Water

Within a single flood event, this study evaluated the empirical relationship between underwater hyperspectral observations and layer-scale suspended sediment concentration (SSC) and calibrated its predictive uncertainty. The dataset comprised 101 paired observations from 25 complete four-position verticals (n = 100) plus one isolated record. Sample-level leave-one-out cross-validation (LOOCV) pro…

Rapid conversion of agricultural land into low-density housing reshapes local water balances at a time when climate change is intensifying hydrological extremes in Central Europe. This study evaluates the rooftop rainwater harvesting (RWH) potential of a newly urbanized housing estate in Rokietnica (Greater Poland Voivodeship, Poland) using a publicly available true orthophoto (5 cm ground sampli…

Phosphorus is recognized as one of the primary contributors to eutrophication in freshwater ecosystems. Among the various strategies proposed to mitigate its impact, adsorption-based removal has emerged as one of the most widely adopted and effective approaches globally. In this study, Zn/Al-layered double hydroxides (LDHs) were synthesized by varying the molar ratio of cations to obtain material…

River ecosystems play a key role in both natural and urbanized environments, acting as essential links in ecological systems. However, they are increasingly exposed to the synergistic effects of anthropogenic pressure and hydrological instability. This study aims to identify and assess changes in land use and their impact on the phytosociological structure and functioning of ash-alder (Fraxino-Al…

The logarithmic law of the wall is a foundational element in turbulence modeling. Its classical derivation, rooted in Prandtl’s mixing-length theory, is predicated on the existence of a constant shear stress layer. This paper demonstrates that this foundational assumption is not strictly satisfied for two-dimensional, uniform open-channel flows, where the Reynolds shear stress profile exhibits a …

This study focused on the generation and characterization of sludge produced by electrocoagulation (EC) combined with Moringa oleifera seed extract (MOSE) to remove water hardness. First, an experimental data set was generated and used as the baseline data for mathematical modeling to identify the effects of different parameters on Ca2+ and Mg2+ ion hardness removal. Then, using the generated dat…

Small lakes are widespread, yet their biogeochemistry, particularly regarding greenhouse gases, remains insufficiently studied. This article presents the findings from an investigation of six small lakes in the Southern European part of Russia, conducted from September to October 2024. The primary aim was to examine the coupled distribution of methane (CH4) and sulfide sulfur (a key metabolite of…

Acidic mine drainage (AMD) rich in heavy metals and sulfates causes severe environmental hazards. SRB and SOB are ideal remediation strains, yet their microaerophilic symbiotic metabolism and metabolite characteristics remain ambiguous. This study explores their symbiotic metabolic mechanisms, optimizing culture parameters via response surface methodology and multi-objective genetic neural networ…

To support groundwater protection and sustainable utilization in southern Sichuan, this study aims to clarify the multi-year variation characteristics of groundwater levels (GWLs) and identify their main driving factors in the Yibin region. In this paper, 2019–2024 GWL monitoring records, hydrometeorological data, and multi-source geospatial datasets were integrated. Trend analysis, centroid migr…

This study presents a numerical investigation into riprap stability for submarine cable protection under high-speed incident waterflow conditions. A coupled CFD-DEM numerical model, implemented within the ANSYS 2024 R1 platform, was developed and validated against controlled laboratory experiments. The stability of the riprap was systematically evaluated across a range of incident waterflow veloc…

Marine fisheries play a vital role in ensuring food supply and sustaining livelihoods in coastal regions of China. However, the expansion of aquaculture has led to increasing carbon emissions and mounting pressure on resources and the environment, making the improvement of ecological efficiency a critical issue for the sustainable development of the industry. From the perspective of carbon emissi…

Water security is a prerequisite for achieving the Sustainable Development Goals, yet water insecurity remains a critical challenge in urban slums. This study assesses the water security in the slums of Dhaka City, Bangladesh by integrating multiple dimensions of water security, such as water supply, sanitation and hygiene, water environment, water and climatic risks, and water governance. Suitab…

Mountain glaciers constitute sensitive indicators of climate variability and represent essential freshwater reservoirs for downstream ecosystems and societies. Although glacier change in the Greater Caucasus has been extensively investigated at regional scales, detailed long-term reconstructions of individual glacier systems remain comparatively scarce. In this study, we reconstruct two centuries…

Climate change and global warming are increasingly affecting freshwater bodies both locally and globally, resulting in fluctuating water levels. Understanding how Cladocera communities are organized across different water body types is important for ecological assessment and conservation. In this study, we compared Cladocera assemblages between different wetland types with different water body ty…

This study specifically investigates the operating range of a normal Francis turbine through the production of experimental data and characteristic performance curves under both constant and variable rotational speed operating conditions. For the constant speed condition, a specific speed of 204.6 was found for turbine maximum efficiency attained with a guide vane aperture at 60%. The variable sp…

This study investigates the kinetic parameters required for the engineering design of treatment plants employing fluorite precipitation technology. Particular emphasis is placed on the selection of a substrate for fluorite precipitation at the minimum acceptable calcium ion concentration, as well as on determining the precipitation rate of fluoride ions onto a substrate of given composition. In a…

Siphon vertical axial-flow pump systems are widely used in large-scale low-head pumping stations, irrigation and drainage projects, urban flood control, and water diversion engineering, where safe and stable operation is essential for hydraulic system reliability. Compared with steady operating conditions, the startup process involves rapid variations in impeller speed, flow rate, pressure distri…

This study evaluates whether existing long-term monitoring data are sufficient to distinguish natural background concentrations from anthropogenic influences on chemical river water quality in Lake Sevan basin. A comprehensive dataset covering physicochemical parameters, nutrients, and trace metals was analyzed for nine major tributaries with different geological settings and land-use characteris…

Reservoir-bank landslides may become unstable after reservoir impoundment and generate impulse waves, posing serious threats to hydropower hub structures, reservoir navigation, and downstream safety. The H1 landslide, with a volume of approximately 5.35 million m3, is located on the left bank of the near-dam reservoir area of Yangqu Hydropower Station. Reservoir operation and water-level fluctuat…

Groundwater in Zhengzhou has experienced substantial changes under the combined effects of long-term abstraction, water-source substitution by the South-to-North Water Diversion Project, and ecological replenishment. During the 13th Five-Year Plan period, shallow and middle-deep groundwater levels in Zhengzhou recovered by 2.83 m and 6.46 m, respectively; nevertheless, extensive groundwater depre…