The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes ...The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes are undergoing a rapid increase in number and size. Human impacts and frequent algae blooms lead to it necessary to make a better constraint on their carbon cycles. Here, we make a primary estimation on the air–water CO_2 transfer flux through an algae bloom year for a subtropical man-made lake—Hongfeng Lake, Southwest China. To do this a new type of glass bottles was designed for content and isotopic analysis of DIC and other environmental parameters. At the early stage of algae bloom,CO_2 was transferred from the atmosphere to the lake with a net flux of 1.770 g·C·m^(-2). Later, the partial pressure(pCO_2) of the aqueous CO_2 increased rapidly and the lake outgassed to the atmosphere with a net flux of 95.727 g·C·m^(-2). In the remaining days, the lake again took up CO_2 from the atmosphere with a net flux of 14.804 g·C·m^(-2). As a whole, Lake Hongfeng released 4527 t C to the atmosphere, accounting for one-third of the atmosphere/soil CO_2 sequestered by chemical weathering in the whole drainage. With an empirical mode decomposition method, we found air temperature plays a major role in controlling water temperature, aqueous pCO_2 and hence CO_2 flux. This work indicates a necessity to make detailed and comprehensive carbon budgets in man-made lakes.展开更多
Numerous rivers and lakes in the monsoon climate zone are heavily influenced by frequent rainstorms that mobilize dissolved organic matter(DOM)from pristine or urbanized environments into downstream lakes.Of particula...Numerous rivers and lakes in the monsoon climate zone are heavily influenced by frequent rainstorms that mobilize dissolved organic matter(DOM)from pristine or urbanized environments into downstream lakes.Of particular concern is the mobilization of DOM from anthropogenic effluents,which are commonly enriched in aliphatic compounds that can be easily degraded by microorganisms.Rapid degradation of highly biodegradable DOM,in turn,may cause significant depletion of dissolved oxygen in the water,which,by creating anoxic conditions at the bottom water-sediment interface,promotes microbial production of CO_(2) and CH4.Further investigations based on high-frequency monitoring and novel techniques such as ultrahigh-resolution mass spectrometry and isotopic measurements,are needed to elucidate the processes and mechanisms by which pulsed aliphatic inputs impact lake carbon emissions.展开更多
Reliable surface height observations over inland water bodies are useful for understanding the hydrological cycle.Satellite radar altimetry particularly contributed with its long-term archive and minimal cloud interfe...Reliable surface height observations over inland water bodies are useful for understanding the hydrological cycle.Satellite radar altimetry particularly contributed with its long-term archive and minimal cloud interference.Specialized inland water altimetry,developed from oceanography and geodesy,is still being extensively investigated.By synthesizing pioneering studies on“retracking algorithms”,this review demonstrates,from a user perspective,why optimizing conventional retracking is still important and how it can extend reliable historical water level retrieval over more ungauged sites.Numerous unrevealed inland water bodies have small sizes or complex surroundings,posing challenges to maintaining accuracy.Applications have shown that a critical key lies in the retracking correction during range retrieval(uncertainty likely on the order of meters),compared with other corrections(on the order of centimeters or decimeters).From multiple uncertainty factors in range retrieval,signal entanglements from land contamination and off-nadir effects are core issues.We evaluate and compared key strategies from prototype retrackers to improved retrackers,especially the empirical ones optimized for inland waters.Sub-waveform extraction and adjustment for Delay-Doppler modes has advanced range retrieval to a new stage.Four innovative inland-water-compatible retrackers are introduced in detail,with a highlight on their distinct approaches to robustly improve performance.Considering the selection of different data and retrackers in varying scenarios,a synthesis analysis is conducted based on results reported in previous literature.In conclusion,the empirical retracking has been enhanced to offer stable decimeter-level accuracy in intricate landscapes(e.g.,small lakes and rivers with varied surroundings).In comparison,the physical retracking has been upgraded to provide greater precision for homogeneous surface in large lakes.For future inland water altimetry,we articulate how additionally retracked results can benefit hydrological applications,and what difficulties would arise when extending study scales.展开更多
This paper presents research aimed at identifying the methods with which prehistoric man interacted with marine and inland water environments. The objective is to determine the degree to which resources from these env...This paper presents research aimed at identifying the methods with which prehistoric man interacted with marine and inland water environments. The objective is to determine the degree to which resources from these environments influenced the socio-economic organization of these peoples. The coastline around Cagliari and its hinterland （southern Sardinia, Italy） were chosen as the subject, on the basis of the presence of both the sea and several ponds. The territory is noted as being home to both Neolithic and Eneolithic settlements. Among these the archaeological excavation of the village of Su Coddu/Canelles produced a large quantity of malacofauna. Data has been processed from part of the settlement that gave radiocarbon dating from the period between 3640 and 2900 cal. BC, and in which it was possible to carry out the level of sampling that was necessary to complete the research. In particular this interdisciplinary project, which aims to make an overall study of the settlement, the data relating to the geography of the area, the archaeological documentation, the fauna and shell artefacts will be extrapolated. Numerous methods are applied above all in reference to the marines and ponds resources. Additionally, the morphological anatomical-comparative analysis （in order to determine the typology of the faunal remains and to identify each individual species） and the technological analysis of the manufactured shells （so as to detect the selection and the transformation type of raw materials） are accomplished. The research has led to the identification of a settlement model in which agriculture formed the primary means of subsistence, that was complemented by the rearing of livestock, through hunting and gathering. The exploitation of marine and inland waters resources, as food source, have to be important because 99% of the faunal remains are shells. Different shell species are recognized, among those the Ostrea edulis provides the raw material to produce bevelled objects, which are documented inside the settlement in considerable number. Some plant species, typical of the lagoon ecosystem, were used for building and craft production.展开更多
Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosyst...Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosystems during the last 15 years in Turkey can be categorized into two main topics. The first group of studies is concerned with heavy metal levels in sediment, with especial reference to the interaction between water, sediment and aquatic organisms. Additionally, the studies in question deal with the potential impacts of heavy metal concentrations on the ecosystem. The second group of studies is concerned with the role of eutrophication in the sediment as a result of serious contamination of inland water ecosystems. It is known that the sediment can directly influence the nutrient level in standing inland waters such as lakes and ponds by way of internal nutrient loading. In this context, studies regarding sediment, overlying water, sediment pore water and nutrient release from the sediment should be emphasized as these are important steps with respect to the eutrophication process. By keeping these studies in mind, the researcher in this study compiled and analyzed studies dealing with inland water ecosystems with differing nutrient levels and uses, including for drinking water, in Turkey’s drainage basins. In addition, field and laboratory studies regarding nutrient release from sediment into Turkey’s inland water ecosystems were evaluated in light of lake management practices.展开更多
Global inland surface water bodies such as lakes and reservoirs,important components of the hydrosphere and ecosphere,are increasingly affected by climate change.Generating bathymetric volume-areaheight (BVAH) curves ...Global inland surface water bodies such as lakes and reservoirs,important components of the hydrosphere and ecosphere,are increasingly affected by climate change.Generating bathymetric volume-areaheight (BVAH) curves for global inland surface water bodies can enhance our understanding of their topography and climate impacts.However,accurately quantifying the topographic patterns of these water bodies remains challenging due to the difficulties in collecting comprehensive bathymetric data.Therefore,we collected and processed over 2000 bathymetric maps of global water bodies from over 50 different data sources and then developed the BVAH model.Finally,the BVAH hydrological curves of 16671 global inland surface water bodies (larger than 10 km~2) were generated.The results include but are not limited to (1) For most targeted water bodies,area (A) and volume (V) exhibit significant power function relationships with surface heights (H),with optimal power values quantified as 1.42 for A and 2.42 for V.(2) The BVAH model outperforms GLOBathy in estimating area and volume changes,achieving higher correlation coefficients (CC) of approximately 0.962 for the area and 0.991 for volume,and demonstrating lower percentages of root mean squared errors (PRMSE) around 10.9% for the area and 4.8% for volume.(3) In the case study of the Xizang Plateau and various large global reservoirs,the BVAH curve database can capture dynamic volume changes.As a unified simulation of the bathymetric topographical patterns,our bathymetric dataset and corresponding BVAH curve database have great potential to contribute to effective water resource management and ecological conservation efforts worldwide.展开更多
The coordinated development is the core of sustainable development and the hot issue of international research.Inland water transport(IWT) is an important part of the water resources exploiting system and comprehensiv...The coordinated development is the core of sustainable development and the hot issue of international research.Inland water transport(IWT) is an important part of the water resources exploiting system and comprehensive transport system under socio-economic context of river basin,and also the country's sustainable development priorities to achieve resource-conserving and environment-friendly strategy.Based on the coordinated development content,the paper combined Germany's successful development experience,explored the elements and problem of the coordinated development of IWT system of China's national economic strategy and basin economy,water resourse system,comprehensive transport system,and system itself,and their countermeasures and suggestions,in order to facilitate rapid and coordinated development of China's inland water transport.展开更多
The persistent rise in concentrations of greenhouse gases (GHGs) in the earth’s atmosphere is responsible for global warming and climate change. Besides the known source of GHGs emissions like energy, industry, and a...The persistent rise in concentrations of greenhouse gases (GHGs) in the earth’s atmosphere is responsible for global warming and climate change. Besides the known source of GHGs emissions like energy, industry, and agriculture, intrinsic emissions from natural inland water bodies like wetland, rivers, reservoirs, estuaries, etc. have also been identified as other hotspots of GHGs emission and gaining the attention of the scientific communities in recent times. Inland fisheries in India are threatened by climate changes such as a change in temperature, precipitation, droughts, storm, sea-level rise, saltwater intrusion, floods that affect mostly the production, productivity and ultimately affect the fishers’ livelihood. There are, however, different mitigation and adaptation strategies to cope with the effects of climate change. Carbon sequestration and other related management interventions are one of the options available minimizing GHGs emissions from inland open waters, particularly the wetlands and coastal mangroves which are well known worldwide for their significant role in the storage of carbon. Assessment of C efflux from exposed sediments in dry streams, reservoirs, lakes, rivers, and ponds into the atmosphere can be considered imperative for a better understanding of their role as a C-sink or as a C-source to the atmosphere.展开更多
Carbon dioxide(CO_(2)) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO_(2) emissions, but empirical data exploring c...Carbon dioxide(CO_(2)) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO_(2) emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO_(2) partial pressures(pCO_(2)) and degassing in a monsoonal river(Yue River)within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO_(2) with a mean ± standard deviation of 1474 ± 1614 μatm, leading to emissions of 557-971 mmol/m^(2)/day from river water to the atmosphere. Annual CO_(2) emissions were 1.6-2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO_(2) was positively correlated to anthropogenic land use(urban and farmland), and negatively correlated to forest cover. p CO_(2) also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict p CO_(2) . Farmland and urban land released nutrients and organic matter to the river system, driving riverine p CO_(2) enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO_(2) , which should be considered in future large-scale estimates of CO_(2) emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.展开更多
This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended m...This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended matter,concentration of chlorophyll-a and non-pigment matter absorption.Two field campaigns for spectra measurements with a total of 40 samples were carried out on June 13 and September 23,2008.The in-situ spectra were recalculated to the spectral bands and sensitivities of the instruments applied in this paper,i.e.Landsat TM,Alos and P6,by using the average method.And the recalculated spectra were used for estimating water quality variables by the single model and multivariate model.The results show that the multivariate model is superior to the single model as the multivariate model takes the combined effects of water components into consideration and can estimate water quality variables simultaneously.According to R2 and RMSE,Alos is superior to other sensors for water quality variables estimation although the precision of non-pigment matter absorption inversion performed the second.展开更多
Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be a...Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be applicable for estimating similar emissions from inlandwater sediments.We addressed this issue by incubating different types of sediments,(including lake,small river,and pond sediments)collected from 36 sites across the Yangtze River basin,under short-term experimentalwarming to explore the effects of climatewarming on sediment carbon emission and the underlying microbe-mediated mechanisms.Our results indicated that under climate warming Cc emissions were affected more than CH_(4) emissions,and that pond sediments may yield a greater relative contribution of CO_(2) to total carbon emissions than lake and river sediments.Warming-induced CO_(2) and CH_(4) increases involve different microbe-mediated mechanisms;Warming-induced sediment CO_(2) emissions were predicted to be directly positively driven by microbial community network modularity,which was significantly negatively affected by the quality and quantity of organic carbon and warming-induced variations in dissolved oxygen,Conversely,warminginduced sediment CH_(4) emissionswere predicted to be directly positively driven bymicrobial community network complexity,which was significantly negatively affected by warminginduced variations in pH.Our findings suggest that biotic and abiotic drivers for sediment CO_(2) and CH_(4) emissions in response to climate warming should be considered separately when predicting sediment organic carbon decomposition dynamics resulting from climate change.展开更多
Phytoplankton play a vital role in nutrient biogeochemical cycling,and their elemental ratios covary with available inorganic nutrients;however,the underlying interaction patterns and mechanisms remain unclear.Here,ba...Phytoplankton play a vital role in nutrient biogeochemical cycling,and their elemental ratios covary with available inorganic nutrients;however,the underlying interaction patterns and mechanisms remain unclear.Here,based on large-scale and long-term field surveys together with culture experiments,we found a stoichiometric convergence over time between phytoplankton nitrogen(N)∶carbon(C)molar ratios and dissolved inorganic N∶CO_(2)molar ratios.Functional genomics evidence demonstrated that this N-C stoichiometric convergence was driven by phytoplankton community succession with its matched N and C metabolism.A theoretical framework was proposed and proved applicable for depicting this convergence.The convergence speed was faster with the greater difference between phytoplankton and water N∶C molar ratios.Moreover,replacing CO_(2)with dissolved inorganic C could alter the direction of convergence.This stoichiometric convergence characterizes the response of phytoplankton elemental ratios to inorganic nutrient dynamics and represents an evolutionary pathway for phytoplankton community assembly over time.展开更多
China Brazil Earth Resource Satellite(CBERS)CCD images have much potential for inland water environmental monitoring.However,their atmospheric accuracy correction can affect their quantitative applications.This paper ...China Brazil Earth Resource Satellite(CBERS)CCD images have much potential for inland water environmental monitoring.However,their atmospheric accuracy correction can affect their quantitative applications.This paper contains an atmospheric correction algorithm for CBERS CCD images with MODIS data from the same day,the use of which improves the atmospheric correction algorithm of ocean color remote sensing developed by Gordon(1993,1994)and makes it applicable to inland waters.The improved algorithm retrieves atmospheric parameters from MODIS data and uses them to perform the atmospheric correction of CBERS CCD images.Experimental results show that the atmospheric correction algorithm of CBERS CCD images assisted by MODIS data is reliable.Furthermore,MODIS data can be freely obtained on a daily basis,making the algorithm developed in this paper useful for environmental monitoring of inland waters.展开更多
The science and management of terrestrial ecosystems require accurate,high-resolution mapping of surface water.We produced a global,30-m-resolution inland surface water dataset with an automated algorithm using Landsa...The science and management of terrestrial ecosystems require accurate,high-resolution mapping of surface water.We produced a global,30-m-resolution inland surface water dataset with an automated algorithm using Landsat-based surface reflectance estimates,multispectral water and vegetation indices,terrain metrics,and prior coarse-resolution water masks.The dataset identified 3,650,723 km2 of inland water globally–nearly three quarters of which was located in North America(40.65%)and Asia(32.77%),followed by Europe(9.64%),Africa(8.47%),South America(6.91%),and Oceania(1.57%).Boreal forests contained the largest portion of terrestrial surface water(25.03%of the global total),followed by the nominal‘inland water’biome(16.36%),tundra(15.67%),and temperate broadleaf and mixed forests(13.91%).Agreement with respect to the Moderate-resolution Imaging Spectroradiometer water mask and Landsat-based national land-cover datasets was very high,with commission errors<4%and omission errors<14%relative to each.Most of these were accounted for in the seasonality of water cover,snow and ice,and clouds–effects which were compounded by differences in image acquisition date relative to reference datasets.The Global Land Cover Facility(GLCF)inland surface water dataset is available for open access at the GLCF website(http://www.landcover.org).展开更多
Inland saline-alkaline water can be used for the low-cost cultivation of microalgae,but whether algal biomass under various light sources has the potential to produce biodiesel remains to be developed.Herein,the influ...Inland saline-alkaline water can be used for the low-cost cultivation of microalgae,but whether algal biomass under various light sources has the potential to produce biodiesel remains to be developed.Herein,the influence of different light-emitting diode(LEDs)light colors(blue,red,white,mixed blue-red,and mixed blue-white LED)on the growth performance,lipid accumulation,and fatty acid composition of Chlorella sp.HQ cultivated in inland saline-alkaline water was investigated.The highest algal density was obtained under blue LEDs at the end of cultivation,reaching 1.93±0.03 × 10^(7) cells/mL.White LEDs can improve biomass yield,total lipid yield,and triacylglycerol yield per algal cell.The main fatty acid components of Chlorella from inland saline-alkaline water were palmitic acid and linoleic acid.The Biodiesel Analyzer software was used to predict algal biodiesel quality by estimating different quality parameters.The cetane number,kinematic viscosity,and density of Chlorella biodiesel were 51.714-67.69,3.583-3.845 mm^(2)/s,and 0.834-0.863 g/cm^(3),respectively.This flirther proved that the Chlorella biomass obtained from inland saline-alkaline water has the potential to be used as a high-quality biodiesel feedstock.展开更多
