Yellow River water transfer for Tianjin is important in solving the water shortage in Tianjin, which facilitate economic development and social progress for many years. Fresh water drawn from Yellow River（ i. e., Yin...Yellow River water transfer for Tianjin is important in solving the water shortage in Tianjin, which facilitate economic development and social progress for many years. Fresh water drawn from Yellow River（ i. e., Yin-Huang water） becomes saltier and saltier when being stored in the Bei-Da-Gang reservoir. We qualitatively analyze the water salinization mechanism based on mass transfer theory. The main factors are salinity transfer of saline soil, evaporation concentrating, and the agitation of wind. A simulative experimental pond and an evaporation pond were built beside the Bei-Da-Gang reservoir to quantitatively investigate the water salinization based on water and solute balance in the simulative pond. 80% of increased [Cl^-] is due to the salinity transfer of the saline soil and the other 20% is due to evaporation concentrating, so the former is the most important factor. We found that the salinization of Yin-Huang water can be described with a zero-dimension linear model.展开更多
To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agric...To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.展开更多
In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resource...In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.展开更多
Black nanosheets(BN,with a specific chemical composition of molybdenum disulfide)have been widely studied for low-permeability reservoir development due to their unique nanoscale dimensions and lamellar structure.Our ...Black nanosheets(BN,with a specific chemical composition of molybdenum disulfide)have been widely studied for low-permeability reservoir development due to their unique nanoscale dimensions and lamellar structure.Our prior research demonstrated that cationically modified BN combined with low-salinity water(LSW)significantly enhances oil displacement.This study compared the imbibition adaptability of the composite system under both ambient-pressure and pressurized conditions,while combining nuclear magnetic resonance(NMR)techniques to analyze related imbibition mechanisms and reservoir permeability adaptability.Results showed that the modified BN-LSW composited system achieved an imbibition recovery efficiency of 43.92% under ambient pressure.The mechanism was capillary force-dominated,preferentially displacing oil from small pores by improving core wettability and emulsification.Under pressurized conditions,the driving force became dominant,further increasing recovery efficiency to 56.52%,with the system displacing oil from both large and small pores.Additionally,the system showed optimal adaptability in cores with 0.05×10^(−3)μm^(2) permeability.Imbibition efficiency declined at higher/lower permeabilities due to weakened capillary forces or nanoparticle aggregation-induced clogging.This study confirmed that the modified BN-LSW composite system enhanced imbibition stability and recovery efficiency,and combined with nuclear magnetic resonance(NMR)technology,its mechanism was revealed at the microscale.This provided theoretical and technical support for the efficient development of low-permeability reservoirs,with significant engineering value.展开更多
In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the ...In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficiency（NUE） was significantly lower in the 8.04 dS/m treatment than in either the 4.61 dS/m or the 0.35 dS/m treatment. There was no significant difference in NUE between the latter two treatments. These results suggest that irrigation water with salinity 〈4.61 dS/m does not have an obvious negative effect on cotton production, WUE or NUE under the experimental conditions. Application of N fertilizer（0–360 kg N/hm2） could alleviate salt damage, promote cotton growth, and increase both cotton yield and water use efficiency.展开更多
Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to o...Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.展开更多
Field experiments were conducted in 2008 and 2009 to study the effects of deficit irrigation with saline water on spring wheat growth and yield in an arid region of Northwest China. Nine treatments included three sali...Field experiments were conducted in 2008 and 2009 to study the effects of deficit irrigation with saline water on spring wheat growth and yield in an arid region of Northwest China. Nine treatments included three salinity levels sl, s2 and s3 （0.65, 3.2, and 6.1 dS/m） in combination with three water levels wl, w2 and w3 （375, 300, and 225 mm）. In 2008, for most treatments, deficit irrigation showed adverse effects on wheat growth; meanwhile, the effect of saline irrigation was not apparent. In 2009, growth parameters of wl treatments were not always optimal under saline irrigation. At 3.2 and 6.1 dS/m in 2008, the highest yield was obtained by wl treatments, however, in 2009, the weight of 1,000 grains and wheat yield both followed the order w2 〉 wl 〉 w3. In this study, spring wheat was sensitive to water deficit, especially at the booting to grain-filling stages, but was not significantly affected by saline irrigation and the combination of the two factors. The results demonstrated that 300-mm irrigation water with a salinity of less than 3.2 dS/m is suitable for wheat fields in the study area.展开更多
Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- por...Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- portation and its spatial distribution characteristics under irrigation with saline water in a maize field experiment. The mathematical relationships for soil salinity, irrigation amount and water salinity are also established to evaluate the contribution of the irrigation amount and the salinity of saline water to soil salt accumulation. The result showed that irrigation with water of high salinity could effectively increase soil water content, but the increment is limited com- paring with the influence from irrigation amount. The soil water content in furrows was higher than that in ridges at the same soil layers, with increments of 12.87% and 13.70% for MMF9 （the treatment with the highest water salinity and the largest amount of irrigation water） and MMF1 （the treatment with the lowest water salinity and the least amount of irrigation water） on 27 June, respectively. The increment for MMF9 was gradually reduced while that for MMF1 increased along with growth stages, the values for 17 August being 2.40% and 19.92%, respectively. Soil water content in the ridge for MMF9 reduced gradually from the surface layer to deeper layers while the surface soil water content for MMF1 was smaller than the contents below 20 cm at the early growing stage. Soil salinities for the treatments with the same amount of irrigation water but different water salinity increased with the water salinity. When water salinity was 6.04 dS/m, the less water resulted in more salt accumulation in topsoil and less in deep layers. When water salinity was 2.89 dS/m, however, the less water resulted in less salt accumulation in topsoil and salinity remained basically stable in deep layers. The salt accumulation in the ridge surface was much smaller than that in the furrow bottom under this technology, which was quite different from traditional furrow irrigation. The soil salinities for MMF7, MMF8 and MMF9 in the ridge surface were 0.191, 0.355 and 0.427 dS/m, respectively, whereas those in the furrow bottom were 0.316, 0.521 and 0.631 dS/m, respectively. The result of correlation analysis indicated that compared with irrigation amount, the irrigation water salinity was still the main factor influ- encing soil salinity in furrow irrigation with plastic mulch on ridge.展开更多
Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation...Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation water salinity and N fertilization on soil physicochemical and biological properties related to nitrification and denitrification. A 3×2 factorial design was used with three levels of irrigation water salinity（0.35, 4.61 and 8.04 d S m-1） and two N rates（0 and 360 kg N ha^（-1））. The results indicated that irrigation water salinity and N fertilization had significant effects on many soil physicochemical properties including water content, salinity, p H, NH_4-N concentration, and NO_3-N concentration. The abundance（i.e., gene copy number） of ammonia-oxidizing archaea（AOA） was greater than that of ammonia-oxidizing bacteria（AOB） in all treatments. Irrigation water salinity had no significant effect on the abundance of AOA or AOB in unfertilized plots. However, saline irrigation water（i.e., the 4.61 and 8.04 d S m-1 treatments） reduced AOA abundance, AOB abundance and potential nitrification rate in N fertilized plots. Regardless of N application rate, saline irrigation water increased urease activity but reduced the activities of both nitrate reductase and nitrite reductase. Irrigation with saline irrigation water significantly reduced cotton biomass, N uptake and yield. Nitrogen application exacerbated the negative effect of saline water. These results suggest that brackish water and saline water irrigation could significantly reduce both the abundance of ammonia oxidizers and potential nitrification rates. The AOA may play a more important role than AOB in nitrification in desert soil.展开更多
An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the ef...An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity,permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.展开更多
Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of signific...Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of significance to resolve water shortage, slow down environmental degradation and support the sustainable development of the local agriculture. Four key points are proposed to be managed by comprehensive measures: (1) adapting salt resistant ability; (2) reducing salt input; (3) decreasing soil surface evaporation and salt accumulation in the root zone, and (4) washing away salt from the root zone. Experiments and farming practices demonstrated that brackish water with TDS (total dissolved solids) of 2-5 g/l can be used for crop irrigation. For example, winter wheat can be sustainably irrigated by brackish water with a water limitation of 120 mm every year. Irrigation in combination with different comprehensive measures can increase the efficiency of saline water irrigation.展开更多
