High-altitude glacier-lake systems in the eastern Pamir Plateau,Tajikistan,are highly sensitive elements of Central Asia’s cryosphere and are vital for sustaining regional water resources.The Yashilkul Lake is locate...High-altitude glacier-lake systems in the eastern Pamir Plateau,Tajikistan,are highly sensitive elements of Central Asia’s cryosphere and are vital for sustaining regional water resources.The Yashilkul Lake is located within a tectonic depression dammed by an ancient rockslide,forming a large alpine lake.This lake is currently impacted by intensified warming,glacier retreat,and poorly quantified hydrological shift.The primary objective of this study is to assess multi-decadal changes in the Yashilkul and Bulunkul lakes and their surrounding cryosphere between 1994 and 2024.The changes were analyzed using multitemporal Landsat imagery and unmanned aerial vehicle (UAV) surveys,complemented by in situ meteorological observations from the Bulunkul meteorological station spanning the period from 1990 to 2024.Glacier and lake boundaries were extracted from Landsat data,primarily by applying the normalized difference water index,supplemented by manual delineation.UAV photogrammetry characterized dam morphology and adjacent ponds,and climate trends were evaluated with the modified Mann-Kendall test.A significant warming trend of 0.096℃/a and pronounced interannual precipitation variability have driven persistent glacier retreat and lake surface area fluctuations.The Yashilkul Lake’s surface area decreased from 36.40 (±1.15) km^(2) in 2010 to 31.94 (±0.54) km^(2) in 2020 and partially rebounded to 33.99 (±0.60) km^(2) in 2024,while the Bulunkul Lake’s surface area remained nearly stable owing to limited glacial influence.Additionally,UAV surveys conducted in 2022 and 2024 revealed main features of the Yashilkul Lake:rockslidedammed origin,perched ponds along the dam body,and an artificial canal regulating its outflow.Nearby glaciers,particularly Glacier No.369,exhibited strong frontal retreat and proglacial lake expansion.The proglacial lake expanded nearly fourfold from 0.08 (±0.01)km^(2) in 2000 to 0.33 (±0.02) km^(2) in 2024,raising concerns about potential glacial lake outburst floods that could impact the Yashilkul Lake and compromise the integrity of its natural dam.The findings highlight accelerating hydrological and cryospheric transformations in the Pamir Plateau,emphasizing the need for sustained monitoring of glacier-lake systems owing to their critical implications for water security,ecological stability,and downstream hazard management.展开更多
Antibiotics are widespread in aquatic environments due to their extensive use in human healthcare and ani-mal husbandry.However,research on the occurrence and bioaccumulation of antibiotics in aquatic organisms within...Antibiotics are widespread in aquatic environments due to their extensive use in human healthcare and ani-mal husbandry.However,research on the occurrence and bioaccumulation of antibiotics in aquatic organisms within shallow wetland lakes remains limited.This study investigated the occurrence and bioaccumulation of ten commonly used antibiotics in the Baiyang Lake,northern China’s largest shallow wetland lake.The results indicated that sulfonamides and fluoroquinolones were the predominant antibiotics in surface water,whereas fluoroquinolones and macrolides were more prevalent in sediment.Fluoroquinolones demonstrated significant potential for bioaccumulation in targeted aquatic organisms,including both animals and plants(Carassius au-ratus and Phragmites australis).The bioaccumulation of antibiotics in Carassius auratus was correlated with their solubility,whereas in Phragmites australis,this was associated with their octanol-water partition coefficients and molecular weights.Ecological risk assessment indicated that most antibiotics posed minimal to low risk levels.However,four antibiotics were exceptions:clarithromycin(12.5%)and sulfamethoxazole(6.25%)presented a high risk in surface water samples,while norfloxacin(25.0%)and ciprofloxacin(25.0%)posed a high risk in sediment samples.Norfloxacin,ciprofloxacin,and roxithromycin were identified as key indicator antibiotics for enhancing the local monitoring and control of antibiotic contamination based on four criteria:(1)high con-centrations,(2)frequent detection,(3)capacity for bioaccumulation,and(4)ecological risk levels.This study contributes to a deeper understanding of the status of antibiotic contamination,bioaccumulation characteristics,and ecological risk in Baiyang Lake,thereby supporting efforts to monitor and regulate antibiotic pollution.展开更多
Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_...Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_(4) emissions between different lakes.However,the carbon emissions and their influencing factors of different areas within a single lake remain poorly understood.Accordingly,this study investigates CO_(2) and CH_(4) emission hetero-geneity in a large floodplain lake system and distribution characteristics of associated functional microorganisms.Findings show that mean CO_(2) and CH_(4) flux values in the sub lake area were 62.03±24.21 mg/(m2·day)and 5.97±3.2μg/(m2·day),which were greater by factors of 1.78 and 2.96 compared to the water channel and the main lake area,respectively.The alpha diversity of methanogens in the sub lake area was lower than that in the main lake and water channel areas.The abundance of methanogens in bottom water layer was higher compared with the middle and surface layers.Conversely,the abundance of methane(CH_(4))-oxidizing bacteria in the surface layer was higher than that in the bottom layer.Additionally,the composition of methanogen and CH_(4)-oxidizing bacterial community,chlorophyll a(Chl-a),pH,total phosphorus(TP)and dissolved organic carbon(DOC)con-tent constituted the dominate driving factors affecting lake C emissions.Results from this study can be used to improve our understanding of lake spatial heterogeneous of CO_(2) and CH_(4) emission and the driving mechanisms within floodplain lakes under the coupling effects of functional C microorganisms and environmental factors.展开更多
Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(AC...Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(ACA)region.However,debate persists regarding whether dryland lakes in this region exhibited aridification or humidification during the Holocene.Lopnur serves as the terminal lake of Tarim rivers during the Holocene,which offers an ideal natural laboratory to address the questions.In this study,a high-resolution chronological framework was established through precise radiocarbon dating.Multi-proxy analyses,including geochemical composition,grain size distributions,MS,LOI,and C/N ratios were conducted from a lacustrine profile in the core area of“Great ear”in the southern part of Lopnur catchment.These analyses enabled the reconstruction of hydrological dynamics and facilitated the disentanglement of independent signals linked to climate variability,runoff fluctuations,and lake-level changes.The results demonstrate that the MidHolocene(7800–4000 cal yr B.P.)was characterized by cold and humid conditions,resulting in elevated surface runoff and lake level.The Late Holocene(4000–1300 cal yr B.P.)experienced intensified aridification,characterized by reduced runoff and declining lake level.These evidences suggested a climatic regime of a distinctive alternation between“cold-wet”and“warm-dry”climatic regimes during the Mid-to-Late Holocene.Compared with the previous studies from adjacent regions,we speculate that the hydroclimatic evolution of Lopnur catchment possibly influenced by a complex interplay of large spatial scale forcings,including variations in annual insolation,greenhouse gas concentrations,and ice sheets,as well as the localized controls such as topographic features,vegetation cover,and cloud-radiative feedbacks.Our findings enhance the understanding of past climatic complexity and provide valuable insights for future water resource management strategies in drylands.展开更多
