in vineyards while providing useful information about plant physiology response to deficit irrigation. [ABSTRACT FROM AUTHOR]

AbstractThe complex hydrogeological conditions and unique hydrochemical environment in the seabed rock often cause serious mine water inrush during undersea mining. With the exploitation of the undersea gold mining area in Sanshandao as the research background, a numerical analysis method for the seepage behavior of the surrounding rock in undersea gold mining considering the hydrochemical corrosion was put forward. A numerical simulation analysis of the undersea mining area in Sanshandao was conducted by the established method, and the results showed that mining the submarine ore body significantly changed the seepage field of the surrounding rock around the stope and water levels dropped obviously in the ore-controlling fault zone. Differences in the hydrochemical environment significantly influenced the distribution of the seepage field of the surrounding rock. The calculation results based on three fluids with different pH values show that the head variation range is the largest when pH = 2, followed by pH = 4, and pH = 7 has the smallest head variation range. The water inflow in the stope was also directly affected by the hydrochemical environment. With the change of pH, the water inflow at each boundary of the stope increases exponentially. [ABSTRACT FROM AUTHOR]

This account presents information on all aspects of the biology of Trapa natans L. (water caltrop and water chestnut) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the International Biological Flora: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, conservation and global heterogeneity.The water caltrop is an annual herbaceous hydrophyte rooted in the sediment of water bodies, forming flexuous underwater stems that create a buoyant, light‐capturing leaf rosette at the water surface. The submerged stem nodes additionally bear linear leaves. These are replaced by photosynthetically active, pinnately branched structures and unbranched adventitious roots early on, which complement previously established roots on the hypocotyl, altogether facilitating anchorage, nutrient and water absorption, aeration and capture of subsurface irradiance. Solitary flowers pollinated primarily through autogamy and incidentally through entomophily give rise to a fully developed edible single‐seeded drupe with two to four barbed horns. Fruits are dispersed with the help of hydrochory, epizoochory and anthropochory.Throughout its lowland, global temperate, subtropical and tropical distribution in Eurasia and Africa, the thermophilic macrophyte is found in shallow, sun‐exposed, nutrient‐rich freshwater bodies with low‐velocity flows and steady water levels. These offer slightly acidic to mildly basic conditions. The accompanying soft substrate is usually characterized by a high organic matter content. Regularly co‐occurring with other macrophytes, some of which are also of conservation concern, such as those in rare stands of the association Trapetum natantis in Europe, the water caltrop has at times been outcompeted, though it may form monodominant stands, due to several competitive features.Formerly widespread in Europe, T. natans is today recognized as a rare, strictly protected macrophyte. It has been introduced to Australia and North America; on the latter continent, its naturalization, spread and aggressive overgrowth have led to extensive control efforts. Having been used as a crop since Neolithic times, it is still exploited in Asia for means of food production, phytoremediation, ornamental purposes, medication and alternative uses. [ABSTRACT FROM AUTHOR]

Change detection processes using remote sensing and Geographic Information System (GIS) techniques were applied to monitor and estimate the water volume in the Mosul Dam reservoir during a period in which it was inaccessible due to ISIS occupation of the Province of Mosul. A total of 17 scenes of LANDSAT 8 images have been captured and the calculated areas have been used to estimate the water level (WL) and water volume (V) in the reservoir using the volume–area–elevation curve that was developed in 2011. The results indicated that WL ranged between a minimum of 308.5 m and a maximum of 321 m, while V ranged between 3.95 and 6.8 km3 for the minimum and maximum WL, respectively. For the blackout period with missing data, the monthly reservoir inflows (RIs) from the drainage watershed and the mean inflows were calculated and found to be compatible with the mean inflows of Mosul reservoir for the years 1986–2011. [ABSTRACT FROM AUTHOR]