As essential parts of the unique ecosystem of Tibetan Plateau(TP),the sizes and associated physical properties of alpine lakes have long been investigated.However,little is known about one of the most critical biogeoc...As essential parts of the unique ecosystem of Tibetan Plateau(TP),the sizes and associated physical properties of alpine lakes have long been investigated.However,little is known about one of the most critical biogeochemical properties,i.e.the Chlorophyll-a(Chl-a)concentrations.Here,for the first time,we presented a comprehensive investigation of the temporal–spatial variations in Chl-a in 82 lakes(>50 km^(2))across the entire TP region,based on MODIS observations in the period of 2003–2017.The results showed that the 82 lakes exhibited an average longterm mean Chl-a of 3.3±4.3 mg m^(−3),with high Chl-a lakes concentrated in the eastern and southern inner TP basin and northeastern parts of the TP.An interannual trend analysis revealed that lakes exhibiting(significantly)decreasing Chl-a trends and(significantly)increasing Chl-a trends were comparable in numbers but differed in distribution patterns.A correlation analysis indicated that at least 70%of the interannual variability in Chl-a values of lakes was significantly correlated with one of the four environmental factors(wind speed,ice cover duration,lake water surface temperature and surface runoff)and lake size.In addition,glacier meltwater tended to reduce lake Chl-a while salinity levels showed minor influences.展开更多
Satellite radar altimetry has become an essential tool for hydrological research over the past 2 decades.Unlike imagery that quantifies the water dynamics from the horizontal dimension,altimetry observations deliver v...Satellite radar altimetry has become an essential tool for hydrological research over the past 2 decades.Unlike imagery that quantifies the water dynamics from the horizontal dimension,altimetry observations deliver vertical information,which is crucial for hydrological research.Geodetic mission(GM)altimetry data,characterized by long repeat periods compared to exact repeat missions,have been underutilized in hydrology.This paper aims to advocate for integrating geodetic altimetry data into inland water research and bring awareness to its potential applications.We demonstrated the values of GM data from CryoSat-2,Saral/AltiKa,Jason-1,and Jason-2 through 3 applications:(a)large-scale lake monitoring for improved understanding of regional and global hydrological cycles,(b)retrieval of local geoid undulations over large lakes to enhance the precision of individual water level observations,and(c)mapping river longitudinal profiles and construction of time series of river levels.We believe that the findings of this study will pave the way for more comprehensive utilization of geodetic altimetry data in diverse hydrological applications,ultimately advancing inland water altimetry.展开更多
The value of seaweed based pharmaceutical products has drastically increased in the past decade.Chaetomorpha linum(Chlorophyta)extract has been described to have a high level of antioxidants and bioactive compounds,ho...The value of seaweed based pharmaceutical products has drastically increased in the past decade.Chaetomorpha linum(Chlorophyta)extract has been described to have a high level of antioxidants and bioactive compounds,however it is unknown how growth conditions,specifically the ionic profile of its culture media,may impact C.linum’s biochemical profile.This study tested growth,antioxidant activity,chlorophyll and mineral profile following culture in a 2×2 factorial methodology,with water type(inland saline water[ISW]or ocean water[OW])and nutrient enrichment(nitrate and phosphate)as co-factors.C.linum was cultivated for 20 days outdoors and fresh weight was recorded every five days.On day 10,50 g of seaweed was harvested,and mineral analysis and ultrasound-assisted extraction were performed.Extracts were tested for antioxidant activity and chlorophyll content.Antioxidant activity was not significantly different across treatments in ferric reducing antioxidant potential and total phenolic content assays,though specific growth rate was lower in ISW than OW treatments.Calcium content(mg.g^(-1) d.b.)was also significantly higher(p<0.001)in ISW than OW.This study found that short-term growth of C.linum in ISW can increase calcium content while maintaining the efficacy of its bioactive profile,presenting a new method for producing a mineral rich food or health supplement for human consumption.展开更多
Water pollution seriously threatens the sustainable development of fisheries in China.To inform effective pollution control policies,a comprehensive understanding of the fishery environment status is needed.However,na...Water pollution seriously threatens the sustainable development of fisheries in China.To inform effective pollution control policies,a comprehensive understanding of the fishery environment status is needed.However,nationwide data on the temporal changes of major pollutants in the fishery waters of China are scarce.This study collected data on the major water pollutants,including total nitrogen,total phosphorus,heavy metals,and total petroleum hydrocarbons(TPHs),from 2003 to 2017 to evaluate dynamic changes in the inland fishery water environment across China.We discovered that the levels of four heavy metals(Cu,Zn,Pb,and Cd)and TPH decreased during the 15-year period,corresponding to the reduced national discharge of pollution sources from 2003 to 2015.However,nitrogen and phosphorus levels in the inland fishery waters showed no significant changes during this period.A comparative analysis of water quality in different periods indicated that these improvements were highly associated with effective measures for water pollution control in China.In addition,the decline in pollution was consistent among the three regions of China(north,west,and southeast)from 2003 to 2017,while southeast China exhibited the weakest pollution mitigation among the three regions.These findings suggest that the inland fishery water quality improved during 2003–2017,but still faced eutrophication risk.展开更多
基金carried out with funding from the National Key Research and Development Project provided by the Ministry of Science and Technology of China through Grant 2016YFA0601000
文摘The carbon cycle of global inland waters is quantitatively comparable to other components in the global carbon budget. Among inland waters, a significant part is man-made lakes formed by damming rivers. Manmade lakes are undergoing a rapid increase in number and size. Human impacts and frequent algae blooms lead to it necessary to make a better constraint on their carbon cycles. Here, we make a primary estimation on the air–water CO_2 transfer flux through an algae bloom year for a subtropical man-made lake—Hongfeng Lake, Southwest China. To do this a new type of glass bottles was designed for content and isotopic analysis of DIC and other environmental parameters. At the early stage of algae bloom,CO_2 was transferred from the atmosphere to the lake with a net flux of 1.770 g·C·m^(-2). Later, the partial pressure(pCO_2) of the aqueous CO_2 increased rapidly and the lake outgassed to the atmosphere with a net flux of 95.727 g·C·m^(-2). In the remaining days, the lake again took up CO_2 from the atmosphere with a net flux of 14.804 g·C·m^(-2). As a whole, Lake Hongfeng released 4527 t C to the atmosphere, accounting for one-third of the atmosphere/soil CO_2 sequestered by chemical weathering in the whole drainage. With an empirical mode decomposition method, we found air temperature plays a major role in controlling water temperature, aqueous pCO_2 and hence CO_2 flux. This work indicates a necessity to make detailed and comprehensive carbon budgets in man-made lakes.
