[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and natural...[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and naturalization were made use of to protect nature and restore wetland as per Succession Theory. [Result] Both of eco- environment and eco-functions of Mille River were restored through reconstruction of biocenosis in wetlands. [Conclusion] It is feasible to implement matched ecological projects in semiarid regions in East Africa, providing references for restoration and protection of local water resources.展开更多
Frequent soil landslide events are recorded in the Three Gorges Reservoir area,China,making it necessary to investigate the failure mode of such riverside landslides.Geotechnical centrifugal test is considered to be t...Frequent soil landslide events are recorded in the Three Gorges Reservoir area,China,making it necessary to investigate the failure mode of such riverside landslides.Geotechnical centrifugal test is considered to be the most realistic laboratory model,which can reconstruct the required geo-stress.In this study,the Liangshuijing landslide in the Three Gorgers Reservoir area is selected for a scaled centrifugal model experiment,and a water pump system is employed to retain the rainfall condition.Using the techniques of digital photography and pore water pressure transducers,water level fluctuation is controlled,and multi-physical data are thus obtained,including the pore water pressure,earth pressure,surface displacement and deep displacement.The analysis results indicate that:Three stages were set in the test(waterflooding stage,rainfall stage and drainage stage).Seven transverse cracks with wide of 1–5 mm appeared during the model test,of which 3 cracks at the toe landslide were caused by reservoir water fluctuation,and the cracks at the middle and rear part were caused by rainfall.During rainfall process,the maximum displacement of landslide model reaches 3 cm.And the maximum deformation of the model exceeds 12 cm at the drainage stage.The failure process of the slope model can be divided into four stages:microcracks appearance and propagation stage,thrust-type failure stage,retrogressive failure stage,and holistic failure stage.When the thrust-type zone caused by rainfall was connected or even overlapped with the retrogressive failure zone caused by the drainage,the landslide would start,which displayed a typical composite failure pattern.The failure mode and deformation mechanism under the coupling actions of water level fluctuation and rainfall are revealed in the model test,which could appropriately guide for the analysis and evaluation of riverside landslides.展开更多
Sea surface temperature （SST） proxies including B/Ca, Mg/Ca, St/Ca, U/Ca and δ180 were analyzed in the skeleton of a Porites coral collected from the Zhujiang River （Pearl River） Estuary （ZRE）. These geochemica...Sea surface temperature （SST） proxies including B/Ca, Mg/Ca, St/Ca, U/Ca and δ180 were analyzed in the skeleton of a Porites coral collected from the Zhujiang River （Pearl River） Estuary （ZRE）. These geochemical proxies are influenced by river runoff and this area of the northern South China Sea is strongly affected by seasonal freshwater floods. We assessed the robustness of each SST proxy through comparison with the local instrumental SST. Coral St/Ca shows the highest correlation with SST variations （r2=0.59）, suggesting St/Ca is the most robust SST proxy. In contrast, coral δ180 （r2=0.46）, B/Ca （r2=0.43） and U/Ca （r2=0.41） ratios were only moderately correlated with SST variations, suggesting that they are disturbed by some other factors in addition to SST. The poor correlation （r2=0.27） between SST and Mg/Ca indicates that Mg/Ca in coral skeletons is not a simple function of SST variations. This may ultimately limit the use of Mg/Ca as a coral paleothermometer.展开更多
Riverine sand dunes develop as a result of fluvial-aeolian interactions. The primarily barchan dune chains along the Xiangshui River(a branch of the Xar Moron River in the western part of the Horqin Sandy Land of Chin...Riverine sand dunes develop as a result of fluvial-aeolian interactions. The primarily barchan dune chains along the Xiangshui River(a branch of the Xar Moron River in the western part of the Horqin Sandy Land of China) form a typical riverine dune field. We collected a series of samples from the riverine sand dunes parallel to the direction of the prevailing wind and investigated the sand sources and formation mechanisms of these dunes by determining the grain size, heavy mineral content and optically stimulated luminescence(OSL) of the samples. The sand of the near-river dunes was coarser than the sand of the dunes distant from the river, indicating that coarse sand of the valley mainly deposited on near-river dunes. The heavy mineral analysis suggested that wind-sand activity levels were intense on the upwind dunes, but relatively weak on the downwind dunes. This indicated that the sand sources for the near-river dunes were more abundant than those of the distant dunes. Our OSL analysis of samples suggested that the deposition rates on dunes near the river were greater than the deposition rates on dunes distant from the river. The development of dunes along the river indicated that the river played an important role in dune formation and development. In addition, airflow fluctuation and the formation of the waveform dunes had a type of feedback relationship. Grain size, heavy mineral and OSL analyses are widely used methods in wind-sand research. Sand dune grain size characteristics reflect the effects of airflow on the transport and separation of sand materials, as well as the physical characteristics of the sand sources. Heavy mineral characteristics are often used to investigate the relationships between sediments and sand sources. OSL indicates dune age, revealing formation of dunes. Therefore, it is useful to explore dune sand sources, as well as the mechanisms underlying dune formation, by determining grain size, heavy mineral content and OSL. This study investigated the sand sources of riverine dunes and provided new information about riverine dune formation and development.展开更多
Antibiotics released into the environment through anthropogenic activities exert selective pressure,driving bacteria towards increasing antimicrobial resistance.The prevalence of antibiotics and the ecological risks p...Antibiotics released into the environment through anthropogenic activities exert selective pressure,driving bacteria towards increasing antimicrobial resistance.The prevalence of antibiotics and the ecological risks posed in the riverine estuarine of Larut River and Sangga Besar River,which included wastewater effl uents from hospital,zoo,and poultry slaughterhouse sources were investigated.Solid phase extraction(SPE)followed by high-performance liquid chromatography tandem mass chromatography(HPLC-MS/MS)were used to extract and quantify the antibiotic residues from 22 antibiotics belonging to six major antibiotic classes(sulfonamide,macrolide,fl uoroquinolone,phenicol,trimethoprim,and tetracycline).Sixteen antibiotic residues were detected with concentrations ranging from limit of detection(LOD)to 1262.3 ng/L.Fluoroquinolones and macrolides were the most frequently detected compounds.Erythromycin,clarithromycin,and ofl oxacin detected in hospital and zoo effl uents posed a high risk to algae while tetracycline had low to medium ecological risks toward all the relevant organisms from aquatic environments(algae,invertebrate Daphnia magna,and fi sh).展开更多