In this study,nineteen brine samples from the Qarhan Salt Lake(QSL)in western China were collected and analyzed for boron(B)and chlorine(Cl)concentrations,total dissolved solids(TDS),pH values and stable B isotopic co...In this study,nineteen brine samples from the Qarhan Salt Lake(QSL)in western China were collected and analyzed for boron(B)and chlorine(Cl)concentrations,total dissolved solids(TDS),pH values and stable B isotopic compositions.The B concentrations andδ^(11)B values of brines in the QSL range from 51.6 mg/L to138.4 mg/L,and from+9.32&to+13.08&,respectively.By comparison of B concentrations and TDS of brines in QSL with evaporation paths of brackish water,we found that B enrichment of brines primarily results from strong evaporation and concentration of Qarhan lake water.Combining with comparisons of B concentrations,TDS,p H values andδ^(11)B values of brines,previously elemental ratios(K/Cl,Mg/Cl,Ca/Cl,B/Cl)andδ^(11)B values of halite from a sediment core(ISL1 A),we observe good correlations between B concentrations and TDS,TDS and pH values,pH andδ^(11)B values of brines,which demonstrate that higher B concentrations and more positiveδ^(11)B values of halite indicate higher salinity of the Qarhan paleolake water as well as drier paleoclimatic conditions.Based on this interpretation of theδ^(11)B values of halite in core ISL1 A,higher salinity of the Qarhan paleolake occurred during two intervals,around 46-34 ka and26-9 ka,which are almost coincident with the upper and lower halite-dominated salt layers in core ISL1 A,drier climate phases documented from theδ^(18)O record of carbonate in core ISL1 A and the paleomoisture record in monsoonal central Asia,and a higher solar insolation at 30°N.These results demonstrate that theδ^(11)B values of halite in the arid Qaidam Basin could be regarded as a new proxy for reconstructing the salinity record of paleolake water as well as paleoclimate conditions.展开更多
Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water pote...Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical analyses.However,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as thought.Therefore,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated conditions.Second,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall incident.Eventually,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of safety.Results reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic conductivity.Despite the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower conductivity.Therefore,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.展开更多
Groundwater-fed lakes are essential for the ecology in arid and semiarid regions.As a typical arid region,the Badain Jaran Desert （BJD） is famous in the world for the presence of a large number of groundwater-fed sa...Groundwater-fed lakes are essential for the ecology in arid and semiarid regions.As a typical arid region,the Badain Jaran Desert （BJD） is famous in the world for the presence of a large number of groundwater-fed saline lakes among the mega dunes.Based on the up to date geological surveys and observations,this study analyzed the groundwater contributions in water-salt balances of the lakes in the desert.We found different types of springs,including the sublacustrine springs that indicate an upward flow of groundwater under the lakebed.A simplified water balance model was developed to analyze the seasonal variations of water level in the Sumu Barun Jaran Lake,which revealed an approximately steady groundwater discharge in the lake and explained why the amplitude of seasonal changes in lake level is less than 0.5 m.In addition,a salt balance model was developed to evaluate the salt accumulations in the groundwater-fed lakes.The relative salt accumulation time is 800–7,000 years in typical saline lakes,which were estimated from the concentration of Cl-,indicating a long history evolution for the lakes in the BJD.Further researches are recommended to provide comprehensive investigations on the interactions between the lakes and groundwater in the BJD.展开更多
Assembly processes of prokaryotic and microeukaryotic community is an important issue in microbial ecology.However,unclear remains about the relative contribution of deterministic and stochastic processes to the shapi...Assembly processes of prokaryotic and microeukaryotic community is an important issue in microbial ecology.However,unclear remains about the relative contribution of deterministic and stochastic processes to the shaping of prokaryotic and microeukaryotic communities in saline lake water.Here,we systematically investigated the assembly processes governing the prokaryotic and microeukaryotic communities in Qinghai Lake with the use of Illumina sequencing and a null model.The results showed that both deterministic and stochastic processes play vital roles in shaping the assemblies of prokaryotic and microeukaryotic communities,in which stochastic processes appeared to dominate(> 70%).Prokaryotic communities were mainly governed by non-dominant processes(60.4%),followed by homogeneous selection(15.8%),variable selection(13.6%) and dispersal limitation(10.2%),whereas microeukaryotes were strongly driven by non-dominant processes(68.9%),followed by variable selection(23.6%) and homogenizing dispersal(6.3%).In terms of variable selection,nutrients(e.g.,ammonium,dissolved inorganic carbon,dissolved organic carbon and total nitrogen) were the major factors influencing prokaryotic and microeukaryotic community structures.In summary,prokaryotes and microeukaryotes can be predominantly structured by different assembly mechanisms,in which stochasticity is stronger than deterministic processes.This finding helps to better comprehend the assembly of prokaryotic and eukaryotic communities in saline lakes.展开更多
Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several st...Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several studies have been conducted in model systems, while experiments with rocks and reservoir fluids are scarce. This study presents a core-flooding experiment of LSW injection, with and without surfactant, using the core and heavy oil samples obtained from a sandstone reservoir in southeastern Mexico. The effluents and the crude oil obtained at each stage were analyzed. The study was complemented by tomographic analysis. The results revealed that LSW injection and hybrid process with surfactants obtained an increase of 11.4 percentage points in recovery factor. Various phenomena were caused by LSW flooding, such as changes in wettability and pH, ion exchange, mineral dissolution, detachment of fines and modification of the hydrocarbon profile. In the surfactant flooding, the reduction of interfacial tension and alteration of wettability were the main mechanisms involved. The findings of this work also showed that the conditions believed to be necessary for enhanced oil recovery with LSW, such as the presence of kaolinite or high acid number oil, are not relevant.展开更多
The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather co...The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather conditions need to be taken into account in the dynamical analysis of LSWL, which is in need of research. In this paper, the POM-σ-z model is used to set up the numerical model for the expansion of the CDW. Then LSWL in summer 1977 is simulated, and its dynamic mechanism driven by wind, tide, river runoff and the Taiwan Warm Current is also analyzed. The simulated results indicate that the isolated LSWL detaches itself from the CDW near the river mouth, and then moves towards the northeast region outside the Changjiang Estuary. Its maintaining period is from July 26 to August 11. Its formation and development is mainly driven by two factors. One is the strong southeasterly wind lasting for ten days. The other is the vertical tidal mixing during the transition from neap tide to spring tide.展开更多
In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline wat...In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline water in the central and eastern of the North China Plain. Results show that:(1) The technical methods have achieved zero increase in rainwater runoff in urban areas,(2) surface drainage depletion problems can be solved through abandoned water and river water separation method,(3) and technical method through promoting rainwater infiltration would be used to solve problem of saline water in the central and eastern parts. This research provides a new perspective to the ultimate solutions to water resources problems in the North China Plain, and a fresh research direction for the development of hydro-geological science.展开更多
The importance of maximizing irrigation water productivity is increasing as the water resources still decreasing and deteriorating due to environmental interactions. An optimal irrigation water depth （including leach...The importance of maximizing irrigation water productivity is increasing as the water resources still decreasing and deteriorating due to environmental interactions. An optimal irrigation water depth （including leaching water depth） was estimated in order to maximize water unit volume productivity by using the optimal leaching fraction （LF）, which is calculated by the new proposed model--unit yield ratio （UYR%） and irrigation depth ratio （IDP）. A computer program was constructed to apply this model for several crops irrigated by two water resources--river and well. The water salinity of river was 1.1 dS/m and the well salinity was 3.85 dS/m. The results showed that there is an optimal leaching requirement （LR） value for each crop irrigated by any water resource. The maximum UYR% of the alfalfa irrigated by saline well water was 58.45% with the optimal LF = 0.4, while the maximum UYR% of the bean irrigated by river water was 78.58% with the optimal LR = 0.2. The optimal LF is saving water by increasing the productivity of irrigation water unit volume, especially when using saline irrigation water, for example, an increase of IDP for alfalfa by only 20%, followed by an increase of UYR% about 47.5% （from 12% to 57%） by increasing LF from 0.1 to 0.3.展开更多
Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core prio...Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).展开更多
基金The Science and Technology Development in Tianjin(No.033112211)
文摘Yellow River water transfer for Tianjin is important in solving the water shortage in Tianjin, which facilitate economic development and social progress for many years. Fresh water drawn from Yellow River（ i. e., Yin-Huang water） becomes saltier and saltier when being stored in the Bei-Da-Gang reservoir. We qualitatively analyze the water salinization mechanism based on mass transfer theory. The main factors are salinity transfer of saline soil, evaporation concentrating, and the agitation of wind. A simulative experimental pond and an evaporation pond were built beside the Bei-Da-Gang reservoir to quantitatively investigate the water salinization based on water and solute balance in the simulative pond. 80% of increased [Cl^-] is due to the salinity transfer of the saline soil and the other 20% is due to evaporation concentrating, so the former is the most important factor. We found that the salinization of Yin-Huang water can be described with a zero-dimension linear model.