基金supported by the National Natural Science Foundation of China(42322104,42471123,and 42207447)the Youth Innovation Promotion Association,CAS(2021312)+3 种基金the Provincial Natural Science Foundation of Jiangsu(BK20220162)the Ecological Environment Research Project of Jiangsu Province of China(2023003)supported by the TÜBITAK program BIDEB2232(project 118C250)G.A.W.received financial support from the Swedish Research Council(VR grant 2020-03222 and Formas grant 2020-01091).
文摘Numerous rivers and lakes in the monsoon climate zone are heavily influenced by frequent rainstorms that mobilize dissolved organic matter(DOM)from pristine or urbanized environments into downstream lakes.Of particular concern is the mobilization of DOM from anthropogenic effluents,which are commonly enriched in aliphatic compounds that can be easily degraded by microorganisms.Rapid degradation of highly biodegradable DOM,in turn,may cause significant depletion of dissolved oxygen in the water,which,by creating anoxic conditions at the bottom water-sediment interface,promotes microbial production of CO_(2) and CH4.Further investigations based on high-frequency monitoring and novel techniques such as ultrahigh-resolution mass spectrometry and isotopic measurements,are needed to elucidate the processes and mechanisms by which pulsed aliphatic inputs impact lake carbon emissions.
基金funded by the National Key Research and Development Program of China(2022YFF0711603)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28020503)+2 种基金the National Natural Science Foundation of China(Grant No.42371399,42301431)Basic Research Program of Jiangsu(Grant No.BK20240112)the Science and Technology Planning Project of NIGLAS(Grant No.2022NIGLAS-CJH04).
文摘Reliable surface height observations over inland water bodies are useful for understanding the hydrological cycle.Satellite radar altimetry particularly contributed with its long-term archive and minimal cloud interference.Specialized inland water altimetry,developed from oceanography and geodesy,is still being extensively investigated.By synthesizing pioneering studies on“retracking algorithms”,this review demonstrates,from a user perspective,why optimizing conventional retracking is still important and how it can extend reliable historical water level retrieval over more ungauged sites.Numerous unrevealed inland water bodies have small sizes or complex surroundings,posing challenges to maintaining accuracy.Applications have shown that a critical key lies in the retracking correction during range retrieval(uncertainty likely on the order of meters),compared with other corrections(on the order of centimeters or decimeters).From multiple uncertainty factors in range retrieval,signal entanglements from land contamination and off-nadir effects are core issues.We evaluate and compared key strategies from prototype retrackers to improved retrackers,especially the empirical ones optimized for inland waters.Sub-waveform extraction and adjustment for Delay-Doppler modes has advanced range retrieval to a new stage.Four innovative inland-water-compatible retrackers are introduced in detail,with a highlight on their distinct approaches to robustly improve performance.Considering the selection of different data and retrackers in varying scenarios,a synthesis analysis is conducted based on results reported in previous literature.In conclusion,the empirical retracking has been enhanced to offer stable decimeter-level accuracy in intricate landscapes(e.g.,small lakes and rivers with varied surroundings).In comparison,the physical retracking has been upgraded to provide greater precision for homogeneous surface in large lakes.For future inland water altimetry,we articulate how additionally retracked results can benefit hydrological applications,and what difficulties would arise when extending study scales.
文摘This paper presents research aimed at identifying the methods with which prehistoric man interacted with marine and inland water environments. The objective is to determine the degree to which resources from these environments influenced the socio-economic organization of these peoples. The coastline around Cagliari and its hinterland （southern Sardinia, Italy） were chosen as the subject, on the basis of the presence of both the sea and several ponds. The territory is noted as being home to both Neolithic and Eneolithic settlements. Among these the archaeological excavation of the village of Su Coddu/Canelles produced a large quantity of malacofauna. Data has been processed from part of the settlement that gave radiocarbon dating from the period between 3640 and 2900 cal. BC, and in which it was possible to carry out the level of sampling that was necessary to complete the research. In particular this interdisciplinary project, which aims to make an overall study of the settlement, the data relating to the geography of the area, the archaeological documentation, the fauna and shell artefacts will be extrapolated. Numerous methods are applied above all in reference to the marines and ponds resources. Additionally, the morphological anatomical-comparative analysis （in order to determine the typology of the faunal remains and to identify each individual species） and the technological analysis of the manufactured shells （so as to detect the selection and the transformation type of raw materials） are accomplished. The research has led to the identification of a settlement model in which agriculture formed the primary means of subsistence, that was complemented by the rearing of livestock, through hunting and gathering. The exploitation of marine and inland waters resources, as food source, have to be important because 99% of the faunal remains are shells. Different shell species are recognized, among those the Ostrea edulis provides the raw material to produce bevelled objects, which are documented inside the settlement in considerable number. Some plant species, typical of the lagoon ecosystem, were used for building and craft production.