The Zhujiang River Estuary is becoming eutrophic due to the impact of anthropogenic activities in the past decades.To understand nutrient dynamics and fluxes to the Lingdingyang water via four outlets(Humen,Jiaomen,Ho...The Zhujiang River Estuary is becoming eutrophic due to the impact of anthropogenic activities in the past decades.To understand nutrient dynamics and fluxes to the Lingdingyang water via four outlets(Humen,Jiaomen,Hongqimen and Hengmen),we investigated the spatial distribution and seasonal variation of dissolved nutrients in the Zhujiang River Estuary,based on fourteen cruises conducted from March 2015 to October 2017,covering both wet(April to September)and dry(October to March next year)seasons.Our results showed that riverine fluxes of dissolved inorganic nitrogen(DIN)and dissolved silicate(DSi)into the Lingdingyang water through four outlets varied seasonally due to the influence of river discharge,with the highest in spring and the lowest in winter.However,riverine flux of phosphate exhibited little significant seasonal variability.Riverine nutrients into the Lingdingyang water most resulted through Humen Outlet.The estuarine export fluxes of DIN out of the Zhujiang River Estuary derived from a box model were higher than fluxes of riverine nutrients in May,likely due to the influence of local sewage,while lower than riverine flux in August.The export fluxes of phosphate were higher than the fluxes of riverine phosphate in May and August.In contrast,large amounts of DSi were buried in the estuary in May and August.Although excess DIN was delivered into the Zhujiang River Estuary,eutrophication effect was not as severe as expected in the Zhujiang River Estuary,since the light limitation restricted the utilization of nutrients by phytoplankton.展开更多
The WRF-lake vertically one-dimensional(1D)water temperature model,as a submodule of the Weather Research and Forecasting(WRF)system,is being widely used to investigate water-atmosphere interactions.But previous appli...The WRF-lake vertically one-dimensional(1D)water temperature model,as a submodule of the Weather Research and Forecasting(WRF)system,is being widely used to investigate water-atmosphere interactions.But previous applications revealed that it cannot accurately simulate the water temperature in a deep riverine reservoir during a large flow rate period,and whether it can produce sufficiently accurate heat flux through the water surface of deep riverine reservoirs remains uncertain.In this study,the WRF-lake model was improved for applications in large,deep riverine reservoirs by parametric scheme optimization,and the accuracy of heat flux calculation was evaluated compared with the results of a better physically based model,the Delft3D-Flow,which was previously applied to different kinds of reservoirs successfully.The results show:(1)The latest version of WRF-lake can describe the surface water temperature to some extent but performs poorly in the large flow period.We revised WRF-lake by modifying the vertical thermal diffusivity,and then,the water temperature simulation in the large flow period was improved significantly.(2)The latest version of WRF-lake overestimates the reservoir-atmosphere heat exchange throughout the year,mainly because of underestimating the downward energy transfer in the reservoir,resulting in more heat remaining at the surface and returning to the atmosphere.The modification of vertical thermal diffusivity can improve the surface heat flux calculation significantly.(3)The longitudinal temperature variation and the temperature difference between inflow and outflow,which cannot be considered in the 1D WRF-lake,can also affect the water surface heat flux.展开更多
The tectonic uplifting and depression in the coastal zones results in the anormal distribution of riverine sediments. The coastal zones of tectonic depression areas received about 95% of the riveine sediments, whereas...The tectonic uplifting and depression in the coastal zones results in the anormal distribution of riverine sediments. The coastal zones of tectonic depression areas received about 95% of the riveine sediments, whereas the tectonic uplift belts received only 5% of that, which is the main reason for the variety of the coastline types and the changes in the coastline. On the basis of this anormal distribution of riverine sediments in Chinese coastline, this paper discusses the scope and time of the maximum transgression, the trend, rate and period of the coastline changes, and the impact of riverine sediments on the future changes in coastline.展开更多
Inorganic carbon, the great part of the riverine carbon exported to the ocean, plays an important role in the global carbon cycle and ultimately impacts the coupled carbon-climate system. An overview was made on both ...Inorganic carbon, the great part of the riverine carbon exported to the ocean, plays an important role in the global carbon cycle and ultimately impacts the coupled carbon-climate system. An overview was made on both methods and results of the riverine inorganic carbon researches. In addition to routine in situ survey, measurement and calculation, the direct precipitation method and the gas evolution technique were commonly used to analyze dissolved inorganic carbon in natural water samples. Soil CO2, carbonate minerals and atmospheric CO2 incorporated into riverine inorganic car- bon pool via different means, with bicarbonate ion being the dominant component. The concentration of inorganic carbon, the composition of carbon isotopes （8^13C and △^14C）, and their temporal or spatial variations in the streams were controlled by carbon input, output and changes of carbon biogeochemistry within the riverine system. More accurate flux es- timation, better understanding of different influential processes, and quantitative determination of various inputs or outputs need to be well researched in future.展开更多
Lake Fibreno is a Mediterranean riverine lake located in Central Italy and fed by large flows of groundwater and characterized by the presence of a wide reed stand area and of the only floating island of the South Eur...Lake Fibreno is a Mediterranean riverine lake located in Central Italy and fed by large flows of groundwater and characterized by the presence of a wide reed stand area and of the only floating island of the South Europe. It is enclosed in a Natural Reserve recognized as Special Area of Conservation (SAC-IT6050015) for the presence of habitats and species (92/43/EEC) of relevant scientific interest. In this paper, we compare the plant-associated meio-macrobenthic invertebrates among sites with different environmental characteristics. Both vegetation and invertebrates of Lake Fibreno were well diversified and abundant and were composed of a mixing of species typical of lentic and lotic waters. Our results show that a gradient of orthophosphate and nitrite contents and current velocity appeared to be the driver factors affecting the flora and fauna spatial distribution at the sampling sites. To obtain a bioassessment of the ecological quality of the vegetation zone, we compared the riverine Lake Fibreno with typical lentic lakes previously studied in Central Italy. We selected metrics, such as macrophyte belt extent and taxa richness, invertebrate species richness and Shannon diversity, ETOM (Ephemeropta + Trichoptera + Odonata + Mollusca), ETOC (Ephemeropta + Trichoptera + Odonata + Coleoptera) and LCrM (Large Crustacea + Mollusca). The comparison indicated a good ecological status of the vegetation zone of Lake Fibreno mainly due to the continuous washout effects (dilution and fast water removal) which reduce the nutrient content available for phytoplankton and maintain the high transparency and good oxygenation of the lake waters.展开更多
