Groundwater In China Research Articles

Impact of grain virtual water flow on surface water and groundwater in China

Virtual water flow can alleviate the pressure of regional water resources. Differences in water resources endowment and industrial structure among regions cause regional differences in water use in China. Water use in agriculture, especially irrigation, heavily relies on both surface water and groundwater. Virtual water flow may have different influence on the utilization and exploitation of regional surface water and groundwater. However, few studies have separately investigated the impacts of virtual water transfer on them. According to virtual water theory, contribution rate and regional differences, this study evaluates the effects of virtual water flow on water resources among provinces in China. The results indicate most regions mainly rely on surface water that accounts for less than 50% of surface water supply in only four provinces, namely Hebei, Henan, Beijing, and Shanxi. In the Northern region and mainly in North China, the dependence on groundwater is very high. The total virtual water flow in China increased from 75.8 Gm³ in 1998 to 124.6 Gm³ in 2014 and showed a trend from the northeast and central regions to the south and western regions. Given the decrease in the scale of virtual water export, the decline of groundwater level in North China is not further aggravated. Water-saving irrigation is the main method to improve the efficiency of irrigation water use. The results of the study can aid in improving the sustainability of surface water and groundwater management in the grain production process via identifying dominant areas.

Water Use Conflict and Coordination between Agricultural and Wetlands—A Case Study of Yanqi Basin

Increased groundwater extraction leads to the decrease of the extent of wetlands due to the implementation of a water-saving transformation project in an arid irrigation area. The application of integrated mitigation tools and strategies in China have increasing significance. In this study, an integrated approach (SWAT-MODFLOW) was followed; it is based on a soil and water assessment tool (SWAT) coupled with a modular three-dimensional finite difference groundwater model (MODFLOW). Recharge and evaporation values were estimated by SWAT and were then used to simulate groundwater in a MODFLOW model. Calibration (over the years 2000–2010) and validation (over the years 2010–2016) were performed, based on observed groundwater-level data; results showed that the combined SWAT-MODFLOW provides more accurate simulation and prediction of the dynamic changes of surface water and groundwater in irrigation areas than results from individual MODFLOW models. This method was applied to the Yanqi Basin, which is one of the most appropriate arid agricultural basins for modeling lake wetland and groundwater in China. The correlation coefficients (R2) between the simulated and real groundwater level are 0.96 and 0.91 in SWAT-MODFLOW and MODFLOW, respectively. With the gradual increase in the extraction to 248%, 0.62 × 108 m3 of groundwater discharged into the lake became −2.25 × 108 m3. The lake level drops 1.3 m compared with the current year, when the groundwater exploitation increases by 10 × 108 m3/year. Overall, the results of the coupling model offer scientific evidence for agricultural water management and lake recovery, so as to enhance the water use coordination.

Factors affecting sustained adoption of irrigation water-saving technologies in groundwater over-exploited areas in the North China Plain

Over-exploitation of groundwater in China has severely affected irrigation agriculture, especially in the North China Plain, and it also threatens the environment. Although water-saving technologies (WSTs) have been introduced for decades, sustained commitment to WST is not being met. This paper investigates factors affecting adoption and sustained adoption of WST based on 261 households in the North China Plain. We employ Heckman’s two-stage sample selection process: (1) households decide whether to adopt WST or not and (2) households decide whether to sustainably adopt (adopt for a long time) WST or not. Particular attention is paid to the role of water scarcity in the initial adoption and sustained adoption stages. Several indicators relating to water scarcity are used to calculate a water scarcity index based on principal component analysis. The results showed that water scarcity exerts a significant and positive effect on both adoption and sustained adoption of WST. Non-adopters and non-sustained adopters face less severe water scarcity than adopters. Membership in cooperative organizations significantly improves the likelihood of sustained adoption; 63.6% of sustained adopters have a membership in cooperative organizations, compared with 18.2% of non-sustained adopters. The number of plots negatively affects the sustained adoption of WST; sustained adopters on average have 3.0 plots, and non-sustained adopters have 5.3 plots. Education, extension service, farm size, off-farm work, relatives working in the local government and irrigation costs are positively and significantly associated with adoption and sustained adoption decisions. Finally, we find that labor-saving capacity significantly influences both stages, whereas capital-saving capacity is only significant in the adoption stage. Only 10% of non-adopters consider adoption of WST as more labor- and capital-saving than conventional irrigation practices, in comparison with nearly 50% of adopters. These results imply that the extension of WST should consider focusing more on cooperative organizations and hold more demonstrations for farmers. Moreover, given that the degree of water shortage varies from region to region, the WST extension standards should vary accordingly. Governments should strengthen awareness by enhancing education and publicity concerning water scarcity and conservation.

