As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable development.H...As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable development.However,the long-term variation characteristics of surface water of different water body types in Northeast China remain rarely explored.This study investigated how surface water bodies of different types(e.g.,lake,reservoir,river,coastal aquaculture,marsh wetland,ephemeral water) changed during1999–2020 in Northeast China based on various remote sensing-based datasets.The results showed that surface water in Northeast China grew dramatically in the past two decades,with an equivalent area increasing from 24 394 km^(2) in 1999 to 34 595 km^(2) in 2020.The surge of ephemeral water is the primary driver of surface water expansion,which could ascribe to shifted precipitation pattern.Marsh wetlands,rivers,and reservoirs experienced a similar trend,with an approximate 20% increase at the interdecadal scale.By contrast,coastal aquacultures and natural lakes remain relatively stable.This study is expected to provide a more comprehensive investigation of the surface water variability in Northeast China and has important practical significance for the scientific management of different types of surface water.展开更多
Objective: The main objective of this study was to assess the degree of contamination of surface waters by heavy metals and pesticides. Method: To this end, data were collected in December 2022 from four specific samp...Objective: The main objective of this study was to assess the degree of contamination of surface waters by heavy metals and pesticides. Method: To this end, data were collected in December 2022 from four specific sampling stations: Okpara, Térou, Affon and Adjiro. Levels of heavy metals, including cadmium, chromium, copper, iron, mercury, nickel and lead, were measured and subjected to in-depth statistical analysis using graphical summation models. In addition, the concentrations of pesticide active ingredients present in the samples were interpreted and evaluated. The statistical data collected during this study were processed using R software, version 3.5.0. Results: The values obtained at the different stations Okpara, Térou, Affon and Adjiro are respectively Arsenic (2 × 10<sup>-4</sup> mg/L;2.2 × 10<sup>-1</sup> mg/L;1.2 × 10<sup>-4</sup> mg/L;2 × 10<sup>-4</sup> mg/L), Cadmium (4.4 × 10<sup>-5</sup> mg/L;1.1 × 10<sup>-2</sup> mg/L;10<sup>-4</sup> mg/L;4 × 10<sup>-4</sup> mg/L). Then Copper (7 × 10<sup>-4</sup> mg/L;3 × 10<sup>-3</sup> mg/L;7 × 10<sup>-4</sup> mg/L;1 × 10<sup>-4</sup> mg/L), Iron (1.51 mg/L;6.4 × 10<sup>-1</sup> mg/L;2.0012 mg/L;2.9 × 10<sup>-1</sup> mg/L), Lead (0 mg/L;0 mg/L;1.5 × 10<sup>-3</sup> mg/L;1.5 × 10<sup>-3</sup> mg/L). Mercury, nickel and chromium were not detected in surface waters. It is important to note that the values obtained for trace metals (Cadmium, Chromium, Copper, Iron, Mercury, nickel and chromium were not detected in surface waters. It is important to note that the values obtained for trace metals (cadmium, chromium, copper, iron, mercury, nickel and lead) were all below the guideline standards set by the WHO in 2006 for uncontaminated surface waters. This indicates that the surface waters of the Upper Ouémé were below acceptable contamination thresholds in terms of heavy metals. However, the presence of pesticide active ingredients such as cyfluthrin, endosulfan-alpha, endosulfan-beta, profenosfos, tihan, atrazine, gala super and glycel clearly indicates that these surface waters are subject to agricultural contamination.展开更多
In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing ...In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing industry with water of a required quality.Its solution is an urgent and difficult task.The water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in depth.As a rule,the water supply of large industrial enterprises is located along the river network.Mergers are the most important nodes of river systems.Understanding the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water quality.In recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has increased.The nature of the merger is influenced by the formation of transverse circulation.Within the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried out.Since the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing zone.These characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones.展开更多
Antibiotics are widely used in the process of human medical treatment,livestock and poultry breeding,and aquaculture.With the excretion of urine and feces,they enter the water environment of human life and become an i...Antibiotics are widely used in the process of human medical treatment,livestock and poultry breeding,and aquaculture.With the excretion of urine and feces,they enter the water environment of human life and become an important source of water environment pollution.Antibiotic residues in the environment have high ecological and health risks.Through the pilot monitoring of antibiotics in the main stream of the Yangtze River,Chaohu Lake and the drinking water source of Hefei City,the current situation and impact of antibiotic pollution were analyzed.The results show that 32 kinds of antibiotics and their derivatives of the six major categories involved were detected to varying degrees,and the concentrations at some points reached 1.26μg/L.Finally,the prevention and control of antibiotic pollution in the surface water of the Yangtze River basin in a province of central China were summarized,and relevant suggestions were given.展开更多
The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream regions.Trace metals flowed with river water can lead to serious impact on ecological system an...The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream regions.Trace metals flowed with river water can lead to serious impact on ecological system and human health.Nevertheless,the documentation on trace elements of Himalayan rivers is inadequately documented.The current study deals with the spatial and temporal variability of the major and trace elements of Ganga river water in epirhithron,metarhithron and hyporhithron zone belonging to Himalayan segment.Water samples from nineteen monitoring locations were collected in pre-monsoon(May-June),monsoon(AugustSeptember)and post-monsoon(December)seasons and subjected to be assessed for 20 elements(Ag,Al,Ba,Cd,Ca,Cr,Cu,Fe,Ga,K,Mn,Mg,Na,Ni,Pb,Sr,Th,U,Zn,and Zr)using ICP-OES(Inductively Coupled Plasma-Optical Emission Spectrometer).Different water pollution indexes such as HPI(Heavy Metal Pollution Index),MI(Metal Index)and PI(Pollution Index)were used to describe current water quality status at each monitoring station under particular classified ecological zone.The studied stations in hyporhithron zone had the value of Metal Index(MI>1),indicating threshold of warning.Further,the highest values of HPI in hyporhithron zone correspond to poor water quality status.Sites with poor water quality were also found to be contaminated as per the Pollution Index(PI),exhibiting high concentrations for element(Fe).However,the epirhithron and metarhithron zone in Himalayan segment showed excellent water quality mainly contributed from natural sources.Cluster Analysis(CA)and Principal Component Analysis(PCA)were applied to identify the main influential sources for Ganga river water pollution.The Kriging interpolation method was also applied to prepare spatial distribution map of computed indexes(HPI,MI,and PI).With the help of index of local Moran’s I(LMI),identified spatial clusters and spatial outliers revealed the elevated concentration of most elements in hyporhithron zone.The dataset presented in this study would be convenient for government officials in developing more effective management policies and necessary steps to check and monitor the Ganga river water quality.It was also suggested that further investigations in terms of trace elemental sources and their role in self-purification properties of Ganga water can be addressed in future.展开更多