Wuzhen is a typical riverine town south of the Yangtze River.Due to the World Internet Conference being held there,it seems to have become a place where CEOs a nd bosses of inter net compa n ies working on plans for t...Wuzhen is a typical riverine town south of the Yangtze River.Due to the World Internet Conference being held there,it seems to have become a place where CEOs a nd bosses of inter net compa n ies working on plans for the industry’s development gather.展开更多
The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurr...The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.展开更多
Rivers are vital freshwater resources that support human livelihoods,yet they are increasingly impacted by upstream flows,anthropogenic activities,and waste discharge from riverside settlements.This study assessed and...Rivers are vital freshwater resources that support human livelihoods,yet they are increasingly impacted by upstream flows,anthropogenic activities,and waste discharge from riverside settlements.This study assessed and compared the livelihood status of transboundary riverine communities along the Jadukata and Nawagang rivers in the acid mine-affected and non-mine-affected regions of northeastern Bangladesh.Data were collected from 200 households using structured interviews,focus group discussions,and key informant interviews.Livelihood status was evaluated through five capitals namely human,physical,natural,social,and financial using an equally weighted composite index,the Livelihood Assessment Index(LAI).The overall LAI was 0.487,with individual capital scores of 0.61(human),0.72(physical),0.36(natural),0.55(social),and 0.198(financial).When disaggregated,Jadukata riverine areas(mine-affected)had lower scores across most capitals(LAI:0.449)compared to Nawagang areas(non-mine-affected)(LAI:0.522).Statistically significant differences were observed in physical,natural,and financial capitals particularly in indicators such as soil erosion protection,air quality,transport infrastructure,hospitality,and income.Although the overall livelihood status in both regions remains low,the Jadukata riverine inhabitants are disproportionately affected by socio-economic vulnerabilities due to acid mining.These findings can inform future research and policy interventions.Targeted awareness programs and environmental safeguards are recommended to mitigate pollution and protect the biodiversity of the Surma River system,to which both rivers are connected.展开更多
Anthropogenic activities are regarded as the main sources of heavy metal pollution,yet few studies have investigated the effects of land-use setting on heavy metal accumulation in riverine sediments.Based on both tota...Anthropogenic activities are regarded as the main sources of heavy metal pollution,yet few studies have investigated the effects of land-use setting on heavy metal accumulation in riverine sediments.Based on both total contents and geochemical fractions,heavy metal pollution,risk and toxicity were determined in riverine sediment cores from different land-use areas(mountain area-MA,farm area-FA,city area-CA,and industrial area-LA)of the Yang River Basin in North China.The results showed that FA had higher contents of riverine sedimentary Cu;CA had higher contents of Cd;LA.had higher contents of both Cd and Zn.Most riverine sediments from FA and IA were contaminated with the investigated metals,although these concentrations were evaluated to have low potential ecological risk and no toxicity to benthic organisms.However,a high proportion of Cd in the B1 fraction of riverine sediments in IA indicating high risk should receive more attention.The B1 fraction largely determined the contamination,risk and toxicity levels associated with heavy metals in the riverine sediments of the Yang River Basin.展开更多
Although riverine carbon fluxes are a minor component of the global carbon cycle, the transfer of organic carbon from land to ocean represents a flux of potential carbon storage, irreversible over 103 to 104 a. Future...Although riverine carbon fluxes are a minor component of the global carbon cycle, the transfer of organic carbon from land to ocean represents a flux of potential carbon storage, irreversible over 103 to 104 a. Future carbon transfers through river basins are expected to accelerate, with respect to both sources and sinks, because of the large-scale human driven land-use and land-cover changes. Thus, the increased amounts of carbon transported to and sequestered in marine sediments (through fertilization by river-borne inorganic nutrients) may be an important net sink for anthropogenic CO2. Particularly, the humid tropics of South Asia are regions very sensitive to this lateral C transport because of high precipitation and high rates of land use and cover change. In this paper we report on the role of upland tributaries in the transport processes influencing the lateral carbon and nitrogen fluxes of the Godavari, a large tropical river of India. By far, dissolved inorganic carbon (DIC) is the dominant form of carbontransport in the river basin. It constitutes as much as 75% to the total carbonload. Particulate and dissolved organic carbon (POC and DOC) fluxes account for21% and 4%, respectively. In the upper basin, DOC fluxes exceed that of POC dueto large-scale anthropogenic activities. In contrast, tributaries in the central basin are characterized by comparable fluxes of POC and DOC. However, downriver POC export is 35% less than the import from upriver and tributaries due to theentrainment of sediments in river channels and dam sites. We argue that for highly disturbed watersheds in tropical regions, downstream transport of sediments and carbon requires long-term sampling programmes.展开更多
Hydropeaking,which refers to rising or falling discharges caused by the turning on or off of hydro-turbines to generate electricity,is a topic of growing interest due to its impact on fluvial ecosystems.To date,most h...Hydropeaking,which refers to rising or falling discharges caused by the turning on or off of hydro-turbines to generate electricity,is a topic of growing interest due to its impact on fluvial ecosystems.To date,most hydropeaking studies have focused on the impact of peak fluctuations on invertebrate and fish communities,but little attention has been paid to its impact on riverine plants and how functional traits may make them resistant to hydropeaking.We performed a review to assess how a set of 32 plant functional traits can be expressed in riverine plant species,and found evidence of how such expression affects their capacity to cope with common sources of hydropeaking disturbance(i.e.,inundation,fast water drawdown,and rapid water fluctuations linked to up-ramping and down-ramping hydropeaking operations).The information here presented can simplify the evaluation of impacts on riverine plant communities worldwide,as well as to detect suitable species to successfully restore rivers affected by hydropower production.展开更多
To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were s...To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were selected.The contents of nephelometric turbidity(NTU),total nitrogen(TN),and total phosphorus(TP)were significantly higher in rivers than that in lakes or reservoirs,whereas the pH and CODMn(chemical oxygen demand or potassium permanganate index)were lower.Results show that,27 PFGs,namely,assemblages A,B,C,D,E,F,G,H,J,K,LM,Lo,M,MP,N,P,S1,S2,T,TC,W1,W2,X1,X2,X3,XPh,and Y,were identified.Additionally,ANOSIM correlation analysis demonstrated significant differences in PFG composition between the riverine and lake-reservoir sections in the Huanghe River basin.In the riverine watersheds,the group MP was dominant,while assemblages B and J were prevalent in lakes and reservoirs.The Mantel correlation tests and RDA analysis showed that environmental variables,such as NTU,water temperature(WT),conductivity(Cond),and TP,were key driving factors of shaping the dominant PFGs of the study area.Using the Venn diagram based on variation partitioning analysis,PFGs were mainly influenced by WT and TP in lake-reservoir sites,while in the river sites were affected mainly by geo-climatic variables.This study helps understanding the PFGs in river ecosystems,and unraveling the key driving factors in different watersheds,which shall be important for the protection and management of entire Huanghe River basin.展开更多