This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and...This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and mass transfer model,the research evaluates the influence of geothermal heat flow,ice thickness,and surface temperature on basal melting.The model incorporates enthalpy formulation and boundary conditions derived from field data,including temperature profiles and geothermal measurements.Results indicate that subglacial lakes could form under ice masses exceeding 300 m thickness,driven by geothermal heating,though current basal temperatures remain below the melting point.Simulations under the IPCC SSP1-2.6 scenario suggest a gradual warming trend,highlighting the long-term thermal inertia of Arctic glaciers.The study underscores the need for enhanced observational data to validate models and improve predictions of glacial dynamics in response to climate change.展开更多
While oceanic and coastal acidification has gained increased attention,long-term pH trends and their drivers in large freshwater systems remain poorly understood.The Laurentian Great Lakes are the world’s largest fre...While oceanic and coastal acidification has gained increased attention,long-term pH trends and their drivers in large freshwater systems remain poorly understood.The Laurentian Great Lakes are the world’s largest freshwater system,and in many ways resemble marine ecosystems.However,unlike the open ocean and coastal waters where pH has declined due to rising atmospheric CO_(2),no significant pH trends have been observed in the Laurentian Great Lakes,despite significant ecosystem changes driven partly by the invasion of dreissenid mussels.This study examined 41 years of field observations from Lake Michigan to investigate the long-term carbonate chemistry dynamics.Observational results revealed substantial declines in both total alkalinity(TA)and dissolved inorganic carbon(DIC)over the four decades.Mussel shell calcification emerged as the primary mechanism behind these declines,accounting for 97%and 47%of the observed changes in TA and DIC,respectively,lowering water column pH by 0.24 units.Elevated carbon accumulation in soft mussel tissues,coupled with long-term changes in the air-water pCO_(2)gradient during summer,significantly contributed to long-term DIC variations,explaining 18%and 28%of the lake-wide DIC loss.These two mechanisms also resulted in an overall pH increase of 0.09 and 0.12 units,largely offsetting the calcification-driven pH decrease.These findings bridge a gap in acidification research for large freshwater systems and provide valuable insights for comprehensive lake-wide management strategies.展开更多
Research into the location and development of rice paddies after the collapse of Neolithic cultures is of crucial importance.This study explores the phytolith assemblages and soil micromorphologies of potential rice p...Research into the location and development of rice paddies after the collapse of Neolithic cultures is of crucial importance.This study explores the phytolith assemblages and soil micromorphologies of potential rice paddy relics found at the Xingang Site(3556–3360 cal.a BP)in the Taihu Lake Plain,Lower Yangtze River,offering insights into these issues.The discriminant function of the phytolith assemblage distinguished six out of 19 samples in the suspected paddy field area as wild rice fields,while the rest were non-rice fields.Soil micromorphology indicated that the alleged paddy field area experienced repeated dry and wet conditions,with signs of plant growth but no evidence of human activity,suggesting it was not an artificially managed paddy field.These findings suggest the area during the Shang Dynasty consisted of abandoned paddies from the post-Neolithic era.The proportion of rice bulliform phytoliths with≥9 fish-scale decorations(35%–47%)was significantly lower at the Xingang Site(marginal area)during the Shang Dynasty compared to periods like Qianshanyang-Guangfulin(4300–3900 a BP)(central area),suggesting that diminished population density in marginal areas after the Neolithic collapse likely led to paddy field abandonment.Additionally,the collapse of the Liangzhu social structure,along with a rice-farming economy that lacked strong resource competitiveness,may have also contributed to this phenomenon.This study provides an empirical example of rice paddy locations following the Neolithic collapse in the Lower Yangtze River,enhancing our understanding of the decline of the Liangzhu civilization.展开更多
The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Inte...The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Integrated field mapping,fault-slip analysis,and focal mechanism inversion reveal a polyphase tectonic history involving sequential compressional,strike-slip,and extensional regimes.Rigorous discrimination of heterogeneous fault-slip datasets into homogeneous subsets enabled reconstruction of geologically consistent stress tensors and clarified the temporal transition from strike-slip to transtensional deformation.Paleostress results indicate NNE–SSW compression and NW–SE extension,consistent with present-day seismotectonic and geomorphic patterns.Variations in stress ratio Rvalues(0.26–0.57 for strike-slip;0.28–0.33 for extensional domains)and low misfit angles(<15°)reflect localized strain partitioning and reactivation of inherited faults.The Lake Hazar basin thus evolved from a pull-apart structure into a negative flower geometry through successive deformation and fault linkage.These findings highlight that discriminating polyphase fault-slip data is essential for resolving deformation dynamics in complex fault systems.The integrated structural,paleostress,and seismotectonic framework presented here refines understanding of strain localization,fault reactivation,and stress transfer along the East Anatolian Fault System.展开更多
Aquatic plants have been widely used for lake ecological restoration.The effect of aquatic plants on lake biogeochemical cycling has been investigated intensively,however,plants’effect on biodegradation of dissolved ...Aquatic plants have been widely used for lake ecological restoration.The effect of aquatic plants on lake biogeochemical cycling has been investigated intensively,however,plants’effect on biodegradation of dissolved organic carbon(DOC)is rarely studied.Here we designed an indoor incubation experiment to explore the priming effect(PE)of aquatic plant leaching solution on DOC in shallow lakes,referring to as the input of active dissolved organic matter(DOM)that would arouse changes in the degradation rate of original refractory DOM.Waters from 20 urban lakes of different tropic states were incubated to study their PE on DOC by adding leaching solutions from two submerged freshwater plants,Hydrilla(H)and Vallisneria(V).The study showed a clear influence of aquatic plants on PE with varying directions and intensities.The H incubation group showed a PE range of-6.19%–9.79%,with an average of 2.15%±2.70%,whereas the V incubation group exhibited a PE range of-10.03%to 3.60%,with an average of-0.65%±3.11%.The positive and negative PEs by the two plant species indicate a key role of plants over trophic states on organic carbon dynamics in freshwater lakes.From the perspective of plant leaching input,our results reveal that planting aquatic plants whose leaching solution can reduce PE like V could be used to enhance carbon storage and constrain carbon emission.展开更多
This study presents an integrated assessment of sedimentological,granulometric,physico-chemical,and biological characteristics in three Romanian coastal lakes,based on 2022 field surveys.A total of 59 sediment samples...This study presents an integrated assessment of sedimentological,granulometric,physico-chemical,and biological characteristics in three Romanian coastal lakes,based on 2022 field surveys.A total of 59 sediment samples were analyzed lithologically and granulometrically,and 12 were examined for macrozoobenthic community composition.Water samples were assessed for nutrient and pigment concentrations to evaluate trophic status and ecological condition.Sediments were predominantly silty-clayey,indicating low-energy depositional environments.Organic matter content was highest in Lakes Agigea and Tuzla,suggesting enhanced primary productivity and organic detritus accumulation,while Lake Costinești showed higher biogenic carbonate content from mollusc shells.Macrozoobenthic assemblages were dominated by taxa tolerant to organic enrichment and hypoxia,including Chironomidae larvae,Oligochaeta,and Cyprideis torosa.Water quality analysis indicated good ecological status in Agigea Lake,whereas Tuzla Lake was severely eutrophic,with phosphate and nitrite in Class Ⅳ and chlorophyll-a exceeding Class Ⅴ thresholds(>250μg/L),consistent with cyanobacterial blooms.Elevated sulfate(Class Ⅲ)and suspended solids further impaired Tuzla’s transparency.In Costinești,marine taxa presence and variable salinity reflected periodic seawater exchange.Anthropogenic influences were evident-nutrient enrichment from fisheries in Tuzla and marine species introduction in Costinești-highlighting system vulnerability to human pressure.The integration of sediment,water quality,and biological indicators emphasizes the need for continuous,interdisciplinary monitoring to track ecological shifts,support adaptive management,and conserve biodiversity and ecosystem integrity in Romanian coastal lakes.展开更多