基金supported by National Key R&D Program of China (2022YFD1900104)。
文摘To maintain soil quality under long-term saline water irrigation,the influence of manure on soil physical properties was examined.Long-term saline irrigation has been conducted from 2015 to 2024 at the Nanpi Eco-Agricultural Experimental Station of Chinese Academy Sciences in the Low Plain of the North China Plain,comprising four irrigation treatments:irrigation once at the jointing stage for winter wheat with irrigation water containing salt at fresh water,3,4 and 5 g·L^(–1),and maize irrigation at sowing using fresh water.Manure application was conducted under all irrigation treatments,with treatments without manure application used as controls.The results showed that under long-term irrigation with saline water,the application of manure increased the soil organic matter content,exchangeable potassium,available phosphorus,and total nitrogen content in the 0–20 cm soil layer by 46.8%,117.0%,75.7%,and 45.5%,respectively,compared to treatments without manure application.The application of manure reduced soil bulk density.It also increased the proportion of water-stable aggregates and the abundance of bacteria,fungi,and actinomycetes in the tillage soil layer compared to the controls.Because of the salt contained in the manure,the application of manure had dual effects on soil salt content.During the winter wheat season,manure application increased soil salt content.The salt content was significantly reduced during the summer maize season,owing to the strong salt-leaching effects under manure application,resulting in a smaller difference in salt content between the manure and non-manure treatments.During the summer rainfall season,improvements in soil structure under manure application increased the soil desalination rate for the 1 m top soil layer.The desalination rate for 0–40 cm and 40–100 cm was averagely by 39.1%and 18.9%higher,respectively,under manure application as compared with that under the nomanure treatments.The yield of winter wheat under manure application was 0.12%lower than that of the control,owing to the higher salt content during the winter wheat season.In contrast,the yield of summer maize improved by 3.9%under manure application,owing to the increased soil nutrient content and effective salt leaching.The results of this study indicated that manure application helped maintain the soil physical structure,which is important for the long-term use of saline water.In practice,using manure with a low salt content is suggested to reduce the adverse effects of saline water irrigation on soil properties and achieve sustainable saline water use.
基金funded by the National Key R&D Program of China (2022YFD1900405)。
文摘In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.
文摘Black nanosheets(BN,with a specific chemical composition of molybdenum disulfide)have been widely studied for low-permeability reservoir development due to their unique nanoscale dimensions and lamellar structure.Our prior research demonstrated that cationically modified BN combined with low-salinity water(LSW)significantly enhances oil displacement.This study compared the imbibition adaptability of the composite system under both ambient-pressure and pressurized conditions,while combining nuclear magnetic resonance(NMR)techniques to analyze related imbibition mechanisms and reservoir permeability adaptability.Results showed that the modified BN-LSW composited system achieved an imbibition recovery efficiency of 43.92% under ambient pressure.The mechanism was capillary force-dominated,preferentially displacing oil from small pores by improving core wettability and emulsification.Under pressurized conditions,the driving force became dominant,further increasing recovery efficiency to 56.52%,with the system displacing oil from both large and small pores.Additionally,the system showed optimal adaptability in cores with 0.05×10^(−3)μm^(2) permeability.Imbibition efficiency declined at higher/lower permeabilities due to weakened capillary forces or nanoparticle aggregation-induced clogging.This study confirmed that the modified BN-LSW composite system enhanced imbibition stability and recovery efficiency,and combined with nuclear magnetic resonance(NMR)technology,its mechanism was revealed at the microscale.This provided theoretical and technical support for the efficient development of low-permeability reservoirs,with significant engineering value.
基金funded by the National Basic Research Program of China (2009CB825101)the National Natural Science Foundation of China (30960210)
文摘In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficiency（NUE） was significantly lower in the 8.04 dS/m treatment than in either the 4.61 dS/m or the 0.35 dS/m treatment. There was no significant difference in NUE between the latter two treatments. These results suggest that irrigation water with salinity 〈4.61 dS/m does not have an obvious negative effect on cotton production, WUE or NUE under the experimental conditions. Application of N fertilizer（0–360 kg N/hm2） could alleviate salt damage, promote cotton growth, and increase both cotton yield and water use efficiency.
基金Project supported by the National Natural Science Foundation of China (Nos. 50339030 and 90202001).
文摘Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.
基金supported by the National Basic Research Program of China (2011CB403406)the National Natural Science Foundation of China (51179166)the Youth Foundation of Taiyuan University of Technology (2012L077)
文摘Field experiments were conducted in 2008 and 2009 to study the effects of deficit irrigation with saline water on spring wheat growth and yield in an arid region of Northwest China. Nine treatments included three salinity levels sl, s2 and s3 （0.65, 3.2, and 6.1 dS/m） in combination with three water levels wl, w2 and w3 （375, 300, and 225 mm）. In 2008, for most treatments, deficit irrigation showed adverse effects on wheat growth; meanwhile, the effect of saline irrigation was not apparent. In 2009, growth parameters of wl treatments were not always optimal under saline irrigation. At 3.2 and 6.1 dS/m in 2008, the highest yield was obtained by wl treatments, however, in 2009, the weight of 1,000 grains and wheat yield both followed the order w2 〉 wl 〉 w3. In this study, spring wheat was sensitive to water deficit, especially at the booting to grain-filling stages, but was not significantly affected by saline irrigation and the combination of the two factors. The results demonstrated that 300-mm irrigation water with a salinity of less than 3.2 dS/m is suitable for wheat fields in the study area.
