The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the A...The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the Arno River and its main tributaries were analyzed to assess the water pollution status.The geochemical composition of the Arno River changes from the source(dominated by a Ca-HCO_(3) facies)to the mouth(where a Na-Cl(SO4)chemistry prevails)with an increasing quality deterioration,as suggested by the Chemical Water Quality Index,due to anthropogenic contributions and seawater intrusion before flowing into the Ligurian Sea.The Ombrone and Usciana tributaries introduce anthropogenic pollutants into the Arno River,whilst Elsa tributary supplies significant contents of geogenic sulfate.The concentrations of dissolved nitrate and nitrite(up to 63 and 9 mg/L,respectively)and the respective isotopic values of𝛿15N and𝛿18O were also determined to understand origin and fate of the N-species in the Arno River Basin surface waters.The combined application of𝛿15N-NO_(3) and𝛿18O-NO_(3) and N-source apportionment modelling allowed the identification of soil organic nitrogen and sewage and domestic wastes as primary sources for dissolved NO_(3)-.The𝛿15N-NO_(2) and𝛿18O-NO_(2) values suggest that the nitrification process affects the ARB waters,thus controlling the abundances and proportion of the N-species.Our work indicates that additional efforts are needed to improve management strategies to reduce the release of nitrogenated species to the surface waters of the Arno River Basin,since little progress has been made from the early 2000s.展开更多
Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the i...Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the impacts of wildfire on hydrology have been widely assessed at the watershed scale,the underlying mechanisms of the responses of summer low flows remain poorly understood.In this study,we employed an integrated research framework that combines hydrometric monitoring with geochemical tracing to evaluate how the 2021 White Rock Lake Wildfire affected summer low flows,and to identify the underlying mechanisms governing these responses in the Okanagan Valley,British Columbia(BC),Canada.We found that(1)summer low flows,represented by Q90(flows exceeded at 90%of the time in summer)significantly increased following the wildfire(p<0.05);(2)summer low flows were primarily regulated by snow water in early summer(July),while dominated by groundwater in late summer(August and September);and(3)enhanced snow water contribution and reduced evapotranspiration(ET)were two primary contributors to the increased summer low flows.Our results provide insights for developing sustainable water management strategies for the region in the context of climate change and increasing forest disturbance.This study also demonstrates that the combination of hydrometric monitoring and geochemical tracing is an effective approach towards uncovering mechanisms that drive low-flow responses.展开更多
Benthic habitat mapping is an emerging discipline in the international marine field in recent years,providing an effective tool for marine spatial planning,marine ecological management,and decision-making applications...Benthic habitat mapping is an emerging discipline in the international marine field in recent years,providing an effective tool for marine spatial planning,marine ecological management,and decision-making applications.Seabed sediment classification is one of the main contents of seabed habitat mapping.In response to the impact of remote sensing imaging quality and the limitations of acoustic measurement range,where a single data source does not fully reflect the substrate type,we proposed a high-precision seabed habitat sediment classification method that integrates data from multiple sources.Based on WorldView-2 multi-spectral remote sensing image data and multibeam bathymetry data,constructed a random forests(RF)classifier with optimal feature selection.A seabed sediment classification experiment integrating optical remote sensing and acoustic remote sensing data was carried out in the shallow water area of Wuzhizhou Island,Hainan,South China.Different seabed sediment types,such as sand,seagrass,and coral reefs were effectively identified,with an overall classification accuracy of 92%.Experimental results show that RF matrix optimized by fusing multi-source remote sensing data for feature selection were better than the classification results of simple combinations of data sources,which improved the accuracy of seabed sediment classification.Therefore,the method proposed in this paper can be effectively applied to high-precision seabed sediment classification and habitat mapping around islands and reefs.展开更多
Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natur...Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natural waters, causing eutro- phication and ecological damage. Moreover, most P in the food is eventually discharged as waste after being digested by human and animals. Thus, industrial activities have created a one-way flow of non-renewable P from rocks to farms to lakes, rivers and oceans.展开更多
The accelerated decline of Arctic sea ice since the 1980s has paradoxically amplified greenhouse gas(GHG)emissions through increased shipping activities in this ecologically vulnerable region.This study investigates h...The accelerated decline of Arctic sea ice since the 1980s has paradoxically amplified greenhouse gas(GHG)emissions through increased shipping activities in this ecologically vulnerable region.This study investigates how to reconcile the decarbonization of Arctic shipping with conflicting environmental,economic,and geopolitical interests.Through systematic literature review and interest-balancing analysis,our findings identify three systemic barriers:(1)inadequate adaptation of International Maritime Organization(IMO)regulations to Arctic-specific environmental risks,(2)fragmented enforcement mechanisms among Arctic and non-Arctic States,and(3)technological limitations in clean fuel adoption for ice-class vessels.To address these challenges,a tripartite governance framework is proposed.First,legally binding amendments to International Convention for the Prevention of Pollution from Ships(MARPOL)Annex VI introducing Arctic-specific Energy Efficiency eXisting ship Index(EEXI)standards and extending energy efficiency regulations to fishing vessels.Second,a phased fuel transition prioritizing liquefied natural gas(LNG)and methanol,followed by hydrogen-ammonia synthetics.Third,enhanced multilateral cooperation through an Arctic Climate Shipping Alliance to coordinate joint research and development in cold-adapted technologies and ice-route optimization.By integrating United Nations Convention on the Law of the Sea(UNCLOS)obligations with IMO Polar Code implementation,this study advances a dynamic interest-balancing framework for policymakers,offering actionable pathways to achieve Paris Agreement targets while safeguarding Arctic ecosystems.展开更多