Subterranean estuaries(STEs)are characterized by the mixing of terrestrial fresh groundwater and seawater in coastal aquifers.Although microorganisms are important components of coastal groundwater ecosystems and play...Subterranean estuaries(STEs)are characterized by the mixing of terrestrial fresh groundwater and seawater in coastal aquifers.Although microorganisms are important components of coastal groundwater ecosystems and play critical roles in biogeochemical transformations in STEs,limited information is available about how their community dynamics interact with hydrological,geochemical and environmental characteristics in STEs.Here,we studied bacterial and archaeal diversities and distributions with 16S rRNA-based Illumina MiSeq sequencing technology between surface water and groundwater in a karstic STE.Principal-coordinate analysis found that the bacterial and archaeal communities in the areas where algal blooms occurred were significantly separated from those in other stations without algal bloom occurrence.Canonical correspondence analysis showed that nutrients and salinity can explain the patterns of bacterial and archaeal community dynamics.The results suggest that hydrological,geochemical and environmental characteristics between surface water and groundwater likely control the bacterial and archaeal diversities and distributions in STEs.Furthermore,we found that some key species can utilize terrestrial pollutants such as nitrate and ammonia in STEs,indicating that these species(e.g.,Nitrosopumilus maritimus,Limnohabitans parvus and Simplicispira limi)may be excellent candidates for in situ degradation/remediation of coastal groundwater contaminations concerned with the nitrate and ammonia.Overall,this study reveals the coupling relationship between the microbial communities and hydrochemical environments in STEs,and provides a perspective of in situ degradation/remediation for coastal groundwater quality management.展开更多
China’s first Mars rover,Zhurong,successfully landed in the south of Utopia Planitia.The surface water content at the landing area can provide constraints on mineral formation conditions and help us better understand...China’s first Mars rover,Zhurong,successfully landed in the south of Utopia Planitia.The surface water content at the landing area can provide constraints on mineral formation conditions and help us better understand the evolution of the Martian aqueous and geological environment.In this work,the surface kinetic temperature of the Zhurong landing area was derived by analyzing data from the Mars Express Observatoire pour la Minéralogie,l’Eau,les Glaces et l’Activité(OMEGA)spectrometer.Using the Discrete Ordinate Radiative Transfer(DISORT)model,we performed atmospheric correction and thermal correction for the OMEGA data to obtain the surface effective single-particle absorption thickness(ESPAT)parameter to evaluate the surface water content.The surface water content distribution at the landing area was relatively uniform at a lateral scale of~10 km.At the Zhurong landing site,the surface water content in the topmost layer(a few hundred micrometers)of the regolith was 5−8 weight percent water(wt%H_(2)O),assuming surface particle sizes of<45μm,or 1.6−2.5 wt%H_(2)O,assuming surface particle sizes in the range of 125−250μm.The Mars Surface Composition Detector(MarSCoDe)onboard Zhurong also observed significant H_(2)O/OH signals in the landing area.Our results provide an important regional context for the hydration state of the area and can be further verified by the H content derived from the Laser-Induced Breakdown Spectrometer(LIBS)data of MarSCoDe.展开更多
Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater sample...Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater samples,twenty-four surface water and six surface sediment samples in Kinsevere industrial zone and its surroundings in February and march 2017,January,February and March 2018 to evaluate the potential human health risk.Chemical analyses were carried out by using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry,Thermo Scientific Element II).The trace metals were detected at various concentrations in all the analyzed samples.Pb,Mn and Fe concentrations exceeded the European Union acceptable maximum limits for water intended for human consumption in 4.76%,28.57%and 61.90%of the groundwater samples,respectively and in 0%,50%and 100%of the surface water samples,respectively.As,Cr,Cu and Ni concentrations exceeded the recommended lower sediment quality guideline values in 33.33%,50%,83.33%and 83.33%of the surface sediment samples,respectively.All those elevated trace metal concentrations in the groundwater,surface water and sediments represent a risk for the health of local population as well as for aquatic organisms.展开更多
A study aimed at evaluating the physicochemical and bacteriological quality of surface water was therefore carried out in a few watercourses in the municipality of Mbankomo, located in the Center Region (Cameroon). Th...A study aimed at evaluating the physicochemical and bacteriological quality of surface water was therefore carried out in a few watercourses in the municipality of Mbankomo, located in the Center Region (Cameroon). The physico-chemical parameters were measured according to the standard method. The organic pollution index (OPI) was determined from the contents of nitrates, phosphates, and ammoniacal nitrogen to characterize the level of organic pollution of the water. The microorganisms sought were total flora, indicators of faecal contamination like total coliforms, faecal coliforms, feacal streptococci and Escherichia coli, as well as the species Clostridium perfringens. The organic pollution index indicates a high-level organic pollution level during the small rainy season and high to moderate during the small dry season. High concentrations of the total and fecal coliforms, streptococci fecal, Escherichia coli and Clostridium perfringens respectively of 1712 × 10<sup>5</sup> CFU/100mL;82 × 10<sup>5</sup> CFU/100mL;10 × 10<sup>5</sup> CFU/100mL;27 × 10<sup>5</sup> and 40 × 10<sup>3</sup> CFU/100mL, all higher than WHO standards, indicate that the waterways of Mbankomo are subject to feacal pollution and harbor pathogenic microflora. The cell densities of main bacteria were significantly correlated with main abiotic parameters, such as Escherichia coli, which was significantly correlated with the pH of the water (r = 0.35;p < 0.05). The variation of organic pollution index category means correspond to a high level of organic pollution during the small rainy season and a high to moderate level during the small dry season. The deterioration of the quality of these waters is favored by their proximity to sources of pollution (toilets, plantation), the runoff of the waters contaminated, the use of detergents and wrong maintenance. These waters without any treatment are not recommendable for human consumption according to standards of the World Health Organization.展开更多
The Berg River Catchment based in the Western Cape Province,South Africa services the greater Cape Town area with water,subsequent to supplying the vast agricultural activities that exist in the middle and the lower r...The Berg River Catchment based in the Western Cape Province,South Africa services the greater Cape Town area with water,subsequent to supplying the vast agricultural activities that exist in the middle and the lower reaches.This study thus investigates the hydrogeochemical interactions between surface and groundwater in the Berg River Catchment with the aim of establishing trends and transfer of constituents between the surface and groundwater systems,investigates the role that geology plays in water chemistry as well as identifies the geochemical processes controlling surface and groundwater chemistry in the catchment.This study was carried out using three types of research designs namely i)experimental research design;ii)field research design and meta-analysis research design.Furthermore,the study made use of hydrochemical data ranging from 2003 to 2013 obtained from the National Water Monitoring Database owned and maintained by the Department of Water and Sanitation and data that were sampled in 2016 by authors and analyzed using the ICP-MS Technique Ground Water Chart,Arc-GIS and Geosoft(Oasis Montaj)were further employed to model the data.The results indicated that:i)in the Upper Berg there is not much interaction and transfer of constituents between surface and groundwater;ii)the Middle Berg,however,indicated a degree of interaction with the sharing of constituents between the two water systems and iii)the Lower Berg indicated only NaCl water type also noting that the area situated near the river mouth whereby there is the mixing of river and seawater.展开更多
[Objectives]To analyze the influence characteristics of surface water quality by agricultural non-point sources in Guigang City of Guangxi.[Methods]The daily concentration series of water quality indicators at three s...[Objectives]To analyze the influence characteristics of surface water quality by agricultural non-point sources in Guigang City of Guangxi.[Methods]The daily concentration series of water quality indicators at three state-controlled monitoring stations in Guigang City from^(2)019 to 2021 was analyzed by using Daubechies(db)wavelet,and Morlet wavelet was used to analyze the daily average concentration of water quality indicators.Continuous wavelet transform(CWT)was used to analyze the monthly concentration series of water quality indicators at three state-controlled monitoring stations in Guigang City from^(2)014 to 2021.[Results]The Daubechies(db)wavelet analysis showed that the concentrations of COD_(Mn),TP,and TN had the maximum values during June-July and October-November,and there were spatial differences among monitoring stations(COD_(Mn) concentration exceeding the standard was the most serious in Shizui,and DO concentration not up to standard was the most in Thermal Power Plant,and NH_(3)-N,TP and TN exceeding the standard was the most in Wulin Ferry).Morlet results showed that principal period of wavelet variance graphs of COD_(Mn),NH_(3)-N,and TP was 340 d,and there was the same sub-period of 140 d,and principal period of wavelet variance graph of DO was 260 d.CWT results showed that COD_(Cr) had similar resonance periods of about 1-2 and 5-7 months;BOD 5 and COD_(Mn) was dominant by the resonance period of 1-4 months(2014-2017);DO had a similar resonance period of about 1-3 months;NH_(3)-N was dominant by the resonance period of 1-5 months.[Conclusions]The surface water quality of Guigang City was mainly affected by the residual nitrogen and phosphorus nutrients and pesticide residues from agricultural production activities.展开更多
The hydrochemical composition of surface water and groundwater is a key parameter for understanding the evolution of water and its quality.In particular,little is known about the impact of transferred water on surface...The hydrochemical composition of surface water and groundwater is a key parameter for understanding the evolution of water and its quality.In particular,little is known about the impact of transferred water on surface water and groundwater.In this study,Baiyangdian Lake was selected as a typical area for extensive groundwater exploration and surface water transfer in the North China Plain.Surface water and groundwater samples were sampled in dry/wet seasons and then analyzed before/after the water transfer,respectively.Generally,surface water and groundwater are extensively hydrologically connected based on hydrochemical evidence.It was found that the hydrochemical composition of the shallow groundwater is affected by the surface water and that the water quality of the deep groundwater is stable.However,inter-aquifer recharge processes from the shallow groundwater to the deep groundwater existed in the anthropogenic region impacted with high nitrate-ion concentrations.Also,the hydrochemical composition of the surface water and groundwater was dominated by rock-weathering and evaporation-precipitation processes.Due to the existence of the deep vadose zone in the alluvial fan,Na^(+)was exchanged into soil matrices during the leakage of the surface water.In addition,the transferred water resulted in surface water with good quality,and it also played as an important recharge source to groundwater.As the most important water resource for irrigation and drinking,deep groundwater should be paid more attention in the alluvial fan with frequent water transfer and extensive groundwater exploration.展开更多
The Tibetan Plateau is known as the“Asian water tower”,and changes in its surface water distribution are important indicators of global climate change and the regional response to these changes.Dynamic monitoring of...The Tibetan Plateau is known as the“Asian water tower”,and changes in its surface water distribution are important indicators of global climate change and the regional response to these changes.Dynamic monitoring of the surface water on the Tibetan Plateau is an important part of the research on the functions of the“third pole”of the earth and the Asian water tower.With the support of the Google Earth Engine cloud platform,this study used a spectral index-based fast extraction method to obtain surface water data from multi-temporal Landsat(Landsat 4,5,and 8)satellite remote sensing images.Based on the extracted surface water data,we analyzed the spatiotemporal variations in the surface water of the Tibetan Plateau from 1980s to 2019.In this study,surface water area refers to the maximum coverage area of the surface water extracted from remote sensing images for one year,hereafter referred to as the surface water area.The results show that since 1980s,the overall surface water area of the Tibetan Plateau has increased,but not in a linear fashion.After a slight decrease from 1980s to 1995,the surface water area of the Tibetan Plateau increased steadily,except for a slight decrease in 2015,which may have been caused by the El Niño phenomenon.In terms of spatiotemporal distribution,different patterns exist in the various ecological regions of the Tibetan Plateau.The Inner ecological region had the greatest changes of surface water area among the ten ecological regions,accounting for 71.0%of the total surface water area increase from 1980s to 2019.The surface water bodies in the cold desert and the dry-winter subtropical climatic regions underwent the most changes,with their coefficients of variation being more than 20%.This study can provide data support for dynamic monitoring of surface water in the Tibetan Plateau.展开更多
To study the current status and causes of the microplastic pollution in surface water of the Qinghai-Tibet Plateau,this paper compared the average microplastic abundance in sediments and surface water of the Qinghai-T...To study the current status and causes of the microplastic pollution in surface water of the Qinghai-Tibet Plateau,this paper compared the average microplastic abundance in sediments and surface water of the Qinghai-Tibet Plateau and the results are as follows.First,the average microplastic abundance in surface water of the independent rivers and the whole area is 247−2686 items/m^(3) and 856 items/m^(3),respectively.The average microplastic abundance in sediments of independent rivers or lakes and the whole area is 0−933 items/m^(2) and 362 items/m^(2),respectively.Meanwhile,the degree of microplastic pollution in river sediments is higher than that in lake sediments,and the rivers suffering from microplastic pollution mainly include the Brahmaputra River,Tongtian River,and Nujiang River.Second,compared with the microplastic pollution in other areas of the world,the levelof microplastic pollution in the lakes and rivers of the Qinghai-Tibet plateau is not lower than that of well-developed areas with more intensive human activities.Finally,this study suggests that relevant government departments of the Qinghai-Tibet Plateau should strengthen waste management strategies while developing tourism and that much attention should be paid to the impacts of microplastics in the water environment.展开更多
Owing to the significant reductions in streamflow and an increase in human activities in recent years,the quality of surface water in Weihe River continues to pose environmental health concerns.We utilized hydrochemis...Owing to the significant reductions in streamflow and an increase in human activities in recent years,the quality of surface water in Weihe River continues to pose environmental health concerns.We utilized hydrochemistry and nitrogen and oxygen isotopes to elucidate the status and identify sources of nitrate pollution in the south and north banks for three seasons(flood,dry,and mean-flow periods)in the Weihe River watershed.A Bayesian isotope mixing model was applied to estimate the contributions of four potential NO_(3)-sources to river pollution(manure and sewage,soil nitrogen,inorganic fertilizer,and nitrate in precipitation).The U.S.Environmental Protection Agency(USEPA)evaluation model was implemented to evaluate the health risks associated with nitrate pollution in the surface water.Nitrate pollution was most severe during the dry period because the river flow was small.Due to the influence of the topography and land use type of the Weihe River,the pollution in the main stream was greater than that of the tributaries,and the pollution of the south bank was greater than that of the north bank.During the flood and mean-flow periods,δ^(15)N and δ^(18)O were mainly distributed in the NH_(4)^(+) of the fertilizer and soil nitrogen.During the dry period,δ^(15)N and δ^(18)O were mainly distributed in domestic sewage and manure regions.According to the Stable Isotope Analysis in R(SIAR)model,manure and sewage were the major nitrate sources during the dry period(73%).However,a decrease in the contribution from domestic sewage and manure was observed during the flood period(45%)compared to the dry period,but with a significantly increased contribution from soil nitrogen(23%)and inorganic fertilizer(21%).The health risk value in the dry period was higher than that in the wet and mean flow periods,and children are more susceptible to nitrate pollution than adults.Therefore,reducing the discharge of domestic sewage and manure and improving the utilization rate of nitrogen fertilizers may be effective measures to improve water quality in the watershed.展开更多
A large number of antibiotics have been discharged into rivers by human activities,posing a threat to aquatic ecosystems.The surface water of the Yellow River Basin also suffers antibiotic pollution,which hinders the ...A large number of antibiotics have been discharged into rivers by human activities,posing a threat to aquatic ecosystems.The surface water of the Yellow River Basin also suffers antibiotic pollution,which hinders the improvement in the aquatic ecological environment.This study investigated and analyzed the characteristics and assessed the ecological risks of antibiotic pollution in surface water bodies such as canals,rivers and fish ponds in Kaifeng,Henan Province,which is a key city along the lower reaches of the Yellow River.The test results are as follows.A total of 15 types of antibiotics were detected in the surface water.They had a total antibiotic concentration of 12.2-249.9μg/L,of which tetracyclines(TCs)and quinolones accounted for the highest percentages.Six types of quinolones had detection rates of up to 100%,and doxycycline(DC)and oxytetracycline(OTC)had average concentrations of 29.52μg/L1 and 13.71μg/L,respectively.The major canals with water diverted from the Yellow River had total concentrations of quinolones and TCs of 22.0μg/L and 14.9μg/L,respectively,which were higher than those in previous studies.This phenomenon may be related to the decrease in the water flow of the Yellow River during the dry season and the increase in the antibiotic consumption of residents in the context of the Covid-19 outbreak.The upper reaches of the Huiji River in the Xiangfu District had higher antibiotic content than other districts in Kaifeng.Specifically,TCs accounted for 72.38%-91.84%of all antibiotics,and the DC and OTC concentrations were significantly higher than other antibiotics in the upper reaches.As indicated by the ecological risk assessment results,TCs had the highest ecological risks to green algae.Among them,DC had medium-high risks;TC,OTC,and chlortetracycline(CTC)had medium-high risks;trimethoprim(TMP)and lomefloxacin(LOM)had low risks;other TC antibiotics had no risk.Compared with green algae,most antibiotics showed higher ecological risks to daphnia and lower ecological risks to fish.DC and OTC dominate antibiotic pollutants in the surface water in Kaifeng City,and especially in Xiangfu District,where DC and OTC have medium-high risks.The TCs in the major Yellow River showed medium risks to both green algae and daphnia.It can be speculated that the antibiotic pollution in the Yellow River might pose a certain threat to the ecological security of water in Kaifeng City.展开更多
The study aims to identify a suitable site for open and bore well in a farmhouseusing ground magnetic survey in south India.It also aims to define depth to granitoid and structural elements which traverse the selected...The study aims to identify a suitable site for open and bore well in a farmhouseusing ground magnetic survey in south India.It also aims to define depth to granitoid and structural elements which traverse the selected area.Magnetic data(n=84)measured,processed and interpreted as qualitative and quantitatively.The results of total magnetic intensities indicate that the area is composed of linear magnetic lows trending NE-SW direction and circular to semi-circular causative bodies.The magnetic values ranged from-137 nT to 2345 nT with a mean of 465 nT.Reduction to equator shows significant shifting of causative bodies in the southern and northern directions.Analytical signal map shows exact boundary of granitic bodies.Cosine directional filter has brought out structural element trending NE-SW direction.Results of individual profile brought to light structurally weak zone between 90 m and 100 m in all the profile lines.Sudden decrease of magnetic values from 2042 nT to 126 nT noticed in profile line 6 between 20 m and 30 m indicates fault occurrence.Magnetic breaks obtained from these maps were visualized,interpreted and identified two suitable sites for open and bore well.Radially averaged power spectrum estimates depth of shallow and deep sources in 5 m and 50 m,respectively.Euler method has also been applied to estimate depth of granitoid and structural elements using structural indexes 0,1,2,and 3 and found depth ranges from<10 m to>90 m.Study indicates magnetic method is one of the geophysical methods suitable for groundwater exploration and site selection for open and borewells.展开更多
Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment meth...Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.展开更多
The purpose of this study is to investigate the effect of using Bicarbonate and Calcium parameters as alternatives to the lithostratigraphic units covered the catchment area, on water quality index (WQI) values that h...The purpose of this study is to investigate the effect of using Bicarbonate and Calcium parameters as alternatives to the lithostratigraphic units covered the catchment area, on water quality index (WQI) values that have been implemented with GIS technique at Wadi Al-Arab Dam. The analyzed results (by WQI method) have been used to depict water quality for the two approaches. Based on physico-chemical parameters, the calculated values for WQI over the 3-year for study period were 169, 168, and 157, respectively. While the WQI values were 184, 183 and 172, respectively, as a result of incorporated Bicarbonate and Calcium parameters in WQI calculations that significantly contributed to increasing the WQI. The elevated values may be attributed to the influence of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent during winter season in the catchment area. As a consequence of lithostratigraphic unites product and GIS technique integration and normalization processes, most of water quality ranks are good and only autumn season has poor water quality in the 2012 and 2013, while in 2014 it has good water quality in the same season. The WQI values increase in general trend from winter to autumn seasons during the study period that may be referred to outflow by daily consumption, evaporation rising, and seepage water. The analysis shows that the modified water quality values of the Wadi Al-Arab Dam Reservoir (WADR) vary after using Bicarbonate and Calcium parameters by constant value. Generally, the results signify that the WADR is not polluted based on the physical and chemical characteristics of water.展开更多
Coal mining has changed the hydrogeological conditions of river basins,and studying how the relationship among different types of water body has changed under the influence of coal mining is of great significance for ...Coal mining has changed the hydrogeological conditions of river basins,and studying how the relationship among different types of water body has changed under the influence of coal mining is of great significance for understanding the regional hydrological cycle.We analyzed the temporal and spatial distribution of hydrochemical properties and environmental isotopes in the Hailiutu River Basin(HRB),China with a mixed model.The results showed that:(1)human activity(e.g.,coal mining and agricultural production)causes considerable changes in the hydrochemical properties of surface water in and around the mining areas,and leads to significant increases in the concentrations of Na^(+)and SO_(4)^(2-);(2)precipitation is the main source of water vapour in the HRB.The transformation between surface water and groundwater in the natural watershed is mainly affected by precipitation;and(3)in the mining areas,the average contribution rates of precipitation to the recharge of surface water and groundwater increased by 2.6%-7.9%and 2.7%-9.9%,respectively.Groundwater in the Salawusu Formation constitutes up to 61.3%-72.4%of mine water.Overall,this study is beneficial for quantifying the effects of coal mining on local hydrological cycles.The research results can provide a reference for local water resources management and ecological environment improvement.展开更多
基金Under the auspices of Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28020503,XDA23100102)National Key Research and Development Program of China(No.2019YFA0607101)+1 种基金Project of China Geological Survey(No.DD20230505)Excellent Scientific Research and Innovation Team of Universities in Anhui Province(No.2023AH010071)。
文摘As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable development.However,the long-term variation characteristics of surface water of different water body types in Northeast China remain rarely explored.This study investigated how surface water bodies of different types(e.g.,lake,reservoir,river,coastal aquaculture,marsh wetland,ephemeral water) changed during1999–2020 in Northeast China based on various remote sensing-based datasets.The results showed that surface water in Northeast China grew dramatically in the past two decades,with an equivalent area increasing from 24 394 km^(2) in 1999 to 34 595 km^(2) in 2020.The surge of ephemeral water is the primary driver of surface water expansion,which could ascribe to shifted precipitation pattern.Marsh wetlands,rivers,and reservoirs experienced a similar trend,with an approximate 20% increase at the interdecadal scale.By contrast,coastal aquacultures and natural lakes remain relatively stable.This study is expected to provide a more comprehensive investigation of the surface water variability in Northeast China and has important practical significance for the scientific management of different types of surface water.
文摘Objective: The main objective of this study was to assess the degree of contamination of surface waters by heavy metals and pesticides. Method: To this end, data were collected in December 2022 from four specific sampling stations: Okpara, Térou, Affon and Adjiro. Levels of heavy metals, including cadmium, chromium, copper, iron, mercury, nickel and lead, were measured and subjected to in-depth statistical analysis using graphical summation models. In addition, the concentrations of pesticide active ingredients present in the samples were interpreted and evaluated. The statistical data collected during this study were processed using R software, version 3.5.0. Results: The values obtained at the different stations Okpara, Térou, Affon and Adjiro are respectively Arsenic (2 × 10<sup>-4</sup> mg/L;2.2 × 10<sup>-1</sup> mg/L;1.2 × 10<sup>-4</sup> mg/L;2 × 10<sup>-4</sup> mg/L), Cadmium (4.4 × 10<sup>-5</sup> mg/L;1.1 × 10<sup>-2</sup> mg/L;10<sup>-4</sup> mg/L;4 × 10<sup>-4</sup> mg/L). Then Copper (7 × 10<sup>-4</sup> mg/L;3 × 10<sup>-3</sup> mg/L;7 × 10<sup>-4</sup> mg/L;1 × 10<sup>-4</sup> mg/L), Iron (1.51 mg/L;6.4 × 10<sup>-1</sup> mg/L;2.0012 mg/L;2.9 × 10<sup>-1</sup> mg/L), Lead (0 mg/L;0 mg/L;1.5 × 10<sup>-3</sup> mg/L;1.5 × 10<sup>-3</sup> mg/L). Mercury, nickel and chromium were not detected in surface waters. It is important to note that the values obtained for trace metals (Cadmium, Chromium, Copper, Iron, Mercury, nickel and chromium were not detected in surface waters. It is important to note that the values obtained for trace metals (cadmium, chromium, copper, iron, mercury, nickel and lead) were all below the guideline standards set by the WHO in 2006 for uncontaminated surface waters. This indicates that the surface waters of the Upper Ouémé were below acceptable contamination thresholds in terms of heavy metals. However, the presence of pesticide active ingredients such as cyfluthrin, endosulfan-alpha, endosulfan-beta, profenosfos, tihan, atrazine, gala super and glycel clearly indicates that these surface waters are subject to agricultural contamination.
基金financial support from the Government of the Perm Territory within the Framework of Scientific Project No.S-26/828the Ministry of Science and High Education of Russia(Theme No.121031700169-1).
文摘In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing industry with water of a required quality.Its solution is an urgent and difficult task.The water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in depth.As a rule,the water supply of large industrial enterprises is located along the river network.Mergers are the most important nodes of river systems.Understanding the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water quality.In recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has increased.The nature of the merger is influenced by the formation of transverse circulation.Within the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried out.Since the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing zone.These characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones.
文摘Antibiotics are widely used in the process of human medical treatment,livestock and poultry breeding,and aquaculture.With the excretion of urine and feces,they enter the water environment of human life and become an important source of water environment pollution.Antibiotic residues in the environment have high ecological and health risks.Through the pilot monitoring of antibiotics in the main stream of the Yangtze River,Chaohu Lake and the drinking water source of Hefei City,the current situation and impact of antibiotic pollution were analyzed.The results show that 32 kinds of antibiotics and their derivatives of the six major categories involved were detected to varying degrees,and the concentrations at some points reached 1.26μg/L.Finally,the prevention and control of antibiotic pollution in the surface water of the Yangtze River basin in a province of central China were summarized,and relevant suggestions were given.
基金the Doon University,Dehradun,India,for the financial support to carry out the research work。
文摘The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream regions.Trace metals flowed with river water can lead to serious impact on ecological system and human health.Nevertheless,the documentation on trace elements of Himalayan rivers is inadequately documented.The current study deals with the spatial and temporal variability of the major and trace elements of Ganga river water in epirhithron,metarhithron and hyporhithron zone belonging to Himalayan segment.Water samples from nineteen monitoring locations were collected in pre-monsoon(May-June),monsoon(AugustSeptember)and post-monsoon(December)seasons and subjected to be assessed for 20 elements(Ag,Al,Ba,Cd,Ca,Cr,Cu,Fe,Ga,K,Mn,Mg,Na,Ni,Pb,Sr,Th,U,Zn,and Zr)using ICP-OES(Inductively Coupled Plasma-Optical Emission Spectrometer).Different water pollution indexes such as HPI(Heavy Metal Pollution Index),MI(Metal Index)and PI(Pollution Index)were used to describe current water quality status at each monitoring station under particular classified ecological zone.The studied stations in hyporhithron zone had the value of Metal Index(MI>1),indicating threshold of warning.Further,the highest values of HPI in hyporhithron zone correspond to poor water quality status.Sites with poor water quality were also found to be contaminated as per the Pollution Index(PI),exhibiting high concentrations for element(Fe).However,the epirhithron and metarhithron zone in Himalayan segment showed excellent water quality mainly contributed from natural sources.Cluster Analysis(CA)and Principal Component Analysis(PCA)were applied to identify the main influential sources for Ganga river water pollution.The Kriging interpolation method was also applied to prepare spatial distribution map of computed indexes(HPI,MI,and PI).With the help of index of local Moran’s I(LMI),identified spatial clusters and spatial outliers revealed the elevated concentration of most elements in hyporhithron zone.The dataset presented in this study would be convenient for government officials in developing more effective management policies and necessary steps to check and monitor the Ganga river water quality.It was also suggested that further investigations in terms of trace elemental sources and their role in self-purification properties of Ganga water can be addressed in future.
基金The National Key R&D Program of China under contract No.2022YFE0209300the National Natural Science Foundation of China under contract No.42006152+1 种基金the Zhejiang Provincial Natural Science Foundation of China under contract No.LQ21D060005the 111 Project under contract No.BP0820020.
文摘Subterranean estuaries(STEs)are characterized by the mixing of terrestrial fresh groundwater and seawater in coastal aquifers.Although microorganisms are important components of coastal groundwater ecosystems and play critical roles in biogeochemical transformations in STEs,limited information is available about how their community dynamics interact with hydrological,geochemical and environmental characteristics in STEs.Here,we studied bacterial and archaeal diversities and distributions with 16S rRNA-based Illumina MiSeq sequencing technology between surface water and groundwater in a karstic STE.Principal-coordinate analysis found that the bacterial and archaeal communities in the areas where algal blooms occurred were significantly separated from those in other stations without algal bloom occurrence.Canonical correspondence analysis showed that nutrients and salinity can explain the patterns of bacterial and archaeal community dynamics.The results suggest that hydrological,geochemical and environmental characteristics between surface water and groundwater likely control the bacterial and archaeal diversities and distributions in STEs.Furthermore,we found that some key species can utilize terrestrial pollutants such as nitrate and ammonia in STEs,indicating that these species(e.g.,Nitrosopumilus maritimus,Limnohabitans parvus and Simplicispira limi)may be excellent candidates for in situ degradation/remediation of coastal groundwater contaminations concerned with the nitrate and ammonia.Overall,this study reveals the coupling relationship between the microbial communities and hydrochemical environments in STEs,and provides a perspective of in situ degradation/remediation for coastal groundwater quality management.
基金funded by the National Key Research and Development Project(Grant No.2019YFE0123300)the National Natural Science Foundation of China(Grant No.42072337)+1 种基金the preresearch project on Civil Aerospace Technologies(Grant Nos.D020101 and D020102)funded by the China National Space Administration through the Pandeng Program of the National Space Science Center,Chinese Academy of Sciences,Key Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-SSW-TLC001).
文摘China’s first Mars rover,Zhurong,successfully landed in the south of Utopia Planitia.The surface water content at the landing area can provide constraints on mineral formation conditions and help us better understand the evolution of the Martian aqueous and geological environment.In this work,the surface kinetic temperature of the Zhurong landing area was derived by analyzing data from the Mars Express Observatoire pour la Minéralogie,l’Eau,les Glaces et l’Activité(OMEGA)spectrometer.Using the Discrete Ordinate Radiative Transfer(DISORT)model,we performed atmospheric correction and thermal correction for the OMEGA data to obtain the surface effective single-particle absorption thickness(ESPAT)parameter to evaluate the surface water content.The surface water content distribution at the landing area was relatively uniform at a lateral scale of~10 km.At the Zhurong landing site,the surface water content in the topmost layer(a few hundred micrometers)of the regolith was 5−8 weight percent water(wt%H_(2)O),assuming surface particle sizes of<45μm,or 1.6−2.5 wt%H_(2)O,assuming surface particle sizes in the range of 125−250μm.The Mars Surface Composition Detector(MarSCoDe)onboard Zhurong also observed significant H_(2)O/OH signals in the landing area.Our results provide an important regional context for the hydration state of the area and can be further verified by the H content derived from the Laser-Induced Breakdown Spectrometer(LIBS)data of MarSCoDe.
基金This study was carried out in the framework of the research project entitled“Assessing and Mapping the Environmental and Health Impacts of Abandoned and Ongoing Mining Activities in Lubumbashi and Its Neighborhood,Democratic Republic of Congo”with UNESCO-Sida Project funds(Contract No.4500309530).
文摘Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater samples,twenty-four surface water and six surface sediment samples in Kinsevere industrial zone and its surroundings in February and march 2017,January,February and March 2018 to evaluate the potential human health risk.Chemical analyses were carried out by using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry,Thermo Scientific Element II).The trace metals were detected at various concentrations in all the analyzed samples.Pb,Mn and Fe concentrations exceeded the European Union acceptable maximum limits for water intended for human consumption in 4.76%,28.57%and 61.90%of the groundwater samples,respectively and in 0%,50%and 100%of the surface water samples,respectively.As,Cr,Cu and Ni concentrations exceeded the recommended lower sediment quality guideline values in 33.33%,50%,83.33%and 83.33%of the surface sediment samples,respectively.All those elevated trace metal concentrations in the groundwater,surface water and sediments represent a risk for the health of local population as well as for aquatic organisms.
文摘A study aimed at evaluating the physicochemical and bacteriological quality of surface water was therefore carried out in a few watercourses in the municipality of Mbankomo, located in the Center Region (Cameroon). The physico-chemical parameters were measured according to the standard method. The organic pollution index (OPI) was determined from the contents of nitrates, phosphates, and ammoniacal nitrogen to characterize the level of organic pollution of the water. The microorganisms sought were total flora, indicators of faecal contamination like total coliforms, faecal coliforms, feacal streptococci and Escherichia coli, as well as the species Clostridium perfringens. The organic pollution index indicates a high-level organic pollution level during the small rainy season and high to moderate during the small dry season. High concentrations of the total and fecal coliforms, streptococci fecal, Escherichia coli and Clostridium perfringens respectively of 1712 × 10<sup>5</sup> CFU/100mL;82 × 10<sup>5</sup> CFU/100mL;10 × 10<sup>5</sup> CFU/100mL;27 × 10<sup>5</sup> and 40 × 10<sup>3</sup> CFU/100mL, all higher than WHO standards, indicate that the waterways of Mbankomo are subject to feacal pollution and harbor pathogenic microflora. The cell densities of main bacteria were significantly correlated with main abiotic parameters, such as Escherichia coli, which was significantly correlated with the pH of the water (r = 0.35;p < 0.05). The variation of organic pollution index category means correspond to a high level of organic pollution during the small rainy season and a high to moderate level during the small dry season. The deterioration of the quality of these waters is favored by their proximity to sources of pollution (toilets, plantation), the runoff of the waters contaminated, the use of detergents and wrong maintenance. These waters without any treatment are not recommendable for human consumption according to standards of the World Health Organization.
文摘The Berg River Catchment based in the Western Cape Province,South Africa services the greater Cape Town area with water,subsequent to supplying the vast agricultural activities that exist in the middle and the lower reaches.This study thus investigates the hydrogeochemical interactions between surface and groundwater in the Berg River Catchment with the aim of establishing trends and transfer of constituents between the surface and groundwater systems,investigates the role that geology plays in water chemistry as well as identifies the geochemical processes controlling surface and groundwater chemistry in the catchment.This study was carried out using three types of research designs namely i)experimental research design;ii)field research design and meta-analysis research design.Furthermore,the study made use of hydrochemical data ranging from 2003 to 2013 obtained from the National Water Monitoring Database owned and maintained by the Department of Water and Sanitation and data that were sampled in 2016 by authors and analyzed using the ICP-MS Technique Ground Water Chart,Arc-GIS and Geosoft(Oasis Montaj)were further employed to model the data.The results indicated that:i)in the Upper Berg there is not much interaction and transfer of constituents between surface and groundwater;ii)the Middle Berg,however,indicated a degree of interaction with the sharing of constituents between the two water systems and iii)the Lower Berg indicated only NaCl water type also noting that the area situated near the river mouth whereby there is the mixing of river and seawater.
基金Supported by Basic Scientific Research Ability Improvement Project of Young and Middle-aged Teachers in Guangxi Colleges and Universities in 2021(2021KY1970).