Influencing factors and health risk assessment of polycyclic aromatic hydrocarbons in groundwater in China

Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants. This study investigated the occurrence of 16 PAHs in groundwater of representative regions of China (the cities of Lanzhou, Shijiazhuang, and Golmud and in Du’an County) using a gas chromatograph mass spectrometer. The total concentrations of 16 PAHs (∑PAHs) were in the range 0–29.06 μg/L (average: 594.8 ng/L). Acenaphthylene (Acy) and Naphthalene (Nap) had the highest detected frequency (74.56 %) and highest average concentration (632.7 ng/L), respectively. The average concentration of ∑PAHs in each study area exhibited the following trend: Lanzhou > Golmud > Du’an dry season > Du’an wet season > Shijiazhuang. The dominant PAHs in the study areas comprised mainly 2–4-ring PAHs, i.e., Nap (38.71 %; Shijiazhuang), BaA (40.09 %; Du’an wet season), Ace (16.84 %; Du’an dry season), Nap (43.51 %; Lanzhou), and BaA (57.43 %; Golmud). Overall, the PAHs of 101 samples were derived primarily from combustion and a small number of samples of PAHs originated from petroleum sources. Owing to strong adsorption in the vadose zone, the concentrations of PAHs in Shijiazhuang groundwater were lower than those in the groundwater of Golmud and Du’an. The groundwater in Du’an, Lanzhou and Golmud exhibits potential carcinogenic risk if consumed without further treatment.

Pollution characteristics of aromatic hydrocarbons in the groundwater of China

Much of the world's groundwater supply has been contaminated by aromatic hydrocarbons originating from anthropogenic sources. To study the occurrence and distribution characteristics of aromatic hydrocarbons in groundwater, 24 aromatic hydrocarbon compounds were selected: Five BTEX compounds (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene), 10 alkyl-substituted benzene, and 9 halogenated aromatics. These aromatic hydrocarbons were then analyzed from 355 samples collected from across China. Results indicated that aromatic hydrocarbons were detected in 59 out of 355 samples. Of the selected aromatic hydrocarbons, BTEX compounds were detected with high frequency and at low concentrations; comparatively, halogenated aromatics were detected with low frequency and at high concentrations. The aromatic hydrocarbon characteristics found in both karst and pore groundwater samples were then determined using their respective hydrogeological conditions and corresponding human activities. In karst groundwater, BTEX compounds were the most frequently detected aromatic hydrocarbon. The high detection frequencies of aromatic hydrocarbons were caused by their rapid migration, owing to the developed conduit system in the sampled karst area. The low concentrations of aromatic hydrocarbons in karst groundwater samples were caused by low-intensity human activity along with special hydrogeological conditions with higher redox potential and the unique compositions of aromatic hydrocarbons. Alkyl-substituted aromatics and halogenated aromatics were detected at higher concentrations in pore groundwater, owing to high-intensity human activity. Aromatic hydrocarbon pollution was gradually decreased along piedmont-alluvial plain-coast line, owing to a decrease in aquifer vulnerability. These were positively correlated with the size of the aquifer's particles. Samples with a high accumulative concentration of these aromatic hydrocarbons tended to occur in pore groundwater with a high concentration of either SO42− or Cl−.