This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria...This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria. The research aimed to assess the diversity and distribution of seaweeds in this region. Seaweed samples were collected by hand, using scrapers, at low tide from four stations identified by local fisherfolk and commercial divers. These samples were analyzed in the laboratory for species identification. A total of 39 seaweed taxa were identified, with Rhodophyta (red algae) being the most abundant (74%), followed by Chlorophyta (green algae) (21%) and Heterokontophyta (brown algae) (5%). The highest biomass species included Grateloupia sp., Chaetomorpha antennina, Gracilaria sp., Ceratodictyon variabile, Cladophora sp., Gelidium pusillum, Ulva sp., Blidingia minima, and Caloglossa leprieurii. Species abundance was highest on breakwater rocks and on the bodies of anchored or sunken vessels, while sandy beaches exhibited lower abundance. The findings reveal significant potential for Nigeria’s seaweed in aquaculture, climate change mitigation, and biotechnology. The study recommends further molecular research, expansion of sampling areas, and the development of sustainable seaweed cultivation practices to support Nigeria’s blue economy.展开更多
The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based t...The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based techniques with Self-Organizing Maps.展开更多
Water scarcity and environment deterioration have become main constraints to sustainable economic and social development.Scientifically assessing Water Resources Carrying Capacity(WRCC)is essential for the optimal all...Water scarcity and environment deterioration have become main constraints to sustainable economic and social development.Scientifically assessing Water Resources Carrying Capacity(WRCC)is essential for the optimal allocation of regional water resources.The hilly area at the northern foot of Yanshan Mountains is a key water conservation zone and an important water source for Beijing,Tianjin and Hebei.Grasping the current status and temporal trends of water quality and WRCC in representative small watersheds within this region is crucial for supporting rational water resources allocation and environment protection efforts.This study focuses on Pingquan City,a typical watershed in northern Hebei Province.Firstly,evaluation index systems for surface water quality,groundwater quality and WRCC were estab-lished based on the Pressure-State-Response(PSR)framework.Then,comprehensive evaluations of water quality and WRCC at the sub-watershed scale were conducted using the Varying Fuzzy Pattern Recogni-tion(VFPR)model.Finally,the rationality of the evaluation results was verified,and future scenarios were projected.Results showed that:(1)The average comprehensive evaluation scores for surface water and groundwater quality in the sub-watersheds were 1.44 and 1.46,respectively,indicating that both met the national Class II water quality standard and reflected a high-quality water environment.(2)From 2010 to 2020,the region's WRCC steadily improved,with scores rising from 2.99 to 2.83 and an average of 2.90,suggesting effective water resources management in Pingquan City.(3)According to scenario-based predic-tion,WRCC may slightly decline between 2025 and 2030,reaching 2.92 and 2.94,respectively,relative to 2020 levels.Therefore,future efforts should focus on strengthening scientific management and promoting the efficient use of water resources.Proactive measures are necessary to mitigate emerging contradiction and ensure the long-term stability and sustainability of the water resources system in the region.The evalua-tion system and spatiotemporal evolution patterns proposed in this study can provide a scientific basis for refined water resource management and ecological conservation in similar hilly areas.展开更多
Water clarity(Secchi disk depth, Z_(SD)) and Forel-Ule Index(FUI) are critical ecological indicators for assessing water quality. Although satellite remote sensing serves as a vital tool for large-scale and long-term ...Water clarity(Secchi disk depth, Z_(SD)) and Forel-Ule Index(FUI) are critical ecological indicators for assessing water quality. Although satellite remote sensing serves as a vital tool for large-scale and long-term water quality monitoring,low accuracy, coarse resolution, and incomplete spatial coverage of existing satellite Z_(SD) and FUI products hindered the reliable ecological assessment of water quality. Here, a long-term(2003-2023) satellite dataset of monthly Z_(SD) and FUI was developed by applying the advanced high-accuracy retrieval algorithms and reconstruction method to 35 546Moderate-resolution Imaging Spectroradiometer(MODIS) images over China coastal waters. The new dataset exhibited superior performance compared to the existing one, in terms of higher accuracy(Mean Absolute Percentage Error,MAPE = 28.89% for Z_(SD) and MAPE = 34.46% for FUI), spatio-temporal resolution(monthly, 1 km), and spatial coverage(99.53%), with the most significant improvement found in the nearshore turbid waters. By leveraging this dataset, the ecological impact of human activities on water quality was accurately revealed, as indicated by the significant Z_(SD) improvements during terrestrial pollution control, which was misinterpreted by previous satellite products.Besides, natural factor-induced water quality variability was also successfully captured, particularly the seasonal dynamics of suspended sediment plumes in the East China Sea. The new dataset and adopted methods may provide essential support for the accurate monitoring, ecological assessment, and sustainable management of marine ecosystems.展开更多
Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chin...Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chinese Ocean Color and Temperature Scanner(COCTS)aboard the HY-1D satellite in 2020,yet its Chl a products require further validation in complex coastal waters.This study assesses HY-1D Chl a products in the Bohai and Yellow Seas,two optically complex coastal regions,using in situ data collected during multiple cruises.Additionally,we compare HY-1D Chl a products with those from the Moderate Resolution Imaging Spectroradiometer(MODIS)and the Visible Infrared Imaging Radiometer Suite(VIIRS).We observed that although Chl a products from HY-1D are generally consistent with those from the MODIS and VIIRS in spatial distribution,there are still significant errors when compared with in situ data.Therefore,we developed a new blended algorithm to improve the accuracy of HY-1D Chl a products.The algorithm distinguishes between turbid and relatively clean waters using a classification index based on the ratio of remote sensing reflectance(R_(rs)(λ)).After the initial classification,we developed targeted algorithms based on the optical properties of different water bodies.The new model shows a significant improvement,reducing the mean absolute percentage error(MAPE)from 43.1%to 24.3%.Additionally,merging Chl a data from HY-1D,MODIS,and VIIRS maintains good accuracy,with HY-1D Chl a products significantly enhancing data coverage and robustness.This research provides important support for producing high-quality HY-1D Chl a products for coastal waters.展开更多