The Coastal Ice Ocean Prediction System for the East Coast of Canada (CIOPS-E) was developed and implemented operationally at Environment and Climate Change Canada (ECCC) to support a variety of critical marine applications. These include support for ice services, search and rescue, environmental emergency response and maritime safety. CIOPS-E uses a 1/36° horizontal grid (~ 2 km) to simulate sea ice and ocean conditions over the northwest Atlantic Ocean and the Gulf of St. Lawrence (GSL). Forcing at lateral open boundaries is taken from ECCC's data assimilative Regional Ice-Ocean Prediction System (RIOPS). A spectral nudging method is applied offshore to keep mesoscale features consistent with RIOPS. Over the continental shelf and GSL, the CIOPS-E solution is free to evolve according to the model dynamics. Overall, CIOPS-E significantly improves the representation of tidal and sub-tidal water levels compared to ECCC's lower resolution systems: RIOPS (~ 6 km) and the Regional Marine Prediction System – GSL (RMPS-GSL, 5 km). Improvements in the GSL are due to the higher resolution and a better representation of bathymetry, boundary forcing and dynamics in the upper St. Lawrence Estuary. Sea surface temperatures show persistent summertime cold bias, larger in CIOPS-E than in RIOPS, as the latter is constrained by observations. The seasonal cycle of sea ice extent and volume, unconstrained in CIOPS-E, compares well with observational estimates, RIOPS and RMPS-GSL. A greater number of fine-scale features are found in CIOPS-E with narrow leads and more intense ice convergence zones, compared to both RIOPS and RMPS-GSL. [ABSTRACT FROM AUTHOR]

Altitude changes induce climate-driven alterations in plants and soils over geographic distances, which provides a framework for predicting the pattern and mechanism of soil microbial evolution in global change scenarios. This study aimed to identify the respective contributions of plant diversity and edaphic variables to soil fungal assemblages across three altitude transects in southwestern China. Illumina sequencing technology was applied to determine the altitude-induced changes in fungal composition and diversity. We found that the responses of soil fungal compositions to altitude changes varied with taxa. A significant decrease in abundance was observed for the dominant Ascomycota from low to high altitude, following the decreased plant diversity. In contrast, that of subdominant Basidiomycota was rich at medium altitude, Mortierellomycota had rich abundances at high altitude in accordance with the increased water and nutrient levels in soil. At the class level, Sordariomycetes abundance from low to high altitude showed a significant decrease, but Agaricomycetes abundance was rich at medium altitude, while Eurotiomycetes and Tremellomycetes had rich abundances at high altitude. At the genus level, Isaria was rich at medium altitude, and Mortierella and Penicillium had rich abundances at high altitude. In particular, the abundance of Mortierella (Mortierellomycota) was richer than the Trechispora (Basidiomycota) at the high altitude. Furthermore, soil fungal diversity decreased on average by 24.62% with increasing altitude, for which was plant diversity primarily contributed by plant diversity (9.56–15.42%). However, the fungi compositions at the phylum (8.63–14.97%), class (7.71–8.97%), and genus (9.29–11.86%) levels were mainly affected by soil properties. At the phylum level, total nitrogen, available nitrogen, soil organic matter, pH, soil temperature, and soil water content contributed to the variations in fungal composition. Our results suggested that altitude-induced changes of plant and edaphic properties had differential contribution to shifts in the soil fungal assemblage, probably associated with their roles in meeting the metabolic and habitat demand of fungi. [ABSTRACT FROM AUTHOR]

Over-exploitation of groundwater in arid and semi-arid regions requires an understanding of dynamics for effective management strategies. This study uses an artificial neural network (ANN) to predict groundwater levels using initial water level, pumping, and hydrological and meteorological input variables. A sensitivity analysis assessed predictors' impact on accurate groundwater level prediction. The accuracy of predictions by the ANN model was examined through different performance evaluation criteria and the result achieved is satisfactory as compared to reasonable statistical indicator values. A comparison of results simulated by the ANN model and numerical groundwater flow model (MODFLOW) was carried out and it was found that the prediction of the ANN model was consistently superior to that of the numerical model. Therefore, data-driven models such as ANN can provide better predictions of groundwater level that will aid in groundwater resource management. [ABSTRACT FROM AUTHOR]

Lakefront Michigan homeowners must manage chronic erosion risks that threaten property and structural damage. Record high water levels led to approvals of more than 2,200 shoreline hardening permits in the 14 months ending December 2022. Hardened shorelines likely alter local environmental amenities, which may capitalize into nearby property values. A change in the price would suggest lakefront homeowners induce negative externalities on the inland coastal community, culminating in suboptimal shoreline adaptation. Utilizing adaptation permits for hardened shorelines, assessments of shoreline typology, and residential housing sales from the Zillow Transaction and Assessment Database, I quantify these spillovers on properties within 0.5 miles from the shoreline. Hedonic estimates suggest that an individual's shoreline hardening does not adversely impact the inland community unless nearby shorelines become "extensively" armored. Extensively armored shorelines are associated with a 20%–33% reduction in property values relative to a more natural shoreline. [ABSTRACT FROM AUTHOR]