Geochemistry of potentially hazardous elements in loess-amended mining sediment

Contaminated mining sediment may cause environmental and human health risk due to potentially hazardous elements (PHEs) leaching into groundwater, especially under very acid (pH ≤ 3) conditions. The capability of Chinese loess to immobilise and retain copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) from element contaminated mining sediment was explored by a column leaching experiment. Results showed that loess could effectively reduce Cu geomobility, and their leachate concentrations were lower than the quality standard (1.0 mg L−1) for ground water in China. The sierozem showed strong adsorption for Zn, Cd and Pb. The geomobility of Cu, Zn, Cd and Pb were affected by pH, electrical conductivity, organic matter and carbonate content of sediment/loess-amended sediment and sierozem. The long-term leaching of PHEs in loess-amended sediment may pose a potential risk to sierozem and groundwater in the region. This study highlights the need to develop a remediation technique to minimise the concentration level of hazardous elements in the mining sediment.

A nationwide study of the occurrence and distribution of atrazine and its degradates in tap water and groundwater in China: Assessment of human exposure potential

Despite frequent detection of atrazine (ATZ) and its degradates (including hydroxyatrazine, ATZ-OH; deethylatrazine, DEA; deisopropylatrazine, DIA; and deethyldeisopropylatrazine, DACT) in a variety of water bodies, documentation of their occurrence and distribution in tap water in China is still scarce. A nationwide survey about ATZ and its degradates (ATZs) in tap water from 31 provinces in 7 regions of mainland China and Hong Kong was conducted during June 2019. At least one of the analytes was found in all the water samples (n = 884). The median sum concentrations of ATZs (ΣATZs) was 21.0 ng/L (range: 0.02 ng/L–3.04 μg/L). The predominant compounds of ATZs in tap water were ATZ and DEA, with a detection frequency of 99.5% and 98.0%, respectively, followed by ATZ-OH (87.3%), DACT (84.0%), and DIA (78.1%). Significant regional variations (p < 0.05) were found in the concentrations of ATZs in tap water, and the highest concentration of ΣATZs (median: 254 ng/L, range: 0.44 ng/L–3.04 μg/L) was found in Northeastern China, followed by Eastern (37.2 ng/L, 0.02–706 ng/L), Northern (30.2 ng/L, 0.04–317 ng/L), Central (29.3 ng/L, 0.04–256 ng/L), Southern (25.0 ng/L, 0.04–297 ng/L), Southwestern (17.2 ng/L, 0.02–388 ng/L), and Northwestern China (3.22 ng/L, 0.06–214 ng/L). The level of ΣATZs in groundwater from rural area of China was about 1/3 of that found in tap water. ATZs cannot be removed by boiling tap water. The highest estimated daily intake of ΣATZs (248 ng/kg-body weight/day) was found in the infant population of Changchun, Jilin, Northeastern China.

Groundwater Arsenic and Fluoride and Associated Arsenicosis and Fluorosis in China: Occurrence, Distribution and Management

Arsenic and fluoride are two natural components affecting human health. Long-term exposure to arsenic and fluoride, mainly through drinking water intake, can lead to arsenicosis and fluorosis. In this paper, we summarized the distribution and hydrochemical characteristics of high-arsenic and high-fluoride groundwater, and reviewed the arsenicosis and fluorosis distribution due to consumption of high-arsenic and high-fluoride groundwater in China. The results show that there are 20 major provinces//autonomous regions (about 60%) in China suffering from high-arsenic groundwater, and these high-arsenic groundwater provinces are mainly located in the fluvial/alluvial-lacustrine plains and basins located in arid/semi-arid regions and alluvial plains/basins and river deltas in humid/semi-humid regions. Drinking water arsenicosis has been found in 13 provinces/autonomous regions, with Shanxi and Inner Mongolia being the two most seriously affected areas. High-fluoride groundwater is widely distributed in north, northeast and northwest parts of China, occurring mainly in shallow groundwater. Fluorosis has been found in 29 provinces/autonomous regions. With the continuous implementation of water quality improvement projects, drinking water fluorosis and arsenic poisoning have been effectively controlled. However, the long-term maintenance and operation of the water quality improvement project need to be further strengthened.

Contamination profiles and risk assessment of per- and polyfluoroalkyl substances in groundwater in China.