Microplastics(MPs)have been widely detected in marine environments,yet the pollution in terrestrial fresh waters in economically underdeveloped and remote areas is poorly understood.We investigated the abundance and d...Microplastics(MPs)have been widely detected in marine environments,yet the pollution in terrestrial fresh waters in economically underdeveloped and remote areas is poorly understood.We investigated the abundance and distribution of MPs in inland waters(including open waters in river,lake,reservoir,stream,and tap water and bottled water)in Guizhou,SW China,detected by Nile Red staining.Results show that MPs were detected in all samples,with the mean abundance of 3.5±1.9 items/mL in 34river water samples,3.9±1.9 items/mL in 14 lake and reservoir water samples,3.4±2.4 items/mL in 87 stream water samples,3.8±3.8 items/mL in 164 tap water samples,and 1.3±3.2 items/mL in 12 bottled water samples from 4 different brands.The MP abundance in open field waters(3.6±3.0 items/mL)was significantly higher than that in bottled water(1.3±3.2 items/mL)(P<0.05).The microplastics with particle sizes of 10-20μm accounted for more than 50%of all samples.The composition ratio of smalland medium-sized microplastics in open waters was higher than in tap and bottled water(P<0.05).The MPs abundance tended to increase with the decrease in particle size.Therefore,microplastic pollution varied in different degrees in open waters in economically underdeveloped and remote areas of the southwestern China,which is consistent with microplastic pollution in other similar water environments.This study provided a reference for understanding the microplastic content and pollution control in the inland waters in western and remote areas of China.展开更多
Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western ...Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western Pacific Ocean remain unclear.Here,we investigated the abundance and distribution characteristics of microplastics in surface waters of the western Pacific Ocean and analyzed their potential sources.Results show that microplastics were widespread in the western Pacific Ocean,with abundance ranging from 0.03 to 2.36 particles/m^(3)(average 0.37±0.47 particles/m^(3)).Fibers/filaments and fragments were the main shapes of microplastics(71.6%)and the most abundant microplastic size class was<1.0 mm(42.4%).Significant differences in microplastic abundance were observed in different regions,with the lowest abundance in the South China Sea(0.03 particles/m^(3))and highest abundance in the seamount area in the western Pacific Ocean(0.58 particles/m^(3)).This study provides baseline data and insights into the fate and transportation of microplastics in the western Pacific region.展开更多
Pingquan City,the origin of five rivers,serves as the core water conservation zone for the Beijing-Tianjin-Hebei region and exemplifies the characteristics of small watersheds in hilly areas.In recent years,excessive ...Pingquan City,the origin of five rivers,serves as the core water conservation zone for the Beijing-Tianjin-Hebei region and exemplifies the characteristics of small watersheds in hilly areas.In recent years,excessive mining and intensified human activities have severely disrupted the local ecosystem,creating an urgent need for ecological vulnerability assessment to enhance water conservation functions.This study employed the sensitivity-resilience-pressure model,integrating various data sources,including regional background,hydro-meteorological data,field investigations,remote sensing analysis,and socio-economic data.The weights of the model indices were determined using an entropy weighting model that combines principal component analysis and the analytic hierarchy process.Using the ArcGIS platform,the spatial distribution and driving forces of ecological vulnerability in 2020 were analyzed,providing valuable insights for regional ecological restoration.The results indicated that the overall Ecological Vulnerability Index(EVI)was 0.389,signifying moderate ecological vulnerability,with significant variation between watersheds.The Daling River Basin had a high EVI,with ecological vulnerability primarily in levels IV and V,indicating high ecological pressure,whereas the Laoniu River Basin had a low EVI,reflecting minimal ecological pressure.Soil type was identified as the primary driving factor,followed by elevation,temperature,and soil erosion as secondary factors.It is recommended to focus on key regions and critical factors while conducting comprehensive monitoring and assessment to ensure the long-term success of ecological management efforts.展开更多
Watersheds play a fundamental role in the hydrological cycle because of their contributions to the water regulation of essential tributaries for ecosystems.However,the balance between soil and climatological component...Watersheds play a fundamental role in the hydrological cycle because of their contributions to the water regulation of essential tributaries for ecosystems.However,the balance between soil and climatological components of these watersheds has been altered by human activities,which directly impacts them through changes in land use.In Colombia,the lack of control over land-use in watersheds has affected the water regulation services of important tributaries,such as the Onzaga River,whose waters are mainly used for agricultural activities.For this reason,this study aims to evaluate how changes in land use in the basin affected the capacity of water regulation.For this,a statistical correlation analysis was conducted between the Water Regulation Index(WRI)and vegetation cover areas from 1985 to 2023.The study results indicate that the expansion of the anthropogenic vegetation covers,such as agriculture parches and grasslands,replacing different types of forests,and producing an adverse effect on the water regulation capacity for the basin.This demonstrated its decrease along with an increase in its variability,indicating that,in addition to its degradation,there is a greater irregularity in this ecosystem service.In conclusion,correlation analysis indicates that 93%of the change in water regulation regime is explained by the contraction of forest cover and the expansion of agricultural areas,degraded lands,and urban development.This study confirms the importance of preserving native vegetation cover in the watershed,especially in areas adjacent to watercourses with riparian forests.展开更多
Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurna...Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurnal and semidiurnal tidal constituents.We integrated the development technique of the Technical University of Denmark(DTU10)model and calculated the residual tides using the intermediary FES2012 model.We utilized all available Topex/Poseidon,Jason-1,Ocean Surface Topography Mission(OSTM)/Jason-2 primary and tandem missions to develop the new model.To reduce the discrepancies between the model and in situ measurements estimated S2 tide constituent,the ERA-Interim model was selected for dry tropospheric correction of altimetry data.The newly developed model with an improved spatial resolution from 1/8°×1/8°to 1/16°×1/16°was assessed and compared against contemporary global ocean tide models using in situ measurements in coastal regions,continental shelf waters,marginal seas,and deep waters.The results demonstrate improvements in shallow waters and coastal regions,particularly in representative coastal re-gions such as the Northwest European Shelf and East Asian Marginal Seas.Moreover,the model performs well in simulating S_(2) and K_(2) tides with root mean square differences of 0.355 and 0.234 cm,respectively,against in situ measurements in deep waters world-wide.Compared with that of DTU10,the root sum square of the new model for the eight main tidal constituents decrease by 8.4%to 0.997 cm.展开更多