A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than ...A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological seasons. The DOC level during the flood season (1.18 mg L-1) was less than that during the non-flood season (1.40 mg L-1). Owing to the concomitance of the flushing and dilution effects of the runoff during the high-water period, the variation of riverine DOC concentration with discharge in the XJR differed from that reported in many other major rivers. The DOC export flux above the city of Wuzhou was about 0.62× 106 g C km-2 yr-1. The DOC transported during the "056" Massive Flood period comprised 30.35% of the annual total, while the discharge accounted for 36.32% of the total annual flow. The characteristics in riverine DOC concentration in the XJR were attributed to the combined effect of the geomorphologic, monsoon climatic and hydrological processes as well as land-use within the drainage basin.展开更多
While it is critical to accurately understand the sources and transformation of sulfate based on time-series analysis, there are limited studies on temporal variation of sulfate in rivers and on rock weathering by sul...While it is critical to accurately understand the sources and transformation of sulfate based on time-series analysis, there are limited studies on temporal variation of sulfate in rivers and on rock weathering by sulfuric acids.We conducted a monthly sampling campaign in the Beipan, Nanpan, and Hongshui Rivers over the course of one hydrological year. This study examined seasonal variations in riverine sulfate impacted by the monsoon climate in the upper reaches of the Xijiang River basin. In general, the SO_4^(2-) contents in these rivers dropped from relatively high levels to low values during the high-flow season, in response to increasing discharge. The sulfate was generally enriched in heavy isotopes during the low-flow season compared to the high-flow season. The calculated results indicate that the riverine sulfate was mainly derived from sulfide oxidation, but that evaporite dissolution could be an important source during the low-flow season, based on isotopic evidence. Mine drainage is likely an important source of sulfate to these rivers during the high-flow season due to contributions from fast surface flow, which responds to frequent heavy rain in monsoonal climate regions. Arelatively high proportion of HCO_3^- was found to be derived from rock weathering by sulfuric acid during the high-flow season when compared to that observed during the low-flow season. The results suggest that approximately one quarter of the HCO_3^- in the Hongshui River originated from carbonate weathering by sulfuric acid derived from the oxidation of sulfide. Such information on the specific dual isotopic characteristics of riverine sulfate throughout a hydrological year can provide unique evidence for understanding the temporal variability of sulfate concentrations and weathering processes in rivers.展开更多
Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural en...Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural environments are rarely known.In the present study,25 PIs,including 9 benzophenones(BZPs),8 amine co-initiators(ACIs),4 thioxanthones(TXs)and 4 phosphine oxides(POs),were analyzed in water and sediment samples collected from eight riverine outlets of the Pearl River Delta(PRD).Eighteen,14,and 14 of the 25 target PIs were detected in water,suspended particulatematter(SPM)and sediment samples,respectively.The total concentrations of PIs in water,SPM,and sediment were in the ranges of 2.88–96.1 ng/L,9.25–923 ng/g dry weight(dw),and 3.79–56.9 ng/g dw,with geometric mean concentration(GM)of 10.8 ng/L,48.6 ng/g dw,and 17.1 ng/g dw,respectively.A significant linear regression was observed between the log partitioning coefficients(Kd)values of PIs and their log octanol water partition coefficient(Kow)values(R^(2)=0.535,p<0.05).The annual riverine input of PIs to the coastal waters of the South China Sea via eightmain outlets of the PRD was estimated to be 4.12×10^(3)kg/year,and the∑BZPs,∑ACIs,∑TXs and∑POs contributed to 1.96×10^(3),1.24×10^(3),89.6 and 830 kg/year,respectively.This is the first report of a systematic description of the occurrence characteristics of PIs exposure in water,SPM,and sediment.The environmental fate and risks of PIs in aquatic environments need further investigations.展开更多
基金Supported by South-South Cooperation Project of SSC/SPFS-FAO-Ethiopia-China~~
文摘[Objective] The aim was to improve and restore destroyed riverine and water ecosystem and to prevent bio-diversity from deteriorating in Jari demonstration plot in Ethiopia. [Method] Biological engineering and naturalization were made use of to protect nature and restore wetland as per Succession Theory. [Result] Both of eco- environment and eco-functions of Mille River were restored through reconstruction of biocenosis in wetlands. [Conclusion] It is feasible to implement matched ecological projects in semiarid regions in East Africa, providing references for restoration and protection of local water resources.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41977244, 42007267)the National Key R&D Program of China (Grant No. 2017YFC1501301)
文摘Frequent soil landslide events are recorded in the Three Gorges Reservoir area,China,making it necessary to investigate the failure mode of such riverside landslides.Geotechnical centrifugal test is considered to be the most realistic laboratory model,which can reconstruct the required geo-stress.In this study,the Liangshuijing landslide in the Three Gorgers Reservoir area is selected for a scaled centrifugal model experiment,and a water pump system is employed to retain the rainfall condition.Using the techniques of digital photography and pore water pressure transducers,water level fluctuation is controlled,and multi-physical data are thus obtained,including the pore water pressure,earth pressure,surface displacement and deep displacement.The analysis results indicate that:Three stages were set in the test(waterflooding stage,rainfall stage and drainage stage).Seven transverse cracks with wide of 1–5 mm appeared during the model test,of which 3 cracks at the toe landslide were caused by reservoir water fluctuation,and the cracks at the middle and rear part were caused by rainfall.During rainfall process,the maximum displacement of landslide model reaches 3 cm.And the maximum deformation of the model exceeds 12 cm at the drainage stage.The failure process of the slope model can be divided into four stages:microcracks appearance and propagation stage,thrust-type failure stage,retrogressive failure stage,and holistic failure stage.When the thrust-type zone caused by rainfall was connected or even overlapped with the retrogressive failure zone caused by the drainage,the landslide would start,which displayed a typical composite failure pattern.The failure mode and deformation mechanism under the coupling actions of water level fluctuation and rainfall are revealed in the model test,which could appropriately guide for the analysis and evaluation of riverside landslides.