To address soil salinization’s significant impact on human production and livelihood in arid regions,especially in high-salinity areas like salt lake regions,this study used multi-source remote sensing data to extrac...To address soil salinization’s significant impact on human production and livelihood in arid regions,especially in high-salinity areas like salt lake regions,this study used multi-source remote sensing data to extract 52 surface factors.Combined with measured soil salinity data,correlation analysis,multicollinearity testing,and projection importance analysis identified eight dominant factors.Subsequently,four machine learning algorithms were applied for modeling,and the optimal models were selected to study the spatiotemporal variation of soil salinization.The results indicate that the average soil salt content in the study area was 20.74%in 2020.LST(land surface temperature)can effectively identify areas with high salinity,such as saline-alkali land and salt flats.Among inversion models,the GBDT(gradient boosting decision trees)model demonstrated the highest predictive ability and minimal errors.The optimal inversion results revealed that soil salinization distribution was influenced by topographic elevation,distance from Qarhan Salt Lake,and river network density.Over the past 21 years,there was significant fluctuation in soil salinity observed in the concentrated area of grassland within the groundwater overflow zone,indicating strong variation in salinization.This fluctuation correlates with changes in groundwater levels in the groundwater overflow zone,which are influenced by temperature variations that determine the amount of snow and ice meltwater,and the precipitation in the upstream area.This study enhances understanding of soil salinization and its drivers in extremely arid salt lake regions.展开更多
Aeolian sediments in the eastern Qinghai Lake region,China serve as sensitive paleoclimate archives,offering an ideal window into past environmental conditions.This study investigated the Dashuitang(QDST)profile in th...Aeolian sediments in the eastern Qinghai Lake region,China serve as sensitive paleoclimate archives,offering an ideal window into past environmental conditions.This study investigated the Dashuitang(QDST)profile in the eastern Qinghai Lake region by integrating sediment grain size,chroma,and magnetic susceptibility(MS)proxies to reconstruct the regional environmental evolution since the Last Glacial Interstadial and to investigate its relationship with the water level fluctuations of Qinghai Lake.Grain size end-member modeling analysis(EMMA)identified three end-members:end-member 1(EM1)represented fine-grained material transported over longer distances through mixing processes,which could reveal the regional moisture conditions;end-member 2(EM2)primarily consisted of coarse-grained material from nearby sources transported via saltation or creep,indicating the intensity of the winter monsoon;and end-member 3(EM3)mainly reflected deposition from dust storm events controlled by regional low-altitude wind systems.In addition,the regional environmental sequence demonstrated coherence with other records,collectively elucidating the sub-orbital-scale dynamics of the Asian monsoon.The environmental sequence was divided into four principal phases on the basis of sedimentary characteristics and climatic responses:the late Last Glacial Interstadial,Last Glacial Maximum,Last Deglaciation,and Holocene phases.Additionally,the results of this study revealed that there is a close linkage between desertification and lake evolution in the eastern Qinghai Lake region.Since the Last Glacial Interstadial,desertification and lake evolution processes have generally exhibited a trade-off relationship,wherein lake level decline and desert expansion exhibited a direct positive feedback.However,during the early period of the Late Holocene(approximately 2.80–1.50 ka BP),a synergistic response pattern emerged,characterized by relatively high lake levels alongside moderate desert expansion,reflecting an asymmetric decoupling mechanism between the hydrological processes and aeolian dynamics during climatic transition periods.This study provides important insights for predicting the future evolution trends of lake-desert systems under climate change.展开更多
Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbani...Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbanization remain unclear.This study explored the spatiotemporal evolution of ER and urbanization in five GLRs in China to analyze the ER dynamic patterns along center−lakeside−periphery gradient.The Spatial Durbin Model(SDM)and Panel Threshold Model(PTM)were combined to reveal the spillover and threshold effects of urbanization in five GLRs.The results indicate that the ER in five GLRs declined with a rate of 21%from 2000 to 2020.There was a clear“center-periphery”contraction trend with low ER areas primarily spreading to human activity-concentrated regions such as lakesides,riversides,and road networks.Driven by economic and land urbanization,the average urbanization level increased from 0.06 to 0.13,where lakesides,riversides,and road networks were key areas undergoing expansion.The urbanization showed a noticeable negative spatial spillover effect on ER.Away from central lakes,the negative impacts on ER exhibited a two-phase decrease with the threshold of 81 km.This study contributes to the understanding of human-environment interactions by examining the ecological resilience response process of GLRs under the impact of urbanization.Based on a multidimensional“center−lakeside−periphery”analytical model,this study provides a strategic framework for ecological construction in GLRs in China,promoting sustainable development and adaptive capacity in vulnerable areas.展开更多
As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments ...As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments and their responses to climate change remains unclear,which hinders the comprehensive understanding of carbon dynamics in lake ecosystems.This study systematically analyzes the spatiotemporal dynamics of carbon burial across the Tibetan Plateau using surface sediments from 119 lakes and sediment cores from four representative lakes.Results show that OC burial dominates in humid and dry sub-humid zones,whereas IC burial prevails in arid and semi-arid regions.This distribution reflects the influences of lake and catchment productivity and water chemistry on OC and IC patterns.Sediment cores confirm that these factors have consistently affected lake carbon burial over the past century.Specifically,in humid and dry sub-humid zones,increased precipitation enhances watershed productivity and sedimentation,promoting coupled OC and IC burial.In arid and semi-arid regions,wind-driven dust supplies nutrients and alters water chemistry,also driving coupled OC and IC burial.Based on these findings,the carbon sink capacity of lake sediments on the Tibetan Plateau is projected to increase under the“warming and wetting”trend.展开更多