Over recent decades,the increasing frequency and intensity of Harmful Algal Blooms(HABs)have resulted in severe environmental impacts worldwide.Understanding the physical drivers of HABs is crucial for understanding t...Over recent decades,the increasing frequency and intensity of Harmful Algal Blooms(HABs)have resulted in severe environmental impacts worldwide.Understanding the physical drivers of HABs is crucial for understanding their dynamics and mitigating their environmental consequences.This study integrates satellite remote sensing and hydrodynamic modeling to investigate two HAB events and their driving mechanisms in Guangdong coastal waters during February and August 2021.An HAB detection method using Sentinel-3 ocean and land color instrument data based on an improved floating algae index algorithm was developed.The spatiotemporal dynamics of physical drivers were analyzed using a submesoscale permitting regional ocean modeling system hydrodynamic simulation.Both HAB detection results and hydrodynamic simulations were validated against in situ buoy measurements.In coastal area of Jiangmen City,local changes of divergence,impacts from the Zhujiang River(Pearl River)fresh water plume were found to be drivers accounted for long-termed variations of chlorophyll and triggers for HABs,while changes in vertical mixing associated with wind speed regulate the short-termed changes.In coastal area of Shantou City,initiations of HABs were mainly driven by wind-induced coastal upwelling.Distribution,aggregation and elongation of HAB patches were modulated by surface fronts and vortices induced by fresh water plume and complex coastlines.These findings underscore the advantages of integrating satellite remote sensing,3D hydrodynamic modeling,and in situ observations for elucidating the complex physical mechanisms governing HAB dynamics in coastal waters.展开更多
Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characte...Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characteristics of surface water in the North of Tehran Rivers(NTRs),an essential water resource in a rapidly urbanizing region,using advanced clustering techniques,including Hierarchical Clustering Analysis(HCA),Fuzzy CMeans(FCM),Genetic Algorithm Fuzzy C-Means(GAFCM),and Self-Organizing Map(SOM).The research aims to address the scientific challenge of understanding spatial and temporal variability in water quality,focusing on physicochemical parameters,hydrochemical facies,and contamination sources.Water samples from six rivers collected over four seasons in 2020 were analyzed and classified into distinct clusters based on their chemical composition,revealing significant seasonal and spatial differences.Results showed that FCM and GAFCM consistently categorized the NTRs into two clusters during winter and spring and three in summer and autumn.These findings were supported by HCA and SOM,which identified clusters corresponding to specific river segments and contamination levels.The primary hydrochemical processes identified were mineral dissolution and weathering,with calcite,dolomite,and aragonite significantly influencing water chemistry.Additionally,human activities,such as wastewater discharge,were shown to contribute to elevated sulfate,nitrate,and phosphate concentrations,further corroborated by microbial analyses.By integrating HCA,FCM,and GAFCM with an artificial neural network(ANN)-based clustering method(SOM),this study provides a robust framework for evaluating surface water quality.The findings,supported by Gibbs diagrams,Hounslow ion ratio,and saturation indices,highlight the dominance of rock weathering and human impacts in shaping the hydrochemical dynamics of the NTRs.These insights contribute to the scientific understanding of water quality dynamics and offer practical guidance for sustainable water resource management and environmental protection in developing urban areas.展开更多
Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen e...Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.展开更多
Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,per...Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.展开更多
Unequal virtual water transfer may aggravate local water scarcity risk.However,the quantitative confirmation of a clear geographic convergence between virtual water transfer and water scarcity risk remains undetermine...Unequal virtual water transfer may aggravate local water scarcity risk.However,the quantitative confirmation of a clear geographic convergence between virtual water transfer and water scarcity risk remains undetermined.We present an analytical framework that reveals the spatial matching between global water scarcity risk and virtual water trade inequality.This framework integrates a three-dimensional water scarcity risk assessment,hybrid input-output analysis,pollution trade term construction,and geographic convergence identification.The framework is applied to 123 countries for long-term validation from 1991 to 2021.We show that despite global improvements in water efficiency and security,countries exceeding the maximum water vulnerability threshold have increased by 50%.South Asia is the largest net exporter of virtual water.Central Asia exhibits the most pronounced virtual water trade inequality.To achieve the same economic growth,Central Asia needs to pay several times the local water consumption costs of developed regions(15.9−83.6 times,2021).In the past 30 years,the average geographic convergence index exceeded 0.8.Countries facing severe water scarcity also exhibit pronounced inequalities in virtual water trade,indicating that a significant geographic convergence relationship exists.Effectively responding to this unsustainable relationship necessitates balancing both domestic resource risk management and global virtual water trade regulation.展开更多
文摘The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the Arno River and its main tributaries were analyzed to assess the water pollution status.The geochemical composition of the Arno River changes from the source(dominated by a Ca-HCO_(3) facies)to the mouth(where a Na-Cl(SO4)chemistry prevails)with an increasing quality deterioration,as suggested by the Chemical Water Quality Index,due to anthropogenic contributions and seawater intrusion before flowing into the Ligurian Sea.The Ombrone and Usciana tributaries introduce anthropogenic pollutants into the Arno River,whilst Elsa tributary supplies significant contents of geogenic sulfate.The concentrations of dissolved nitrate and nitrite(up to 63 and 9 mg/L,respectively)and the respective isotopic values of𝛿15N and𝛿18O were also determined to understand origin and fate of the N-species in the Arno River Basin surface waters.The combined application of𝛿15N-NO_(3) and𝛿18O-NO_(3) and N-source apportionment modelling allowed the identification of soil organic nitrogen and sewage and domestic wastes as primary sources for dissolved NO_(3)-.The𝛿15N-NO_(2) and𝛿18O-NO_(2) values suggest that the nitrification process affects the ARB waters,thus controlling the abundances and proportion of the N-species.Our work indicates that additional efforts are needed to improve management strategies to reduce the release of nitrogenated species to the surface waters of the Arno River Basin,since little progress has been made from the early 2000s.