基金The National Basic Research Program(973 program) of China under contract No.2013CB956104the National Natural Science Foundation of China under contract Nos 41106054,41306109 and 41476038
文摘Sea surface temperature （SST） proxies including B/Ca, Mg/Ca, St/Ca, U/Ca and δ180 were analyzed in the skeleton of a Porites coral collected from the Zhujiang River （Pearl River） Estuary （ZRE）. These geochemical proxies are influenced by river runoff and this area of the northern South China Sea is strongly affected by seasonal freshwater floods. We assessed the robustness of each SST proxy through comparison with the local instrumental SST. Coral St/Ca shows the highest correlation with SST variations （r2=0.59）, suggesting St/Ca is the most robust SST proxy. In contrast, coral δ180 （r2=0.46）, B/Ca （r2=0.43） and U/Ca （r2=0.41） ratios were only moderately correlated with SST variations, suggesting that they are disturbed by some other factors in addition to SST. The poor correlation （r2=0.27） between SST and Mg/Ca indicates that Mg/Ca in coral skeletons is not a simple function of SST variations. This may ultimately limit the use of Mg/Ca as a coral paleothermometer.
基金funded by the National Natural Science Foundation of China (41271025)the National Basic Research Program of China (2016YFA0601901)
文摘Riverine sand dunes develop as a result of fluvial-aeolian interactions. The primarily barchan dune chains along the Xiangshui River(a branch of the Xar Moron River in the western part of the Horqin Sandy Land of China) form a typical riverine dune field. We collected a series of samples from the riverine sand dunes parallel to the direction of the prevailing wind and investigated the sand sources and formation mechanisms of these dunes by determining the grain size, heavy mineral content and optically stimulated luminescence(OSL) of the samples. The sand of the near-river dunes was coarser than the sand of the dunes distant from the river, indicating that coarse sand of the valley mainly deposited on near-river dunes. The heavy mineral analysis suggested that wind-sand activity levels were intense on the upwind dunes, but relatively weak on the downwind dunes. This indicated that the sand sources for the near-river dunes were more abundant than those of the distant dunes. Our OSL analysis of samples suggested that the deposition rates on dunes near the river were greater than the deposition rates on dunes distant from the river. The development of dunes along the river indicated that the river played an important role in dune formation and development. In addition, airflow fluctuation and the formation of the waveform dunes had a type of feedback relationship. Grain size, heavy mineral and OSL analyses are widely used methods in wind-sand research. Sand dune grain size characteristics reflect the effects of airflow on the transport and separation of sand materials, as well as the physical characteristics of the sand sources. Heavy mineral characteristics are often used to investigate the relationships between sediments and sand sources. OSL indicates dune age, revealing formation of dunes. Therefore, it is useful to explore dune sand sources, as well as the mechanisms underlying dune formation, by determining grain size, heavy mineral content and OSL. This study investigated the sand sources of riverine dunes and provided new information about riverine dune formation and development.
基金Supported by the Ministry of Higher Education of Malaysia(Nos.IOES-2014D,FP048-2013A,SF022-2013)the University Malaya(Nos.RU009D-2015,PG309-2016A)。
文摘Antibiotics released into the environment through anthropogenic activities exert selective pressure,driving bacteria towards increasing antimicrobial resistance.The prevalence of antibiotics and the ecological risks posed in the riverine estuarine of Larut River and Sangga Besar River,which included wastewater effl uents from hospital,zoo,and poultry slaughterhouse sources were investigated.Solid phase extraction(SPE)followed by high-performance liquid chromatography tandem mass chromatography(HPLC-MS/MS)were used to extract and quantify the antibiotic residues from 22 antibiotics belonging to six major antibiotic classes(sulfonamide,macrolide,fl uoroquinolone,phenicol,trimethoprim,and tetracycline).Sixteen antibiotic residues were detected with concentrations ranging from limit of detection(LOD)to 1262.3 ng/L.Fluoroquinolones and macrolides were the most frequently detected compounds.Erythromycin,clarithromycin,and ofl oxacin detected in hospital and zoo effl uents posed a high risk to algae while tetracycline had low to medium ecological risks toward all the relevant organisms from aquatic environments(algae,invertebrate Daphnia magna,and fi sh).