The Balkhash Lake Basin(BLB),a vital Central Asian watershed,faces hydrological uncertainty under climate warming.This study integrated multi-source remote sensing data(Sentinel-1 snow depth,Randolph Glacier Inventory...The Balkhash Lake Basin(BLB),a vital Central Asian watershed,faces hydrological uncertainty under climate warming.This study integrated multi-source remote sensing data(Sentinel-1 snow depth,Randolph Glacier Inventory(RGI)v.7.0 glacier inventory,and Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)mass balance)with a degree-day model to reconstruct decadal snow and ice dynamics across 13 sub-basins and analyzed their hydrological impacts from 1950 to 2014.The results showed that:(1)while flows from the downstream river of the BLB decreased from 1950 to 1982 due to land surface changes,runoff increased significantly after 1982 in the Ili River(18.0%)and moderately increased in most rivers in the east(1.3%–8.3%),driven by increased precipitation and glacier melt.Runoff in the Ayaguz catchment(no glaciers with the highest climate warming)declined(10.5%);(2)climate warming reduced precipitation falling as snow caused snow melt water to decline(0.03–0.22 mm/a)across the BLB,leading to downward shifts in runoff and runoff coefficient,especially in the rivers in the east.However,snow melt during April–June positively correlated with runoff coefficient,contributing to an upward shift in the Ili River Basin;and(3)meltwater from glacierized areas(<5.0%of basin area)contributed to 14.3%of total ablation water.Net glacier melt provided substantial excess flows(11.6 m3/s in the Ili River and<1.0 m3/s in the rivers in the east),generally counterbalancing the negative effect of rising potential evaporation at decadal scales and positively correlating with the runoff coefficient.Therefore,water stress in the BLB may be more severe in the future due to the accelerating glacier melt after the abrupt increase in air temperature in 2000,the continuing decline in snow melt,and the significant inter-annual variations in precipitation.展开更多
Caohai Lake,a typical freshwater lake on the southwestern plateau of China,is threatened by drainage projects,domestic sewage,and agricultural pollution,which jeopardize its ecological functions.This study aimed to as...Caohai Lake,a typical freshwater lake on the southwestern plateau of China,is threatened by drainage projects,domestic sewage,and agricultural pollution,which jeopardize its ecological functions.This study aimed to assess the ecological health of Caohai Lake and to develop a phytoplankton-based Index of Biotic Integrity(P-IBI)adapted to its ecological characteristics.From July to November 2024,fourteen sampling sites were established across the lake,and samples were collected monthly to analyze physicochemical water parameters and phytoplankton community structure,followed by the construction of the P-IBI.A total of 88 phytoplankton species belonging to six phyla were identified,with Chlorophyta being the most species-rich group(46 species,52.27%)and Cyanophyta as the dominant group.Nutrient concentrations,including total nitrogen(TN)and total phosphorus(TP),were higher in July-August and gradually decreased from September to November.The mean P-IBI of Caohai Lake was 3.851,corresponding to a“sub-healthy”ecological status.Key metrics,including the percentage of Bacillariophyta cell density(M16),percentage of cell density contributed by the three dominant species(M18),Shannon-Wiener diversity index(M19),and the overall P-IBI,were significantly correlated with water temperature(WT),chlorophyll-a(Chl.a),and nutrient concentrations.These results provide a scientific basis for the environmental management and ecological protection of Caohai Lake.展开更多
Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have n...Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have not been thoroughly investigated.In this study,multiple tracers(hydrochemistry,𝛿D,𝛿18O and 222Rn)were used to compare mechanisms of LGD in Daihai and Ulansuhai Lake in Inner Mongoli1,Northwest China.The hydrochemical types showed a trend from groundwater to lake water,indicating a hydraulic connection between them.In addition,the𝛿D and𝛿18O values of sediment pore water were between the groundwater and lake water,indicating the LGD processes.The radon mass balance model was used to estimate the average groundwater discharge rates of Daihai and Ulansuhai Lake,which were 2.79 mm/day and 3.02 mm/day,respectively.The total nitrogen(TN),total phosphorus(TP),and fluoride inputs associated with LGD in Daihai Lake accounted for 97.52%,96.59%,and 95.84%of the total inputs,respectively.In contrast,TN,TP and fluoride inputs in Ulansuhai Lake were 53.56%,40.98%,and 36.25%,respectively.This indicates that the pollutant inputs associated with LGD posed a potential threat to the ecological stability of Daihai and Ulansuhai Lake.By comparison,the differences of LGD process and associated pollutant flux were controlled by hydrogeological conditions,lakebed permeability and human activities.This study provides a reference for water resources management in Daihai and Ulansuhai Lake basins while improving the understanding of LGD in the Yellow River basin.展开更多
This research optimized the structure of lithium extraction solar ponds to enhance the crystallization rate and yield of Li_(2)CO_(3).Using the response surface methodology in Design-Expert 10.0.3,the authors conducte...This research optimized the structure of lithium extraction solar ponds to enhance the crystallization rate and yield of Li_(2)CO_(3).Using the response surface methodology in Design-Expert 10.0.3,the authors conducted experiments to investigate the influence of four factors related to solar pond structure on the crystallization of Li_(2)CO_(3) and their pairwise interactions.Computational Fluid Dynamics(CFD)simulations of the flow field within the solar pond were performed using COMSOL Multiphysics software to compare temperature distributions before and after optimization.The results indicate that the optimal structure for lithium extraction from the Zabuye Salt Lake solar ponds includes UCZ(Upper Convective Zone)thickness of 53.63 cm,an LCZ(Lower Convective Zone)direct heating temperature of 57.39℃,a CO32−concentration of 32.21 g/L,and an added soda ash concentration of 6.52 g/L.Following this optimized pathway,the Li_(2)CO_(3) precipitation increased by 7.34% compared to the initial solar pond process,with a 33.33% improvement in lithium carbonate crystallization rate.This study demonstrates the feasibility of optimizing lithium extraction solar pond structures,offering a new approach for constructing such ponds in salt lakes.It provides valuable guidance for the efficient extraction of lithium resources from carbonate-type salt lake brines.展开更多
基金funded by the Key Program of National Natural Science Foundation of China (42230708,42361144887)the Tianshan Talent Project of Xinjiang Uygur Autonomous Region,China (2022TSYCLJ0056)。
文摘High-altitude glacier-lake systems in the eastern Pamir Plateau,Tajikistan,are highly sensitive elements of Central Asia’s cryosphere and are vital for sustaining regional water resources.The Yashilkul Lake is located within a tectonic depression dammed by an ancient rockslide,forming a large alpine lake.This lake is currently impacted by intensified warming,glacier retreat,and poorly quantified hydrological shift.The primary objective of this study is to assess multi-decadal changes in the Yashilkul and Bulunkul lakes and their surrounding cryosphere between 1994 and 2024.The changes were analyzed using multitemporal Landsat imagery and unmanned aerial vehicle (UAV) surveys,complemented by in situ meteorological observations from the Bulunkul meteorological station spanning the period from 1990 to 2024.Glacier and lake boundaries were extracted from Landsat data,primarily by applying the normalized difference water index,supplemented by manual delineation.UAV photogrammetry characterized dam morphology and adjacent ponds,and climate trends were evaluated with the modified Mann-Kendall test.A significant warming trend of 0.096℃/a and pronounced interannual precipitation variability have driven persistent glacier retreat and lake surface area fluctuations.The Yashilkul Lake’s surface area decreased from 36.40 (±1.15) km^(2) in 2010 to 31.94 (±0.54) km^(2) in 2020 and partially rebounded to 33.99 (±0.60) km^(2) in 2024,while the Bulunkul Lake’s surface area remained nearly stable owing to limited glacial influence.Additionally,UAV surveys conducted in 2022 and 2024 revealed main features of the Yashilkul Lake:rockslidedammed origin,perched ponds along the dam body,and an artificial canal regulating its outflow.Nearby glaciers,particularly Glacier No.369,exhibited strong frontal retreat and proglacial lake expansion.The proglacial lake expanded nearly fourfold from 0.08 (±0.01)km^(2) in 2000 to 0.33 (±0.02) km^(2) in 2024,raising concerns about potential glacial lake outburst floods that could impact the Yashilkul Lake and compromise the integrity of its natural dam.The findings highlight accelerating hydrological and cryospheric transformations in the Pamir Plateau,emphasizing the need for sustained monitoring of glacier-lake systems owing to their critical implications for water security,ecological stability,and downstream hazard management.
基金supported by Hebei Natural Science Foundation(No.JZX2023018)Hebei Natural Science Foundation(No.C2022201042)the 100 Foreign Experts Plans of Hebei Province(No.606080123001).
文摘Antibiotics are widespread in aquatic environments due to their extensive use in human healthcare and ani-mal husbandry.However,research on the occurrence and bioaccumulation of antibiotics in aquatic organisms within shallow wetland lakes remains limited.This study investigated the occurrence and bioaccumulation of ten commonly used antibiotics in the Baiyang Lake,northern China’s largest shallow wetland lake.The results indicated that sulfonamides and fluoroquinolones were the predominant antibiotics in surface water,whereas fluoroquinolones and macrolides were more prevalent in sediment.Fluoroquinolones demonstrated significant potential for bioaccumulation in targeted aquatic organisms,including both animals and plants(Carassius au-ratus and Phragmites australis).The bioaccumulation of antibiotics in Carassius auratus was correlated with their solubility,whereas in Phragmites australis,this was associated with their octanol-water partition coefficients and molecular weights.Ecological risk assessment indicated that most antibiotics posed minimal to low risk levels.However,four antibiotics were exceptions:clarithromycin(12.5%)and sulfamethoxazole(6.25%)presented a high risk in surface water samples,while norfloxacin(25.0%)and ciprofloxacin(25.0%)posed a high risk in sediment samples.Norfloxacin,ciprofloxacin,and roxithromycin were identified as key indicator antibiotics for enhancing the local monitoring and control of antibiotic contamination based on four criteria:(1)high con-centrations,(2)frequent detection,(3)capacity for bioaccumulation,and(4)ecological risk levels.This study contributes to a deeper understanding of the status of antibiotic contamination,bioaccumulation characteristics,and ecological risk in Baiyang Lake,thereby supporting efforts to monitor and regulate antibiotic pollution.
基金supported by the National Natural Science Foundation of China(No.42225103).
文摘Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_(4) emissions between different lakes.However,the carbon emissions and their influencing factors of different areas within a single lake remain poorly understood.Accordingly,this study investigates CO_(2) and CH_(4) emission hetero-geneity in a large floodplain lake system and distribution characteristics of associated functional microorganisms.Findings show that mean CO_(2) and CH_(4) flux values in the sub lake area were 62.03±24.21 mg/(m2·day)and 5.97±3.2μg/(m2·day),which were greater by factors of 1.78 and 2.96 compared to the water channel and the main lake area,respectively.The alpha diversity of methanogens in the sub lake area was lower than that in the main lake and water channel areas.The abundance of methanogens in bottom water layer was higher compared with the middle and surface layers.Conversely,the abundance of methane(CH_(4))-oxidizing bacteria in the surface layer was higher than that in the bottom layer.Additionally,the composition of methanogen and CH_(4)-oxidizing bacterial community,chlorophyll a(Chl-a),pH,total phosphorus(TP)and dissolved organic carbon(DOC)con-tent constituted the dominate driving factors affecting lake C emissions.Results from this study can be used to improve our understanding of lake spatial heterogeneous of CO_(2) and CH_(4) emission and the driving mechanisms within floodplain lakes under the coupling effects of functional C microorganisms and environmental factors.
基金supported by the National Natural Science Foundation of China(No.42001084)the Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(Nos.2022A03009-2,2022A03009)the Third Xinjiang Scientific Expedition Program(No.2022xjkk1303)。
文摘Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(ACA)region.However,debate persists regarding whether dryland lakes in this region exhibited aridification or humidification during the Holocene.Lopnur serves as the terminal lake of Tarim rivers during the Holocene,which offers an ideal natural laboratory to address the questions.In this study,a high-resolution chronological framework was established through precise radiocarbon dating.Multi-proxy analyses,including geochemical composition,grain size distributions,MS,LOI,and C/N ratios were conducted from a lacustrine profile in the core area of“Great ear”in the southern part of Lopnur catchment.These analyses enabled the reconstruction of hydrological dynamics and facilitated the disentanglement of independent signals linked to climate variability,runoff fluctuations,and lake-level changes.The results demonstrate that the MidHolocene(7800–4000 cal yr B.P.)was characterized by cold and humid conditions,resulting in elevated surface runoff and lake level.The Late Holocene(4000–1300 cal yr B.P.)experienced intensified aridification,characterized by reduced runoff and declining lake level.These evidences suggested a climatic regime of a distinctive alternation between“cold-wet”and“warm-dry”climatic regimes during the Mid-to-Late Holocene.Compared with the previous studies from adjacent regions,we speculate that the hydroclimatic evolution of Lopnur catchment possibly influenced by a complex interplay of large spatial scale forcings,including variations in annual insolation,greenhouse gas concentrations,and ice sheets,as well as the localized controls such as topographic features,vegetation cover,and cloud-radiative feedbacks.Our findings enhance the understanding of past climatic complexity and provide valuable insights for future water resource management strategies in drylands.
基金supported by the Shanghai Science and Technology Innovation Action Plan(Grant no.23230712200).
文摘This study investigates the potential formation of subglacial lakes beneath the glaciers of the Franz Josef Land archipelago,Russian Arctic,under current and future climatic conditions.Using a one-dimensional heat and mass transfer model,the research evaluates the influence of geothermal heat flow,ice thickness,and surface temperature on basal melting.The model incorporates enthalpy formulation and boundary conditions derived from field data,including temperature profiles and geothermal measurements.Results indicate that subglacial lakes could form under ice masses exceeding 300 m thickness,driven by geothermal heating,though current basal temperatures remain below the melting point.Simulations under the IPCC SSP1-2.6 scenario suggest a gradual warming trend,highlighting the long-term thermal inertia of Arctic glaciers.The study underscores the need for enhanced observational data to validate models and improve predictions of glacial dynamics in response to climate change.
基金Supported by the National Natural Science Foundation of China(No.43277051)the Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education(No.B230203006).
文摘While oceanic and coastal acidification has gained increased attention,long-term pH trends and their drivers in large freshwater systems remain poorly understood.The Laurentian Great Lakes are the world’s largest freshwater system,and in many ways resemble marine ecosystems.However,unlike the open ocean and coastal waters where pH has declined due to rising atmospheric CO_(2),no significant pH trends have been observed in the Laurentian Great Lakes,despite significant ecosystem changes driven partly by the invasion of dreissenid mussels.This study examined 41 years of field observations from Lake Michigan to investigate the long-term carbonate chemistry dynamics.Observational results revealed substantial declines in both total alkalinity(TA)and dissolved inorganic carbon(DIC)over the four decades.Mussel shell calcification emerged as the primary mechanism behind these declines,accounting for 97%and 47%of the observed changes in TA and DIC,respectively,lowering water column pH by 0.24 units.Elevated carbon accumulation in soft mussel tissues,coupled with long-term changes in the air-water pCO_(2)gradient during summer,significantly contributed to long-term DIC variations,explaining 18%and 28%of the lake-wide DIC loss.These two mechanisms also resulted in an overall pH increase of 0.09 and 0.12 units,largely offsetting the calcification-driven pH decrease.These findings bridge a gap in acidification research for large freshwater systems and provide valuable insights for comprehensive lake-wide management strategies.
基金The Archaeological Talent Promotion Program of China(2024-272)National Natural Science Foundation of China No.42301173,No.42101152+5 种基金Natural Science Foundation of Jiangsu Province,China,No.BK20230386,No.BK20221027Humanities and Social Science Fund of Ministry of Education of China,No.23YJCZH096The Fundamental Research Funds for the Central Universities,No.SKCX2024011,No.SKYZ2024026Key Project of Higher Education Teaching Reform Research and Practice in Henan Province,No.2024 SJGLX0209Humanities and Social Sciences Prestigious Fellowship Scheme,University Grants Committee,Hong Kong,No.34000323Comprehensive Research Project on Scientific and Technological Archaeology of Changzhou City’s Daxujiacun Site and Chuanfangtou Site(Phase III),No.JSZC-320400-FW2025-06406。
文摘Research into the location and development of rice paddies after the collapse of Neolithic cultures is of crucial importance.This study explores the phytolith assemblages and soil micromorphologies of potential rice paddy relics found at the Xingang Site(3556–3360 cal.a BP)in the Taihu Lake Plain,Lower Yangtze River,offering insights into these issues.The discriminant function of the phytolith assemblage distinguished six out of 19 samples in the suspected paddy field area as wild rice fields,while the rest were non-rice fields.Soil micromorphology indicated that the alleged paddy field area experienced repeated dry and wet conditions,with signs of plant growth but no evidence of human activity,suggesting it was not an artificially managed paddy field.These findings suggest the area during the Shang Dynasty consisted of abandoned paddies from the post-Neolithic era.The proportion of rice bulliform phytoliths with≥9 fish-scale decorations(35%–47%)was significantly lower at the Xingang Site(marginal area)during the Shang Dynasty compared to periods like Qianshanyang-Guangfulin(4300–3900 a BP)(central area),suggesting that diminished population density in marginal areas after the Neolithic collapse likely led to paddy field abandonment.Additionally,the collapse of the Liangzhu social structure,along with a rice-farming economy that lacked strong resource competitiveness,may have also contributed to this phenomenon.This study provides an empirical example of rice paddy locations following the Neolithic collapse in the Lower Yangtze River,enhancing our understanding of the decline of the Liangzhu civilization.
文摘The Lake Hazar basin,located along the Palu segment of the East Anatolian Fault System(EAFS),provides a key natural laboratory for examining transtensional deformation in a major intracontinental strike-slip zone.Integrated field mapping,fault-slip analysis,and focal mechanism inversion reveal a polyphase tectonic history involving sequential compressional,strike-slip,and extensional regimes.Rigorous discrimination of heterogeneous fault-slip datasets into homogeneous subsets enabled reconstruction of geologically consistent stress tensors and clarified the temporal transition from strike-slip to transtensional deformation.Paleostress results indicate NNE–SSW compression and NW–SE extension,consistent with present-day seismotectonic and geomorphic patterns.Variations in stress ratio Rvalues(0.26–0.57 for strike-slip;0.28–0.33 for extensional domains)and low misfit angles(<15°)reflect localized strain partitioning and reactivation of inherited faults.The Lake Hazar basin thus evolved from a pull-apart structure into a negative flower geometry through successive deformation and fault linkage.These findings highlight that discriminating polyphase fault-slip data is essential for resolving deformation dynamics in complex fault systems.The integrated structural,paleostress,and seismotectonic framework presented here refines understanding of strain localization,fault reactivation,and stress transfer along the East Anatolian Fault System.
基金supported by the funding from Wuhan Institute of Technology to Dr.Siyue Li(Nos.24QD26 and 21QD02).
文摘Aquatic plants have been widely used for lake ecological restoration.The effect of aquatic plants on lake biogeochemical cycling has been investigated intensively,however,plants’effect on biodegradation of dissolved organic carbon(DOC)is rarely studied.Here we designed an indoor incubation experiment to explore the priming effect(PE)of aquatic plant leaching solution on DOC in shallow lakes,referring to as the input of active dissolved organic matter(DOM)that would arouse changes in the degradation rate of original refractory DOM.Waters from 20 urban lakes of different tropic states were incubated to study their PE on DOC by adding leaching solutions from two submerged freshwater plants,Hydrilla(H)and Vallisneria(V).The study showed a clear influence of aquatic plants on PE with varying directions and intensities.The H incubation group showed a PE range of-6.19%–9.79%,with an average of 2.15%±2.70%,whereas the V incubation group exhibited a PE range of-10.03%to 3.60%,with an average of-0.65%±3.11%.The positive and negative PEs by the two plant species indicate a key role of plants over trophic states on organic carbon dynamics in freshwater lakes.From the perspective of plant leaching input,our results reveal that planting aquatic plants whose leaching solution can reduce PE like V could be used to enhance carbon storage and constrain carbon emission.
基金financed by the Ministry of Research and Innovation-“Program Nucleu”-13N/08.02.2019-PN19-20-04-01The APC was funded by PN 23.30.02.02,PN 23.30.01.03.
文摘This study presents an integrated assessment of sedimentological,granulometric,physico-chemical,and biological characteristics in three Romanian coastal lakes,based on 2022 field surveys.A total of 59 sediment samples were analyzed lithologically and granulometrically,and 12 were examined for macrozoobenthic community composition.Water samples were assessed for nutrient and pigment concentrations to evaluate trophic status and ecological condition.Sediments were predominantly silty-clayey,indicating low-energy depositional environments.Organic matter content was highest in Lakes Agigea and Tuzla,suggesting enhanced primary productivity and organic detritus accumulation,while Lake Costinești showed higher biogenic carbonate content from mollusc shells.Macrozoobenthic assemblages were dominated by taxa tolerant to organic enrichment and hypoxia,including Chironomidae larvae,Oligochaeta,and Cyprideis torosa.Water quality analysis indicated good ecological status in Agigea Lake,whereas Tuzla Lake was severely eutrophic,with phosphate and nitrite in Class Ⅳ and chlorophyll-a exceeding Class Ⅴ thresholds(>250μg/L),consistent with cyanobacterial blooms.Elevated sulfate(Class Ⅲ)and suspended solids further impaired Tuzla’s transparency.In Costinești,marine taxa presence and variable salinity reflected periodic seawater exchange.Anthropogenic influences were evident-nutrient enrichment from fisheries in Tuzla and marine species introduction in Costinești-highlighting system vulnerability to human pressure.The integration of sediment,water quality,and biological indicators emphasizes the need for continuous,interdisciplinary monitoring to track ecological shifts,support adaptive management,and conserve biodiversity and ecosystem integrity in Romanian coastal lakes.
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK0805-02The Innovation Team Foundation of Qinghai Office of Science and Technology,No.2022-ZJ-903+2 种基金The Comprehensive Development and Utilization of Salt Lake Resources,No.2023ZXKYA05100The Special Research Assistant of Chinese Academy of Sciences(Han Jinjun)The Kunlun Talented People of Qinghai Province,High-end Innovation and Entrepreneurship Talents,2023(Han Jinjun)。
文摘To address soil salinization’s significant impact on human production and livelihood in arid regions,especially in high-salinity areas like salt lake regions,this study used multi-source remote sensing data to extract 52 surface factors.Combined with measured soil salinity data,correlation analysis,multicollinearity testing,and projection importance analysis identified eight dominant factors.Subsequently,four machine learning algorithms were applied for modeling,and the optimal models were selected to study the spatiotemporal variation of soil salinization.The results indicate that the average soil salt content in the study area was 20.74%in 2020.LST(land surface temperature)can effectively identify areas with high salinity,such as saline-alkali land and salt flats.Among inversion models,the GBDT(gradient boosting decision trees)model demonstrated the highest predictive ability and minimal errors.The optimal inversion results revealed that soil salinization distribution was influenced by topographic elevation,distance from Qarhan Salt Lake,and river network density.Over the past 21 years,there was significant fluctuation in soil salinity observed in the concentrated area of grassland within the groundwater overflow zone,indicating strong variation in salinization.This fluctuation correlates with changes in groundwater levels in the groundwater overflow zone,which are influenced by temperature variations that determine the amount of snow and ice meltwater,and the precipitation in the upstream area.This study enhances understanding of soil salinization and its drivers in extremely arid salt lake regions.
基金supported by the National Natural Science Foundation of China(41171018,41161036).
文摘Aeolian sediments in the eastern Qinghai Lake region,China serve as sensitive paleoclimate archives,offering an ideal window into past environmental conditions.This study investigated the Dashuitang(QDST)profile in the eastern Qinghai Lake region by integrating sediment grain size,chroma,and magnetic susceptibility(MS)proxies to reconstruct the regional environmental evolution since the Last Glacial Interstadial and to investigate its relationship with the water level fluctuations of Qinghai Lake.Grain size end-member modeling analysis(EMMA)identified three end-members:end-member 1(EM1)represented fine-grained material transported over longer distances through mixing processes,which could reveal the regional moisture conditions;end-member 2(EM2)primarily consisted of coarse-grained material from nearby sources transported via saltation or creep,indicating the intensity of the winter monsoon;and end-member 3(EM3)mainly reflected deposition from dust storm events controlled by regional low-altitude wind systems.In addition,the regional environmental sequence demonstrated coherence with other records,collectively elucidating the sub-orbital-scale dynamics of the Asian monsoon.The environmental sequence was divided into four principal phases on the basis of sedimentary characteristics and climatic responses:the late Last Glacial Interstadial,Last Glacial Maximum,Last Deglaciation,and Holocene phases.Additionally,the results of this study revealed that there is a close linkage between desertification and lake evolution in the eastern Qinghai Lake region.Since the Last Glacial Interstadial,desertification and lake evolution processes have generally exhibited a trade-off relationship,wherein lake level decline and desert expansion exhibited a direct positive feedback.However,during the early period of the Late Holocene(approximately 2.80–1.50 ka BP),a synergistic response pattern emerged,characterized by relatively high lake levels alongside moderate desert expansion,reflecting an asymmetric decoupling mechanism between the hydrological processes and aeolian dynamics during climatic transition periods.This study provides important insights for predicting the future evolution trends of lake-desert systems under climate change.
基金supported by the National Natural Science Foundation of China(Grants No.42301226,42271209 and 42471199)the Fundamental Research Funds for the Central Universities(Grant No.2024CDJXY014)+2 种基金the Natural Science Foundation of Jiangxi Province(Grant No.20242BAB25170)Special Funds for Water Resources in Jiangxi Province(Science and Technology Projects)(Grant No.202425YBKT16)the Young Talent Cultivation and Innovation Fund Project of Nanchang University(Grant No.XX202506030028).
文摘Great Lakes Regions(GLRs)in China often confront landscape fragmentation,wetland degradation,and ecological resilience(ER)losses owing to extensive and intensive urbanization.In GLRs,however,the ER responses to urbanization remain unclear.This study explored the spatiotemporal evolution of ER and urbanization in five GLRs in China to analyze the ER dynamic patterns along center−lakeside−periphery gradient.The Spatial Durbin Model(SDM)and Panel Threshold Model(PTM)were combined to reveal the spillover and threshold effects of urbanization in five GLRs.The results indicate that the ER in five GLRs declined with a rate of 21%from 2000 to 2020.There was a clear“center-periphery”contraction trend with low ER areas primarily spreading to human activity-concentrated regions such as lakesides,riversides,and road networks.Driven by economic and land urbanization,the average urbanization level increased from 0.06 to 0.13,where lakesides,riversides,and road networks were key areas undergoing expansion.The urbanization showed a noticeable negative spatial spillover effect on ER.Away from central lakes,the negative impacts on ER exhibited a two-phase decrease with the threshold of 81 km.This study contributes to the understanding of human-environment interactions by examining the ecological resilience response process of GLRs under the impact of urbanization.Based on a multidimensional“center−lakeside−periphery”analytical model,this study provides a strategic framework for ecological construction in GLRs in China,promoting sustainable development and adaptive capacity in vulnerable areas.
基金National Natural Science Foundation of China,No.42225105,No.42201175The China Postdoctoral Science Foundation,No.2023M733605。
文摘As an essential component of terrestrial carbon sinks,lake sediments store vast quantities of both organic carbon(OC)and inorganic carbon(IC).However,the spatiotemporal relationship between the OC and IC in sediments and their responses to climate change remains unclear,which hinders the comprehensive understanding of carbon dynamics in lake ecosystems.This study systematically analyzes the spatiotemporal dynamics of carbon burial across the Tibetan Plateau using surface sediments from 119 lakes and sediment cores from four representative lakes.Results show that OC burial dominates in humid and dry sub-humid zones,whereas IC burial prevails in arid and semi-arid regions.This distribution reflects the influences of lake and catchment productivity and water chemistry on OC and IC patterns.Sediment cores confirm that these factors have consistently affected lake carbon burial over the past century.Specifically,in humid and dry sub-humid zones,increased precipitation enhances watershed productivity and sedimentation,promoting coupled OC and IC burial.In arid and semi-arid regions,wind-driven dust supplies nutrients and alters water chemistry,also driving coupled OC and IC burial.Based on these findings,the carbon sink capacity of lake sediments on the Tibetan Plateau is projected to increase under the“warming and wetting”trend.