基金the China Scholarship Council(CSC)the Uplifting Reciprocal Research Scholarship Program for sponsoring Shixuan Lyu+1 种基金supported by MITACS Accelerate(No.IT39116)the Okanagan Basin Water Board water conservation and quality improvement grant program。
文摘Forests are experiencing more frequent and intense wildfires in Canada,which pose considerable threats to water quantity and quality,particularly during the summer low-flow period when water demand is high.While the impacts of wildfire on hydrology have been widely assessed at the watershed scale,the underlying mechanisms of the responses of summer low flows remain poorly understood.In this study,we employed an integrated research framework that combines hydrometric monitoring with geochemical tracing to evaluate how the 2021 White Rock Lake Wildfire affected summer low flows,and to identify the underlying mechanisms governing these responses in the Okanagan Valley,British Columbia(BC),Canada.We found that(1)summer low flows,represented by Q90(flows exceeded at 90%of the time in summer)significantly increased following the wildfire(p<0.05);(2)summer low flows were primarily regulated by snow water in early summer(July),while dominated by groundwater in late summer(August and September);and(3)enhanced snow water contribution and reduced evapotranspiration(ET)were two primary contributors to the increased summer low flows.Our results provide insights for developing sustainable water management strategies for the region in the context of climate change and increasing forest disturbance.This study also demonstrates that the combination of hydrometric monitoring and geochemical tracing is an effective approach towards uncovering mechanisms that drive low-flow responses.
基金Supported by the National Natural Science Foundation of China(Nos.42376185,41876111)the Shandong Provincial Natural Science Foundation(No.ZR2023MD073)。
文摘Benthic habitat mapping is an emerging discipline in the international marine field in recent years,providing an effective tool for marine spatial planning,marine ecological management,and decision-making applications.Seabed sediment classification is one of the main contents of seabed habitat mapping.In response to the impact of remote sensing imaging quality and the limitations of acoustic measurement range,where a single data source does not fully reflect the substrate type,we proposed a high-precision seabed habitat sediment classification method that integrates data from multiple sources.Based on WorldView-2 multi-spectral remote sensing image data and multibeam bathymetry data,constructed a random forests(RF)classifier with optimal feature selection.A seabed sediment classification experiment integrating optical remote sensing and acoustic remote sensing data was carried out in the shallow water area of Wuzhizhou Island,Hainan,South China.Different seabed sediment types,such as sand,seagrass,and coral reefs were effectively identified,with an overall classification accuracy of 92%.Experimental results show that RF matrix optimized by fusing multi-source remote sensing data for feature selection were better than the classification results of simple combinations of data sources,which improved the accuracy of seabed sediment classification.Therefore,the method proposed in this paper can be effectively applied to high-precision seabed sediment classification and habitat mapping around islands and reefs.
基金supported by the National Key Research and Development Program of China (No. 2017YFA0207204)
文摘Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natural waters, causing eutro- phication and ecological damage. Moreover, most P in the food is eventually discharged as waste after being digested by human and animals. Thus, industrial activities have created a one-way flow of non-renewable P from rocks to farms to lakes, rivers and oceans.
基金supported by the Major Research Projects of the National Social Science Fund of China(NSFC,Grant no.23VHQ015).
文摘The accelerated decline of Arctic sea ice since the 1980s has paradoxically amplified greenhouse gas(GHG)emissions through increased shipping activities in this ecologically vulnerable region.This study investigates how to reconcile the decarbonization of Arctic shipping with conflicting environmental,economic,and geopolitical interests.Through systematic literature review and interest-balancing analysis,our findings identify three systemic barriers:(1)inadequate adaptation of International Maritime Organization(IMO)regulations to Arctic-specific environmental risks,(2)fragmented enforcement mechanisms among Arctic and non-Arctic States,and(3)technological limitations in clean fuel adoption for ice-class vessels.To address these challenges,a tripartite governance framework is proposed.First,legally binding amendments to International Convention for the Prevention of Pollution from Ships(MARPOL)Annex VI introducing Arctic-specific Energy Efficiency eXisting ship Index(EEXI)standards and extending energy efficiency regulations to fishing vessels.Second,a phased fuel transition prioritizing liquefied natural gas(LNG)and methanol,followed by hydrogen-ammonia synthetics.Third,enhanced multilateral cooperation through an Arctic Climate Shipping Alliance to coordinate joint research and development in cold-adapted technologies and ice-route optimization.By integrating United Nations Convention on the Law of the Sea(UNCLOS)obligations with IMO Polar Code implementation,this study advances a dynamic interest-balancing framework for policymakers,offering actionable pathways to achieve Paris Agreement targets while safeguarding Arctic ecosystems.
文摘This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria. The research aimed to assess the diversity and distribution of seaweeds in this region. Seaweed samples were collected by hand, using scrapers, at low tide from four stations identified by local fisherfolk and commercial divers. These samples were analyzed in the laboratory for species identification. A total of 39 seaweed taxa were identified, with Rhodophyta (red algae) being the most abundant (74%), followed by Chlorophyta (green algae) (21%) and Heterokontophyta (brown algae) (5%). The highest biomass species included Grateloupia sp., Chaetomorpha antennina, Gracilaria sp., Ceratodictyon variabile, Cladophora sp., Gelidium pusillum, Ulva sp., Blidingia minima, and Caloglossa leprieurii. Species abundance was highest on breakwater rocks and on the bodies of anchored or sunken vessels, while sandy beaches exhibited lower abundance. The findings reveal significant potential for Nigeria’s seaweed in aquaculture, climate change mitigation, and biotechnology. The study recommends further molecular research, expansion of sampling areas, and the development of sustainable seaweed cultivation practices to support Nigeria’s blue economy.
文摘The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based techniques with Self-Organizing Maps.
基金financially supported by China Geological Survey Project(No.DD20220954)Open Funding Project of the Key Laboratory of Groundwater Sciences and Engineering,Ministry of Natural Resources(No.SK202301-4)+2 种基金Science and Technology Innovation Foundation of Comprehensive Survey&Command Center for Natural Resources(No.KC20240003)Yanzhao Shanshui Science and Innovation Fund of Langfang Integrated Natural Resources Survey Center,China Geological Survey(No.YZSSJJ202401-001)Open Foundation of the Key Laboratory of Coupling Process and Effect of Natural Resources Elements(No.2022KFKTC009).
文摘Water scarcity and environment deterioration have become main constraints to sustainable economic and social development.Scientifically assessing Water Resources Carrying Capacity(WRCC)is essential for the optimal allocation of regional water resources.The hilly area at the northern foot of Yanshan Mountains is a key water conservation zone and an important water source for Beijing,Tianjin and Hebei.Grasping the current status and temporal trends of water quality and WRCC in representative small watersheds within this region is crucial for supporting rational water resources allocation and environment protection efforts.This study focuses on Pingquan City,a typical watershed in northern Hebei Province.Firstly,evaluation index systems for surface water quality,groundwater quality and WRCC were estab-lished based on the Pressure-State-Response(PSR)framework.Then,comprehensive evaluations of water quality and WRCC at the sub-watershed scale were conducted using the Varying Fuzzy Pattern Recogni-tion(VFPR)model.Finally,the rationality of the evaluation results was verified,and future scenarios were projected.Results showed that:(1)The average comprehensive evaluation scores for surface water and groundwater quality in the sub-watersheds were 1.44 and 1.46,respectively,indicating that both met the national Class II water quality standard and reflected a high-quality water environment.(2)From 2010 to 2020,the region's WRCC steadily improved,with scores rising from 2.99 to 2.83 and an average of 2.90,suggesting effective water resources management in Pingquan City.(3)According to scenario-based predic-tion,WRCC may slightly decline between 2025 and 2030,reaching 2.92 and 2.94,respectively,relative to 2020 levels.Therefore,future efforts should focus on strengthening scientific management and promoting the efficient use of water resources.Proactive measures are necessary to mitigate emerging contradiction and ensure the long-term stability and sustainability of the water resources system in the region.The evalua-tion system and spatiotemporal evolution patterns proposed in this study can provide a scientific basis for refined water resource management and ecological conservation in similar hilly areas.
基金The National Key Research and Development Program of China under contract No.2023YFB3905305。
文摘Water clarity(Secchi disk depth, Z_(SD)) and Forel-Ule Index(FUI) are critical ecological indicators for assessing water quality. Although satellite remote sensing serves as a vital tool for large-scale and long-term water quality monitoring,low accuracy, coarse resolution, and incomplete spatial coverage of existing satellite Z_(SD) and FUI products hindered the reliable ecological assessment of water quality. Here, a long-term(2003-2023) satellite dataset of monthly Z_(SD) and FUI was developed by applying the advanced high-accuracy retrieval algorithms and reconstruction method to 35 546Moderate-resolution Imaging Spectroradiometer(MODIS) images over China coastal waters. The new dataset exhibited superior performance compared to the existing one, in terms of higher accuracy(Mean Absolute Percentage Error,MAPE = 28.89% for Z_(SD) and MAPE = 34.46% for FUI), spatio-temporal resolution(monthly, 1 km), and spatial coverage(99.53%), with the most significant improvement found in the nearshore turbid waters. By leveraging this dataset, the ecological impact of human activities on water quality was accurately revealed, as indicated by the significant Z_(SD) improvements during terrestrial pollution control, which was misinterpreted by previous satellite products.Besides, natural factor-induced water quality variability was also successfully captured, particularly the seasonal dynamics of suspended sediment plumes in the East China Sea. The new dataset and adopted methods may provide essential support for the accurate monitoring, ecological assessment, and sustainable management of marine ecosystems.
基金The National Key Research and Development Program of China under contract No.2021YFB3901304the National Natural Science Foundation of China under contract No.42842176181,42476173,and 42176179the Natural Science Foundation of Jiangsu Province under contract No.BK20211289.
文摘Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chinese Ocean Color and Temperature Scanner(COCTS)aboard the HY-1D satellite in 2020,yet its Chl a products require further validation in complex coastal waters.This study assesses HY-1D Chl a products in the Bohai and Yellow Seas,two optically complex coastal regions,using in situ data collected during multiple cruises.Additionally,we compare HY-1D Chl a products with those from the Moderate Resolution Imaging Spectroradiometer(MODIS)and the Visible Infrared Imaging Radiometer Suite(VIIRS).We observed that although Chl a products from HY-1D are generally consistent with those from the MODIS and VIIRS in spatial distribution,there are still significant errors when compared with in situ data.Therefore,we developed a new blended algorithm to improve the accuracy of HY-1D Chl a products.The algorithm distinguishes between turbid and relatively clean waters using a classification index based on the ratio of remote sensing reflectance(R_(rs)(λ)).After the initial classification,we developed targeted algorithms based on the optical properties of different water bodies.The new model shows a significant improvement,reducing the mean absolute percentage error(MAPE)from 43.1%to 24.3%.Additionally,merging Chl a data from HY-1D,MODIS,and VIIRS maintains good accuracy,with HY-1D Chl a products significantly enhancing data coverage and robustness.This research provides important support for producing high-quality HY-1D Chl a products for coastal waters.
基金Supported by the National Key Research and Development Program of China(Nos.2018YFC1004300,2018YFC1004302)the Science&Technology Program of Guizhou Province(Nos.QKHHBZ[2020]3002,QKHPTRC-GCC[2022]039-1,QKH-J[2022]YB614)+1 种基金the Science&Technology Program of Zunyi City(No.ZHZ[2021]294)the National Innovation Program for College Students in China(No.201910661012)。
文摘Microplastics(MPs)have been widely detected in marine environments,yet the pollution in terrestrial fresh waters in economically underdeveloped and remote areas is poorly understood.We investigated the abundance and distribution of MPs in inland waters(including open waters in river,lake,reservoir,stream,and tap water and bottled water)in Guizhou,SW China,detected by Nile Red staining.Results show that MPs were detected in all samples,with the mean abundance of 3.5±1.9 items/mL in 34river water samples,3.9±1.9 items/mL in 14 lake and reservoir water samples,3.4±2.4 items/mL in 87 stream water samples,3.8±3.8 items/mL in 164 tap water samples,and 1.3±3.2 items/mL in 12 bottled water samples from 4 different brands.The MP abundance in open field waters(3.6±3.0 items/mL)was significantly higher than that in bottled water(1.3±3.2 items/mL)(P<0.05).The microplastics with particle sizes of 10-20μm accounted for more than 50%of all samples.The composition ratio of smalland medium-sized microplastics in open waters was higher than in tap and bottled water(P<0.05).The MPs abundance tended to increase with the decrease in particle size.Therefore,microplastic pollution varied in different degrees in open waters in economically underdeveloped and remote areas of the southwestern China,which is consistent with microplastic pollution in other similar water environments.This study provided a reference for understanding the microplastic content and pollution control in the inland waters in western and remote areas of China.