基金The Special Project for Marine Economic Development(Six Major Marine Industries)of Guangdong Province under contract No.GDNRC[2020]064the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract Nos GML2019ZD0303,GML2019ZD0305 and GML2019ZD0402+2 种基金the Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract Nos ISEE2019ZR02 and ISEE2019ZR03the National Natural Science Foundation of China under contract Nos 41676075 and 41706085the Department of Science and Technology of Guangdong Province under contract No.2018B030320005。
文摘The Zhujiang River Estuary is becoming eutrophic due to the impact of anthropogenic activities in the past decades.To understand nutrient dynamics and fluxes to the Lingdingyang water via four outlets(Humen,Jiaomen,Hongqimen and Hengmen),we investigated the spatial distribution and seasonal variation of dissolved nutrients in the Zhujiang River Estuary,based on fourteen cruises conducted from March 2015 to October 2017,covering both wet(April to September)and dry(October to March next year)seasons.Our results showed that riverine fluxes of dissolved inorganic nitrogen(DIN)and dissolved silicate(DSi)into the Lingdingyang water through four outlets varied seasonally due to the influence of river discharge,with the highest in spring and the lowest in winter.However,riverine flux of phosphate exhibited little significant seasonal variability.Riverine nutrients into the Lingdingyang water most resulted through Humen Outlet.The estuarine export fluxes of DIN out of the Zhujiang River Estuary derived from a box model were higher than fluxes of riverine nutrients in May,likely due to the influence of local sewage,while lower than riverine flux in August.The export fluxes of phosphate were higher than the fluxes of riverine phosphate in May and August.In contrast,large amounts of DSi were buried in the estuary in May and August.Although excess DIN was delivered into the Zhujiang River Estuary,eutrophication effect was not as severe as expected in the Zhujiang River Estuary,since the light limitation restricted the utilization of nutrients by phytoplankton.
基金the financial support from the National Key R&D Program of China(Grant No.2018YFE0196000)the National Natural Science Foundation of China(Grant No.52179069)。
文摘The WRF-lake vertically one-dimensional(1D)water temperature model,as a submodule of the Weather Research and Forecasting(WRF)system,is being widely used to investigate water-atmosphere interactions.But previous applications revealed that it cannot accurately simulate the water temperature in a deep riverine reservoir during a large flow rate period,and whether it can produce sufficiently accurate heat flux through the water surface of deep riverine reservoirs remains uncertain.In this study,the WRF-lake model was improved for applications in large,deep riverine reservoirs by parametric scheme optimization,and the accuracy of heat flux calculation was evaluated compared with the results of a better physically based model,the Delft3D-Flow,which was previously applied to different kinds of reservoirs successfully.The results show:(1)The latest version of WRF-lake can describe the surface water temperature to some extent but performs poorly in the large flow period.We revised WRF-lake by modifying the vertical thermal diffusivity,and then,the water temperature simulation in the large flow period was improved significantly.(2)The latest version of WRF-lake overestimates the reservoir-atmosphere heat exchange throughout the year,mainly because of underestimating the downward energy transfer in the reservoir,resulting in more heat remaining at the surface and returning to the atmosphere.The modification of vertical thermal diffusivity can improve the surface heat flux calculation significantly.(3)The longitudinal temperature variation and the temperature difference between inflow and outflow,which cannot be considered in the 1D WRF-lake,can also affect the water surface heat flux.
文摘The tectonic uplifting and depression in the coastal zones results in the anormal distribution of riverine sediments. The coastal zones of tectonic depression areas received about 95% of the riveine sediments, whereas the tectonic uplift belts received only 5% of that, which is the main reason for the variety of the coastline types and the changes in the coastline. On the basis of this anormal distribution of riverine sediments in Chinese coastline, this paper discusses the scope and time of the maximum transgression, the trend, rate and period of the coastline changes, and the impact of riverine sediments on the future changes in coastline.
基金Under the auspices of the National Natural Science Foundation of China (No. 40471120), the Specialized ResearchFund for the Doctoral Program of Higher Education (No. 20040558025), the '985 Project' of GIS and Remote Sensing for Geo-sciences from the Ministry of Education of China (No. 105203200400006), and the Guangdong Provincial Natural Science Founda-tion (No. 031548)
文摘Inorganic carbon, the great part of the riverine carbon exported to the ocean, plays an important role in the global carbon cycle and ultimately impacts the coupled carbon-climate system. An overview was made on both methods and results of the riverine inorganic carbon researches. In addition to routine in situ survey, measurement and calculation, the direct precipitation method and the gas evolution technique were commonly used to analyze dissolved inorganic carbon in natural water samples. Soil CO2, carbonate minerals and atmospheric CO2 incorporated into riverine inorganic car- bon pool via different means, with bicarbonate ion being the dominant component. The concentration of inorganic carbon, the composition of carbon isotopes （8^13C and △^14C）, and their temporal or spatial variations in the streams were controlled by carbon input, output and changes of carbon biogeochemistry within the riverine system. More accurate flux es- timation, better understanding of different influential processes, and quantitative determination of various inputs or outputs need to be well researched in future.
文摘Lake Fibreno is a Mediterranean riverine lake located in Central Italy and fed by large flows of groundwater and characterized by the presence of a wide reed stand area and of the only floating island of the South Europe. It is enclosed in a Natural Reserve recognized as Special Area of Conservation (SAC-IT6050015) for the presence of habitats and species (92/43/EEC) of relevant scientific interest. In this paper, we compare the plant-associated meio-macrobenthic invertebrates among sites with different environmental characteristics. Both vegetation and invertebrates of Lake Fibreno were well diversified and abundant and were composed of a mixing of species typical of lentic and lotic waters. Our results show that a gradient of orthophosphate and nitrite contents and current velocity appeared to be the driver factors affecting the flora and fauna spatial distribution at the sampling sites. To obtain a bioassessment of the ecological quality of the vegetation zone, we compared the riverine Lake Fibreno with typical lentic lakes previously studied in Central Italy. We selected metrics, such as macrophyte belt extent and taxa richness, invertebrate species richness and Shannon diversity, ETOM (Ephemeropta + Trichoptera + Odonata + Mollusca), ETOC (Ephemeropta + Trichoptera + Odonata + Coleoptera) and LCrM (Large Crustacea + Mollusca). The comparison indicated a good ecological status of the vegetation zone of Lake Fibreno mainly due to the continuous washout effects (dilution and fast water removal) which reduce the nutrient content available for phytoplankton and maintain the high transparency and good oxygenation of the lake waters.