基金supported by the National Natural Science Foundation of China (91025002,30970492)the National Key Technology R & D Program (2012BAC08B05)
文摘Furrow irrigation when combined with plastic mulch on ridge is one of the current uppermost wa- ter-saving irrigation technologies for arid regions. The present paper studies the dynamics of soil water-salt trans- portation and its spatial distribution characteristics under irrigation with saline water in a maize field experiment. The mathematical relationships for soil salinity, irrigation amount and water salinity are also established to evaluate the contribution of the irrigation amount and the salinity of saline water to soil salt accumulation. The result showed that irrigation with water of high salinity could effectively increase soil water content, but the increment is limited com- paring with the influence from irrigation amount. The soil water content in furrows was higher than that in ridges at the same soil layers, with increments of 12.87% and 13.70% for MMF9 （the treatment with the highest water salinity and the largest amount of irrigation water） and MMF1 （the treatment with the lowest water salinity and the least amount of irrigation water） on 27 June, respectively. The increment for MMF9 was gradually reduced while that for MMF1 increased along with growth stages, the values for 17 August being 2.40% and 19.92%, respectively. Soil water content in the ridge for MMF9 reduced gradually from the surface layer to deeper layers while the surface soil water content for MMF1 was smaller than the contents below 20 cm at the early growing stage. Soil salinities for the treatments with the same amount of irrigation water but different water salinity increased with the water salinity. When water salinity was 6.04 dS/m, the less water resulted in more salt accumulation in topsoil and less in deep layers. When water salinity was 2.89 dS/m, however, the less water resulted in less salt accumulation in topsoil and salinity remained basically stable in deep layers. The salt accumulation in the ridge surface was much smaller than that in the furrow bottom under this technology, which was quite different from traditional furrow irrigation. The soil salinities for MMF7, MMF8 and MMF9 in the ridge surface were 0.191, 0.355 and 0.427 dS/m, respectively, whereas those in the furrow bottom were 0.316, 0.521 and 0.631 dS/m, respectively. The result of correlation analysis indicated that compared with irrigation amount, the irrigation water salinity was still the main factor influ- encing soil salinity in furrow irrigation with plastic mulch on ridge.
基金funded by the National Natural Science Foundation of China (31360504)the Innovative Research Foundation for Excellent Young Scientists of Xinjiang Production and Construction Crops, China (2014CD002)
文摘Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation water salinity and N fertilization on soil physicochemical and biological properties related to nitrification and denitrification. A 3×2 factorial design was used with three levels of irrigation water salinity（0.35, 4.61 and 8.04 d S m-1） and two N rates（0 and 360 kg N ha^（-1））. The results indicated that irrigation water salinity and N fertilization had significant effects on many soil physicochemical properties including water content, salinity, p H, NH_4-N concentration, and NO_3-N concentration. The abundance（i.e., gene copy number） of ammonia-oxidizing archaea（AOA） was greater than that of ammonia-oxidizing bacteria（AOB） in all treatments. Irrigation water salinity had no significant effect on the abundance of AOA or AOB in unfertilized plots. However, saline irrigation water（i.e., the 4.61 and 8.04 d S m-1 treatments） reduced AOA abundance, AOB abundance and potential nitrification rate in N fertilized plots. Regardless of N application rate, saline irrigation water increased urease activity but reduced the activities of both nitrate reductase and nitrite reductase. Irrigation with saline irrigation water significantly reduced cotton biomass, N uptake and yield. Nitrogen application exacerbated the negative effect of saline water. These results suggest that brackish water and saline water irrigation could significantly reduce both the abundance of ammonia oxidizers and potential nitrification rates. The AOA may play a more important role than AOB in nitrification in desert soil.
基金the National Iranian South Oil Company (NISOC) for generously funding the project
文摘An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity,permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.
文摘Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of significance to resolve water shortage, slow down environmental degradation and support the sustainable development of the local agriculture. Four key points are proposed to be managed by comprehensive measures: (1) adapting salt resistant ability; (2) reducing salt input; (3) decreasing soil surface evaporation and salt accumulation in the root zone, and (4) washing away salt from the root zone. Experiments and farming practices demonstrated that brackish water with TDS (total dissolved solids) of 2-5 g/l can be used for crop irrigation. For example, winter wheat can be sustainably irrigated by brackish water with a water limitation of 120 mm every year. Irrigation in combination with different comprehensive measures can increase the efficiency of saline water irrigation.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41872093,41502096)Foundation of Qinghai Science&Technology Department(2016-ZJ-715)One-Thousand InnovativeTalent Project of Qinghai Province(Grant to QS Fan)
文摘In this study,nineteen brine samples from the Qarhan Salt Lake(QSL)in western China were collected and analyzed for boron(B)and chlorine(Cl)concentrations,total dissolved solids(TDS),pH values and stable B isotopic compositions.The B concentrations andδ^(11)B values of brines in the QSL range from 51.6 mg/L to138.4 mg/L,and from+9.32&to+13.08&,respectively.By comparison of B concentrations and TDS of brines in QSL with evaporation paths of brackish water,we found that B enrichment of brines primarily results from strong evaporation and concentration of Qarhan lake water.Combining with comparisons of B concentrations,TDS,p H values andδ^(11)B values of brines,previously elemental ratios(K/Cl,Mg/Cl,Ca/Cl,B/Cl)andδ^(11)B values of halite from a sediment core(ISL1 A),we observe good correlations between B concentrations and TDS,TDS and pH values,pH andδ^(11)B values of brines,which demonstrate that higher B concentrations and more positiveδ^(11)B values of halite indicate higher salinity of the Qarhan paleolake water as well as drier paleoclimatic conditions.Based on this interpretation of theδ^(11)B values of halite in core ISL1 A,higher salinity of the Qarhan paleolake occurred during two intervals,around 46-34 ka and26-9 ka,which are almost coincident with the upper and lower halite-dominated salt layers in core ISL1 A,drier climate phases documented from theδ^(18)O record of carbonate in core ISL1 A and the paleomoisture record in monsoonal central Asia,and a higher solar insolation at 30°N.These results demonstrate that theδ^(11)B values of halite in the arid Qaidam Basin could be regarded as a new proxy for reconstructing the salinity record of paleolake water as well as paleoclimate conditions.
基金the Iran’s National Elites Foundation and the Research Grant Office at Sharif University Technology for supporting this research by way of “Dr Kazemi-Ashtiani Award” and grant “G970902”,respectively。
文摘Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical analyses.However,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as thought.Therefore,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated conditions.Second,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall incident.Eventually,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of safety.Results reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic conductivity.Despite the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower conductivity.Therefore,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.
基金supported by the China Foundation for the Author of National Excellent Doctoral Dissertation (201457)the National Natural Science Foundation of China (91125024)
文摘Groundwater-fed lakes are essential for the ecology in arid and semiarid regions.As a typical arid region,the Badain Jaran Desert （BJD） is famous in the world for the presence of a large number of groundwater-fed saline lakes among the mega dunes.Based on the up to date geological surveys and observations,this study analyzed the groundwater contributions in water-salt balances of the lakes in the desert.We found different types of springs,including the sublacustrine springs that indicate an upward flow of groundwater under the lakebed.A simplified water balance model was developed to analyze the seasonal variations of water level in the Sumu Barun Jaran Lake,which revealed an approximately steady groundwater discharge in the lake and explained why the amplitude of seasonal changes in lake level is less than 0.5 m.In addition,a salt balance model was developed to evaluate the salt accumulations in the groundwater-fed lakes.The relative salt accumulation time is 800–7,000 years in typical saline lakes,which were estimated from the concentration of Cl-,indicating a long history evolution for the lakes in the BJD.Further researches are recommended to provide comprehensive investigations on the interactions between the lakes and groundwater in the BJD.
基金supported by grants from the National Natural Science Foundation of China (Nos.92251304 and 41972317)the 111 Program (State Administration of Foreign Experts Affairs&the Ministry of Education of China,No.B18049)+2 种基金the Second Tibetan Plateau Scientific Expedition and Research Program (STEP)(No.2019QZKK0805)the Science and Technology Plan Project of Qinghai Province (No.2022-ZJ-Y08)State Key Laboratory of Biogeology and Environmental Geology,CUG (No.GBL11805)。
文摘Assembly processes of prokaryotic and microeukaryotic community is an important issue in microbial ecology.However,unclear remains about the relative contribution of deterministic and stochastic processes to the shaping of prokaryotic and microeukaryotic communities in saline lake water.Here,we systematically investigated the assembly processes governing the prokaryotic and microeukaryotic communities in Qinghai Lake with the use of Illumina sequencing and a null model.The results showed that both deterministic and stochastic processes play vital roles in shaping the assemblies of prokaryotic and microeukaryotic communities,in which stochastic processes appeared to dominate(> 70%).Prokaryotic communities were mainly governed by non-dominant processes(60.4%),followed by homogeneous selection(15.8%),variable selection(13.6%) and dispersal limitation(10.2%),whereas microeukaryotes were strongly driven by non-dominant processes(68.9%),followed by variable selection(23.6%) and homogenizing dispersal(6.3%).In terms of variable selection,nutrients(e.g.,ammonium,dissolved inorganic carbon,dissolved organic carbon and total nitrogen) were the major factors influencing prokaryotic and microeukaryotic community structures.In summary,prokaryotes and microeukaryotes can be predominantly structured by different assembly mechanisms,in which stochasticity is stronger than deterministic processes.This finding helps to better comprehend the assembly of prokaryotic and eukaryotic communities in saline lakes.