基金Supported by the National Key Research and Development Program(No.2016YFC1402201)the China Ocean Mineral Resources R&D Association Project(No.DY135-E2-2-04)。
文摘Microplastic contamination is considered a major threat to the marine environment.Although microplastic pollution in the Pacific Ocean has been studied,its abundance,distribution,composition,and origin in the western Pacific Ocean remain unclear.Here,we investigated the abundance and distribution characteristics of microplastics in surface waters of the western Pacific Ocean and analyzed their potential sources.Results show that microplastics were widespread in the western Pacific Ocean,with abundance ranging from 0.03 to 2.36 particles/m^(3)(average 0.37±0.47 particles/m^(3)).Fibers/filaments and fragments were the main shapes of microplastics(71.6%)and the most abundant microplastic size class was<1.0 mm(42.4%).Significant differences in microplastic abundance were observed in different regions,with the lowest abundance in the South China Sea(0.03 particles/m^(3))and highest abundance in the seamount area in the western Pacific Ocean(0.58 particles/m^(3)).This study provides baseline data and insights into the fate and transportation of microplastics in the western Pacific region.
基金supported by the project of China Geological Survey(No.DD20220954)Open Funding Project of the Key Laboratory of Groundwater Sciences and Engineering,Ministry of Natural Resources(No.SK202301-4)+1 种基金Open Foundation of the Key Laboratory of Coupling Process and Effect of Natural Resources Elements(No.2022KFKTC009)Yanzhao Shanshui Science and Innovation Fund of Langfang Integrated Natural Resources Survey Center,China Geological Survey(No.YZSSJJ202401-001).
文摘Pingquan City,the origin of five rivers,serves as the core water conservation zone for the Beijing-Tianjin-Hebei region and exemplifies the characteristics of small watersheds in hilly areas.In recent years,excessive mining and intensified human activities have severely disrupted the local ecosystem,creating an urgent need for ecological vulnerability assessment to enhance water conservation functions.This study employed the sensitivity-resilience-pressure model,integrating various data sources,including regional background,hydro-meteorological data,field investigations,remote sensing analysis,and socio-economic data.The weights of the model indices were determined using an entropy weighting model that combines principal component analysis and the analytic hierarchy process.Using the ArcGIS platform,the spatial distribution and driving forces of ecological vulnerability in 2020 were analyzed,providing valuable insights for regional ecological restoration.The results indicated that the overall Ecological Vulnerability Index(EVI)was 0.389,signifying moderate ecological vulnerability,with significant variation between watersheds.The Daling River Basin had a high EVI,with ecological vulnerability primarily in levels IV and V,indicating high ecological pressure,whereas the Laoniu River Basin had a low EVI,reflecting minimal ecological pressure.Soil type was identified as the primary driving factor,followed by elevation,temperature,and soil erosion as secondary factors.It is recommended to focus on key regions and critical factors while conducting comprehensive monitoring and assessment to ensure the long-term success of ecological management efforts.
基金The authors would like to thank the Vice-chancellor of Research at the Universidad Militar Nueva Granada for the opportunity to develop project INV-ING-3966.
文摘Watersheds play a fundamental role in the hydrological cycle because of their contributions to the water regulation of essential tributaries for ecosystems.However,the balance between soil and climatological components of these watersheds has been altered by human activities,which directly impacts them through changes in land use.In Colombia,the lack of control over land-use in watersheds has affected the water regulation services of important tributaries,such as the Onzaga River,whose waters are mainly used for agricultural activities.For this reason,this study aims to evaluate how changes in land use in the basin affected the capacity of water regulation.For this,a statistical correlation analysis was conducted between the Water Regulation Index(WRI)and vegetation cover areas from 1985 to 2023.The study results indicate that the expansion of the anthropogenic vegetation covers,such as agriculture parches and grasslands,replacing different types of forests,and producing an adverse effect on the water regulation capacity for the basin.This demonstrated its decrease along with an increase in its variability,indicating that,in addition to its degradation,there is a greater irregularity in this ecosystem service.In conclusion,correlation analysis indicates that 93%of the change in water regulation regime is explained by the contraction of forest cover and the expansion of agricultural areas,degraded lands,and urban development.This study confirms the importance of preserving native vegetation cover in the watershed,especially in areas adjacent to watercourses with riparian forests.
基金supported by the open funding of the Technology Innovation Center for South China Sea Re-mote Sensing,Surveying and Mapping Collaborative Ap-plication,Ministry of Natural Resources,P.R.China(No.RSSMCA-2024-B001)the National Natural Science Foundation of China(Nos.T2261149752 and 42476172).
文摘Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurnal and semidiurnal tidal constituents.We integrated the development technique of the Technical University of Denmark(DTU10)model and calculated the residual tides using the intermediary FES2012 model.We utilized all available Topex/Poseidon,Jason-1,Ocean Surface Topography Mission(OSTM)/Jason-2 primary and tandem missions to develop the new model.To reduce the discrepancies between the model and in situ measurements estimated S2 tide constituent,the ERA-Interim model was selected for dry tropospheric correction of altimetry data.The newly developed model with an improved spatial resolution from 1/8°×1/8°to 1/16°×1/16°was assessed and compared against contemporary global ocean tide models using in situ measurements in coastal regions,continental shelf waters,marginal seas,and deep waters.The results demonstrate improvements in shallow waters and coastal regions,particularly in representative coastal re-gions such as the Northwest European Shelf and East Asian Marginal Seas.Moreover,the model performs well in simulating S_(2) and K_(2) tides with root mean square differences of 0.355 and 0.234 cm,respectively,against in situ measurements in deep waters world-wide.Compared with that of DTU10,the root sum square of the new model for the eight main tidal constituents decrease by 8.4%to 0.997 cm.
基金The fund from Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2024SP029the National Natural Science Foundation of China under contract Nos 42176173,42476268,and 42106173the fund from Beijing Engineering Research Center of Aerial Intelligent Remote Sensing Equipments under contract No.AIRSE20234.
文摘Over recent decades,the increasing frequency and intensity of Harmful Algal Blooms(HABs)have resulted in severe environmental impacts worldwide.Understanding the physical drivers of HABs is crucial for understanding their dynamics and mitigating their environmental consequences.This study integrates satellite remote sensing and hydrodynamic modeling to investigate two HAB events and their driving mechanisms in Guangdong coastal waters during February and August 2021.An HAB detection method using Sentinel-3 ocean and land color instrument data based on an improved floating algae index algorithm was developed.The spatiotemporal dynamics of physical drivers were analyzed using a submesoscale permitting regional ocean modeling system hydrodynamic simulation.Both HAB detection results and hydrodynamic simulations were validated against in situ buoy measurements.In coastal area of Jiangmen City,local changes of divergence,impacts from the Zhujiang River(Pearl River)fresh water plume were found to be drivers accounted for long-termed variations of chlorophyll and triggers for HABs,while changes in vertical mixing associated with wind speed regulate the short-termed changes.In coastal area of Shantou City,initiations of HABs were mainly driven by wind-induced coastal upwelling.Distribution,aggregation and elongation of HAB patches were modulated by surface fronts and vortices induced by fresh water plume and complex coastlines.These findings underscore the advantages of integrating satellite remote sensing,3D hydrodynamic modeling,and in situ observations for elucidating the complex physical mechanisms governing HAB dynamics in coastal waters.
文摘Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characteristics of surface water in the North of Tehran Rivers(NTRs),an essential water resource in a rapidly urbanizing region,using advanced clustering techniques,including Hierarchical Clustering Analysis(HCA),Fuzzy CMeans(FCM),Genetic Algorithm Fuzzy C-Means(GAFCM),and Self-Organizing Map(SOM).The research aims to address the scientific challenge of understanding spatial and temporal variability in water quality,focusing on physicochemical parameters,hydrochemical facies,and contamination sources.Water samples from six rivers collected over four seasons in 2020 were analyzed and classified into distinct clusters based on their chemical composition,revealing significant seasonal and spatial differences.Results showed that FCM and GAFCM consistently categorized the NTRs into two clusters during winter and spring and three in summer and autumn.These findings were supported by HCA and SOM,which identified clusters corresponding to specific river segments and contamination levels.The primary hydrochemical processes identified were mineral dissolution and weathering,with calcite,dolomite,and aragonite significantly influencing water chemistry.Additionally,human activities,such as wastewater discharge,were shown to contribute to elevated sulfate,nitrate,and phosphate concentrations,further corroborated by microbial analyses.By integrating HCA,FCM,and GAFCM with an artificial neural network(ANN)-based clustering method(SOM),this study provides a robust framework for evaluating surface water quality.The findings,supported by Gibbs diagrams,Hounslow ion ratio,and saturation indices,highlight the dominance of rock weathering and human impacts in shaping the hydrochemical dynamics of the NTRs.These insights contribute to the scientific understanding of water quality dynamics and offer practical guidance for sustainable water resource management and environmental protection in developing urban areas.
基金Supported by the National Natural Science Foundation of China(No.52273056)the Science and Technology Development Program of Jilin Province,China(No.YDZJ202501ZYTS305)。
文摘Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.
基金supported by the National Key Research and Development Program of China (2022YFE0138900)the “Scientific and Technical Innovation Action Plan” Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)。
文摘Ion-solvaing membranes(ISMs)have received extensive attention in recent years as a key component in electrochemical energy conversion and storage devices.This article provides an overview of structural composition,performance advan-tages,research progress,ion conduction mechanism and existing issues of ISMs,primarily classifying them according to the matrix structure.A detailed analysis of performance enhancement methods,key performance indicators of ISMs and performance influencing factors is also presented.The article contributes to further optimizing the design and application of ion-solvation membranes,providing theoretical support for the development of fields such as hydrogen production through electrolysis of water and electrochemical energy in the future.
基金supported by National Natural Science Foundation of China(Grant No.52279027)National Key R&D Program of China(Grant No.2021YFC3200201)+1 种基金Key Research Project on Decision Consultation of the Strategic Development Department of China Association for Science and Technology(Grant No.2023070615CG111504)China Engineering Science and Technology Development Strategy Henan Research Institute Strategic Consulting Research Project(Grant No.2024HENYB01).
文摘Unequal virtual water transfer may aggravate local water scarcity risk.However,the quantitative confirmation of a clear geographic convergence between virtual water transfer and water scarcity risk remains undetermined.We present an analytical framework that reveals the spatial matching between global water scarcity risk and virtual water trade inequality.This framework integrates a three-dimensional water scarcity risk assessment,hybrid input-output analysis,pollution trade term construction,and geographic convergence identification.The framework is applied to 123 countries for long-term validation from 1991 to 2021.We show that despite global improvements in water efficiency and security,countries exceeding the maximum water vulnerability threshold have increased by 50%.South Asia is the largest net exporter of virtual water.Central Asia exhibits the most pronounced virtual water trade inequality.To achieve the same economic growth,Central Asia needs to pay several times the local water consumption costs of developed regions(15.9−83.6 times,2021).In the past 30 years,the average geographic convergence index exceeded 0.8.Countries facing severe water scarcity also exhibit pronounced inequalities in virtual water trade,indicating that a significant geographic convergence relationship exists.Effectively responding to this unsustainable relationship necessitates balancing both domestic resource risk management and global virtual water trade regulation.