Per- and polyfluoroalkyl substances (PFASs) have attracted attention due to the potential risk they pose to ecosystems and human health. A total of 169 groundwater samples were collected from four representative regions in order to analyze PFASs concentrations in China. The total concentration of PFASs (∑PFASs) in groundwater ranged from 0.05 to 198.80ngL-1, with an average of 3.97ngL-1. All targeted PFASs were detected in the studied areas. The detection frequency and average concentration of perfluorooctanoic acid (PFOA) were the highest (79.29% and 1.61ngL-1, respectively). The contamination profiles of PFASs in each study area varied due to natural geographical conditions and human activities. According to the results of the potential source identification, the point sources of perfluorooctane sulfonate (PFOS) were mainly concentrated in Lanzhou, and the distribution of PFASs was slightly affected by atmospheric deposition in all the studied areas. The obtained concentrations of PFOA and PFOS may pose no threat to the residents due to water consumption.

The role of scientific research in the formulation of the double-control policy for groundwater management in China

Abstract Groundwater is a major source of water supply in China. However, groundwater levels have declined in many regions of China due to groundwater over-extraction, leading to adverse impacts on the eco-environment in China. It is urgent to formulate policy for sustainable groundwater management. In this study, we described and discussed the role of scientific research in China when creating a policy of double-control groundwater management. We used examples of three regions with the groundwater over-extraction problem, i.e., the Sanjiang Plain of northeast China, North China Plain, and the Xilin River Basin of northwest China, to demonstrate the support of scientific research in developing the policy. In addition, it was found that that the interactions between science and policy need to be further improved for the management of groundwater in China. Therefore, we developed a control-loop theory to enhance the interactions between science and policy in China.

Groundwater depletion and contamination: Spatial distribution of groundwater resources sustainability in China

China is facing a groundwater depletion and deterioration crisis, culminating from long-term over-exploitation and groundwater contamination. Aggravating factors include population growth, unprecedented urbanization and climate change. Sustainable groundwater management is called for, however, a valid means for a national-scale assessment of groundwater resource sustainability does not currently exist. Here we present a drivers-pressures-states-impact-response (DPSIR) assessment framework. Based on this framework, groundwater sustainability indices for mainland China's 31 provinces and municipalities were derived, with an average score of 59.5 out of 100, ranging from 47.3 for Tianjin to 72.9 for Tibet. We found that due to fewer Drivers and better States, groundwater resources in southern China are far more sustainable than those in the northern and eastern areas. An appraisal of subcategories shed light on the importance of affording attention to externalities such as societal, economic and environmental factors, which are interrelated as complex systems. Based on the assessment findings, implications for policy and decision-making suggestions for sustainable management of China's groundwater resources are put forward.

Comparative study on models of groundwater salinity in Yongnian County

The stability of groundwater salinity has important practical significance for the healthy development of groundwater in China, especially in areas where groundwater is over-exploited. In order to improve the fitting precision and prediction effect of groundwater salinity, this paper constructed a series of fitting and prediction models of groundwater salinity based on grey theory and MATLAB.Taking Yongnian County of Handan City as an example, this paper adopted the data of groundwater salinity of three monitoring wells in this region from 2010 to 2015 for an empirical study.The fitting results of GM(1,N) model were compared with the fitting results of GM(1,1) and MATLAB linear regression models. The results showed that the absolute relative error of the GM(1,N) model in the three monitoring wells was 0.4391%, 0.2540%, 0.4675%, and the accuracy was A. Compared with other models, the prediction effect is better, which can meet the needs of groundwater mineralization prediction in Yongnian County. The prediction results can provide a scientific basis for the work of groundwater management and groundwater mineralization in Yongnian County in the next few years.

Review: Progress in permafrost hydrogeology in China

Groundwater in China’s permafrost region is vital for humans and cold-climate ecosystems. Permafrost responses to global warming have significantly changed the spatio-temporal patterns and distribution of properties associated with the groundwater system. The main areas of current and past studies on permafrost hydrogeology in China include four aspects: groundwater distribution and dynamics in permafrost regions, interplay between groundwater and permafrost, the impact of permafrost degradation on groundwater, and the regional effect of groundwater changes on the environment in permafrost regions. Over the last 10 years, the development and use of coupled heat-transport and groundwater models have focused on the hydrogeology of permafrost, and on groundwater development and distribution in permafrost regions. Progress in groundwater-related research on issues surrounding permafrost regions of China are comprehensively summarized and discussed in this review paper, which should provide a theoretical basis for further study of the groundwater system and its effects on the ecological environment under climate change.