文摘Turkey’s inland water ecosystem consists of 33 rivers (177.714 miles), 200 natural lakes (906.118 ha), 159 reservoirs (342.377 ha) and 750 ponds (15.500 ha). Sedimentological studies conducted on inland water ecosystems during the last 15 years in Turkey can be categorized into two main topics. The first group of studies is concerned with heavy metal levels in sediment, with especial reference to the interaction between water, sediment and aquatic organisms. Additionally, the studies in question deal with the potential impacts of heavy metal concentrations on the ecosystem. The second group of studies is concerned with the role of eutrophication in the sediment as a result of serious contamination of inland water ecosystems. It is known that the sediment can directly influence the nutrient level in standing inland waters such as lakes and ponds by way of internal nutrient loading. In this context, studies regarding sediment, overlying water, sediment pore water and nutrient release from the sediment should be emphasized as these are important steps with respect to the eutrophication process. By keeping these studies in mind, the researcher in this study compiled and analyzed studies dealing with inland water ecosystems with differing nutrient levels and uses, including for drinking water, in Turkey’s drainage basins. In addition, field and laboratory studies regarding nutrient release from sediment into Turkey’s inland water ecosystems were evaluated in light of lake management practices.
基金supported by the National Natural Science Foundation of China (No. 41971377 & No. 41901346)the Fundamental Research Funds for the Central Universities, Peking University。
文摘Global inland surface water bodies such as lakes and reservoirs,important components of the hydrosphere and ecosphere,are increasingly affected by climate change.Generating bathymetric volume-areaheight (BVAH) curves for global inland surface water bodies can enhance our understanding of their topography and climate impacts.However,accurately quantifying the topographic patterns of these water bodies remains challenging due to the difficulties in collecting comprehensive bathymetric data.Therefore,we collected and processed over 2000 bathymetric maps of global water bodies from over 50 different data sources and then developed the BVAH model.Finally,the BVAH hydrological curves of 16671 global inland surface water bodies (larger than 10 km~2) were generated.The results include but are not limited to (1) For most targeted water bodies,area (A) and volume (V) exhibit significant power function relationships with surface heights (H),with optimal power values quantified as 1.42 for A and 2.42 for V.(2) The BVAH model outperforms GLOBathy in estimating area and volume changes,achieving higher correlation coefficients (CC) of approximately 0.962 for the area and 0.991 for volume,and demonstrating lower percentages of root mean squared errors (PRMSE) around 10.9% for the area and 4.8% for volume.(3) In the case study of the Xizang Plateau and various large global reservoirs,the BVAH curve database can capture dynamic volume changes.As a unified simulation of the bathymetric topographical patterns,our bathymetric dataset and corresponding BVAH curve database have great potential to contribute to effective water resource management and ecological conservation efforts worldwide.
基金German BMBF(No. APR10 /810)Hunan Social Science Fund key Project(No. 12ZDB04)+1 种基金Innovation Group Foundation of China Education Department(No. IRT0916)International Project in Hunan Province(No. 2010WK3041)
文摘The coordinated development is the core of sustainable development and the hot issue of international research.Inland water transport(IWT) is an important part of the water resources exploiting system and comprehensive transport system under socio-economic context of river basin,and also the country's sustainable development priorities to achieve resource-conserving and environment-friendly strategy.Based on the coordinated development content,the paper combined Germany's successful development experience,explored the elements and problem of the coordinated development of IWT system of China's national economic strategy and basin economy,water resourse system,comprehensive transport system,and system itself,and their countermeasures and suggestions,in order to facilitate rapid and coordinated development of China's inland water transport.
文摘The persistent rise in concentrations of greenhouse gases (GHGs) in the earth’s atmosphere is responsible for global warming and climate change. Besides the known source of GHGs emissions like energy, industry, and agriculture, intrinsic emissions from natural inland water bodies like wetland, rivers, reservoirs, estuaries, etc. have also been identified as other hotspots of GHGs emission and gaining the attention of the scientific communities in recent times. Inland fisheries in India are threatened by climate changes such as a change in temperature, precipitation, droughts, storm, sea-level rise, saltwater intrusion, floods that affect mostly the production, productivity and ultimately affect the fishers’ livelihood. There are, however, different mitigation and adaptation strategies to cope with the effects of climate change. Carbon sequestration and other related management interventions are one of the options available minimizing GHGs emissions from inland open waters, particularly the wetlands and coastal mangroves which are well known worldwide for their significant role in the storage of carbon. Assessment of C efflux from exposed sediments in dry streams, reservoirs, lakes, rivers, and ponds into the atmosphere can be considered imperative for a better understanding of their role as a C-sink or as a C-source to the atmosphere.
基金supported by the National Natural Science Foundation of China (No. 31670473)the Key Program of the Chinese Academy of Sciences (No. ZDRW-ZS-2016-7-2)the Youth Innovation Promotion Association of CAS (No. 2020378)。
文摘Carbon dioxide(CO_(2)) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO_(2) emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO_(2) partial pressures(pCO_(2)) and degassing in a monsoonal river(Yue River)within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO_(2) with a mean ± standard deviation of 1474 ± 1614 μatm, leading to emissions of 557-971 mmol/m^(2)/day from river water to the atmosphere. Annual CO_(2) emissions were 1.6-2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO_(2) was positively correlated to anthropogenic land use(urban and farmland), and negatively correlated to forest cover. p CO_(2) also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict p CO_(2) . Farmland and urban land released nutrients and organic matter to the river system, driving riverine p CO_(2) enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO_(2) , which should be considered in future large-scale estimates of CO_(2) emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-340,KZCX2-YW-341)Key Project of Jilin Province Scientific and Technological Development Program (No. 20080425)
文摘This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended matter,concentration of chlorophyll-a and non-pigment matter absorption.Two field campaigns for spectra measurements with a total of 40 samples were carried out on June 13 and September 23,2008.The in-situ spectra were recalculated to the spectral bands and sensitivities of the instruments applied in this paper,i.e.Landsat TM,Alos and P6,by using the average method.And the recalculated spectra were used for estimating water quality variables by the single model and multivariate model.The results show that the multivariate model is superior to the single model as the multivariate model takes the combined effects of water components into consideration and can estimate water quality variables simultaneously.According to R2 and RMSE,Alos is superior to other sensors for water quality variables estimation although the precision of non-pigment matter absorption inversion performed the second.