文摘Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several studies have been conducted in model systems, while experiments with rocks and reservoir fluids are scarce. This study presents a core-flooding experiment of LSW injection, with and without surfactant, using the core and heavy oil samples obtained from a sandstone reservoir in southeastern Mexico. The effluents and the crude oil obtained at each stage were analyzed. The study was complemented by tomographic analysis. The results revealed that LSW injection and hybrid process with surfactants obtained an increase of 11.4 percentage points in recovery factor. Various phenomena were caused by LSW flooding, such as changes in wettability and pH, ion exchange, mineral dissolution, detachment of fines and modification of the hydrocarbon profile. In the surfactant flooding, the reduction of interfacial tension and alteration of wettability were the main mechanisms involved. The findings of this work also showed that the conditions believed to be necessary for enhanced oil recovery with LSW, such as the presence of kaolinite or high acid number oil, are not relevant.
基金supported by the National Natural Science Foundation of China(Grant Nos.40906044,41076048 and 41376012)the Fundamental Research Funds for the Central Universities(Grant No.2011B05714)the Doctoral Starting up Foundation of College of Meteorology and Oceanography of the PLA University of Science and Technology,China
文摘The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather conditions need to be taken into account in the dynamical analysis of LSWL, which is in need of research. In this paper, the POM-σ-z model is used to set up the numerical model for the expansion of the CDW. Then LSWL in summer 1977 is simulated, and its dynamic mechanism driven by wind, tide, river runoff and the Taiwan Warm Current is also analyzed. The simulated results indicate that the isolated LSWL detaches itself from the CDW near the river mouth, and then moves towards the northeast region outside the Changjiang Estuary. Its maintaining period is from July 26 to August 11. Its formation and development is mainly driven by two factors. One is the strong southeasterly wind lasting for ten days. The other is the vertical tidal mixing during the transition from neap tide to spring tide.
基金funded by National Key Basic Research Program of China(2010CB428800),Geological Survey(20023064)(12120113102400)
文摘In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline water in the central and eastern of the North China Plain. Results show that:(1) The technical methods have achieved zero increase in rainwater runoff in urban areas,(2) surface drainage depletion problems can be solved through abandoned water and river water separation method,(3) and technical method through promoting rainwater infiltration would be used to solve problem of saline water in the central and eastern parts. This research provides a new perspective to the ultimate solutions to water resources problems in the North China Plain, and a fresh research direction for the development of hydro-geological science.
文摘The importance of maximizing irrigation water productivity is increasing as the water resources still decreasing and deteriorating due to environmental interactions. An optimal irrigation water depth （including leaching water depth） was estimated in order to maximize water unit volume productivity by using the optimal leaching fraction （LF）, which is calculated by the new proposed model--unit yield ratio （UYR%） and irrigation depth ratio （IDP）. A computer program was constructed to apply this model for several crops irrigated by two water resources--river and well. The water salinity of river was 1.1 dS/m and the well salinity was 3.85 dS/m. The results showed that there is an optimal leaching requirement （LR） value for each crop irrigated by any water resource. The maximum UYR% of the alfalfa irrigated by saline well water was 58.45% with the optimal LF = 0.4, while the maximum UYR% of the bean irrigated by river water was 78.58% with the optimal LR = 0.2. The optimal LF is saving water by increasing the productivity of irrigation water unit volume, especially when using saline irrigation water, for example, an increase of IDP for alfalfa by only 20%, followed by an increase of UYR% about 47.5% （from 12% to 57%） by increasing LF from 0.1 to 0.3.
基金funded by Abdulaziz City for Science and Technology,Saudi Arabia(Grant Research No.1-17-04-001-0021).
文摘Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).