Regional Variability of Agriculturally-Derived Nitrate-Nitrogen in Shallow Groundwater in China, 2004–2014

Increasing diffuse nitrate loading of groundwater has long been a major environmental and health concern in China, but little is known about the spatial and temporal variability of nitrate concentrations in groundwater at regional scales. The aim of this study was to assess the spatial distribution and variation of nitrate-nitrogen (NO3−-N) concentrations in groundwater. We used groundwater quality monitoring data and soil physical characteristics from 21 agro-ecosystems in China for years 2004 to 2014. The results indicated that NO3−-N concentrations were highly variable in shallow groundwater across the landscape. Over the study period, most of the NO3−-N concentrations were below the World Health Organization permissible limit for drinking water (&lt;10 mg N·L). NO3−-N concentrations in groundwater neither significantly increased nor decreased in most agro-ecosystems, but fluctuated with seasons. In addition, groundwater NO3−-N under purple soil (6.81 mg·L−1) and Aeolian sandy soil (6.02 mg·L−1) were significantly higher (p &lt; 0.05) than that under other soil types, and it was medium-high (4.49 mg·L−1) under aquic cinnamon soil. Elevated nitrate concentrations occurred mainly in oasis agricultural areas of northwestern China, where farmlands with coarse-textured soils use flood irrigation. Therefore, arid and semi-arid areas are expected to sustain high NO3−-N concentrations in groundwater. Mitigation strategies can prevent this problem, and include control of N fertilizer input, balanced fertilization, proper rotation system, adoption of improved irrigation methods, and establishment of environmental policies.

Review: Micro-organic contaminants in groundwater in China

Micro-organic contaminants (MOs) in groundwater, which may have adverse effects on human health and ecosystems worldwide, are gaining increased attention in China. A great deal of research has been conducted to investigate their sources, occurrences and behavior in aquifers. This paper reviews the main sources, distribution, concentrations and behavior of a wide range of MOs in groundwater in China. These MOs include well-established persistent organic pollutants—polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs), polychlorinated biphenyls (PCBs), endocrine disrupting chemicals (poly brominated diphenyl ethers (PBDEs), phthalic acid esters (PAEs), bisphenol A (BPA)—and some contaminants of emerging concern such as pharmaceutical and personal care products (antibiotics, caffeine, shampoos) and perfluorinated compounds (PFCs). The results reveal that the main MOs in groundwater are PAHs, organochlorine pesticides (OCPs), PBDEs, PAEs, and antibiotics. Moreover, some PFCs such as perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) have only recently been observed in groundwater as emerging organic contaminants. Additionally, most MOs are distributed in populated and industrialized areas such as the southeast coast of China. Finally, industrial emissions, wastewater treatment plant effluents and agricultural wastewater are found to be dominant sources of MOs in groundwater. Based on the existing pollution levels, regulation and amelioration of MOs are warranted.

Effect of simulated acid rain on fluorine mobility and the bacterial community of phosphogypsum.

Contamination of soil and water with fluorine (F) leached from phosphogypsum (PG) stacks is a global environmental issue. Millions of tons of PG is produced each year as a by-product of fertilizer manufacture, and in China, weathering is exacerbated by acid rain. In this work, column leaching experiments using simulated acid rain were run to evaluate the mobility of F and the impact of weathering on native bacterial community composition in PG. After a simulated summer rainfall, 2.42-3.05wt% of the total F content of PG was leached and the F concentration in leachate was above the quality standard for surface water and groundwater in China. Acid rain had no significant effect on the movement of F in PG. A higher concentration of F was observed at the bottom than the top section of PG columns suggesting mobility and reprecipitation of F. Throughout the simulation, the PG was environmentally safe according the TCLP testing. The dominant bacteria in PG were from the Enterococcus and Bacillus genus. Bacterial community composition in PG leached by simulated acid rain (pH3.03) was more abundant than at pH6.88. Information on F mobility and bacterial community in PG under conditions of simulated rain is relevant to management of environmental risk in stockpiled PG waste.