文摘Wuzhen is a typical riverine town south of the Yangtze River.Due to the World Internet Conference being held there,it seems to have become a place where CEOs a nd bosses of inter net compa n ies working on plans for the industry’s development gather.
基金Maa-ja Vesitekniikan Tuki RyDepartment of Built Environment(OV),Aalto University。
文摘The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.
基金funded by University Grants Commission of Bangladesh,grant number(Ser.No-14(2021-2022),Mon.No-37.01.0000.071.36.040.22).
文摘Rivers are vital freshwater resources that support human livelihoods,yet they are increasingly impacted by upstream flows,anthropogenic activities,and waste discharge from riverside settlements.This study assessed and compared the livelihood status of transboundary riverine communities along the Jadukata and Nawagang rivers in the acid mine-affected and non-mine-affected regions of northeastern Bangladesh.Data were collected from 200 households using structured interviews,focus group discussions,and key informant interviews.Livelihood status was evaluated through five capitals namely human,physical,natural,social,and financial using an equally weighted composite index,the Livelihood Assessment Index(LAI).The overall LAI was 0.487,with individual capital scores of 0.61(human),0.72(physical),0.36(natural),0.55(social),and 0.198(financial).When disaggregated,Jadukata riverine areas(mine-affected)had lower scores across most capitals(LAI:0.449)compared to Nawagang areas(non-mine-affected)(LAI:0.522).Statistically significant differences were observed in physical,natural,and financial capitals particularly in indicators such as soil erosion protection,air quality,transport infrastructure,hospitality,and income.Although the overall livelihood status in both regions remains low,the Jadukata riverine inhabitants are disproportionately affected by socio-economic vulnerabilities due to acid mining.These findings can inform future research and policy interventions.Targeted awareness programs and environmental safeguards are recommended to mitigate pollution and protect the biodiversity of the Surma River system,to which both rivers are connected.
基金This research was supported by the Youth Innovation Promotion Association CAS(No.2017059)the National Natural Science Foundation of China(Nos.41877368 and 41701546).
文摘Anthropogenic activities are regarded as the main sources of heavy metal pollution,yet few studies have investigated the effects of land-use setting on heavy metal accumulation in riverine sediments.Based on both total contents and geochemical fractions,heavy metal pollution,risk and toxicity were determined in riverine sediment cores from different land-use areas(mountain area-MA,farm area-FA,city area-CA,and industrial area-LA)of the Yang River Basin in North China.The results showed that FA had higher contents of riverine sedimentary Cu;CA had higher contents of Cd;LA.had higher contents of both Cd and Zn.Most riverine sediments from FA and IA were contaminated with the investigated metals,although these concentrations were evaluated to have low potential ecological risk and no toxicity to benthic organisms.However,a high proportion of Cd in the B1 fraction of riverine sediments in IA indicating high risk should receive more attention.The B1 fraction largely determined the contamination,risk and toxicity levels associated with heavy metals in the riverine sediments of the Yang River Basin.
文摘Although riverine carbon fluxes are a minor component of the global carbon cycle, the transfer of organic carbon from land to ocean represents a flux of potential carbon storage, irreversible over 103 to 104 a. Future carbon transfers through river basins are expected to accelerate, with respect to both sources and sinks, because of the large-scale human driven land-use and land-cover changes. Thus, the increased amounts of carbon transported to and sequestered in marine sediments (through fertilization by river-borne inorganic nutrients) may be an important net sink for anthropogenic CO2. Particularly, the humid tropics of South Asia are regions very sensitive to this lateral C transport because of high precipitation and high rates of land use and cover change. In this paper we report on the role of upland tributaries in the transport processes influencing the lateral carbon and nitrogen fluxes of the Godavari, a large tropical river of India. By far, dissolved inorganic carbon (DIC) is the dominant form of carbontransport in the river basin. It constitutes as much as 75% to the total carbonload. Particulate and dissolved organic carbon (POC and DOC) fluxes account for21% and 4%, respectively. In the upper basin, DOC fluxes exceed that of POC dueto large-scale anthropogenic activities. In contrast, tributaries in the central basin are characterized by comparable fluxes of POC and DOC. However, downriver POC export is 35% less than the import from upriver and tributaries due to theentrainment of sediments in river channels and dam sites. We argue that for highly disturbed watersheds in tropical regions, downstream transport of sediments and carbon requires long-term sampling programmes.
基金supported by the Fundação para a Ciência e a Tecnologia(FCT)[scholarship reference number:PD/BD/143020/2018]The authors are also grateful to FCT for its support through funding UIDB/04625/2020 from the research unit CERISThis study has been also supported by the Spanish Ministry of Science and Innovation(Programa Estatal de Proyectos de I+D+i,Ref.PID2019-111252RA-I00 CTA).
文摘Hydropeaking,which refers to rising or falling discharges caused by the turning on or off of hydro-turbines to generate electricity,is a topic of growing interest due to its impact on fluvial ecosystems.To date,most hydropeaking studies have focused on the impact of peak fluctuations on invertebrate and fish communities,but little attention has been paid to its impact on riverine plants and how functional traits may make them resistant to hydropeaking.We performed a review to assess how a set of 32 plant functional traits can be expressed in riverine plant species,and found evidence of how such expression affects their capacity to cope with common sources of hydropeaking disturbance(i.e.,inundation,fast water drawdown,and rapid water fluctuations linked to up-ramping and down-ramping hydropeaking operations).The information here presented can simplify the evaluation of impacts on riverine plant communities worldwide,as well as to detect suitable species to successfully restore rivers affected by hydropower production.