文摘[Objectives]To analyze the influence characteristics of surface water quality by agricultural non-point sources in Guigang City of Guangxi.[Methods]The daily concentration series of water quality indicators at three state-controlled monitoring stations in Guigang City from^(2)019 to 2021 was analyzed by using Daubechies(db)wavelet,and Morlet wavelet was used to analyze the daily average concentration of water quality indicators.Continuous wavelet transform(CWT)was used to analyze the monthly concentration series of water quality indicators at three state-controlled monitoring stations in Guigang City from^(2)014 to 2021.[Results]The Daubechies(db)wavelet analysis showed that the concentrations of COD_(Mn),TP,and TN had the maximum values during June-July and October-November,and there were spatial differences among monitoring stations(COD_(Mn) concentration exceeding the standard was the most serious in Shizui,and DO concentration not up to standard was the most in Thermal Power Plant,and NH_(3)-N,TP and TN exceeding the standard was the most in Wulin Ferry).Morlet results showed that principal period of wavelet variance graphs of COD_(Mn),NH_(3)-N,and TP was 340 d,and there was the same sub-period of 140 d,and principal period of wavelet variance graph of DO was 260 d.CWT results showed that COD_(Cr) had similar resonance periods of about 1-2 and 5-7 months;BOD 5 and COD_(Mn) was dominant by the resonance period of 1-4 months(2014-2017);DO had a similar resonance period of about 1-3 months;NH_(3)-N was dominant by the resonance period of 1-5 months.[Conclusions]The surface water quality of Guigang City was mainly affected by the residual nitrogen and phosphorus nutrients and pesticide residues from agricultural production activities.
基金financially supported by the National Key Research and Development Program of China(Grant Nos.2016YFC0401407 and 2018YFC0506904)the National Natural Science Foundation of China(Grant No.41971037)。
文摘The hydrochemical composition of surface water and groundwater is a key parameter for understanding the evolution of water and its quality.In particular,little is known about the impact of transferred water on surface water and groundwater.In this study,Baiyangdian Lake was selected as a typical area for extensive groundwater exploration and surface water transfer in the North China Plain.Surface water and groundwater samples were sampled in dry/wet seasons and then analyzed before/after the water transfer,respectively.Generally,surface water and groundwater are extensively hydrologically connected based on hydrochemical evidence.It was found that the hydrochemical composition of the shallow groundwater is affected by the surface water and that the water quality of the deep groundwater is stable.However,inter-aquifer recharge processes from the shallow groundwater to the deep groundwater existed in the anthropogenic region impacted with high nitrate-ion concentrations.Also,the hydrochemical composition of the surface water and groundwater was dominated by rock-weathering and evaporation-precipitation processes.Due to the existence of the deep vadose zone in the alluvial fan,Na^(+)was exchanged into soil matrices during the leakage of the surface water.In addition,the transferred water resulted in surface water with good quality,and it also played as an important recharge source to groundwater.As the most important water resource for irrigation and drinking,deep groundwater should be paid more attention in the alluvial fan with frequent water transfer and extensive groundwater exploration.
基金This study was funded by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0307)the National Natural Science Foundation of China(NSFC,Grant No.61731022)the National Key Research and Development Program of China(Grant No.2016YFA0600302).
文摘The Tibetan Plateau is known as the“Asian water tower”,and changes in its surface water distribution are important indicators of global climate change and the regional response to these changes.Dynamic monitoring of the surface water on the Tibetan Plateau is an important part of the research on the functions of the“third pole”of the earth and the Asian water tower.With the support of the Google Earth Engine cloud platform,this study used a spectral index-based fast extraction method to obtain surface water data from multi-temporal Landsat(Landsat 4,5,and 8)satellite remote sensing images.Based on the extracted surface water data,we analyzed the spatiotemporal variations in the surface water of the Tibetan Plateau from 1980s to 2019.In this study,surface water area refers to the maximum coverage area of the surface water extracted from remote sensing images for one year,hereafter referred to as the surface water area.The results show that since 1980s,the overall surface water area of the Tibetan Plateau has increased,but not in a linear fashion.After a slight decrease from 1980s to 1995,the surface water area of the Tibetan Plateau increased steadily,except for a slight decrease in 2015,which may have been caused by the El Niño phenomenon.In terms of spatiotemporal distribution,different patterns exist in the various ecological regions of the Tibetan Plateau.The Inner ecological region had the greatest changes of surface water area among the ten ecological regions,accounting for 71.0%of the total surface water area increase from 1980s to 2019.The surface water bodies in the cold desert and the dry-winter subtropical climatic regions underwent the most changes,with their coefficients of variation being more than 20%.This study can provide data support for dynamic monitoring of surface water in the Tibetan Plateau.
基金funded by the survey projects initiated by the Ministry of Natural Resources of the People’s Republic of China(DD20189220,1212010741003,1212011220224,and 121201011000150022)the Public Welfare Scientific Research Project launched by the Ministry of Natural Resources of the People’s Republic of China(201111020)+3 种基金the project of 2015 Natural Science Basic Research Plan of Shaanxi Province(2015JM4129)the project of 2016 Fundamental Research Funds for the Central Universities(open fund310829161128)the project of 2021 Fundamental Research Funds for the Central Universities(open fund).
文摘To study the current status and causes of the microplastic pollution in surface water of the Qinghai-Tibet Plateau,this paper compared the average microplastic abundance in sediments and surface water of the Qinghai-Tibet Plateau and the results are as follows.First,the average microplastic abundance in surface water of the independent rivers and the whole area is 247−2686 items/m^(3) and 856 items/m^(3),respectively.The average microplastic abundance in sediments of independent rivers or lakes and the whole area is 0−933 items/m^(2) and 362 items/m^(2),respectively.Meanwhile,the degree of microplastic pollution in river sediments is higher than that in lake sediments,and the rivers suffering from microplastic pollution mainly include the Brahmaputra River,Tongtian River,and Nujiang River.Second,compared with the microplastic pollution in other areas of the world,the levelof microplastic pollution in the lakes and rivers of the Qinghai-Tibet plateau is not lower than that of well-developed areas with more intensive human activities.Finally,this study suggests that relevant government departments of the Qinghai-Tibet Plateau should strengthen waste management strategies while developing tourism and that much attention should be paid to the impacts of microplastics in the water environment.