基金This work was supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China(No.2017ZX07206)the National Natural Science Foundation of China(No.41977322)the National Natural Science Foundation of China(No.41907335).
文摘Due to significant differences in biotic and abiotic properties of soils compared to those of sediments,the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be applicable for estimating similar emissions from inlandwater sediments.We addressed this issue by incubating different types of sediments,(including lake,small river,and pond sediments)collected from 36 sites across the Yangtze River basin,under short-term experimentalwarming to explore the effects of climatewarming on sediment carbon emission and the underlying microbe-mediated mechanisms.Our results indicated that under climate warming Cc emissions were affected more than CH_(4) emissions,and that pond sediments may yield a greater relative contribution of CO_(2) to total carbon emissions than lake and river sediments.Warming-induced CO_(2) and CH_(4) increases involve different microbe-mediated mechanisms;Warming-induced sediment CO_(2) emissions were predicted to be directly positively driven by microbial community network modularity,which was significantly negatively affected by the quality and quantity of organic carbon and warming-induced variations in dissolved oxygen,Conversely,warminginduced sediment CH_(4) emissionswere predicted to be directly positively driven bymicrobial community network complexity,which was significantly negatively affected by warminginduced variations in pH.Our findings suggest that biotic and abiotic drivers for sediment CO_(2) and CH_(4) emissions in response to climate warming should be considered separately when predicting sediment organic carbon decomposition dynamics resulting from climate change.
基金financially supported by the National Natural Science Foundation of China(42293264 and 42293262)the Postdoctoral Fellowship Program of CPSF(GZC20241196)。
文摘Phytoplankton play a vital role in nutrient biogeochemical cycling,and their elemental ratios covary with available inorganic nutrients;however,the underlying interaction patterns and mechanisms remain unclear.Here,based on large-scale and long-term field surveys together with culture experiments,we found a stoichiometric convergence over time between phytoplankton nitrogen(N)∶carbon(C)molar ratios and dissolved inorganic N∶CO_(2)molar ratios.Functional genomics evidence demonstrated that this N-C stoichiometric convergence was driven by phytoplankton community succession with its matched N and C metabolism.A theoretical framework was proposed and proved applicable for depicting this convergence.The convergence speed was faster with the greater difference between phytoplankton and water N∶C molar ratios.Moreover,replacing CO_(2)with dissolved inorganic C could alter the direction of convergence.This stoichiometric convergence characterizes the response of phytoplankton elemental ratios to inorganic nutrient dynamics and represents an evolutionary pathway for phytoplankton community assembly over time.
基金This work was supported by the Key Project of the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX3-SW-350).
文摘China Brazil Earth Resource Satellite(CBERS)CCD images have much potential for inland water environmental monitoring.However,their atmospheric accuracy correction can affect their quantitative applications.This paper contains an atmospheric correction algorithm for CBERS CCD images with MODIS data from the same day,the use of which improves the atmospheric correction algorithm of ocean color remote sensing developed by Gordon(1993,1994)and makes it applicable to inland waters.The improved algorithm retrieves atmospheric parameters from MODIS data and uses them to perform the atmospheric correction of CBERS CCD images.Experimental results show that the atmospheric correction algorithm of CBERS CCD images assisted by MODIS data is reliable.Furthermore,MODIS data can be freely obtained on a daily basis,making the algorithm developed in this paper useful for environmental monitoring of inland waters.
基金supported by the following NASA programs:Making Earth System Data Records for Use in Research Environments(MEaSUREs)[NNX08AP33A]Land-Cover and Land-Use Change(LCLUC)[NNX08AN72G]Advancing Collaborative Connections for Earth System Science(ACCESS)[NNX12AH18A].
文摘The science and management of terrestrial ecosystems require accurate,high-resolution mapping of surface water.We produced a global,30-m-resolution inland surface water dataset with an automated algorithm using Landsat-based surface reflectance estimates,multispectral water and vegetation indices,terrain metrics,and prior coarse-resolution water masks.The dataset identified 3,650,723 km2 of inland water globally–nearly three quarters of which was located in North America(40.65%)and Asia(32.77%),followed by Europe(9.64%),Africa(8.47%),South America(6.91%),and Oceania(1.57%).Boreal forests contained the largest portion of terrestrial surface water(25.03%of the global total),followed by the nominal‘inland water’biome(16.36%),tundra(15.67%),and temperate broadleaf and mixed forests(13.91%).Agreement with respect to the Moderate-resolution Imaging Spectroradiometer water mask and Landsat-based national land-cover datasets was very high,with commission errors<4%and omission errors<14%relative to each.Most of these were accounted for in the seasonality of water cover,snow and ice,and clouds–effects which were compounded by differences in image acquisition date relative to reference datasets.The Global Land Cover Facility(GLCF)inland surface water dataset is available for open access at the GLCF website(http://www.landcover.org).
基金This study was supported by the Fundamental Research Funds for the Central Universities(No.2021ZY75)the National Natural Science Foundation of China(Grant No.52071030).