基金Supported by the Young Backbone Teachers Project of Henan Province (No. 2020GGJS064)the Key Scientific and Technological Project of Henan Province (No. 232102321056)+1 种基金the Scientific Fund of Henan Normal University (No. 2020QK02)the Project of Huanghe River Fisheries Resources and Environment Investigation from the MARA,China,and the Observation and Research Station on Water Ecosystem in Danjiangkou Reservoir of Henan Province
文摘To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were selected.The contents of nephelometric turbidity(NTU),total nitrogen(TN),and total phosphorus(TP)were significantly higher in rivers than that in lakes or reservoirs,whereas the pH and CODMn(chemical oxygen demand or potassium permanganate index)were lower.Results show that,27 PFGs,namely,assemblages A,B,C,D,E,F,G,H,J,K,LM,Lo,M,MP,N,P,S1,S2,T,TC,W1,W2,X1,X2,X3,XPh,and Y,were identified.Additionally,ANOSIM correlation analysis demonstrated significant differences in PFG composition between the riverine and lake-reservoir sections in the Huanghe River basin.In the riverine watersheds,the group MP was dominant,while assemblages B and J were prevalent in lakes and reservoirs.The Mantel correlation tests and RDA analysis showed that environmental variables,such as NTU,water temperature(WT),conductivity(Cond),and TP,were key driving factors of shaping the dominant PFGs of the study area.Using the Venn diagram based on variation partitioning analysis,PFGs were mainly influenced by WT and TP in lake-reservoir sites,while in the river sites were affected mainly by geo-climatic variables.This study helps understanding the PFGs in river ecosystems,and unraveling the key driving factors in different watersheds,which shall be important for the protection and management of entire Huanghe River basin.
基金supported by the Natural Science Foundation of China (Grant Nos. 40871143 and 41071054)funds of China Geological Survey (karst[2011] Geo-surveying 01-01-23)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Guangdong Provincial Natural Science Foundation of China (Grant No. 7003669)
文摘A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological seasons. The DOC level during the flood season (1.18 mg L-1) was less than that during the non-flood season (1.40 mg L-1). Owing to the concomitance of the flushing and dilution effects of the runoff during the high-water period, the variation of riverine DOC concentration with discharge in the XJR differed from that reported in many other major rivers. The DOC export flux above the city of Wuzhou was about 0.62× 106 g C km-2 yr-1. The DOC transported during the "056" Massive Flood period comprised 30.35% of the annual total, while the discharge accounted for 36.32% of the total annual flow. The characteristics in riverine DOC concentration in the XJR were attributed to the combined effect of the geomorphologic, monsoon climatic and hydrological processes as well as land-use within the drainage basin.
基金financially supported by the Ministry of Science and Technology of China through Grant Nos.2016YFA0601000 and 2013CB956700National Natural Science Foundation of China(Grant Nos.41422303,41130536 and 41625006)
文摘While it is critical to accurately understand the sources and transformation of sulfate based on time-series analysis, there are limited studies on temporal variation of sulfate in rivers and on rock weathering by sulfuric acids.We conducted a monthly sampling campaign in the Beipan, Nanpan, and Hongshui Rivers over the course of one hydrological year. This study examined seasonal variations in riverine sulfate impacted by the monsoon climate in the upper reaches of the Xijiang River basin. In general, the SO_4^(2-) contents in these rivers dropped from relatively high levels to low values during the high-flow season, in response to increasing discharge. The sulfate was generally enriched in heavy isotopes during the low-flow season compared to the high-flow season. The calculated results indicate that the riverine sulfate was mainly derived from sulfide oxidation, but that evaporite dissolution could be an important source during the low-flow season, based on isotopic evidence. Mine drainage is likely an important source of sulfate to these rivers during the high-flow season due to contributions from fast surface flow, which responds to frequent heavy rain in monsoonal climate regions. Arelatively high proportion of HCO_3^- was found to be derived from rock weathering by sulfuric acid during the high-flow season when compared to that observed during the low-flow season. The results suggest that approximately one quarter of the HCO_3^- in the Hongshui River originated from carbonate weathering by sulfuric acid derived from the oxidation of sulfide. Such information on the specific dual isotopic characteristics of riverine sulfate throughout a hydrological year can provide unique evidence for understanding the temporal variability of sulfate concentrations and weathering processes in rivers.
基金This work was supported by the National Natural Science Foundation of China(Nos.21876063,22076064 and 22106169)the Guangdong Special Support Program(No.2019TX05L129)+2 种基金the Science and Technology Program of Guangzhou(No.202206010191)the Guangdong(China)Innovative and Entrepreneurial Research Team Program(No.2016ZT06N258)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(No.2019B121205004)。
文摘Photoinitiators(PIs)are widely used in industrial polymerization processes.It has been reported that PIs are ubiquitous in indoor environments and that humans are exposed to PIs,but the occurrence of PIs in natural environments are rarely known.In the present study,25 PIs,including 9 benzophenones(BZPs),8 amine co-initiators(ACIs),4 thioxanthones(TXs)and 4 phosphine oxides(POs),were analyzed in water and sediment samples collected from eight riverine outlets of the Pearl River Delta(PRD).Eighteen,14,and 14 of the 25 target PIs were detected in water,suspended particulatematter(SPM)and sediment samples,respectively.The total concentrations of PIs in water,SPM,and sediment were in the ranges of 2.88–96.1 ng/L,9.25–923 ng/g dry weight(dw),and 3.79–56.9 ng/g dw,with geometric mean concentration(GM)of 10.8 ng/L,48.6 ng/g dw,and 17.1 ng/g dw,respectively.A significant linear regression was observed between the log partitioning coefficients(Kd)values of PIs and their log octanol water partition coefficient(Kow)values(R^(2)=0.535,p<0.05).The annual riverine input of PIs to the coastal waters of the South China Sea via eightmain outlets of the PRD was estimated to be 4.12×10^(3)kg/year,and the∑BZPs,∑ACIs,∑TXs and∑POs contributed to 1.96×10^(3),1.24×10^(3),89.6 and 830 kg/year,respectively.This is the first report of a systematic description of the occurrence characteristics of PIs exposure in water,SPM,and sediment.The environmental fate and risks of PIs in aquatic environments need further investigations.