基金supported by National Natural Science Foundation of China(Grant No.41601017)Young Talent fund of University Association for Science and Technology in Shaanxi,China(Grant No.20190702)。
文摘Owing to the significant reductions in streamflow and an increase in human activities in recent years,the quality of surface water in Weihe River continues to pose environmental health concerns.We utilized hydrochemistry and nitrogen and oxygen isotopes to elucidate the status and identify sources of nitrate pollution in the south and north banks for three seasons(flood,dry,and mean-flow periods)in the Weihe River watershed.A Bayesian isotope mixing model was applied to estimate the contributions of four potential NO_(3)-sources to river pollution(manure and sewage,soil nitrogen,inorganic fertilizer,and nitrate in precipitation).The U.S.Environmental Protection Agency(USEPA)evaluation model was implemented to evaluate the health risks associated with nitrate pollution in the surface water.Nitrate pollution was most severe during the dry period because the river flow was small.Due to the influence of the topography and land use type of the Weihe River,the pollution in the main stream was greater than that of the tributaries,and the pollution of the south bank was greater than that of the north bank.During the flood and mean-flow periods,δ^(15)N and δ^(18)O were mainly distributed in the NH_(4)^(+) of the fertilizer and soil nitrogen.During the dry period,δ^(15)N and δ^(18)O were mainly distributed in domestic sewage and manure regions.According to the Stable Isotope Analysis in R(SIAR)model,manure and sewage were the major nitrate sources during the dry period(73%).However,a decrease in the contribution from domestic sewage and manure was observed during the flood period(45%)compared to the dry period,but with a significantly increased contribution from soil nitrogen(23%)and inorganic fertilizer(21%).The health risk value in the dry period was higher than that in the wet and mean flow periods,and children are more susceptible to nitrate pollution than adults.Therefore,reducing the discharge of domestic sewage and manure and improving the utilization rate of nitrogen fertilizers may be effective measures to improve water quality in the watershed.
基金jointly supported by the project of the China Geological Survey (DD20211309)the National Natural Science Foundation of China (41602273)the High-Level Talent Funding Program of Hebei province(A202101004).
文摘A large number of antibiotics have been discharged into rivers by human activities,posing a threat to aquatic ecosystems.The surface water of the Yellow River Basin also suffers antibiotic pollution,which hinders the improvement in the aquatic ecological environment.This study investigated and analyzed the characteristics and assessed the ecological risks of antibiotic pollution in surface water bodies such as canals,rivers and fish ponds in Kaifeng,Henan Province,which is a key city along the lower reaches of the Yellow River.The test results are as follows.A total of 15 types of antibiotics were detected in the surface water.They had a total antibiotic concentration of 12.2-249.9μg/L,of which tetracyclines(TCs)and quinolones accounted for the highest percentages.Six types of quinolones had detection rates of up to 100%,and doxycycline(DC)and oxytetracycline(OTC)had average concentrations of 29.52μg/L1 and 13.71μg/L,respectively.The major canals with water diverted from the Yellow River had total concentrations of quinolones and TCs of 22.0μg/L and 14.9μg/L,respectively,which were higher than those in previous studies.This phenomenon may be related to the decrease in the water flow of the Yellow River during the dry season and the increase in the antibiotic consumption of residents in the context of the Covid-19 outbreak.The upper reaches of the Huiji River in the Xiangfu District had higher antibiotic content than other districts in Kaifeng.Specifically,TCs accounted for 72.38%-91.84%of all antibiotics,and the DC and OTC concentrations were significantly higher than other antibiotics in the upper reaches.As indicated by the ecological risk assessment results,TCs had the highest ecological risks to green algae.Among them,DC had medium-high risks;TC,OTC,and chlortetracycline(CTC)had medium-high risks;trimethoprim(TMP)and lomefloxacin(LOM)had low risks;other TC antibiotics had no risk.Compared with green algae,most antibiotics showed higher ecological risks to daphnia and lower ecological risks to fish.DC and OTC dominate antibiotic pollutants in the surface water in Kaifeng City,and especially in Xiangfu District,where DC and OTC have medium-high risks.The TCs in the major Yellow River showed medium risks to both green algae and daphnia.It can be speculated that the antibiotic pollution in the Yellow River might pose a certain threat to the ecological security of water in Kaifeng City.
文摘The study aims to identify a suitable site for open and bore well in a farmhouseusing ground magnetic survey in south India.It also aims to define depth to granitoid and structural elements which traverse the selected area.Magnetic data(n=84)measured,processed and interpreted as qualitative and quantitatively.The results of total magnetic intensities indicate that the area is composed of linear magnetic lows trending NE-SW direction and circular to semi-circular causative bodies.The magnetic values ranged from-137 nT to 2345 nT with a mean of 465 nT.Reduction to equator shows significant shifting of causative bodies in the southern and northern directions.Analytical signal map shows exact boundary of granitic bodies.Cosine directional filter has brought out structural element trending NE-SW direction.Results of individual profile brought to light structurally weak zone between 90 m and 100 m in all the profile lines.Sudden decrease of magnetic values from 2042 nT to 126 nT noticed in profile line 6 between 20 m and 30 m indicates fault occurrence.Magnetic breaks obtained from these maps were visualized,interpreted and identified two suitable sites for open and bore well.Radially averaged power spectrum estimates depth of shallow and deep sources in 5 m and 50 m,respectively.Euler method has also been applied to estimate depth of granitoid and structural elements using structural indexes 0,1,2,and 3 and found depth ranges from<10 m to>90 m.Study indicates magnetic method is one of the geophysical methods suitable for groundwater exploration and site selection for open and borewells.
文摘Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.
文摘The purpose of this study is to investigate the effect of using Bicarbonate and Calcium parameters as alternatives to the lithostratigraphic units covered the catchment area, on water quality index (WQI) values that have been implemented with GIS technique at Wadi Al-Arab Dam. The analyzed results (by WQI method) have been used to depict water quality for the two approaches. Based on physico-chemical parameters, the calculated values for WQI over the 3-year for study period were 169, 168, and 157, respectively. While the WQI values were 184, 183 and 172, respectively, as a result of incorporated Bicarbonate and Calcium parameters in WQI calculations that significantly contributed to increasing the WQI. The elevated values may be attributed to the influence of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent during winter season in the catchment area. As a consequence of lithostratigraphic unites product and GIS technique integration and normalization processes, most of water quality ranks are good and only autumn season has poor water quality in the 2012 and 2013, while in 2014 it has good water quality in the same season. The WQI values increase in general trend from winter to autumn seasons during the study period that may be referred to outflow by daily consumption, evaporation rising, and seepage water. The analysis shows that the modified water quality values of the Wadi Al-Arab Dam Reservoir (WADR) vary after using Bicarbonate and Calcium parameters by constant value. Generally, the results signify that the WADR is not polluted based on the physical and chemical characteristics of water.
基金This research was supported by the National Key Research and Development Program of China(2018YFC0406401)the Inner Mongolia Autonomous Region“Grassland Talents”Project.
文摘Coal mining has changed the hydrogeological conditions of river basins,and studying how the relationship among different types of water body has changed under the influence of coal mining is of great significance for understanding the regional hydrological cycle.We analyzed the temporal and spatial distribution of hydrochemical properties and environmental isotopes in the Hailiutu River Basin(HRB),China with a mixed model.The results showed that:(1)human activity(e.g.,coal mining and agricultural production)causes considerable changes in the hydrochemical properties of surface water in and around the mining areas,and leads to significant increases in the concentrations of Na^(+)and SO_(4)^(2-);(2)precipitation is the main source of water vapour in the HRB.The transformation between surface water and groundwater in the natural watershed is mainly affected by precipitation;and(3)in the mining areas,the average contribution rates of precipitation to the recharge of surface water and groundwater increased by 2.6%-7.9%and 2.7%-9.9%,respectively.Groundwater in the Salawusu Formation constitutes up to 61.3%-72.4%of mine water.Overall,this study is beneficial for quantifying the effects of coal mining on local hydrological cycles.The research results can provide a reference for local water resources management and ecological environment improvement.