基金supported by the National Natural Science Foundation of China(U2003202,42071054)the Key Research and Development Program of Jiangxi Province,China(20223BBG74003)the Science and Technology Planning Project of Nanjing Institute of Geography and Limnology(NIGLAS2022GS09).
文摘The Balkhash Lake Basin(BLB),a vital Central Asian watershed,faces hydrological uncertainty under climate warming.This study integrated multi-source remote sensing data(Sentinel-1 snow depth,Randolph Glacier Inventory(RGI)v.7.0 glacier inventory,and Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)mass balance)with a degree-day model to reconstruct decadal snow and ice dynamics across 13 sub-basins and analyzed their hydrological impacts from 1950 to 2014.The results showed that:(1)while flows from the downstream river of the BLB decreased from 1950 to 1982 due to land surface changes,runoff increased significantly after 1982 in the Ili River(18.0%)and moderately increased in most rivers in the east(1.3%–8.3%),driven by increased precipitation and glacier melt.Runoff in the Ayaguz catchment(no glaciers with the highest climate warming)declined(10.5%);(2)climate warming reduced precipitation falling as snow caused snow melt water to decline(0.03–0.22 mm/a)across the BLB,leading to downward shifts in runoff and runoff coefficient,especially in the rivers in the east.However,snow melt during April–June positively correlated with runoff coefficient,contributing to an upward shift in the Ili River Basin;and(3)meltwater from glacierized areas(<5.0%of basin area)contributed to 14.3%of total ablation water.Net glacier melt provided substantial excess flows(11.6 m3/s in the Ili River and<1.0 m3/s in the rivers in the east),generally counterbalancing the negative effect of rising potential evaporation at decadal scales and positively correlating with the runoff coefficient.Therefore,water stress in the BLB may be more severe in the future due to the accelerating glacier melt after the abrupt increase in air temperature in 2000,the continuing decline in snow melt,and the significant inter-annual variations in precipitation.
文摘Caohai Lake,a typical freshwater lake on the southwestern plateau of China,is threatened by drainage projects,domestic sewage,and agricultural pollution,which jeopardize its ecological functions.This study aimed to assess the ecological health of Caohai Lake and to develop a phytoplankton-based Index of Biotic Integrity(P-IBI)adapted to its ecological characteristics.From July to November 2024,fourteen sampling sites were established across the lake,and samples were collected monthly to analyze physicochemical water parameters and phytoplankton community structure,followed by the construction of the P-IBI.A total of 88 phytoplankton species belonging to six phyla were identified,with Chlorophyta being the most species-rich group(46 species,52.27%)and Cyanophyta as the dominant group.Nutrient concentrations,including total nitrogen(TN)and total phosphorus(TP),were higher in July-August and gradually decreased from September to November.The mean P-IBI of Caohai Lake was 3.851,corresponding to a“sub-healthy”ecological status.Key metrics,including the percentage of Bacillariophyta cell density(M16),percentage of cell density contributed by the three dominant species(M18),Shannon-Wiener diversity index(M19),and the overall P-IBI,were significantly correlated with water temperature(WT),chlorophyll-a(Chl.a),and nutrient concentrations.These results provide a scientific basis for the environmental management and ecological protection of Caohai Lake.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region of China(No.2023QN04011)the National Natural Science Foundation of China(Nos.42307092 and 52279067)+1 种基金Ordos Science and Technology Major Project(No.ZD20232303)Project of Key Laboratory of River and Lake in Inner Mongolia Autonomous Region(No.2022QZBZ0003).
文摘Lacustrine groundwater discharge(LGD)plays an important role in water resources management.Previous studies have focused on LGD process in a single lake,but the differences in LGD process within the same region have not been thoroughly investigated.In this study,multiple tracers(hydrochemistry,𝛿D,𝛿18O and 222Rn)were used to compare mechanisms of LGD in Daihai and Ulansuhai Lake in Inner Mongoli1,Northwest China.The hydrochemical types showed a trend from groundwater to lake water,indicating a hydraulic connection between them.In addition,the𝛿D and𝛿18O values of sediment pore water were between the groundwater and lake water,indicating the LGD processes.The radon mass balance model was used to estimate the average groundwater discharge rates of Daihai and Ulansuhai Lake,which were 2.79 mm/day and 3.02 mm/day,respectively.The total nitrogen(TN),total phosphorus(TP),and fluoride inputs associated with LGD in Daihai Lake accounted for 97.52%,96.59%,and 95.84%of the total inputs,respectively.In contrast,TN,TP and fluoride inputs in Ulansuhai Lake were 53.56%,40.98%,and 36.25%,respectively.This indicates that the pollutant inputs associated with LGD posed a potential threat to the ecological stability of Daihai and Ulansuhai Lake.By comparison,the differences of LGD process and associated pollutant flux were controlled by hydrogeological conditions,lakebed permeability and human activities.This study provides a reference for water resources management in Daihai and Ulansuhai Lake basins while improving the understanding of LGD in the Yellow River basin.
基金This study was supported by the National Natural Science Foundation of China(U20A20148)the Major Science and Technology Projects of the Xizang(Tibet)Autonomous Region(XZ202201ZD0004G and XZ202201ZD0004G01).
文摘This research optimized the structure of lithium extraction solar ponds to enhance the crystallization rate and yield of Li_(2)CO_(3).Using the response surface methodology in Design-Expert 10.0.3,the authors conducted experiments to investigate the influence of four factors related to solar pond structure on the crystallization of Li_(2)CO_(3) and their pairwise interactions.Computational Fluid Dynamics(CFD)simulations of the flow field within the solar pond were performed using COMSOL Multiphysics software to compare temperature distributions before and after optimization.The results indicate that the optimal structure for lithium extraction from the Zabuye Salt Lake solar ponds includes UCZ(Upper Convective Zone)thickness of 53.63 cm,an LCZ(Lower Convective Zone)direct heating temperature of 57.39℃,a CO32−concentration of 32.21 g/L,and an added soda ash concentration of 6.52 g/L.Following this optimized pathway,the Li_(2)CO_(3) precipitation increased by 7.34% compared to the initial solar pond process,with a 33.33% improvement in lithium carbonate crystallization rate.This study demonstrates the feasibility of optimizing lithium extraction solar pond structures,offering a new approach for constructing such ponds in salt lakes.It provides valuable guidance for the efficient extraction of lithium resources from carbonate-type salt lake brines.