文摘Inland saline-alkaline water can be used for the low-cost cultivation of microalgae,but whether algal biomass under various light sources has the potential to produce biodiesel remains to be developed.Herein,the influence of different light-emitting diode(LEDs)light colors(blue,red,white,mixed blue-red,and mixed blue-white LED)on the growth performance,lipid accumulation,and fatty acid composition of Chlorella sp.HQ cultivated in inland saline-alkaline water was investigated.The highest algal density was obtained under blue LEDs at the end of cultivation,reaching 1.93±0.03 × 10^(7) cells/mL.White LEDs can improve biomass yield,total lipid yield,and triacylglycerol yield per algal cell.The main fatty acid components of Chlorella from inland saline-alkaline water were palmitic acid and linoleic acid.The Biodiesel Analyzer software was used to predict algal biodiesel quality by estimating different quality parameters.The cetane number,kinematic viscosity,and density of Chlorella biodiesel were 51.714-67.69,3.583-3.845 mm^(2)/s,and 0.834-0.863 g/cm^(3),respectively.This flirther proved that the Chlorella biomass obtained from inland saline-alkaline water has the potential to be used as a high-quality biodiesel feedstock.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20060402)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0202)+2 种基金the National Natural Science Foundation of China(91747204 and 4197130)the Shenzhen Science and Technology Innovation Committee(JCYJ20190809155205559)the Colleges Pearl River Scholar FundedScheme 2018.
文摘As essential parts of the unique ecosystem of Tibetan Plateau(TP),the sizes and associated physical properties of alpine lakes have long been investigated.However,little is known about one of the most critical biogeochemical properties,i.e.the Chlorophyll-a(Chl-a)concentrations.Here,for the first time,we presented a comprehensive investigation of the temporal–spatial variations in Chl-a in 82 lakes(>50 km^(2))across the entire TP region,based on MODIS observations in the period of 2003–2017.The results showed that the 82 lakes exhibited an average longterm mean Chl-a of 3.3±4.3 mg m^(−3),with high Chl-a lakes concentrated in the eastern and southern inner TP basin and northeastern parts of the TP.An interannual trend analysis revealed that lakes exhibiting(significantly)decreasing Chl-a trends and(significantly)increasing Chl-a trends were comparable in numbers but differed in distribution patterns.A correlation analysis indicated that at least 70%of the interannual variability in Chl-a values of lakes was significantly correlated with one of the four environmental factors(wind speed,ice cover duration,lake water surface temperature and surface runoff)and lake size.In addition,glacier meltwater tended to reduce lake Chl-a while salinity levels showed minor influences.
基金supported by the CRSRI Open Research Program(Program SN:CKWV20221009/KY)Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks(ZDSYS20220606100604008)+1 种基金High-level University Special Fund(G03050K001)the SUSTech Research Start-up Grants(Y01296129 and Y01296229).
文摘Satellite radar altimetry has become an essential tool for hydrological research over the past 2 decades.Unlike imagery that quantifies the water dynamics from the horizontal dimension,altimetry observations deliver vertical information,which is crucial for hydrological research.Geodetic mission(GM)altimetry data,characterized by long repeat periods compared to exact repeat missions,have been underutilized in hydrology.This paper aims to advocate for integrating geodetic altimetry data into inland water research and bring awareness to its potential applications.We demonstrated the values of GM data from CryoSat-2,Saral/AltiKa,Jason-1,and Jason-2 through 3 applications:(a)large-scale lake monitoring for improved understanding of regional and global hydrological cycles,(b)retrieval of local geoid undulations over large lakes to enhance the precision of individual water level observations,and(c)mapping river longitudinal profiles and construction of time series of river levels.We believe that the findings of this study will pave the way for more comprehensive utilization of geodetic altimetry data in diverse hydrological applications,ultimately advancing inland water altimetry.
基金supported by an Australian Government Research Training Program(RTP)Scholarship.
文摘The value of seaweed based pharmaceutical products has drastically increased in the past decade.Chaetomorpha linum(Chlorophyta)extract has been described to have a high level of antioxidants and bioactive compounds,however it is unknown how growth conditions,specifically the ionic profile of its culture media,may impact C.linum’s biochemical profile.This study tested growth,antioxidant activity,chlorophyll and mineral profile following culture in a 2×2 factorial methodology,with water type(inland saline water[ISW]or ocean water[OW])and nutrient enrichment(nitrate and phosphate)as co-factors.C.linum was cultivated for 20 days outdoors and fresh weight was recorded every five days.On day 10,50 g of seaweed was harvested,and mineral analysis and ultrasound-assisted extraction were performed.Extracts were tested for antioxidant activity and chlorophyll content.Antioxidant activity was not significantly different across treatments in ferric reducing antioxidant potential and total phenolic content assays,though specific growth rate was lower in ISW than OW treatments.Calcium content(mg.g^(-1) d.b.)was also significantly higher(p<0.001)in ISW than OW.This study found that short-term growth of C.linum in ISW can increase calcium content while maintaining the efficacy of its bioactive profile,presenting a new method for producing a mineral rich food or health supplement for human consumption.
基金This research work was supported by the Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD11)+1 种基金the Central Public-Interest Scientific Institution Basal Research Fund(No.Y2022QC18)the Conservation of Species Resources Fond of Chinese Ministry of Agriculture,“Ecological Environment Monitoring of Important Fishery Waters in China”。
文摘Water pollution seriously threatens the sustainable development of fisheries in China.To inform effective pollution control policies,a comprehensive understanding of the fishery environment status is needed.However,nationwide data on the temporal changes of major pollutants in the fishery waters of China are scarce.This study collected data on the major water pollutants,including total nitrogen,total phosphorus,heavy metals,and total petroleum hydrocarbons(TPHs),from 2003 to 2017 to evaluate dynamic changes in the inland fishery water environment across China.We discovered that the levels of four heavy metals(Cu,Zn,Pb,and Cd)and TPH decreased during the 15-year period,corresponding to the reduced national discharge of pollution sources from 2003 to 2015.However,nitrogen and phosphorus levels in the inland fishery waters showed no significant changes during this period.A comparative analysis of water quality in different periods indicated that these improvements were highly associated with effective measures for water pollution control in China.In addition,the decline in pollution was consistent among the three regions of China(north,west,and southeast)from 2003 to 2017,while southeast China exhibited the weakest pollution mitigation among the three regions.These findings suggest that the inland fishery water quality improved during 2003–2017,but still faced eutrophication risk.