An emerging market for groundwater remediation in China: Policies, statistics, and future outlook

There is a rapidly emerging and potentially huge market for the remediation of contaminated groundwater in China. The Chinese government published a Water Action Plan in April 2015, a Soil Action Plan in May 2016, and a draft Soil Pollution Prevention and Control Law in June 2017. All of these new policies and regulations put pressures on local governments and contaminated site owners, obliging them to conduct site investigation and to cleanup contaminated groundwater. The Chinese population in northern regions heavily depend on groundwater, with nearly 70% of water supply coming from aquifer sources in the Beijing-Tianjin-Hebei region. However, poor groundwater quality due to natural geochemical background and anthropogeic pollution is a serious concern, with poor or very poor quality water observed in nearly 80% of groundwater monitoring wells in 17 northern provinces. Shallow groundwater in many areas has been contaminated by toxic pollutants such as heavy metals and chlorinated organic compounds. There is an urgent need to better understand the situation and to conduct groundwater remediation at contaminated sites. The Chinese government is investing heavily in the research and development for groundwater remediation, which is expected to greatly add to the quality and quantity of groundwater remediation projects in the near future.

Presence of Antibiotics in Shallow Groundwater in the Northern and Southwestern Regions of China.

Antibiotics are widely used, and there is a serious concern about its adverse impacts on the environment and human health. To our knowledge, prior to this work, there was no evidence of the potential presence of antibiotics in groundwater in China, despite populous speculations. This study reported the detection of 35 target antibiotics of 6 groups (chloramphenicois, lincosamides, marcrolides, quinolones, sulfonamides, and tetracyclines), in shallow groundwater samples collected in northern and southwestern China. Thirty-four of thirty-five target antibiotics were detected in the groundwater samples; 73 of 74 monitoring wells contained at least one antibiotic; and at least two antibiotics were detected in 72 of the 74 wells. Ofloxacin (1199.7 ng/L), lincomycin (860.7 ng/L), and norfloxacin (441.9 ng/L) as well as antibiotics with the highest detection frequency such as sulfapyridine (70%), norfloxacin (69%), and lincomycin (64%) were detected at elevated concentrations. The highest detection frequency and concentration of lincosamides were observed in those groundwater samples, but no clear distribution patterns were observed for the six antibiotic groups. Moreover, shallow groundwater in southwestern China seemed to contain most antibiotics, likely due to the high antibiotics discharge and frequent exchange of groundwater with surface matrices. The findings from this work suggest that groundwater in China has been widely contaminated by antibiotics, and presumably other pharmaceutical compounds that have not been investigated to date.

China's Transboundary Groundwater Cooperation in the Context of Emerging Transboundary Aquifer Law.

China shares more than 20 transboundary aquifers with its coaquifer states, but they have not exploited their transboundary groundwater resources, and these resources have not been governed by any international agreements. Given the close interaction between surface water and groundwater, and the growing demands for transboundary groundwater in China and its coaquifer states, there is increasing necessity for these countries to undertake international cooperation on this issue. This article overviews China's transboundary aquifers, reviews the duty to cooperate on China's transboundary groundwater as well as the emerging transboundary aquifer law. It concludes by providing some proposals on international cooperation in this context, based on the two theories of international water law-limited territorial sovereignty and common interests, taking into account the practicability of China's cooperation with its coaquifer states. The author suggests that China cooperates with its coaquifer states through such means as the exchange of data and information, joint monitoring, the conclusion of bilateral or multilateral aquifer agreements, the establishment of joint management mechanisms, and international technical cooperation.

Effects of anions on corrosion behaviour of carbon steel in simulated groundwater in China

ABSTRACTCarbon steel is a candidate material for the disposal container of high-level nuclear waste in a deep geological repository in China, which will be subject to general corrosion and localised attack. In this work, the effects of Cl−, SO42– and CO32− concentrations on the general corrosion and crevice corrosion of carbon steel were studied by immersion tests and electrochemical measurements. The results show that Cl− promotes general corrosion, while SO42− and CO32− inhibit general corrosion. In a single ion solution, SO42− is the most obvious in promoting the crevice corrosion, which is different from the result of carbon steel in groundwater solution. Cl−, rather than SO42−, dominates the crevice corrosion process of carbon steel in groundwater solution.This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems