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Sample records for estuary area china

  1. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    Science.gov (United States)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  2. Petroleum hydrocarbons in a water-sediment system from Yellow River estuary and adjacent coastal area, China: Distribution pattern, risk assessment and sources.

    Science.gov (United States)

    Wang, Min; Wang, Chuanyuan; Li, Yuanwei

    2017-09-15

    Aliphatic hydrocarbons (AHs), biomarker and polycyclic aromatic hydrocarbons (PAHs) concentrations of surface water and sediment samples collected from Yellow River Estuary and adjacent coastal area in China were measured to determine their spatial distributions, analyze their sources and evaluate the ecological risk of PAHs in the water-sediment system. The spatial distributions of n-alkane in sediments are mainly controlled by the mixing inputs of terrigenous and marine components. In comparison with AHs, the total concentrations of Σ16PAHs in surface sediments from a transect of the offshore area were noticeably higher than that of the riverine and estuary areas. Additionally, the AHs and total PAHs concentrations all indicated an overall pattern of a seaward decrease. The PAHs concentrations during the dry season (mainly in the form of dissolved phase) were higher than that of PAHs (mainly dissolved phase and particulate phase form) in the flooding season. In comparison with global concentration levels of PAHs, the level of PAHs in suspended particulate matter and sediments from the Yellow River Estuary was lower than those from other countries, while the concentration of PAHs in the dissolved phase were in the middle range. Petroleum contamination, mainly from oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. The PAHs in the river were mostly of petrogenic origin, while those in the estuarial and marine areas originated mainly from pyrogenic sources. The results of the toxicology assessment suggested that the PAHs in sediments from Yellow River Estuary and adjacent coastal area exhibited a low potential eco-toxicological contamination level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Microplastic in three urban estuaries, China.

    Science.gov (United States)

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-11-01

    Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. Copyright © 2015. Published by Elsevier Ltd.

  4. Morphodynamic modeling of a large inside sand bar and its dextral morphology in a convergent estuary: Qiantang Estuary, China

    NARCIS (Netherlands)

    Xie, Dongfeng; Gao, Shu; Wang, Zhengbing; Pan, Cunhong; Wu, Xiuguang; Wang, Qiushun

    2017-01-01

    We investigate the evolution of a large-scale sand body, a unique type of sandbars in a convergent estuary. Specifically, we analyze and simulate the sand deposition system (defined as an inside bar) in the Qiantang Estuary (QE) in China. The deposit is 130 km long and up to 10 m thick, and is

  5. National Estuary Program Study Area Boundaries

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 28 National Estuary Programs (NEPs) in the U.S.that implement habitat protection and restoration projects with their partners. This work takes place within...

  6. Microplastics in sediments of the Changjiang Estuary, China.

    Science.gov (United States)

    Peng, Guyu; Zhu, Bangshang; Yang, Dongqi; Su, Lei; Shi, Huahong; Li, Daoji

    2017-06-01

    Microplastics are plastics that measure less than 5 mm in diameter. They enter the marine environment as primary sources directly from industrial uses, as well as secondary sources resulting from the degradation of large plastic debris. To improve the knowledge of microplastic pollution in China, we investigated samples from 53 estuarine sediment locations collected with a box corer within the Changjiang Estuary. Microplastics (microplastics in the Changjiang Estuary was mapped. The mean concentration was 121 ± 9 items per kg of dry weight, varying from 20 to 340 items per kg of dry weight. It was found that the concentration of microplastics was the highest on the southeast coast of Shanghai. The distribution pattern of microplastics may be affected by the Changjiang diluted water in summer. All of the microplastics collected were categorized according to shape, color and size. Among which fiber (93%), transparent (42%) and small microplastics (microplastics and the finer sediment fraction was found. Rayon, polyester, and acrylic were the most abundant types of microplastics identified, indicating that the main source of microplastics in the Changjiang Estuary was from washing clothes (the primary source). It is possible to compare microplastic abundance in this study with the results of other related studies using the same quantification method. The identification of microplastics raises the awareness of microplastic pollution from drainage systems. The prevalence of microplastic pollution calls for monitoring microplastics at a national scale on a regular basis. Copyright © 2016. Published by Elsevier Ltd.

  7. Variation of phytoplankton community structure from the Pearl River estuary to South China Sea.

    Science.gov (United States)

    Jiang, Zhao-Yu; Wang, You-Shao; Cheng, Hao; Sun, Cui-Ci; Wu, Mei-Lin

    2015-10-01

    The Pearl River is located in the northern part of South China Sea. The environment of the Pearl River estuary (PRE) is significantly impacted by nutrients from anthropogenic activities. Along the anthropogenic pollution gradient from the PRE to South China Sea, the phylogenetic diversity and biomass of phytoplankton was examined in relation to physic-chemical variables. The richness of rbcL gene was higher in the open sea than the estuary, while the concentration of chlorophyll a (Chl a) was higher in the estuary than in the open sea. The cluster analysis of the sequences data resulted in seven phytoplankton community types and the dominant species of phytoplankton changed from Cryptophytes and Diatoms to Prymnesiophytes and Diatoms along the gradient. The community structure of phytoplankton was shaped by nutrients and salinity. The phytoplankton biomass was significantly positively affected by phosphorus, nitrite and ammonium (P phytoplankton diversity was highly positively affected by salinity (P phytoplankton distribution and biomass of the study area. Further research is necessary to reveal the influence mechanism of environmental factors on the phytoplankton.

  8. Musquash Estuary: A management plan for the marine protected area and administered intertidal area

    National Research Council Canada - National Science Library

    2008-01-01

    .... In 1998, the Conservation Council of New Brunswick, with support from the Fundy North Fishermen.s Association, proposed Musquash Estuary and the surrounding intertidal area, as a candidate Marine Protected Area (MPA...

  9. Microplastics in oysters Saccostrea cucullata along the Pearl River Estuary, China.

    Science.gov (United States)

    Li, Heng-Xiang; Ma, Li-Sha; Lin, Lang; Ni, Zhi-Xin; Xu, Xiang-Rong; Shi, Hua-Hong; Yan, Yan; Zheng, Guang-Ming; Rittschof, Daniel

    2018-02-09

    As a transitional zone between riverine and marine environments, an estuary plays an important role for the sources, accumulation and transport of microplastics. Although estuarine environments are hotspots of microplastic pollution, the correlation between microplastic pollution and aquatic organisms is less known. Here we investigated microplastic pollution in wild oysters Saccostrea cucullata from 11 sampling sites along the Pearl River Estuary in South China. The microplastic abundances in oysters ranged from 1.4 to 7.0 items per individual or from 1.5 to 7.2 items per gram tissue wet weight, which were positively related to those in surrounding waters. The oysters near urban areas contained significantly more microplastics than those near rural areas. Fibers accounted for 69.4% of the total microplastics in oysters. Microplastic sizes varied from 20 to 5000 μm and 83.9% of which were less than 100 μm. Light color microplastics were significantly more common than dark color ones. Based on the results, oysters are recommended as a biomonitor for the microplastic pollution in estuaries. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Area Studies: China.

    Science.gov (United States)

    Blouin, Virginia; And Others

    The guide outlines a course of study for elementary students on the history, geography, language, and general culture of China. Course objectives are to identify the major mountains, the major cities, and the types of climate affecting each region of China; locate and record on a time line the important events in the development of Chinese…

  11. Heavy metals in surface sediments from nine estuaries along the coast of Bohai Bay, Northern China.

    Science.gov (United States)

    Wu, Guanghong; Shang, Jingmin; Pan, Ling; Wang, Zhongliang

    2014-05-15

    Concentrations of heavy metals in river water and sediment were investigated in nine estuaries along the coast of Bohai Bay, Northern China. Multivariate statistical techniques such as principal component analysis and cluster analysis, in combination with metal concentration analysis and correlation analysis, were used to identify the possible sources of the metals and the pollution pattern in nine estuaries along the coast of Bohai Bay. The environmental risks of metals, evaluated by sediment quality guidelines and background values, revealed Hg contamination in the estuaries. However, levels of Cd in estuarine sediments were low, and they were less than those levels in river sediments, partly due to the high mobility and dilution of river or seawater. Cd did not contribute to sediment deposits in estuaries. High organic matter from effluents from large municipal sewage treatment plants was predominantly responsible for restricting Hg mobility from the river to Bohai Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. A Landsat-based model for retrieving total suspended solids concentration of estuaries and coasts in China

    Science.gov (United States)

    Wang, Chongyang; Chen, Shuisen; Li, Dan; Wang, Danni; Liu, Wei; Yang, Ji

    2017-11-01

    Retrieving total suspended solids (TSS) concentration accurately is essential for sustainable management of estuaries and coasts, which plays a key role in the interaction between hydrosphere, pedosphere and atmosphere. Although many TSS retrieval models have been published, the general inversion method that is applicable to different field conditions is still under research. In order to obtain a TSS remote sensing model that is suitable for estimating TSS concentrations with wide range in estuaries and coasts by Landsat imagery, after reviewing a number of Landsat-based TSS retrieval models and improving a comparatively better one among them, this study developed a quadratic model using the ratio of logarithmic transformation of red band and near-infrared band and logarithmic transformation of TSS concentration (QRLTSS) based on 119 in situ samples collected in 2006-2013 from five regions of China. It was found that the QRLTSS model works well and shows a satisfactory performance. The QRLTSS model based on Landsat TM (Thematic Mapper), ETM+ (Enhanced Thematic Mapper Plus) and OLI (Operational Land Imager) sensors explained about 72 % of the TSS concentration variation (TSS: 4.3-577.2 mg L-1, N = 84, P value proposed to solve the two-valued issue of the QRLTSS model and to retrieve TSS concentration from Landsat imagery. After a 6S model-based atmospheric correction of Landsat OLI and ETM+ imagery, the TSS concentrations of three regions (Moyangjiang River estuary, Pearl River estuary and Hanjiang River estuary) in Guangdong Province in China were mapped by the QRLTSS model. The results indicated that TSS concentrations in the three estuaries showed large variation ranging from 0.295 to 370.4 mg L-1. Meanwhile we found that TSS concentrations retrieved from Landsat imagery showed good validation accuracies with the synchronous water samples (TSS: 7-160 mg L-1, RMSE: 11.06 mg L-1, N = 22). The further validation from EO-1 Hyperion imagery also showed good

  13. Musquash Estuary: a proposed monitoring framework for the marine protected area and intertidal area administered by Fisheries and Oceans Canada

    National Research Council Canada - National Science Library

    Kennedy, E

    2011-01-01

    ...) and Administered Intertidal Area (AIA) boundaries. The implementation of monitoring, however, may not be undertaken on the scale of the estuary, and this is to be determined at a later date dependent on factors such as partnerships and availability...

  14. Economic compensation standard for irrigation processes to safeguard environmental flows in the Yellow River Estuary, China

    Science.gov (United States)

    Pang, Aiping; Sun, Tao; Yang, Zhifeng

    2013-03-01

    SummaryAgriculture and ecosystems are increasingly competing for water. We propose an approach to assess the economic compensation standard required to release water from agricultural use to ecosystems while taking into account seasonal variability in river flow. First, we defined agricultural water shortage as the difference in water volume between agricultural demands and actual supply after maintaining environmental flows for ecosystems. Second, we developed a production loss model to establish the relationship between production losses and agricultural water shortages in view of seasonal variation in river discharge. Finally, we estimated the appropriate economic compensation for different irrigation stakeholders based on crop prices and production losses. A case study in the Yellow River Estuary, China, demonstrated that relatively stable economic compensation for irrigation processes can be defined based on the developed model, taking into account seasonal variations in river discharge and different levels of environmental flow. Annual economic compensation is not directly related to annual water shortage because of the temporal variability in river flow rate and environmental flow. Crops that have stable planting areas to guarantee food security should be selected as indicator crops in economic compensation assessments in the important grain production zone. Economic compensation may be implemented by creating funds to update water-saving measures in agricultural facilities.

  15. Hydrocarbons in surface sediments from the Changjiang (Yangtze River) estuary, East China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Bouloubassi, Ioanna; Fillaux, Joelle; Saliot, Alain [Universite Pierre et Marie Curie, Lab. de Biogeochimie et Chimie Marines, Paris, 75 (France)

    2001-07-01

    Sedimentary aliphatic (AH) and polycyclic aromatic hydrocarbons (PAHs) were studied in the Changjiang Estuary and the adjacent East China Sea. Total AH ranged from 2.20 to 11.82 {mu}g g {sup -1} and consisted of n-alkanes and a dominant petroleum-related unresolved complex mixture (UCM). Within the n-alkanes, terrestrial plant wax compounds prevailed at nearly all stations. Of the PAHs, biogenic perylene dominated at stations receiving riverine inputs. Anthropogenic PAHs originating from combustion/pyrolysis processes varied from 17 to 157 ng g {sup -1}, while fossil PAH concentrations ranged from 42 to 187 ng g {sup -1}. Both biogenic and anthropogenic hydrocarbons are primarily derived from riverine discharges and accumulate at shallow-water stations. Distinct phase associations lead, nevertheless, to different sedimentation patterns. Fossil PAHs are enhanced at offshore stations where they are introduced directly by shipping activities. Biomarker fingerprints ascribe their source to Chinese crude oils. The overall levels of anthropogenic hydrocarbons are low compared to relevant areas worldwide and reveal a low/moderate level of hydrocarbon pollution. (Author)

  16. Benthic Nutrient Fluxes from Mangrove Sediments of an Anthropogenically Impacted Estuary in Southern China

    Directory of Open Access Journals (Sweden)

    David Kaiser

    2015-06-01

    Full Text Available Mangroves serve as either sinks or sources for inorganic and organic nutrients and can mitigate anthropogenic nutrient pollution, control the production in adjacent systems, and prevent eutrophication. To better understand the nutrient dynamics in a subtropical mangrove, we employed a three-way approach in the Nanliu River Estuary, southern China: Pore water profiles and sediment incubations revealed benthic early diagenesis as well as sediment–water exchange of dissolved nutrients and oxygen, while tidal sampling of estuarine and mangrove water identified source and sink functions of the entire mangrove forest. Fluxes of oxygen during incubations were always directed into the sediment, indicating heterotrophy of the system. There was a net uptake of dissolved inorganic nitrogen, mainly caused by nitrate influx, while ammonium and nitrite showed variable flux direction. Despite high pore water concentrations, phosphate and silica showed net uptake. Fluxes of dissolved organic carbon were generally low except for high efflux in the dark following a storm event. Due to the combination of small forest area and strong anthropogenic nutrient input, the net sink function for dissolved nitrogen and phosphorus provides no significant buffer against the eutrophication of coastal waters.

  17. Assessment on vulnerability of coastal wetlands to sea level rise in the Yangtze Estuary, China

    Science.gov (United States)

    Cui, L.; Ge, Z.; Zhang, L.

    2013-12-01

    The Yangtze Delta in China is vital economic hubs in terms of settlement, industry, agriculture, trade and tourism as well as of great environmental significance. In recent decades, the prospect of climate change, in particular sea level rise and its effects on low lying coastal areas have generated worldwide attention to coastal ecosystems. Coastal wetlands, as important parts of coastal ecosystem, are particularly sensitive to sea level rise. To study the responses of coastal wetlands to climate change, assess the impacts of climate change on coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisites for securing the coastal zone ecosystems. In this study, taking the coastal wetlands in the Yangtze Estuary as a case study, the potential impacts of sea-level rise to coastal wetlands habitat were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model. The key indicators, such as the sea-level rise rate, subsidence rate, elevation, daily inundation duration of habitat and sedimentation rate, were selected to build a vulnerability assessment system according to the IPCC definition of vulnerability, i.e. the aspects of exposure, sensitivity and adaptation. A quantitatively spatial assessment method on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. The vulnerability assessment on the coastal wetlands in the Yangtze Estuary under the sea level rise rate of the present trend and IPCC A1F1 scenario were performed for three sets of projections of short-term (2030s), mid-term (2050s) and long-term (2100s). The results showed that at the present trend of sea level rise rate of 0.26 cm/a, 92.3 % of the coastal wetlands in the Yangtze Estuary was in the EVI score of 0 in 2030s, i.e. the impact of sea level rise on habitats/species of coastal wetlands was negligible. While 7.4 % and 0.3 % of the coastal wetlands were in the EVI score of

  18. Salinity-oriented environmental flows for keystone species in the Modaomen Estuary, China

    Science.gov (United States)

    Zhang, Menglu; Cui, Baoshan; Zhang, Zhiming; Jiang, Xuelian

    2017-12-01

    Rapid development and urbanization in recent years have contributed to a reduction in freshwater discharge and intensified saltwater intrusion in the Pearl River Delta. This comprises a significant threat to potable water supplies and overall estuary ecosystem health. In this study, the environmental flows of the Modaomen Estuary, one of the estuaries of the Pearl River Delta in China, were determined based on the salinity demand of keystone species and the linear relationship between river discharge and estuarine salinity. The estimated minimum and optimal annual environmental flows in the Modaomen Estuary were 116.8 × 109 m3 and 273.8 × 109 m3, respectively, representing 59.3% and 139.0% of the natural runoff. Water quality assessments in recent years indicate that the environmental flows have not been satisfied most of the time, particularly the optimal environmental flow, despite implementation of various water regulations since 2005. Therefore, water regulations and wetland network recoveries based on rational environmental flows should be implemented to alleviate saltwater intrusion and for the creation of an ideal estuarine habitat.

  19. Impact of intertidal area characteristics on estuarine tidal hydrodynamics: A modelling study for the Scheldt Estuary

    Science.gov (United States)

    Stark, J.; Smolders, S.; Meire, P.; Temmerman, S.

    2017-11-01

    Marsh restoration projects are nowadays being implemented as ecosystem-based strategies to reduce flood risks and to restore intertidal habitat along estuaries. Changes in estuarine tidal hydrodynamics are expected along with such intertidal area changes. A validated hydrodynamic model of the Scheldt Estuary is used to gain fundamental insights in the role of intertidal area characteristics on tidal hydrodynamics and tidal asymmetry in particular through several geomorphological scenarios in which intertidal area elevation and location along the estuary is varied. Model results indicate that the location of intertidal areas and their storage volume relative to the local tidal prism determine the intensity and reach along the estuary over which tidal hydrodynamics are affected. Our model results also suggest that intertidal storage areas that are located within the main estuarine channel system, and hence are part of the flow-carrying part of the estuary, may affect tidal hydrodynamics differently than intertidal areas that are side-basins of the main estuarine channel, and hence only contribute little to the flow-carrying cross-section of the estuary. If tidal flats contribute to the channel cross-section and exert frictional effects on the tidal propagation, the elevation of intertidal flats influences the magnitude and direction of tidal asymmetry along estuarine channels. Ebb-dominance is most strongly enhanced if tidal flats are around mean sea level or slightly above. Conversely, flood-dominance is enhanced if the tidal flats are situated low in the tidal frame. For intertidal storage areas at specific locations besides the main channel, flood-dominance in the estuary channel peaks in the vicinity of those areas and generally reduces upstream and downstream compared to a reference scenario. Finally, the model results indicate an along-estuary varying impact on the tidal prism as a result of adding intertidal storage at a specific location. In addition to known

  20. Benthic habitat quality assessment based on biological indices in Xiaoqing River estuary and its adjacent sea of Laizhou Bay, China

    Science.gov (United States)

    Luo, Xianxiang; Lin, Song; Yang, Jianqiang; Shen, Jiayu; Fan, Yuqing; Zhang, Longjun

    2017-06-01

    Based on the macrofauna data (2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index (AMBI) and Multivariate AMBI (M-AMBI) were used for benthic habitat quality (BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.

  1. Occurrence of PPCPs in Pearl River Estuary and South China Sea

    Science.gov (United States)

    Fisch, Kathrin; Waniek, Joanna J.; Schulz-Bull, Detlef E.

    2017-04-01

    The development of a coastal megacity has put the South China Sea under human induced stress. Pharmaceuticals and personal care products (PPCPs) are ubiquitous contaminants and can be used as anthropogenic indicators for pollution of the marine environment. They enter the marine environment indirectly via waste water or directly due to recreational activities. PPCPs make up a group of different pharmaceuticals such as antibiotic, anti-inflammatories etc. and personal care products such as UV-filters. A mayor concern is the unknown fate and the effect these pollutants on the marine environment and especially its organisms. In some studies it was proven that some of these PPCPs have an endocrine disrupting and/or a subtle chronic effect on aquatic organisms. They are of concern for the health of the marine environment and may have an effect on human health. With our study we could determine the occurrence of PPCPs in the Pearl River estuary and the South China Sea. Salicylic acid (metabolite of acetylsalicylic acid) and octocrylene (UV-filter) were found in the open Sea in low ng/L concentration. Octocrylene is used in sunscreen and as a light stabilizer in paints and polymer-based products. It is of environmental concern because of its potential to be bioaccumulative. In addition to our findings in the open South China Sea, could we detect PPCPs, especially antibiotics, in higher ng/L-concentrations in the Pearl River Estuary.

  2. Local and regional sources as given by aerosol measurements and biomonitoring at Sado estuary area, Portugal

    NARCIS (Netherlands)

    Farinha, M.M.; Verburg, T.G.; Freitas, M.C.; Wolterbeek, H.Th.

    2009-01-01

    Gent air samplers were used for air particulate matter sampling in Sado estuary area, separating fine and coarse fractions. Three sampling sites were chosen (Palmela, Faralhão and Tróia), inside a 15 km × 25 km area at Setúba region, 50 km south of Lisbon, Portugal. Transplants of Parmelia sulcata

  3. Polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries of China: Distribution, seasonal variations and ecological risk assessment.

    Science.gov (United States)

    Yan, Jinxia; Liu, Jingling; Shi, Xuan; You, Xiaoguang; Cao, Zhiguo

    2016-08-15

    The distribution, seasonal variations and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries in Hai River Basin of China, which has been suffering from different anthropogenic pressures, were investigated. In three estuaries, the average concentration of ΣPAHs was the lowest in Luan River estuary, followed by Hai River estuary, and the highest in Zhangweixin River estuary. There were significant seasonal variations in ΣPAHs, the concentrations of ΣPAHs were higher in November than in May and August. The composition profiles of PAHs in different sites were significantly different, and illustrated seasonal variations. Generally, 2-ring (Nap) and 3-ring PAHs (Acp, Fl and Phe) were the most abundant components at most sampling sites in three estuaries. The PAHs in three estuaries were mainly originated from pyrogenic sources. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) was proposed to assess the ecological risk of ΣPAHs, with the ecological risk of individual PAHs being considered separately. The results showed that the ecological risks caused by ΣPAHs were high in Hai River estuary and Zhangweixin River estuary, and moderate in Luan River estuary. The mean values of ecological risk in August were lower than those in November. The contributions of individual PAHs to ecological risk were different in May, August and November. 3-ring and 4-ring PAHs accounted for much more ecological risk than 2-ring, 5-ring and 6-ring, although the contributions of 5-ring and 6-ring to ecological risk were higher than these to PAHs concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Selected emerging organic contaminants in the Yangtze Estuary, China: a comprehensive treatment of their association with aquatic colloids.

    Science.gov (United States)

    Yan, Caixia; Yang, Yi; Zhou, Junliang; Nie, Minghua; Liu, Min; Hochella, Michael F

    2015-01-01

    Contaminants that are becoming detected in the environment but are not yet generally regulated or monitored are known collectively as emerging contaminants. In the present study, the occurrence and distribution of 42 emerging organic compounds (EOCs) were investigated in the Yangtze River Estuary and adjacent East China Sea coastal areas. Study compounds were mainly pharmaceuticals, including antibiotics, hormones and sterols, and also included two industrial endocrine disruptors. Samples were analyzed using cross-flow ultrafiltration (CFUF) and ultra-performance liquid chromatograph-tandem mass spectrometry (UPLC-MS/MS). Results revealed that chloramphenicols, sulfonamides and non-steroidal anti-inflammatory drugs were the dominant compounds in filtered samples with relatively high concentrations and detection frequencies. EOC levels varied with location, with the highest concentrations being observed around rivers discharging into the estuary, and near sewage outfalls. Colloids that were separated by CFUF tended to be a sink for EOCs with up to 60% being colloid-associated in the water phase. In addition, colloidal properties, including hydrodynamic size, zeta-potential and organic carbon composition, were found to be the main factors controlling the association of EOCs with aquatic colloids. Moreover, these colloidal properties were all significantly related to salinity, indicating the critical role played by increasing salinity in EOCs-colloids interaction in an estuarine system. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Arsenic speciation and spatial and interspecies differences of metal concentrations in mollusks and crustaceans from a South China estuary.

    Science.gov (United States)

    Zhang, Wei; Wang, Wen-Xiong; Zhang, Li

    2013-05-01

    Arsenic speciation and concentrations were determined in mollusks and crustaceans in the intertidal zone from twelve locations in Zhanjiang estuary, South China. Metal concentrations (Ag, As, Cd, Cu, Hg, Ni, Pb, and Zn) were also concurrently determined in these species. Arsenic speciation analysis showed that the less-toxic arsenobetaine (AsB) constituted 80.6-98.8 % of all As compounds, and dimethylarsinic acid (DMA) constituted 0.47-3.44 %. Monomethylarsonic acid (MMA) and As(V) were only detected in the whelk Drupa fiscella and the crab Heteropilumnus ciliatus, respectively. Arsenite [As(III)] was not detected in any of the sampled specimens, but there were also unidentified other As species. A strong spatial variation of metals in the oyster Saccostrea cucullata was found in the estuary, confirming that oysters can be used as a good biomonitor of metal contamination in the studied area. The concentrations of eight metals in the studied mollusks and crustaceans clearly revealed that these invertebrates accumulated different metals to different degrees. Furthermore, As, Cd, Cu, Hg, and Pb contents in mollusks and crustacean samples were below the Food and Agricultural Organization (FAO) safe concentrations, thus there was no obvious health risk from the intake of the metals through marine mollusks and crustaceans consumption.

  6. Using mercury isotopes to understand the bioaccumulation of Hg in the subtropical Pearl River Estuary, South China.

    Science.gov (United States)

    Yin, Runsheng; Feng, Xinbin; Zhang, Junjun; Pan, Ke; Wang, Wenxiong; Li, Xiangdong

    2016-03-01

    Coastal and estuarine regions are important areas of mercury pollution. Therefore, it is important to properly characterize the sources and bioaccumulation processes of mercury in these regions. Here, we present mercury stable isotopic compositions in 18 species of wild marine fish collected from the Pearl River Estuary (PRE), south China. Our results showed variations in mass-independent fractionation (Δ(199)Hg: +0.05 ± 0.10‰ to +0.59 ± 0.30‰) with a Δ(199)Hg/Δ(201)Hg of ∼1.26, suggesting that aqueous MeHg underwent photo-degradation prior to incorporation into the food chain. For the results, we discovered small but significant differences of Δ(199)Hg values among herbivorous, demersal, and carnivorous fish, indicating that different feeding guilds of fish may have incorporated MeHg with various degrees of photo-demethylation. The consistent mercury isotope compositions between fish feeding habitat and mercury sources in the estuary provide potentially important findings on the transformation and bioaccumulation of this toxic metal in subtropical coastal environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Spatial assessment of water quality using chemometrics in the Pearl River Estuary, China

    Science.gov (United States)

    Wu, Meilin; Wang, Youshao; Dong, Junde; Sun, Fulin; Wang, Yutu; Hong, Yiguo

    2017-03-01

    A cruise was commissioned in the summer of 2009 to evaluate water quality in the Pearl River Estuary (PRE). Chemometrics such as Principal Component Analysis (PCA), Cluster analysis (CA) and Self-Organizing Map (SOM) were employed to identify anthropogenic and natural influences on estuary water quality. The scores of stations in the surface layer in the first principal component (PC1) were related to NH4-N, PO4-P, NO2-N, NO3-N, TP, and Chlorophyll a while salinity, turbidity, and SiO3-Si in the second principal component (PC2). Similarly, the scores of stations in the bottom layers in PC1 were related to PO4-P, NO2-N, NO3-N, and TP, while salinity, Chlorophyll a, NH4-N, and SiO3-Si in PC2. Results of the PCA identified the spatial distribution of the surface and bottom water quality, namely the Guangzhou urban reach, Middle reach, and Lower reach of the estuary. Both cluster analysis and PCA produced the similar results. Self-organizing map delineated the Guangzhou urban reach of the Pearl River that was mainly influenced by human activities. The middle and lower reaches of the PRE were mainly influenced by the waters in the South China Sea. The information extracted by PCA, CA, and SOM would be very useful to regional agencies in developing a strategy to carry out scientific plans for resource use based on marine system functions.

  8. Spatio-temporal distribution and environmental risk of sedimentary heavy metals in the Yangtze River Estuary and its adjacent areas.

    Science.gov (United States)

    Chen, Bin; Liu, Jian; Qiu, Jiandong; Zhang, Xilin; Wang, Shuang; Liu, Jinqing

    2017-03-15

    Twenty-five surface sediments and one sediment core sample were collected from the study area. Grain size, major elements, and heavy metals were determined. The content of fine-grained sediments (silt and clay), as well as the concentrations of major elements and heavy metals, showed seaward decreasing trends, with high content in the coastal areas of the East China Sea (ECS) and south west of Jeju Island. Low enrichment factor (EF) and geoaccumulation index (Igeo) values were found, indicating that the ecological risk of heavy metals was low. The EF values obtained from the high-resolution sedimentary records of heavy metals in the Yangtze River Estuary could be divided into Stage 1 (1950s to the late 1970s) and Stage 2 (late 1970s to the current sampling day), which coincided with economic development of the Yangtze River Basin, implementation of environmental protection, and impoundment of the Three Gorges Dam. Copyright © 2016. Published by Elsevier Ltd.

  9. A continuing 30-year decline in water quality of Jiaojiang Estuary, China

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    Chun-ye WANG

    2015-01-01

    Full Text Available A quantitative description of a long-term series of aquatic environmental factors and their spatial distributions was generated using measured data from the Jiaojiang Estuary from 1982 to 2011. The aquatic environmental factors included suspended matter, salinity, and nutrients. Based on these factors, the aquatic ecosystem health in the Jiaojiang Estuary over the last 30 years was analyzed. The results indicated that the suspended matter concentration in the estuary was mainly affected by the amounts of suspended sediment and solid waste, with the value fluctuating over a long period, and the range of high concentration expanded continually; the salinity was mainly affected by precipitation and surface water resources, showing an overall decreasing trend, and the region with low salinity moved seaward and toward the reclamation areas; and the nutritional status, mainly affected by discharge of industrial wastewater and domestic sewage, was satisfactory in the 1980s and 1990s, but the status became severe in recent years. Reclamation had a great influence on these three factors: high reclamation strength led to a significant increase in the suspended matter concentration and a deterioration of the nutritional status, and the reclamation rate was negatively related with the salinity in the estuary. There was a significant positive correlation between the health status of the aquatic ecosystem and salinity, with a correlation coefficient of 0.93. The correlation coefficient between the health status and nutritional status was −0.71, while the correlation between the suspended matter concentration and health status was not as significant as that of the other two factors. The dynamics of the aquatic environment could be divided into four stages: sustainable health from the 1980s to the 1990s, continued deterioration from 2000 to 2003, improvement from 2004 to 2005, and secondary deterioration from 2006 to 2011. The Jiaojiang Estuary is faced with

  10. Tracing the origin of the oxygen-consuming organic matter in the hypoxic zone in a large eutrophic estuary: the lower reach of the Pearl River Estuary, China

    Science.gov (United States)

    Su, Jianzhong; Dai, Minhan; He, Biyan; Wang, Lifang; Gan, Jianping; Guo, Xianghui; Zhao, Huade; Yu, Fengling

    2017-09-01

    We assess the relative contributions of different sources of organic matter, marine vs. terrestrial, to oxygen consumption in an emerging hypoxic zone in the lower Pearl River Estuary (PRE), a large eutrophic estuary located in Southern China. Our cruise, conducted in July 2014, consisted of two legs before and after the passing of Typhoon Rammasun, which completely de-stratified the water column. The stratification recovered rapidly, within 1 day after the typhoon. We observed algal blooms in the upper layer of the water column and hypoxia underneath in bottom water during both legs. Repeat sampling at the initial hypoxic station showed severe oxygen depletion down to 30 µmol kg-1 before the typhoon and a clear drawdown of dissolved oxygen after the typhoon. Based on a three endmember mixing model and the mass balance of dissolved inorganic carbon and its isotopic composition, the δ13C of organic carbon remineralized in the hypoxic zone was -23.2 ± 1.1 ‰. We estimated that 65 ± 16 % of the oxygen-consuming organic matter was derived from marine sources, and the rest (35 ± 16 %) was derived from the continent. In contrast to a recently studied hypoxic zone in the East China Sea off the Changjiang Estuary where marine organic matter dominated oxygen consumption, here terrestrial organic matter significantly contributed to the formation and maintenance of hypoxia. How varying amounts of these organic matter sources drive oxygen consumption has important implications for better understanding hypoxia and its mitigation in bottom waters.

  11. Linkages between the spatial toxicity of sediments and sediment dynamics in the Yangtze River Estuary and neighboring East China Sea.

    Science.gov (United States)

    Gao, Jinjuan; Shi, Huahong; Dai, Zhijun; Mei, Xuefei; Zong, Haibo; Yang, Hongwei; Hu, Lingling; Li, Shushi

    2018-02-01

    Anthropogenic activities are driving an increase in sediment contamination in coastal areas. This poses significant challenges for the management of estuarine ecosystems and their adjacent seas worldwide. However, few studies have been conducted on how dynamic mechanisms affect the sediment toxicity in the estuarine environment. This study was designed to investigate the linkages between sediment toxicity and hydrodynamics in the Yangtze River Estuary (YRE) area. High sediment toxicity was found in the Yangtze River mouth (Region I), the depocenter of the Yangtze River Delta (Region II), and the southeastern area of the adjacent sea (Region III), while low sediment toxicity was found in the northeastern offshore region (Region IV). A spatial comparison analysis and regression model indicated that the distributed pattern of sediment toxicity was likely related to hydrodynamics and circumfluence in the East China Sea (ECS) shelf. Specifically, high sediment toxicity in Region I may be affected by the Yangtze River Pump (YRP) and the low hydrodynamics there, and high toxicity in Region II can be influenced by the low sediment dynamics and fine sediment in the depocenter. The high sediment toxicity in Region III might be related to the combination of the YRP and Taiwan Warm Current, while the low toxicity in Region IV may be influenced by the local coarse-grained relict sand with strong sediment dynamics there. The present research results further suggest that it is necessary to link hydrodynamics and the spatial behavior of sediment and sediment-derived pollutants when assessing the pollution status of estuarine environments, especially for those mega-estuaries and their neighboring ocean environments with complex waves, tides and ocean currents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Spatial distribution and seasonal variation of phthalate esters in the Jiulong River estuary, Southeast China.

    Science.gov (United States)

    Li, Rongli; Liang, Jing; Duan, Hualing; Gong, Zhenbin

    2017-09-15

    The spatial distribution and seasonal variation of 16 phthalate esters (PAEs) in water, suspended particulate matter (SPM) and sediment were investigated in the Jiulong River estuary, Fujian, Southeast China. Of the 16 PAE congeners analyzed, only six PAEs, including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP), were identified and quantified. The total concentrations of the six PAEs (∑6PAEs) detected for all seasons ranged from 3.01 to 26.4μg/L in water, 1.56 to 48.7mg/kg in SPM, and 0.037 to 0.443μg/kg in sediment. DEHP, DIBP and DBP were the most abundant PAE congeners in all of the water, SPM and sediment phases. The spatial distributions of PAEs in the estuary were controlled not only by the riverine runoff, seasons, hydrodynamic condition and human activities but also the physicochemical properties of PAEs. Copyright © 2017. Published by Elsevier Ltd.

  13. Metagenomic Analysis of Virioplankton of the Subtropical Jiulong River Estuary, China

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    Lanlan Cai

    2016-02-01

    Full Text Available Viruses are the most abundant biological entities in the oceans, and encompass a significant reservoir of genetic diversity. However, little is known about their biodiversity in estuary environments, which represent a highly dynamic and potentially more diverse habitat. Here, we report a metagenomic analysis of the dsDNA viral community from the Jiulong River Estuary (JRE, China, and provide a comparative analysis with other closely related environments. The results showed that the majority of JRE virome did not show any significant similarity to the database. For the major viral group (Caudovirales detected in the sample, Podoviridae (44.88% were the most abundant family, followed by Siphoviridae (32.98% and Myoviridae (17.32%. The two most abundant viruses identified in the virome were phages HTVC010P and HMO-2011, which infect bacteria belonging to marine SAR11 and SAR116 clades, respectively. Two contigs larger than 20 kb, which show similar overall genome architectures to Celeribacter phage P12053L and Thalosomonas phage BA3, respectively, were generated during assembly. Comparative analysis showed that the JRE virome was more similar to marine viromes than to freshwater viromes, and shared a relative coarse-grain genetic overlap (averaging 14.14% ± 1.68% with other coastal viromes. Our study indicated that the diversity and community structure of the virioplankton found in JRE were mainly affected by marine waters, with less influence from freshwater discharge.

  14. The source of natural and anthropogenic heavy metals in the sediments of the Minjiang River Estuary (SE China): implications for historical pollution.

    Science.gov (United States)

    Xu, Yonghang; Sun, Qinqin; Yi, Liang; Yin, Xijie; Wang, Aijun; Li, Yunhai; Chen, Jian

    2014-09-15

    Two sedimentary cores in the Minjiang River estuary (SE China) are documented for grain size, clay minerals, heavy metals, magnetic parameters and Pb isotopes to investigate the source and historical variation of heavy metals. The MJK9 core was collected outside of the Minjiang River estuary, and the core is composed of mixed sediments, of which ~70% from the Yangtze River and 30% from the Minjiang River. It is thus difficult to be used for tracing the human activity along the Minjiang River. In contrast, the sediments of MJK16 core which was collected in a nearshore area are primarily from the Minjiang River. The enrichment factors of the sediments were pollution. The results indicate that the sediments of the MJK16 core have Cu and Pb concentrations increasing since 1980, associated with the increase of magnetic mineral concentration and (206)Pb/(207)Pb and (206)Pb/(208)Pb of the sediments. We compared the Pb isotopic compositions between our results and those for the deposit mining in the Minjiang River basin, and aerosols and coal dust in south China, and considered that Pb in the sediments of the MJK16 core was derived primarily from weathered rocks as well as industrial emission (e.g. coal combustion). The sediments have anthropogenic Pb concentrations ranging from 6% in 1950 to 23.7% in 2010, consistent with the impact of rapid urban and industrial development in China. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The Guayas Estuary and sea level corrections to calculate flooding areas for climate change scenarios

    Science.gov (United States)

    Moreano, H. R.; Paredes, N.

    2011-12-01

    The Guayas estuary is the inner area of the Gulf of Guayaquil, it holds a water body of around 5000 km2 and the Puna island divides the water flow in two main streams : El Morro and Estero Salado Channel (length: 90 Km.) and Jambeli and Rio Guayas Channel (length: 125km.). The geometry of the estuarine system with the behavior of the tidal wave (semidiurnal) makes tidal amplitude higher at the head than at the mouth, whereas the wave crest at the head is delayed from one and a half to two hours from that at the mouth and sea level recorded by gages along the estuary are all different because of the wave propagation and mean sea level (msl) calculated for each gage show differences with that of La Libertad which is the base line for all altitudes on land (zero level). A leveling and calculations were made to correct such differences in a way that all gages (msl) records were linked to La Libertad and this in turn allowed a better estimates of flooding areas and draw them on topographic maps where zero level corresponds to the mean sea level at La Libertad. The procedure and mathematical formulation could be applied to any estuary or coastal area and it is a useful tool to calculate such areas especially when impacts are on people or capital goods and related to climate change scenarios.

  16. Trace metal pollution and carbon and nitrogen isotope tracing through the Yongdingxin River estuary in Bohai Bay, Northern China.

    Science.gov (United States)

    Sun, Conghui; Wei, Qi; Ma, Lixia; Li, Li; Wu, Guanghong; Pan, Ling

    2017-02-15

    A tide gate was built in 2010 to prevent seawater from moving upstream into the Yongdingxin River estuary in Bohai Bay, Northern China. We analysed the concentrations of Hg, Cd, Pb, TOC, TN, δ13C and δ15N and studied their variations in the surface layer and vertical profiles of sediment cores collected from the Yongdingxin River estuary. Contamination factors and geo-accumulation indices were calculated for each metal, which revealed high levels of contamination for Hg and Cd in the sediments, likely from anthropogenic sources. δ13C and δ15N were used as natural tracers to determine the sources of TOC and TN. The results revealed that sewage was the main source of TOC, while TN may have more than one source in the Yongdingxin River estuary. Sewage dominated trace metal pollution in the Yongdingxin River estuary. Our results provide a baseline for trace metal contamination in an estuary facing a large water project. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Tracing the origin of the oxygen-consuming organic matter in the hypoxic zone in a large eutrophic estuary: the lower reach of the Pearl River Estuary, China

    Directory of Open Access Journals (Sweden)

    J. Su

    2017-09-01

    Full Text Available We assess the relative contributions of different sources of organic matter, marine vs. terrestrial, to oxygen consumption in an emerging hypoxic zone in the lower Pearl River Estuary (PRE, a large eutrophic estuary located in Southern China. Our cruise, conducted in July 2014, consisted of two legs before and after the passing of Typhoon Rammasun, which completely de-stratified the water column. The stratification recovered rapidly, within 1 day after the typhoon. We observed algal blooms in the upper layer of the water column and hypoxia underneath in bottom water during both legs. Repeat sampling at the initial hypoxic station showed severe oxygen depletion down to 30 µmol kg−1 before the typhoon and a clear drawdown of dissolved oxygen after the typhoon. Based on a three endmember mixing model and the mass balance of dissolved inorganic carbon and its isotopic composition, the δ13C of organic carbon remineralized in the hypoxic zone was −23.2 ± 1.1 ‰. We estimated that 65 ± 16 % of the oxygen-consuming organic matter was derived from marine sources, and the rest (35 ± 16 % was derived from the continent. In contrast to a recently studied hypoxic zone in the East China Sea off the Changjiang Estuary where marine organic matter dominated oxygen consumption, here terrestrial organic matter significantly contributed to the formation and maintenance of hypoxia. How varying amounts of these organic matter sources drive oxygen consumption has important implications for better understanding hypoxia and its mitigation in bottom waters.

  18. Levels, distributions and sources of veterinary antibiotics in the sediments of the Bohai Sea in China and surrounding estuaries.

    Science.gov (United States)

    Liu, Xinghua; Zhang, Haibo; Li, Lianzhen; Fu, Chuancheng; Tu, Chen; Huang, Yujuan; Wu, Longhua; Tang, Jianhui; Luo, Yongming; Christie, Peter

    2016-08-15

    Veterinary antibiotics are emerging contaminants of concern. A total of 139 samples comprising 104 marine sediments and 35 estuarine sediments were collected from the Bohai Sea area and analyzed for seventeen antibiotics. The results reveal that the presence and concentration of antibiotics were generally higher in the estuaries than in the sea. The highest antibiotic concentration, 4695μgkg(-1) of oxytetracycline, occurred in the estuarine sediment from Ziya New River. Bohai Bay and Laizhou Bay and the surrounding estuaries had higher concentrations of antibiotics. However, low levels of antibiotics detected were detected in Liaodong Bay in contrast to the high concentrations present in the surrounding estuaries. Spatial heterogeneity and principal component analysis suggest a large impact of terrestrial sources of the antibiotics contaminating the Bohai Sea. Risk quotients indicate that current levels of norfloxacin and oxytetracycline might be potentially hazardous to sensitive biota both in the Bohai Sea and in its surrounding estuaries. Copyright © 2016. Published by Elsevier Ltd.

  19. Trace metals in estuaries in the Russian Far East and China: case studies from the Amur River and the Changjiang.

    Science.gov (United States)

    Shulkin, Vladimir; Zhang, Jing

    2014-11-15

    This paper compares the distributions of dissolved and particulate forms of Mn, Fe, Ni, Cu, Zn, Cd, and Pb in the estuaries of the largest rivers in East Asia: the Amur River and the Changjiang (Yangtze River). High suspended solid concentrations, elevated pH, and relatively low dissolved trace metal concentrations are characteristics of the Changjiang. Elevated dissolved Fe and Mn concentrations, neutral pH, and relatively low suspended solid concentrations are characteristics of the Amur River. The transfer of dissolved Fe to suspended forms is typical in the Amur River estuary, though Cd and Mn tend to mobilize to solution, and Cu and Ni are diluted in the estuarine system. Metal concentrations in suspended matter in the Amur River estuary are controlled by the ratio of terrigenous riverine material, enriched in Al and Fe, and marine biogenic particles, enriched in Cu, Mn, Cd, and in some cases Ni. The increase in dissolved forms of Mn, Fe, Ni, Cu, Cd, and Pb compared with river end-member is unique to the Changjiang estuary. Particle-solution interactions are not reflected in bulk suspended-solid metal concentrations in the Changjiang estuary due to the dominance of particulate forms of these metals. Cd is an exception in the Changjiang estuary, where the increase in dissolved Cd is of comparable magnitude to the decrease in particulate Cd. Despite runoff in the Amur River being lower than that in the Changjiang, the fluxes of dissolved Mn, Zn and Fe in the Amur River exceed those in the Changjiang. Dissolved Ni, and Cd fluxes are near equal in both estuaries, but dissolved Cu is lower in the Amur River estuary. The hydrological and physico-chemical river characteristics are dominated at the assessment of river influence on the adjoining coastal sea areas despite differences in estuarine processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Environmental significance of biogenic elements in surface sediments of the Changjiang Estuary and its adjacent areas.

    Science.gov (United States)

    Yu, Yu; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Duan, Liqin

    2013-11-01

    Biogenic elements and six phosphorus (P) fractions in surface sediments from the Changjiang Estuary and adjacent waters were determined to investigate the governing factors of these elements, and further to discuss their potential uses as paleo-environment proxies and risks of P release from sediment. Total organic carbon (TOC) and leachable organic P (Lea-OP) showed high concentrations in the estuary, Zhejiang coast and offshore upwelling area. They came from both the Changjiang River and marine biological input. Biogenic silicon (BSi) exhibited a high concentration band between 123 and 124 degree E. BSi mainly came from diatom production and its concentration in the inshore area was diluted by river sediment. Total nitrogen (TN) was primarily of marine biogenic origin. Seaward decreasing trends of Fe-bound P and Al-bound P revealed their terrestrial origins. Influenced by old Huanghe sediment delivered by the Jiangsu coastal current, the maximum concentration of detrital P (Det-P) was observed in the area north of the estuary. Similar high concentrations of carbonate fluorapatite (CFA-P) and CaCO3in the southern study area suggested marine calcium-organism sources of CFA-P. TOC, TN and non-apatite P were enriched in fine sediment, and Det-P partially exhibited coarse-grain enrichment, but BSi had no correlation with sediment grain size. Different sources and governing factors made biogenic elements and P species have distinct potential uses in indicating environmental conditions. Transferable P accounted for 14%-46% of total P. In an aerobic environment, there was low risk of P release from sediment, attributed to excess Fe oxides in sediments.

  1. [Ecological characteristics of phytoplankton in coastal area of Pearl River estuary].

    Science.gov (United States)

    Dai, Ming; Li, Chunhou; Jia, Xiaoping; Zhang, Hanhua; Chen, Ruiwen

    2004-08-01

    Five cruises of phytoplankton survey were made in costal area of Pearl River estuary in 1998-1999. The results showed that 239 species were identified, 72.4% of which belonging to Bacillariophyta, 23.8% to Pyrrophyta, and 3.8% to others. The dominant species were warm and eurythermic species Thalassiothrix frauenfeldii, Nitzschia delicatissima, Thalassiothrix frauenfeldii and Thalassiosira subtilis, and changed with an obvious seasonal succession. The cell density ranged from 0.2 x 10(4) to 2,767.1 x 10(4) cell x m(-3), with an average of 98.7 x 10(4) cell x m(-3), and the mean cell density was obviously higher in summer and winter than in spring and autumn. The regional variation revealed that the cell density in shore area was visibly higher than that in offshore area, and the largest density area was at the southeast of Shangchuan Island all the year around. The range of mean Shannon-Wiener index, Pielou evenness index and biodiversity threshold was 2.63-3.17, 0.53-0.71 and 1.74-2.23, respectively. According to the diversity index, it was concluded that the diversity level of phytoplankton community in coastal area of Pearl River estuary was relatively high and stable.

  2. Diversity and abundance of ammonia-oxidizing prokaryotes in sediments from the coastal Pearl River estuary to the South China Sea.

    Science.gov (United States)

    Cao, Huiluo; Hong, Yiguo; Li, Meng; Gu, Ji-Dong

    2011-11-01

    In the present study the diversity and abundance of nitrifying microbes including ammonia-oxidizing archaea (AOA) and betaproteobacteria (beta-AOB) were investigated, along with the physicochemical parameters potentially affecting them, in a transect of surface sediments from the coastal margin adjacent to the Pearl River estuary to the slope in the deep South China Sea. Nitrifying microbial diversity was determined by detecting the amoA (ammonia monooxygenase subunit A) gene. An obvious community structure shift for both AOA and beta-AOB from the coastal marginal areas to the slope in the deep-sea was detected, while the OTU numbers of AOA amoA were more stable than those of the beta-AOB. The OTUs of beta-AOB increased with the distance from the coastal margin areas to the slope in the deep-sea. Beta-AOB showed lower diversity with dominant strains in a polluted area but higher diversity without dominant strains in a clean area. Moreover, the diversity of beta-AOB was correlated with pH values, while no noticeable relationships were established between AOA and physicochemical parameters. Beta-AOB was more sensitive to transect environmental variability and might be a potential indicator for environmental changes. Additionally, the surface sediments surveyed in the South China Sea harboured diverse and distinct AOA and beta-AOB phylotypes different from other environments, suggesting the endemicity of some nitrifying prokaryotes in the South China Sea.

  3. Heavy metal pollution in coastal areas of South China: a review.

    Science.gov (United States)

    Wang, Shuai-Long; Xu, Xiang-Rong; Sun, Yu-Xin; Liu, Jin-Ling; Li, Hua-Bin

    2013-11-15

    Coastal areas of South China face great challenges due to heavy metal contamination caused by rapid urbanization and industrialization. In this paper, more than 90 articles on levels, distributions, and sources of heavy metals in sediments and organisms were collected to review the status of heavy metal pollution along coastal regions of South China. The results show that heavy metal levels were closely associated with local economic development. Hong Kong and the Pearl River Estuary were severely contaminated by heavy metals. However, concentrations of heavy metals in sediments from Hong Kong have continually decreased since the early 1990 s. High levels of heavy metals were found in biota from Lingdingyang in Guangdong province. Mollusks had higher concentrations of heavy metals than other species. Human health risk assessments suggested that levels of heavy metals in some seafood from coastal areas of South China exceeded the safety limit. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Secular bathymetric variations of the North Channel in the Changjiang (Yangtze) Estuary, China, 1880-2013: Causes and effects

    Science.gov (United States)

    Mei, Xuefei; Dai, Zhijun; Wei, Wen; Li, Weihua; Wang, Jie; Sheng, Hao

    2018-02-01

    As the interface between the fluvial upland system and the open coast, global estuaries are facing serious challenges owing to various anthropogenic activities, especially to the Changjiang Estuary. Since the establishment of the Three Gorges Dam (TGD), currently the world's largest hydraulic structure, and certain other local hydraulic engineering structures, the Changjiang Estuary has experienced severe bathymetric variations. It is urgent to analyze the estuarine morphological response to the basin-wide disturbance to enable a better management of estuarine environments. North Channel (NC), the largest anabranched estuary in the Changjiang Estuary, is the focus of this study. Based on the analysis of bathymetric data between 1880 and 2013 and related hydrological data, we developed the first study on the centennial bathymetric variations of the NC. It is found that the bathymetric changes of NC include two main modes, with the first mode representing 64% of the NC variability, which indicates observable deposition in the mouth bar and its outer side area (lower reach); the second mode representing 11% of the NC variability, which further demonstrates channel deepening along the inner side of the mouth bar (upper reach) during 1970-2013. Further, recent erosion observed along the inner side of the mouth bar is caused by riverine sediment decrease, especially in relation to TGD induced sediment trapping since 2003, while the deposition along the lower reach since 2003 can be explained by the landward sediment transport because of flood-tide force strengthen under the joint action of TGD induced seasonal flood discharge decrease and land reclamation induced lower reach narrowing. Generally, the upper and lower NC reach are respectively dominated by fluvial and tidal discharge, however, episodic extreme floods can completely alter the channel morphology by smoothing the entire channel. The results presented herein for the NC enrich our understanding of bathymetric

  5. Vulnerability assessment of the coastal wetlands in the Yangtze Estuary, China to sea-level rise

    Science.gov (United States)

    Cui, Lifang; Ge, Zhenming; Yuan, Lin; Zhang, Liquan

    2015-04-01

    with the objective and quantitative assessment of the vulnerability of coastal wetlands undergoing the impacts of SLR elsewhere. Without proper mitigation measures, the potential decrease in the area and loss of habitats and ecosystem services from the wetlands is inevitable. Based on the results of this study, mitigation measures should be considered for securing the future of the coastal wetlands in the Yangtze Estuary, which include the management of sedimentation, rehabilitation and re-creation of wetland habitat, reduction of land subsidence and control of reclamation.

  6. Development of a GNSS Buoy for Monitoring Water Surface Elevations in Estuaries and Coastal Areas

    Directory of Open Access Journals (Sweden)

    Yen-Pin Lin

    2017-01-01

    Full Text Available In this work, a Global Navigation Satellite System (GNSS buoy that utilizes a Virtual Base Station (VBS combined with the Real-Time Kinematic (RTK positioning technology was developed to monitor water surface elevations in estuaries and coastal areas. The GNSS buoy includes a buoy hull, a RTK GNSS receiver, data-transmission devices, a data logger, and General Purpose Radio Service (GPRS modems for transmitting data to the desired land locations. Laboratory and field tests were conducted to test the capability of the buoy and verify the accuracy of the monitored water surface elevations. For the field tests, the GNSS buoy was deployed in the waters of Suao (northeastern part of Taiwan. Tide data obtained from the GNSS buoy were consistent with those obtained from the neighboring tide station. Significant wave heights, zero-crossing periods, and peak wave directions obtained from the GNSS buoy were generally consistent with those obtained from an accelerometer-tilt-compass (ATC sensor. The field tests demonstrate that the developed GNSS buoy can be used to obtain accurate real-time tide and wave data in estuaries and coastal areas.

  7. Development of a GNSS Buoy for Monitoring Water Surface Elevations in Estuaries and Coastal Areas.

    Science.gov (United States)

    Lin, Yen-Pin; Huang, Ching-Jer; Chen, Sheng-Hsueh; Doong, Dong-Jiing; Kao, Chia Chuen

    2017-01-18

    In this work, a Global Navigation Satellite System (GNSS) buoy that utilizes a Virtual Base Station (VBS) combined with the Real-Time Kinematic (RTK) positioning technology was developed to monitor water surface elevations in estuaries and coastal areas. The GNSS buoy includes a buoy hull, a RTK GNSS receiver, data-transmission devices, a data logger, and General Purpose Radio Service (GPRS) modems for transmitting data to the desired land locations. Laboratory and field tests were conducted to test the capability of the buoy and verify the accuracy of the monitored water surface elevations. For the field tests, the GNSS buoy was deployed in the waters of Suao (northeastern part of Taiwan). Tide data obtained from the GNSS buoy were consistent with those obtained from the neighboring tide station. Significant wave heights, zero-crossing periods, and peak wave directions obtained from the GNSS buoy were generally consistent with those obtained from an accelerometer-tilt-compass (ATC) sensor. The field tests demonstrate that the developed GNSS buoy can be used to obtain accurate real-time tide and wave data in estuaries and coastal areas.

  8. Hypoxia off the Changjiang (Yangtze River) estuary and in the adjacent East China Sea: Quantitative approaches to estimating the tidal impact and nutrient regeneration.

    Science.gov (United States)

    Zhu, Zhuo-Yi; Wu, Hui; Liu, Su-Mei; Wu, Ying; Huang, Da-Ji; Zhang, Jing; Zhang, Guo-Sen

    2017-12-15

    Large areas of hypoxia have been reported off The Changjiang Estuary and in the East China Sea. Five cruises, covering winter, spring, and summer, were carried out from 2007 to 2013 in this region, and in August 2013 (summer), an extensive hypoxic event (11,150km2) was observed, which was characterized by an estimated bulk oxygen depletion of 5.1 million tons. A strong tidal impact was observed associated with the bottom oxygen depletion, with the periodicity of diel variations in dissolved oxygen being 12h (i.e., similar to the tidal cycle). A conservative estimate of nutrient regeneration suggested that during the hypoxic event of August 2013, the amount of regenerated nitrogen (as nitrate) and phosphorus (as dissolved inorganic phosphorus) was 27,000-30,000 tons and 1300-41,000tons, respectively. Estimates of the absolute (bulk) regenerated nutrient fluxes were much greater than the conservative estimates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. [Diet composition and seasonal variation in feeding habits of Collichthy lucidus in Yangtze Estuary, China].

    Science.gov (United States)

    Wang, Jian-feng; Zhao, Feng; Song, Chao; Yang, Gang; Hou, Jun-li; Zhuang, Ping

    2016-01-01

    Spiny head croaker (Collichthy lucidus) is an important bottom fish distributing from the East China Sea to the Yellow Sea. In order to investigate the seasonal variation in diet composition and feeding habits, a total of 270 specimens were collected in the Yangtze Estuary from November, 2013 to August, 2014, and analyzed by using the stomach contents analysis method. The importance of different prey items was evaluated by the frequency of occurrence, abundance and mass followed by using these data to calculate the index of relative importance (IRI) and the index of preponderance (Ip) for each taxonomic category. The results showed that the diet of C. lucidus consisted of 30 species belonging to 8 orders, in which shrimps, with 38.5 IRI% and 79.1 Ip values, was the most important prey species. The followings were Mysidacea and Amphipoda. The dominant species in the diet of C. lucidus were Palaemon gravieri, Exopalaemon annandalei, E. carinicauda, Acanthomysis longirostris, A. brevirostris, Synidotea laevidorsalis and Calanus sinicus. The dominant species in the diet varied in different seasons. P. gravieri, E. annandalei and A. brevirostris were dominant species in spring and summer, A. longirostris, A. brevirostris and E. carinicauda in autumn, and P. gravieri, C. sinicus and Pesudeuphausia sinica in winter. There was 10.4% of total samples with empty stomachs, and the highest percent appeared in winter, and the lowest in autumn. The mean stomach fullness index of the whole samples was 0.6%, with the highest found in spring, the lowest in winter, indicating the feeding activity of C. lucidus varied significantly among seasons.

  10. Stratified active archaeal communities in the sediments of Jiulong River Estuary, China

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    Qianqian eLi

    2012-08-01

    Full Text Available Here the composition of total and active archaeal communities in a sediment core of Jiulong River estuary at Fujian Province, Southern China was reported. Profiles of CH4 and SO42- concentrations from the sediment core indicated the existence of a sulfate-methane transition zone (SMTZ in which sulfate reduction-coupled anaerobic oxidation of methane occurs. Accordingly, three sediment layers (16-18.5 cm, 71-73.5 cm, 161-163.5 cm from the 1.2 m sediment core were sectioned and named top, middle and bottom, respectively. Total DNA and RNA of each layer were extracted and used for clone libraries and sequence analysis of 16S rRNA genes, the reverse transcription (RT-PCR products of 16S rRNA and methyl CoM reductase alpha subunit (mcrA genes. Phylogenetic analysis indicated that archaeal communities of the three layers were dominated by the Miscellaneous Crenarchaeotal Group (MCG whose ecological functions were still unknown. The MCG could be further divided into seven subgroups, named MCG-A, B, C, D, E, F and G. MCG-A and MCG-G were the most active groups in the estuarine sediments. Known anaerobic methanotrophic archaea (ANMEs were only found as minor components in these estuarine archaeal communities. This study, together with the studies of deep subsurface sediments, would be a very good start point to target and compare the specific active archaeal groups and their roles in the dark, deep subsurface sediment environments.

  11. Evolution of the Jiuduansha wetland and the impact of navigation works in the Yangtze Estuary, China

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    Li, Xing; Liu, J. Paul; Tian, Bo

    2016-01-01

    The estuarine wetlands in the Yangtze Estuary face increasing threats due to large-scale engineering projects and huge land requirements. As a Wetland National Nature Reserve and important stopover site for migratory shorebirds of the East Asian-Australasian Flyway, the Jiuduansha wetland, one of four main islands in the estuary, is of both national and international importance. Since 1998 the previously undisturbed wetland has been considerably modified by the adjacent Deep-water Navigation Channel project (DNC). In order to understand the role of the DNC for the evolution of the Jiuduansha wetland, we performed a diagnostic study from multiple perspectives, including deposition rate, area change, evolution track, geometric characteristics, and geomorphological change. By coupling GIS, geostatistics, and remote sensing techniques, this study demonstrates the impact of the DNC on the Jiuduansha wetland in a spatially explicit way. Multi-temporal bathymetric maps and Landsat images from before and after the DNC was constructed were adopted to conduct our study. We find that deposition has occurred in most parts of the wetland over the past almost 30 years, accounting for 67.3% of the total area. However, over 40% of the study area shows a decreasing trend in deposition rate. The spatial distribution of deposition-erosion patterns is closely linked to the DNC. We also find that the DNC has substantial effects on the evolution of the Jiuduansha wetland. The 0, 2, and 5 m isobaths in the Jiuduansha Shoal (JDS), as well as in the Jiangya Shoal (JYS), the Upper Shoal (US) and the Middle-Lower Shoal (MLS), show different response patterns to the DNC. Specifically, the south training jetty of the DNC has an "adsorption effect" on the JDS above the 2 m isobaths intersecting with it. As a result, the evolution track, geometric and geomorphological characteristics of the JDS were markedly altered in the short term. Our comprehensive analysis suggests that in the future, the

  12. The influence of seasonal climate on the morphology of the mouth-bar in the Yangtze Estuary, China

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    Zhang, Min; Townend, Ian; Cai, Huayang; He, Jiawei; Mei, Xuefei

    2018-02-01

    The geomorphology of the Yangtze Estuary in the Changjiang River Delta in Eastern China has been the subject of extensive research. This study extends previous work to examine the influence of wind-waves on the mouth-bar, where about half of the river-borne material settles to the bed. The site is located just outside of Changjiang River mouth, which is meso-tidal and subject to seasonally varying river flows and wind-wave conditions. Modeling was performed with a coupled wave-current hydrodynamic model using TELEMAC and TOMAWAC and validated against observed data. Bottom Shear Stress (BSS) from river, tide and waves based on the numerical model output was used to infer the respective contribution to the evolution of the subaqueous delta. Our examination did not however extend to modeling the sediment transport or the morphological bed changes. The results suggest that (i) the dominance of river discharge is limited to an area inside the mouth, while outside, the mouth-bar is tide-wave dominant; (ii) considering just the tide, the currents on the shallow shoals are flood dominant and deep channels are ebb dominant, which induces continued accretion over the shallows and erodes the deeper parts of the mouth-bar until the tidal currents become too weak to transport sediment; (iii) whereas waves are very efficient at reshaping the shallow shoals, with the effect being subtly dependent on the depth distribution over the mouth-bar; (iv) the stability of shallow shoal morphology is highly dependent on the presence of seasonal wind-waves and characterized as "summer storing and winter erosion", while deep channels perform like corridors of water and sediment, exporting sediment all year round. The nature of the mouth-bar response has important implications for coastal management, such as the ongoing deep water channel maintenance, reclamations and coastal defense measures.

  13. Nutrient characteristics in the Yangtze River Estuary and the adjacent East China Sea before and after impoundment of the Three Gorges Dam.

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    Chai, Chao; Yu, Zhiming; Shen, Zhiliang; Song, Xiuxian; Cao, Xihua; Yao, Yun

    2009-08-01

    From November 2002 to 2006, five cruises were undertaken in the Yangtze River Estuary and the adjacent East China Sea to compare the nutrient concentrations, ratios and potential nutrient limitation of phytoplankton growth before and after impoundment (June 2003) of the Three Gorges Dam (TGD). Concentrations of dissolved inorganic nitrogen (DIN), soluble reactive phosphorus (SRP) and total nitrogen (TN) exhibited an increasing trend from 2002 to 2006. In contrast, total phosphorus (TP) concentration exhibited a decreasing trend. The mean concentrations of DIN, SRP, and TN in the total study area increased from 21.4 microM, 0.9 microM, and 41.8 microM in 2002 to 37.5 microM, 1.3 microM, and 82.2 microM in 2006, respectively, while TP decreased from 2.1 microM to 1.7 microM. The concentration of dissolved reactive silica (DRSi) had no major fluctuations and the differences were not significant. The mean concentration of DRSi in the total study area ranged from 52.5 to 92.3 microM. The Si:N ratio decreased significantly from 2.7 in 2002 to 1.3 in 2006, while TN:TP ratio increased from 22.1 to 80.3. The area of potential P limitation of phytoplankton growth expanded after 2003 and potential Si limitation appeared in 2005 and 2006. Potential P limitation mainly occurred in an area of salinity less than 30 after 2003, while potential Si limitation occurred where the salinity was greater than 30. By comparison with historical data, the concentrations of nitrate and SRP in this upper estuary during November 1980-2006 increased obviously after impoundment of TGD but DRSi decreased. Meanwhile, the ratios of N:P, Si:N and Si:P decreased obviously.

  14. Environmental factors affecting larval fish community in the salt marsh area of Guadiana estuary (Algarve, Portugal

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    Renata Gonçalves

    2015-03-01

    Full Text Available Salt marsh areas in the Guadiana estuary are important nursery sites for many fish species of commercial and recreational value. More effective protection measures should be adopted as the area is highly affected by anthropogenic and natural threats. Studying larval fish communities in these impacted nursery areas will be relevant to the management of local ecosystems and to larval fish ecology in general. Spatial and seasonal distribution and the effect of environmental factors on the larval fish community of this ecosystem were studied for one year (April 2010 to March 2011. Larvae were sampled monthly in parallel with phytoplankton and zooplankton. Hydrological data and physical parameters were monitored. A decision tree model was used to assess the influence of environmental factors on the larval fish community. A total of 130 larvae and 1171 eggs were caught. Diplodus sargus, Sardina pilchardus, and Pomatoschistus microps were the most abundant larval fish species. The peaks of fish larvae abundance occurred in March and April. The output of the model demonstrates that the abundance of larval fish is determined by the abundance of eggs, zooplanktonic food, and water flood and flow. This study shows the importance of the Guadiana salt marsh as an area for fish nursery and highlights the need for conservation of this area.

  15. Diversity of fish sound types in the Pearl River Estuary, China

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    Zhi-Tao Wang

    2017-10-01

    Full Text Available Background Repetitive species-specific sound enables the identification of the presence and behavior of soniferous species by acoustic means. Passive acoustic monitoring has been widely applied to monitor the spatial and temporal occurrence and behavior of calling species. Methods Underwater biological sounds in the Pearl River Estuary, China, were collected using passive acoustic monitoring, with special attention paid to fish sounds. A total of 1,408 suspected fish calls comprising 18,942 pulses were qualitatively analyzed using a customized acoustic analysis routine. Results We identified a diversity of 66 types of fish sounds. In addition to single pulse, the sounds tended to have a pulse train structure. The pulses were characterized by an approximate 8 ms duration, with a peak frequency from 500 to 2,600 Hz and a majority of the energy below 4,000 Hz. The median inter-pulsepeak interval (IPPI of most call types was 9 or 10 ms. Most call types with median IPPIs of 9 ms and 10 ms were observed at times that were exclusive from each other, suggesting that they might be produced by different species. According to the literature, the two section signal types of 1 + 1 and 1 + N10 might belong to big-snout croaker (Johnius macrorhynus, and 1 + N19 might be produced by Belanger’s croaker (J. belangerii. Discussion Categorization of the baseline ambient biological sound is an important first step in mapping the spatial and temporal patterns of soniferous fishes. The next step is the identification of the species producing each sound. The distribution pattern of soniferous fishes will be helpful for the protection and management of local fishery resources and in marine environmental impact assessment. Since the local vulnerable Indo-Pacific humpback dolphin (Sousa chinensis mainly preys on soniferous fishes, the fine-scale distribution pattern of soniferous fishes can aid in the conservation of this species. Additionally, prey and predator

  16. Waterbird Population Changes in the Wetlands at Chongming Dongtan in the Yangtze River Estuary, China

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    Ma, Zhijun; Wang, Yong; Gan, Xiaojing; Li, Bo; Cai, Yinting; Chen, Jiakuan

    2009-06-01

    We studied the changes in wetland habitats and waterbird communities between the 1980s and the 2000s at Chongming Dongtan, a Ramsar site in the Yangtze River estuary, an ecologically important region. This region is an important stopover site for shorebirds along the East Asian-Australasian flyway and is extensively used by waterfowl. A net loss of 11% of the wetland area was estimated during study periods at Chongming Dongtan. The change was dependent on wetland types: while the area of artificial habitats such as paddy fields and aquacultural ponds more than doubled, more than 65% of natural habitats including sea bulrush ( Scirpus mariqueter) and common reed ( Phragmites australis) marshes were lost over the two decades. An exotic plant species introduced from North America, smooth cordgrass ( Spartina alterniflora), occupied 30% of the vegetated intertidal zone by the 2000s. Although waterbird species richness did not change between the 1980s (110) and the 2000s (111), 13 species found in 1980s were replaced by 14 newly recorded species. Moreover, there were more species with declining trends (58) than with increasing trends (19). The population trends of species were affected by residential status and habitat types. Transients, wintering migrants, and habitat specialists were more likely to show declining trends compared to those breeding at Dongtan (including year-round and summer residents) and habitat generalists. Furthermore, species associated mainly with natural wetlands were more likely to decline than those associated mainly with artificial wetlands. These patterns suggest that the loss and change of wetland habitats at Chongming Dongtan adversely affected local population dynamics and might have contributed to the global decline of some waterbird species. Because Chongming Dongtan provides stopover and wintering habitats for many migratory waterbirds, protection and restoration of natural wetlands at Chongming Dongtan are urgently needed.

  17. Tidal straining effect on the suspended sediment transport in the Huanghe (Yellow River) Estuary, China

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    Wang, Xiao Hua; Wang, Houjie

    2010-10-01

    Tidal straining effect on sediment transport dynamics in the Huanghe (Yellow River) estuary was studied by field observations and numerical simulations. The measurement of salinity, suspended sediment concentration, and current velocity was conducted during a flood season in 1995 at the Huanghe river mouth with six fishing boats moored at six stations for 25-h hourly time series observations. Based on the measurements, the intra-tidal variations of sediment transport in the highly turbid river mouth was observed and the tidal straining effect occurred. Our study showed that tidal straining of longitudinal sediment concentration gradients can contribute to intra-tidal variability in sediment stratification and to asymmetries in sediment distribution within a tidal cycle. In particular, the tidal straining effect in the Huanghe River estuary strengthened the sediment-induced stratification at the flood tide, thus producing a higher bottom sediment concentration than that during the ebb. A sediment transport model that is capable of simulating sediment-induced stratification effect on the hydrodynamics in the bottom boundary layers and associated density currents was applied to an idealized estuary to demonstrate the processes and to discuss the mechanism. The model-predicted sediment processes resembled the observed characteristics in the Huanghe River estuary. We concluded that tidal straining effect is an important but poorly understood mechanism in the transport dynamics of cohesive sediments in turbid estuaries and coastal seas.

  18. The distribution and partitioning of common antibiotics in water and sediment of the Pearl River Estuary, South China.

    Science.gov (United States)

    Liang, Ximei; Chen, Baowei; Nie, Xiangping; Shi, Zhen; Huang, Xiaoping; Li, Xiangdong

    2013-09-01

    Antibiotics released into the aquatic environment play an important role in the spread of antibiotic resistance. In the Pearl River Estuary (PRE) and the coastal zone, the concentrations of antibiotics decreased from the Pearl River to the estuary, suggesting that antibiotics primarily originated from river tributaries and terrigenous sources. Within the PRE area, the concentrations of antibiotics in water were higher in the west coast than the east side, reflecting the high density of anthropogenic activities and hydraulic conditions along the west riverbank. Seasonal variations were also observed for most of detected antibiotics in water. The pseudo-partitioning coefficient of norfloxacin had a good correlation with the TOC content of sediments, as did erythromycin-H2O with the pH of water. The results suggest that environmental conditions can significantly affect the distribution of antibiotics between water and sediment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Effect of mangrove restoration on crab burrow density in Luoyangjiang Estuary, China

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    Wei Li

    2015-07-01

    Full Text Available Background Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches (non-mangrove than under mature Kandelia candel, Aegiceras corniculatum and Avicennia marina communities. In general, the amount of leaf litter and debris on mangrove mudflats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance (ANOVA shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on

  20. Surface sediment properties and heavy metal pollution assessment in the Pearl River Estuary, China.

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    Zhao, Guangming; Ye, Siyuan; Yuan, Hongming; Ding, Xigui; Wang, Jin

    2017-01-01

    Grain size and concentrations of heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn)) of 148 surface sediments and activities of 210Pb and heavy metal concetrantions of one sediment core from the Pearl River Estuary were analyzed. The surface sediments were dominated by silt and sandy silt. Sediment type controlled the spatial distribution patterns of the heavy metals. The heavy metal concentrations in the sediments ranged from 3.34 to 37.11 mg/kg for As, 0.06 to 2.06 mg/kg for Cd, 12 to 130 mg/kg for Cr, 5.8 to 170.6 mg/kg for Cu, 0.01 to 0.25 mg/kg for Hg, 23 to 78 mg/kg for Pb, and 32 to 259 mg/kg for Zn. Both contents of clay and organic carbons were significantly positively correlated with heavy metals. The baseline values of elements in the study area were 12.97 mg/kg for As, 0.14 mg/kg for Cd, 68 mg/kg for Cr, 28.9 mg/kg for Cu, 0.08 mg/kg for Hg, 33 mg/kg for Pb, and 92 mg/kg for Zn. The metal enrichment factor (EF) and geoaccumulation index (Igeo) were calculated to assess anthropogenic contamination. Results showed slight to moderate Cd contamination in the region. Principle component analysis indicated that Cd could be attributed to anthropogenic sources; As and Hg were predominantly affected by human activities; and Pb, Cr, Cu, and Zn were associated with both natural and anthropogenic sources.

  1. Molecular evidence for nitrite-dependent anaerobic methane-oxidising bacteria in the Jiaojiang Estuary of the East Sea (China).

    Science.gov (United States)

    Li-Dong, Shen; Qun, Zhu; Shuai, Liu; Ping, Du; Jiang-Ning, Zeng; Dong-Qing, Cheng; Xiang-Yang, Xu; Ping, Zheng; Bao-Lan, Hu

    2014-06-01

    Nitrite-dependent anaerobic methane oxidation (N-DAMO) is a recently discovered process linking the global carbon and nitrogen cycles. This process was reported to be mediated by "Candidatus Methylomirabilis oxyfera". To date, M. oxyfera-like bacteria have been detected in a limited number of freshwater habitats, but whether these bacteria occur in estuarine habitats is currently unknown. In this study, the distribution, diversity and abundance of M. oxyfera-like bacteria were studied in the sediment of the Jiaojiang Estuary of the East Sea (China). Both the 16S ribosomal RNA (rRNA) and pmoA genes confirmed the occurrence of M. oxyfera-like bacteria in the examined estuary. The recovered 16S rRNA gene sequences showed 91.5-97.2 % identity to the 16S rRNA gene of M. oxyfera, and the recovered pmoA gene sequences showed 85.1-95.4 % identity to the pmoA gene of M. oxyfera. Quantitative PCR further confirmed the occurrence of M. oxyfera-like bacteria in this estuary, with the abundance varying from 5.80 ± 0.28 × 10(4) to 8.35 ± 0.52 × 10(7) copies g (dry weight)(-1). Correlation analysis indicated that the sediment organic content was the most important factor affecting the distribution of M. oxyfera-like bacterial communities in the examined sediments among the environmental factors investigated. This study demonstrated for the first time the existence of M. oxyfera-like bacteria in an estuarine environment and showed the correlations between the distribution of these bacteria and the estuarine environmental conditions.

  2. Use of intertidal areas by shrimps (Decapoda in a brazilian Amazon estuary

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    HEBERT A. SAMPAIO

    2014-03-01

    Full Text Available The present work investigated the occupation and the correlation of the shrimp abundance in relation to environmental variables in different habitats (mangroves, salt marshes and rocky outcrops in an Amazon estuary. The collections were made in August and November 2009, at low syzygy tide on Areuá Beach, situated in the Extractive Reserve of Mãe Grande de Curuçá, Pará, Brazil totaling 20 pools. In each environment, we recorded the physical-chemical factors (pH, salinity, and temperature and measured the area (m2 and volume (m3 of every pool through bathymetry. The average pH, salinity, temperature, area and volume of tide pools were 8.75 (± 0.8 standard deviation, 35.45 (± 3, 29.49 °C (± 2.32, 27.41 m2 (± 41.18, and 5.19 m3 (± 8.01, respectively. We caught a total of 4,871 shrimps, distributed in three families and four species: Farfantepenaeus subtilis (98.36% (marine followed by Alpheus pontederiae (0.76% (estuarine, Macrobrachium surinamicum (0.45% and Macrobrachium amazonicum (0.43% predominantly freshwater. The species F. subtilis and A. pontederiae occurred in the three habitats, whereas M. surinamicum occurred in salt marsh and rocky outcrop and M. amazonicum only in marisma. Temperature and pH were the most important environmental descriptors that significantly affected the density and biomass of shrimps.

  3. Use of intertidal areas by shrimps (Decapoda) in a Brazilian Amazon estuary.

    Science.gov (United States)

    Sampaio, Hebert A; Martinelli-Lemos, Jussara M

    2014-03-01

    The present work investigated the occupation and the correlation of the shrimp abundance in relation to environmental variables in different habitats (mangroves, salt marshes and rocky outcrops) in an Amazon estuary. The collections were made in August and November 2009, at low syzygy tide on Areuá Beach, situated in the Extractive Reserve of Mãe Grande de Curuçá, Pará, Brazil totaling 20 pools. In each environment, we recorded the physical-chemical factors (pH, salinity, and temperature) and measured the area (m2) and volume (m3) of every pool through bathymetry. The average pH, salinity, temperature, area and volume of tide pools were 8.75 (± 0.8 standard deviation), 35.45 (± 3), 29.49 °C (± 2.32), 27.41 m2 (± 41.18), and 5.19 m3 (± 8.01), respectively. We caught a total of 4,871 shrimps, distributed in three families and four species: Farfantepenaeus subtilis (98.36%) (marine) followed by Alpheus pontederiae (0.76%) (estuarine), Macrobrachium surinamicum (0.45%) and Macrobrachium amazonicum (0.43%) predominantly freshwater. The species F. subtilis and A. pontederiae occurred in the three habitats, whereas M. surinamicum occurred in salt marsh and rocky outcrop and M. amazonicum only in marisma. Temperature and pH were the most important environmental descriptors that significantly affected the density and biomass of shrimps.

  4. Growth and production of Pisidium amnicum in the freshwater tidal area of the River Minho estuary

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    Sousa, Ronaldo; Nogueira, António J. A.; Antunes, Carlos; Guilhermino, Lúcia

    2008-09-01

    Pisidium amnicum is an important indigenous species in the freshwater tidal portion of the River Minho estuary and until the introduction of the non-indigenous invasive species Corbicula fluminea was the most abundant bivalve in this ecosystem. Between January 2005 and August 2006 monthly samples were collected in three sites to study the abundance, biomass, growth and production of P. amnicum. Results indicate that P. amnicum has continuous growth throughout its life span and growth rates were higher during the early phases of development, coincident with the spring and summer months. Life span estimated was 24 months. The annual 2005 growth production of P. amnicum estimated was 2.339 g AFDW m -2 year -1, and the mean annual biomass was 1.594 g AFDW m -2, resulting in a P/B¯ ratio of 1.47 year -1 and a turnover time of 248.7 days. The annual 2005 elimination production estimated was 7.541 g AFDW m -2 year -1, resulting in an E/B¯ ratio of 4.73 year -1. It is concluded that P. amnicum continues to play an important role in the food web in areas where it coexists with C. fluminea. Previous studies showed declines in the indigenous population after the introduction of C. fluminea and currently, areas of high abundance are restricted to small patches in the upper limit of the tidal influence. Consequently, P. amnicum is now under considerable pressure and this situation requires ecological and conservational attention.

  5. The Accumulation and Seasonal Dynamic of the Soil Organic Carbon in Wetland of the Yellow River Estuary, China

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    Xianxiang Luo

    2014-01-01

    Full Text Available The wetland of the Yellow River estuary is a typical new coastal wetland in northern China. It is essential to study the carbon pool and its variations for evaluating the carbon cycle process. The study results regarding the temporal-spatial distribution and influential factors of soil organic carbon in four typical wetlands belonging to the Yellow River estuary showed that there was no significant difference in the contents of the surface soil TOC to the same season among the four types of wetlands. For each type of wetlands, the TOC content in surface soils was significantly higher in October than that in both May and August. On the whole, the obvious differences in DOC contents in surface soils were not observed in the different wetland types and seasons. The peak of TOC appeared at 0–10 cm in the soil profiles. The contents of TOC and DOC were significantly higher in salsa than those in reed, suggesting that the rhizosphere effect of organic carbon in salsa was more obvious than that in reed. The results of the principal component analysis showed that the nitrogen content, salinity, bulk density, and water content were dominant influential factors for organic carbon accumulation and seasonal variation.

  6. Effect of the exotic plant Spartina alterniflora on macrobenthos communities in salt marshes of the Yangtze River Estuary, China

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    Chen, Zhongbing; Guo, Li; Jin, Binsong; Wu, Jihua; Zheng, Guanghong

    2009-04-01

    The Yangtze River Estuary is an important eco-region of China; it has, however, been heavily infested with the invasive plant Spartina alterniflora. This study examined the benthic communities associated with the invasive S. alterniflora and two native plants ( Scirpus mariqueter and Phragmites australis) at three tidal elevations to provide a comprehensive evaluation of the impacts of marsh plant invasions on intertidal macrofauna of the Yangtze River Estuary. Spartina alterniflora had significantly sparser and taller stems than S. mariqueter, whereas the traits of S. alterniflora and P. australis were relatively similar. A total of 23 macrofaunal taxa were recorded during this study and their mean density was 1885 ind. m -2. Numerically, gastropods and bivalves were the dominant group; together they constituted 95.72% of the total macrofaunal individuals. The differences in macrofaunal community structure were greater among different elevations than between native and exotic plants. The effects of plant types on species richness and densities of macroinvertebrates were generally weak. Densities of only one species ( Glaucomya chinensis) differed significantly between S. alterniflora and S. mariqueter marshes at the lower elevation. The tolerance of the macrobenthos to plant invasions thus depends on various factors, including habitats, species of macrofauna, and local plants.

  7. Responses of seawater temperature and chlorophyll-a to typhoons passing through the Changjiang Estuary and the adjacent East China Sea

    Science.gov (United States)

    Liu, G.; Gao, L.; Li, D.

    2013-12-01

    Sea surface temperature (SST) data obtained from the Physical Oceanography Distributed Active Archive Center (PODAAC) and chlorophyll-a (Chl-a) concentrations extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua were used to study the passed typhoons' influence on the Changjiang Estuary and the adjacent East China Sea (28-33° N, 122-126° E), during the past ten years from 2002 to 2012. All together data before and after four typhoons, i.e., typhoons named Rananim in 2004, Shanshan in 2006, Jangmi in 2008 and Kompasu in 2010, were successfully retrieved due to the good weather conditions. After the four typhoons, the overall Chl-a concentrations in the study area were greatly increased by 62% (averaged by the four typhoon events) within the circles of storm wind (> 88 km/h) and by 38% within the circles of gale wind (> 62 km/h), however, no obvious change was detected in regions outside the gale wind circles. On the other hand, significant SST decrease was observed during the same periods but in a larger area. SST declined by an average level of 4.5% within the storm wind circle and approximately 3% both inside and outside the gale wind circle. Although these typhoons could potentially decrease the SST in the Changjiang Estuary and the adjacent East China Sea, however, these decrease ranges were still smaller compared to those SST variations caused by the natural climate change. In addition, typhoons with different paths and different intensities influenced the Chl-a concentrations in different ways. From 2002 to 2012, 18 typhoons had passed the study area, among which 13 typhoons moved in a northward or northwestward direction, and 16 had ranked to be the storm wind. Among the typhoons that showed similar intensities, those that moved northwards or northwestwards seemed to have played the stronger effects on the study area. The different physical and chemical conditions (including nutrient-limitation status, terrestrial discharge from

  8. Temporal trends of hydrocarbons in sediment cores from the Pearl River Estuary and the northern South China Sea

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    Xianzhi Peng; Zhendi Wang; Yiyi Yu (and others) [Chinese Academy of Sciences, Guangzhou (China). State Key Laboratory of Organic Geochemistry

    2008-11-15

    Concentrations and fluxes of unresolved complex mixture of hydrocarbons (UCM) and polycyclic aromatic hydrocarbons (PAHs) were analyzed for two {sup 210}Pb dated sediment cores from the Pearl River Estuary (PRE) and the adjacent northern South China Sea (NSCS). Compound-specific stable carbon isotopic compositions of individual n-alkanes were also measured for identification of the hydrocarbon sources. The historical records of PAHs in the NSCS reflected the economic development in the Pearl River Delta during the 20th century. PAHs in the NSCS predominantly derive from combustion of coal and biomass, whereas PAHs in the PRE are a mixture of petrogenic and pyrogenic in origins. The isotopic profiles reveal that the petrogenic hydrocarbons in the PRE originate predominantly from local spillage/leakage of lube oil and crude oils. The accumulation rates of pyrogenic PAHs have significantly increased, whereas UCM accumulation has slightly declined in the NSCS in the recent three decades.

  9. Non-local drivers of the summer hypoxia in the East China Sea off the Changjiang Estuary

    Science.gov (United States)

    Qian, Wei; Dai, Minhan; Xu, Min; Kao, Shuh-ji; Du, Chuanjun; Liu, Jinwen; Wang, Hongjie; Guo, Liguo; Wang, Lifang

    2017-11-01

    The East China Sea (ECS) off the Changjiang (Yangtze River) Estuary, located around the near field of the Changjiang plume (CJP) is a hot spot where phytoplankton blooms in the surface water and hypoxias in the subsurface/bottom waters are frequently observed. Based on field observations conducted in summer 2009 and 2011, we examined non-local drivers associated with the initial dissolved oxygen (DO) levels that had significant impact on the development of summer hypoxias in the ECS off the Changjiang Estuary. The bottom water mass therein could be traced isopycnally at 24.2 < σθ < 25.2 back to the vicinity of the Luzon Strait, ∼1300 km upstream, where subsurface Kuroshio water (∼220 m deep with ∼190 μmol DO kg-1) mixed with the South China Sea subsurface water (∼120 m deep with ∼130 μmol DO kg-1). Owing to the difference in DO of these two source water masses, their mixing ratio ultimately determined the initial DO supply to the ECS bottom water that eventually reached the hypoxic zone. This water mass mixture was also subject to biogeochemical alteration during its travel (∼60 days) after it intruded into the ECS at the northeastern tip of Taiwan. Along the pathway of the intruded bottom-hugging water, we found systematic increases in nutrient concentrations and apparent oxygen utilization, or drawdown in DO following Redfield stoichiometry as a result of marine organic matter decomposition. These non-local factors exerted a synergistic control on the initial DO of CJP bottom water promoting hypoxia formation, although the residence time of the CJP bottom water was relatively short (∼11 days). We contend that such far field drivers should be taken into account in order to better predict the future scenarios of coastal hypoxias in the context of global warming.

  10. [Distributions and pollution status of heavy metals in the suspended particles of the estuaries and coastal area of eastern Hainan].

    Science.gov (United States)

    Xin, Cheng-Lin; Ren, Jing-Ling; Zhang, Gui-Ling; Shao, Ya-Ping; Zhang, Guo-Ling; Liu, Su-Mei

    2013-04-01

    The distributions and pollution status of heavy metals in the suspended particles were investigated in the Wanquan and Wenchang/Wenjiao estuaries and the coastal area of eastern Hainan in July 2008. The concentrations of metal elements (Al, Fe, Mn, Cr, Cu, Ni, V, Zn) were determined by ICP-AES after microwave digestion. Multivariate statistical methods (e. g. correlation analysis and principal factor analysis) were used to discuss the major factors controlling the variability of heavy metal concentrations and the pollution status in those areas. There was an obvious variability in particulate metal concentrations from upstream to estuary of both rivers. The concentrations first increased with increasing salinity and then decreased with further increase of the salinity; the concentrations were slightly higher at the coastal area in the east. The variability of particulate metal concentrations reduced significantly after the normalization by Al, indicating the effects of grain size. Enrichment factor calculation results showed that there was heavy metal pollution (especially Cu, Ni) in the Wenchang/Wenjiao River and estuary, while the situation in Wanquan River remained at pristine level. Concentrations of particulate metals in the study area were mainly controlled by source geology and provenance, as well as contamination from the discharge of waste water and biological activity.

  11. Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China.

    Science.gov (United States)

    Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuixuan; Tang, Jingliang

    2013-07-15

    Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan-Shengshan-Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km(2) in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Effects of Spartina alterniflora invasion on soil respiration in the Yangtze River estuary, China.

    Directory of Open Access Journals (Sweden)

    Naishun Bu

    Full Text Available Many studies have found that plant invasion can enhance soil organic carbon (SOC pools, by increasing net primary production (NPP and/or decreased soil respiration. While most studies have focused on C input, little attention has been paid to plant invasion effects on soil respiration, especially in wetland ecosystems. Our study examined the effects of Spartina alterniflora invasion on soil respiration and C dynamics in the Yangtze River estuary. The estuary was originally occupied by two native plant species: Phragmites australis in the high tide zone and Scirpus mariqueter in the low tide zone. Mean soil respiration rates were 185.8 and 142.3 mg CO2 m(-2 h(-1 in S. alterniflora and P. australis stands in the high tide zone, and 159.7 and 112.0 mg CO2 m(-2 h(-1 in S. alterniflora and S. mariqueter stands in the low tide zone, respectively. Aboveground NPP (ANPP, SOC, and microbial biomass were also significantly higher in the S. alterniflora stands than in the two native plant stands. S. alterniflora invasion did not significantly change soil inorganic carbon or pH. Our results indicated that enhanced ANPP by S. alterniflora exceeded invasion-induced C loss through soil respiration. This suggests that S. alterniflora invasion into the Yangtze River estuary could strengthen the net C sink of wetlands in the context of global climate change.

  13. [Preliminary analysis of the characteristics of red tide areas in Changjiang River estuary and its adjacent sea].

    Science.gov (United States)

    Zhou, Mingjiang; Yan, Tian; Zhou, Jingzhong

    2003-07-01

    A review was made on the main environmental characteristics such as currents and water body, diluted water and its turning direction, upwelling, front, nutrients and its sources and plankton community in the Changjiang River estuary and its adjacent sea areas which could affect the growth, migration, assembling, resting and competition of harmful algae to form red tides. Analyses were also conducted to reveal features of the red tides events recorded in this area in terms of time, location and causative species. Some preliminary results from recent cruises carried out in the investigated sea area, where red tides were frequently occurring, were introduced.

  14. Distribution, mass inventories, and ecological risk assessment of legacy and emerging contaminants in sediments from the Pearl River Estuary in China.

    Science.gov (United States)

    Pintado-Herrera, Marina G; Wang, Cuicui; Lu, Jungtai; Chang, Yuan-Pin; Chen, Weifang; Li, Xiaolin; Lara-Martín, Pablo A

    2017-02-05

    This study focused on comparing the occurrences and environmental toxic risks for diverse priority and emerging contaminants (>100 chemicals) in the sediments from the Pearl River Estuary (PRE, China). The most predominant compounds were cationic surfactants, organophosphate flame retardants (e.g., triisobutylphosphate), and polycyclic aromatic hydrocarbons (PAHs), accounting for >75% of the total mass inventory (∼330 metric tons). Wastewater discharges seem to be one of the main sources of pollution in the area, as the highest concentrations (>1000ngg-1 for some chemicals) were reported in the upper part of the PRE (near Guangzhou city) and Macau. Highest levels of ultraviolet (UV) filters, however, were observed in recreational areas, revealing the importance of direct sources (e.g., outdoor activities). An environmental risk assessment showed that PAHs and dichlorodiphenyl dichloroethylene had the highest hazard quotient (HQ) values (up to 233). Nonylphenol, a metabolite from nonionic surfactant, and two UV filters (2-ethyl-hexyl-4-trimethoxycinnamate and 4-methylbenzylidene camphor) also posed a significant threat to benthic species (HQ>1). Further research through the realization of monitoring campaigns and toxicity tests is encouraged, as the exposure of the resident aquatic organisms and human population to these and other emerging chemicals is expected to increase over the years. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Temporal trends of hydrocarbons in sediment cores from the Pearl River Estuary and the northern South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Peng Xianzhi [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehau Street, Guangzhou 510640 (China)], E-mail: pengx@gig.ac.cn; Wang Zhendi [Environmental Science and Technology Centre, Environment Canada, 335 River Road, Ottawa, Ontario K1A 0H3 (Canada); Yu Yiyi; Tang Caiming; Lu Hong; Xu Shiping; Chen Fanrong; Mai Bixian; Chen Shejun; Li Kechang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehau Street, Guangzhou 510640 (China); Yang Chun [Environmental Science and Technology Centre, Environment Canada, 335 River Road, Ottawa, Ontario K1A 0H3 (Canada)

    2008-11-15

    Concentrations and fluxes of unresolved complex mixture of hydrocarbons (UCM) and polycyclic aromatic hydrocarbons (PAHs) were analyzed for two {sup 210}Pb dated sediment cores from the Pearl River Estuary (PRE) and the adjacent northern South China Sea (NSCS). Compound-specific stable carbon isotopic compositions of individual n-alkanes were also measured for identification of the hydrocarbon sources. The historical records of PAHs in the NSCS reflected the economic development in the Pearl River Delta during the 20th century. PAHs in the NSCS predominantly derive from combustion of coal and biomass, whereas PAHs in the PRE are a mixture of petrogenic and pyrogenic in origins. The isotopic profiles reveal that the petrogenic hydrocarbons in the PRE originate predominantly from local spillage/leakage of lube oil and crude oils. The accumulation rates of pyrogenic PAHs have significantly increased, whereas UCM accumulation has slightly declined in the NSCS in the recent three decades. - The accumulation rates of pyrogenic PAHs have significantly increased in the northern South China Sea in the recent decades.

  16. Non-aromatic hydrocarbons in surface sediments near the Pearl River estuary in the South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Gao Xuelu [Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, CAS, Guangzhou 510301 (China) and Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, SOA, Hangzhou 310012 (China)]. E-mail: xlgao@scsio.ac.cn; Chen Shaoyong [Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, CAS, Guangzhou 510301 (China); Xie Xueliang [Shandong Light Industry Engineering School, Qingdao 266112 (China); Long Aimin [Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, CAS, Guangzhou 510301 (China); Ma Fujun [Key Laboratory of Tropical Marine Environmental Dynamics, South China Sea Institute of Oceanology, CAS, Guangzhou 510301 (China)

    2007-07-15

    Surface sediment samples at 4 sites along an offshore transect from outer continental shelf off the Pearl River estuary to the shelf slope region of the northern South China Sea, have been analyzed for total organic carbon (TOC), total nitrogen (TN), solvent extractable organic matter (EOM) and non-aromatic hydrocarbons. TOC, TN and EOM show distinct spatial variations. Their highest values are all recorded at the shelf slope region. EOM varies from 18.70-38.58 {mu}g g{sup -1} dry sediment and accounts for 0.20-0.72% of the TOC contents. The non-aromatic hydrocarbons are an important fraction of EOM. Their contents range from 3.43-7.06 {mu}g g{sup -1} dry sediment. n-Alkanes with carbon number ranging from 15-38 are identified. They derive from both biogenic and petrogenic sources in different proportions. Results of isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. - Anthropogenic activities have influences on the composition of non-aromatic hydrocarbons in the surface sediments of the northern South China Sea outer continental shelf.

  17. Nutrient dynamics in mangrove areas of the Red River Estuary in Vietnam

    NARCIS (Netherlands)

    Wösten, J.H.M.; Willigen, de P.; Tri, N.H.; Lien, T.V.; Smith, S.V.

    2003-01-01

    Nutrient dynamics of mangrove in the 107 kmr large estuary of the Red River Delta in Vietnam are studied using the existing LOICZ-CABARET budget model. The methodology and assumptions underlying this model are described. Input data for evaporation, rainfall, river discharge, and concentrations of

  18. Effects of navigational works on morphological changes in the bar area of the Yangtze Estuary

    NARCIS (Netherlands)

    Jiang, C.; Li, Jiufa; de Swart, H.E.

    2012-01-01

    To improve navigability of the major access channel into Shanghai Harbor, a large-scale Deep Waterway Project was carried out in the North Passage (NP) of the Yangtze Estuary. In this paper, we investigate how the navigational works affected morphological changes of this channel, as well as those of

  19. Analysis on the coastline change and erosion-accretion evolution of the Pearl River Estuary, China, based on remote-sensing images and nautical charts

    Science.gov (United States)

    Wang, Xiao-Zhen; Zhang, Hua-Guo; Fu, Bin; Shi, Ai-qin

    2013-01-01

    Coastline change, erosion-accretion evolution, and their relationship in the Pearl River Estuary (PRE) of China over the past 25 years are analyzed using six remote-sensing images from 1986 to 2011 and two nautical charts. Due to land reclamation in the period from 1986 to 2011, the total length of the PRE coastline increased by 149.2 km, which is equivalent to a growth of 0.57% per year, and the coastal land increased by 251.76 km2, which is equivalent to a growth of 0.23% per year; in addition, water depth change showed a trend in that foreshores became shallower, while deep channels became deeper. Areas where the coastline extended seaward had deposition to some extent, except for deepwater ports. Human activities played an important role in coastline change and erosion-accretion evolution in the PRE, which intervened with the natural variation of coastline and erosion-accretion. In addition, pollutants from the reclamation land became the major factors of coastal water pollution, which may significantly influence the environment of the PRE in a negative way.

  20. A multi-scale integrated modeling framework to measure comprehensive impact of coastal reclamation activities in Yellow River estuary, China.

    Science.gov (United States)

    Xu, Yan; Cai, Yanpeng; Sun, Tao; Tan, Qian

    2017-09-15

    In this paper, an improved multi-scale integrated modeling framework has been established to evaluate coastal reclamation intensity (CRI). About 7 indicators are considered, including ecological degradation intensity (EDI), hydrodynamic disturbance (IHD), engineering types, water quality, economic investment, population growth, and reclaimed land area. Meanwhile, an integrated framework enhanced methods in terms of (a) measuring intensity of ecological degradation process under multi-scale impact, (b) developing the indicator system of CRI, and discussing the driving forces and trends of coastal reclamation, (c) determining fuzzy preference relations of weight and calculating the specific value of CRI with the case study areas of Yellow River estuary from 2000 to 2015. As the result, the CRI has been expanded unceasingly in recent years. The total growth rate from 2000 to 2015 is about 37.97%. It is concluded that CRI has climbed to a higher intensity level in resent 15years. Copyright © 2017. Published by Elsevier Ltd.

  1. [Distribution, sources and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Yangtze estuary and Zhejiang coastal areas].

    Science.gov (United States)

    Mu, Qing-Lin; Fang, Jie; Shao, Jun-Bo; Zhang, Qing-Hong; Wang, Xiao-Hua; Huang, Bei

    2015-03-01

    PAHs contents of surface sediments were tested from 62 sampling sites of the Yangtze River estuary and Zhejiang coastal zone in 2013. The results showed that: 16 kinds of PAHs, which are listed as priority pollutants by EPA, were found in all the samples. The total PAHs level (dry weight) reached 31. 8-384 μg x kg(-1) and the average amount was 131.1 μg x kg(-1). The distribution of PAHs was affected by terrigenous input and point source pollution, the high-value zones were found at 2# sampling site of the Yangtze River estuary and 21# sampling site of Ningbo. Compared with other sea areas, the survey sea area was at a low PAHs pollution level. PAHs were primarily tetracyclic or tricyclic, and source analysis showed that most of PAHs were originated from combustion of wood and coal. Based on the Sediment Quality Guidelines (SQGs), the assessment result showed that the PAHs content of surface sediments from survey sea area was at a relatively low level of ecological risk; While according to the assessment result of the Sediment Quality Standards (SQSs), PAHs pollution of surface sediments from survey sea area displayed an "Obviously negative ecological effect" to some extent, and some countermeasures are required to control and eliminate pollutions.

  2. Spartina alterniflora invasion increases soil inorganic nitrogen pools through interactions with tidal subsidies in the Yangtze Estuary, China.

    Science.gov (United States)

    Peng, Rong Hao; Fang, Chang Ming; Li, Bo; Chen, Jia Kuan

    2011-03-01

    Invasive alien plants increase both plant N and soil inorganic N pools in many terrestrial ecosystems. This is believed to be the result of altered plant-soil-microbe feedbacks that accelerate N cycling. However, it may also be due to the greater ability of invasive species to uptake lateral N subsidies that can modify ecosystem N dynamics. We conducted manipulative field experiments to determine the impact of smooth cordgrass (Spartina alterniflora) invasion on the N cycling of salt marsh ecosystems in the Yangtze Estuary, China. The results showed that the aboveground plant N and soil inorganic N pools in S. alterniflora marshes, 14.39 and 3.16 g N m(-2), were significantly higher than those in native common reed (Phragmites australis) marshes, 11.61 and 2.29 g N m(-2). These increases after invasion were explained by a significantly higher uptake of dissolved inorganic N (DIN) from tidal subsidies in S. alterniflora marshes (6.59 g N m(-2)) than from those in P. australis marshes (1.61 g N m(-2)), and not by soil organic N mineralization, which was not significantly different between S. alterniflora (6.45 g N m(-2)) and P. australis marshes (6.84 g N m(-2)) during the growing season. Our study indicated that the ecosystem engineering effects of S. alterniflora, which increases the interception of external N input, can be an alternative mechanism that increases plant N and soil inorganic N pools--especially in ecosystems with ample anthropogenic N subsidies, such as the coastal wetlands of China.

  3. Tissue distribution and fate of persistent organic pollutants in Indo-Pacific humpback dolphins from the Pearl River Estuary, China.

    Science.gov (United States)

    Gui, Duan; Yu, Riqing; He, Xuan; Tu, Qin; Wu, Yuping

    2014-09-15

    Eleven persistent organic pollutant (POP) compounds including ∑PCBs, ∑DDTs, ∑HCHs, aldrin, mirex, endrin, ∑CHLs, dieldrin, HCB, heptachlor and pentachlorobenzene were measured in the kidney, liver, muscle, melon and other tissues of Sousa chinensis stranded on the western coast of the Pearl River Estuary in China during 2007-2013. For most parameters of POPs measured, melon tissues contained the highest mean concentrations with the exception of aldrin, which was higher in the kidney and liver tissues. The concentrations of PCBs, DDTs, heptachlor and endrin in the melon tissue exhibited significant correlations with body length, whereas PCBs and heptachlor also displayed significant regression with age. Our studies showed hepatic concentrations of ∑DDTs, ∑HCHs and mirex in S. chinensis were generally higher than those found in cetaceans from other geographic locations. The high levels of POP residues in the testis of one male dolphin suggested an increasing risk of infertility in the species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Distribution and mobility of copper, zinc and lead in plant-sediment systems of Quanzhou Bay estuary, China.

    Science.gov (United States)

    Li, Yu-Hong; Hu, Hong-You; Liu, Jing-Chun; Wu, Gui-Lan

    2010-03-01

    The distribution, mobility and potential risks of Cu, Zn, and Pb in four typical plant-sediment co-systems of the Quanzhou Bay estuary wetland in southeast China were investigated using a sequential extraction procedure. The results show that the sediments were moderately or heavily contaminated with Zn and Pb in all four plant communities, and the plant-sediment systems could act as a sink for the heavy metals. In all investigated sediments, only a small proportion of measured heavy metals were distributed in exchangeable fraction and carbonate fraction, while the reducible fraction contained the highest amount of Zn and Pb of the total readily bioavailable fractions, and the oxidizable fraction exhibited a higher retention capacity for Zn and Cu, but lower for Pb. Alternanthera philoxeroides had the best ability to accumulate heavy metals among the four species. Phragmites communis was quite tolerant to Zn and Pb and had a good capability to transfer Zn and Pb. Aegiceras corniculatum seems to be effective in resisting heavy metal pollution, and therefore cannot serve as an indicator of contamination. The urgent need for many local enterprises is to carry out high-tech cleaner production to reduce the emission of pollutants and achieve a resource-economical and environment-friendly development.

  5. Estimation of chlorophyll-a concentration in estuarine waters: case study of the Pearl River estuary, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanzhi; Lin Hui [Institute of Space and Earth Information Science, Yuen Yuen Research Centre for Satellite Remote Sensing, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Chen, Chuqun [South China Institute of Oceanology, Chinese Academy of Sciences, Guangzhou (China); Chen Liding [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing (China); Zhang Bing [Center for Earth Observation and Digital Earth, Chinese Academy of Sciences, Beijing (China); Gitelson, Anatoly A, E-mail: yuanzhizhang@cuhk.edu.hk [Center for Advanced Land Management Information Technologies (CALMIT), School of Natural Resources, University of Nebraska-Lincoln (United States)

    2011-04-15

    The objective of this work is to estimate chlorophyll-a (chl-a) concentration in the Pearl River estuary in China. To test the performance of algorithms for the estimation of the chl-a concentration in these productive turbid waters, the maximum band ratio (MBR) and near-infrared-red (NIR-red) models are used in this study. Specific focus is placed on (a) comparing the ability of the models to estimate chl-a in the range 1-12 mg m{sup -3}, which is typical for coastal and estuarine waters, and (b) assessing the potential of the Moderate Resolution Imaging Spectrometer (MODIS) and Medium Resolution Imaging Spectrometer (MERIS) to estimate chl-a concentrations. Reflectance spectra and water samples were collected at 13 stations with chl-a ranging from 0.83 to 11.8 mg m{sup -3} and total suspended matter from 9.9 to 21.5 g m{sup -3}. A close relationship was found between chl-a concentration and total suspended matter concentration with the determining coefficient (R{sup 2}) above 0.89. The MBR calculated in the spectral bands of MODIS proved to be a good proxy for chl-a concentration (R{sup 2} > 0.93). On the other hand, both the NIR-red three-band model, with wavebands around 665, 700, and 730 nm, and the NIR-red two-band model (with bands around 665 and 700 nm) explained more than 95% of the chl-a variation, and we were able to estimate chl-a concentrations with a root mean square error below 1 mg m{sup -3}. The two- and three-band NIR-red models with MERIS spectral bands accounted for 93% of the chl-a variation. These findings imply that the extensive database of MODIS and MERIS images could be used to quantitatively monitor chl-a in the Pearl River estuary.

  6. Sources and preservation of organic matter in recent sediment from the Changjiang (Yangtze River Estuary, China

    Directory of Open Access Journals (Sweden)

    Lü Xiaoxia

    2006-03-01

    Full Text Available The vertical distributions of bulk and molecular biomarker compositions in the samples from four sediment cores of the Changjiang (Yangtze River Estuary were determined. The changes in the bulk and molecular compositions with depth suggest that there have been recent changes in the marine autogenic and terrigenous supply. In the site at the boundary of the turbidity maximum (Site 8 and the most southern site (Site 26, the autogenic and allochthonous inputs make almost the same contribution to sedimentary organic matter. In the site close to the river mouth (Site 11, the organic matter mainly comes from the terrestrial input carried by the Changjiang water, whereas, in the most eastern site (Site 17, the organic matter consists of a mixture of recent and ancient Changjiang delta sedimentary residues. Significant downcore fluctuations were observed in the patterns of the bulk and molecular compositions, as well as in several biomarker ratios, which also indicates the different anoxic conditions at different depths of the core besides the source variation. In addition, the distributions of molecular compounds show that the organic matter is a mixture of immature and mature in the sediments of the four cores, which further indicates that the microbial activity is active in anoxic conditions, especially in the surface sediment. The vertical distributions of molecular compounds also show that the autogenic marine organic matter is more easily degraded, and that the molecular compounds evolve from unstable steric configurations to stable ones in the early diagenetic processes.

  7. Diurnal variation of nitric oxide emission flux from a mangrove wetland in Zhangjiang River Estuary, China

    Science.gov (United States)

    Chen, Juan; Wu, Fei-Hua; Xiao, Qiang; Yang, Zhang-Hua; Huang, Sheng-Kai; Wang, Jian; Wu, Yu-Guang; Dong, Xue-Jun; Pei, Zhen-Ming; Zheng, Hai-Lei

    2010-12-01

    The diurnal variation of nitric oxide (NO) emission fluxes from a Kandelia obovata and Avicennia marina mangrove wetland were studied in the Zhangjiang River Estuary Mangrove National Nature Reserve using a dynamic chamber-based technique and a chemiluminescent analyzer. Results from field experiments show that NO emission from K. obovata and A. marina sampling sites reached maximal values of 1.07 ng N m -2 s -1 and 1.23 ng N m -2 s -1, respectively after the night tide. Meanwhile NO emission maintained at a steady lower level in daytime for both wetland sites. In laboratory experiments, NO emission from the mangrove wetland soil samples treated with simulated tides in the darkness exhibited higher values than those in the light, therefore it seems that tides and darkness could increase NO emission from mangrove wetlands, while intensive light, high temperature, and dryness in the daytime decreased NO emission. Compared with K. obovata soil samples, the diurnal average NO emission rate of the A. marina site was significantly higher, which was closely related to relatively higher diurnal average CO 2 emission rate, soil available nitrogen content and soil net nitrification rate of the A. marina site. Moreover, soil samples of the A. marina site were more responsive to simulated tides and the addition of nitrogen than those of the K. obovata site.

  8. Heavy metal distribution of natural and reclaimed tidal riparian wetlands in south estuary, China.

    Science.gov (United States)

    Zhang, Honggang; Cui, Baoshan; Zhang, Kejiang

    2011-01-01

    We evaluated the distribution and accumulation of Cd, Cr, Cu, Ni, Pb and Zn in two plant species (Scirpus tripueter Linn. and Cyperus malaccensis Lam.), in water and soils sampled from the reclaimed tidal riparian wetlands (RTRWs) and the natural riparian wetlands (NRWs) in the Pearl River Estuary (PRE). The results showed that the concentrations of studied heavy metals in soils exceeded the eco-toxic threshold recommended by US EPA. The concentrations of Cd, Cr and Zn in plants may lead to toxic effects. The heavy metal concentrations were high in water and low in soils of RTRWs compared with that in the NRWs. The accumulation of heavy metals in the roots of plants was higher in NRWs than those in RTRWs while the opposite result was found for heavy metal accumulation in shoots. Based on the bioaccumulation and translocation factors, the plants in NRWs had a higher capacity to accumulate heavy metals while higher abilities to transport heavy metals from roots to shoots were observed in RTRWs. Heavy metal contaminations in RTRWs were dominated by anthropogenic sources from both side uplands and river water, whereas in NRWs, the metal accumulations were simultaneously affected by anthropogenic and natural factors

  9. Heavy metal fractions and ecological risk assessment in sediments from urban, rural and reclamation-affected rivers of the Pearl River Estuary, China.

    Science.gov (United States)

    Zhang, Guangliang; Bai, Junhong; Xiao, Rong; Zhao, Qingqing; Jia, Jia; Cui, Baoshan; Liu, Xinhui

    2017-10-01

    Rapid urbanization and reclamation processes in coastal areas have resulted in serious pollution to the aquatic environment. Less is known on the geochemical fractions and ecological risks in river sediment under various human activities pressures, which is essential for addressing the connections between heavy metal pollution and anthropogenic influences. River sediments were collected from different landscapes (i.e., urban, rural and reclamation areas) to investigate the impacts of urbanization and reclamation on the metallic pollution levels and ecological risks in the Pear River Estuary of China. Results showed that Cd, Zn and Cu with high total contents and geoaccumulation index (Igeo) were the primary metals in the Peal River sediments. Generally, urban river sediments, especially the surface sediment layer (0-10 cm), exhibited higher metallic pollution levels. As for geochemical fractions, reducible and residual fractions were the dominant forms for six determined metals. And the percentage of heavy metals bound to Fe-Mn oxides decreased with increasing soil depth but the reverse tendency was observed for residual fractions. Compared with rural river sediments, heavy metals were highly associated with the exchangeable and carbonate fractions in both urban and reclamation-affected river sediments, suggesting that anthropogenic activities mainly increased the active forms of metals. Approximately 80% of Cd existed in the non-residual fraction and posed medium to high ecological risk according to the risk assessment code (RAC) values. The redundancy analysis (RDA) revealed that both urbanization and reclamation processes would cause similar metallic characteristics, and sediment organic matter (SOC) might be the prominent influencing factor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Human-environment sustainable development of rural areas in China

    Science.gov (United States)

    Zhao, Lei; Zhu, Hongbing; Hu, Shanfeng

    2017-05-01

    Human-environment sustainable development has become the important issue of rural transformation development in China. This paper analyses the development status of rural sustainability in China, and also presents the challenges facing the sustainability from the economic, social and environmental levels, including land and energy efficiency, solid waste, water and other types of environmental pollution. At last, the paper proposes the measures to establish the sustainable and liveable rural areas in China, like raising rural community awareness of sustainable development thinking; improving resource efficiency and new energy; and creating rural green industries and green products.

  11. Seasonal dynamics of particulate organic matter and its response to flooding in the Pearl River Estuary, China, revealed by stable isotope (δ13C and δ15N) analyses

    Science.gov (United States)

    Ye, Feng; Guo, Wei; Shi, Zhen; Jia, Guodong; Wei, Gangjian

    2017-08-01

    Nine cruises were conducted on a seasonal basis from 2013 to 2015 to investigate the spatial distribution and seasonal variability of δ13C and δ15N in particulate organic matter (POM), and its response to flooding in the Pearl River Estuary (PRE), south China. Our study reveals highly variable isotope ratios between seasons in this subtropical estuary, following seasonal climatic and hydrological cycles. Wet seasons had more isotopically depleted δ13C values, indicating the dominance of terrestrial and freshwater algae POM, whereas the contribution from marine phytoplankton (16%-59%) was higher during the dry seasons. In contrast, δ15N exhibited a sharp increase (up to 17.6‰) at low salinities (0-5) during high flow seasons. This was consistent with high NO3- concentrations, reflecting phytoplankton and bacteria assimilation of δ15N enriched-NO3- as well as notable isotope fractionation during microbial mineralization. There was little annual variability in δ13C over the 2 year period; however, particulate nitrogen (PN) exhibited lower concentrations but more enriched isotope values in 2015 than in 2014. This can be best explained by temperature-modulated biological processing of particulate organic nitrogen, partially due to different biogeochemical responses during normal (2014) and strong El Niño (2015) years. After flooding in June 2015, terrestrial organic matter and freshwater phytoplankton were the major components of POM within the estuary and shelf areas, whereas marine phytoplankton was the dominant component in the adjacent coastal waters with mid-salinities (10 10 μg L-1) and δ13C-enriched but δ15N-depleted POM.

  12. Developing and sustainably utilize the coastal mudflat areas in China.

    Science.gov (United States)

    Long, Xiao-Hua; Liu, Li-Ping; Shao, Tian-Yun; Shao, Hong-Bo; Liu, Zhao-Pu

    2016-11-01

    Coastal mudflat areas are regarded as the important reserve land resource in China. Rational exploitation and development of the mudflat areas can relieve the stress of inadequate land resources. Probing into the developing models of resource exploitation of coastal tidal mudflats is one of the important components of achieving the sustainable development in the coastal areas. Therefore, the development history of coastal mudflats after 1950s in China is briefly introduced in this paper. Then, the status in quo of the modes of development and utilization of coastal mudflat in China the paper is reviewed with a special attention payed to the agricultural use of coastal resource, especially halophytes and improved salt-tolerant varieties planting, agricultural dyke pond and coastal saline-alkali soil remediation. Based on related research frontier, sustainable developmental prospects of these coastal areas are presented as well. Copyright © 2016. Published by Elsevier B.V.

  13. Total mercury flux and offshore transport via submarine groundwater discharge and coal-fired power plant in the Jiulong River estuary, China.

    Science.gov (United States)

    Wang, Jigang; Liu, Qian; Chen, Jinmin; Chen, Hongzhe; Lin, Hui; Sun, Xiuwu

    2018-02-01

    A mass balance of total mercury (Hg T , dissolved+particulate) is constructed for China's Jiulong River estuary based on measured Hg T concentrations in the surface water, sediment, porewater, and groundwater for May, August, and November 2009, combined with data from the literature. The Hg T mass budget results show that the dominant source (39-55%) is desulfurized seawater discharged from the Songyu coal-fired power plant. Submarine groundwater discharge (SGD)-derived Hg T flux into the estuary is equivalent to 8-58% of the Hg T input from the Jiulong River, which is remarkable when compared with SGD-derived Hg T fluxes reported in coastal systems worldwide. Hence, SGD is a significant pathway for the transport of Hg T into the Jiulong River estuary. The primary Hg T sinks is export to the Taiwan Strait (53-88%), which has important environmental implications on the Hg cycling and marine ecosystems in marginal seas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Estuaries 1

    OpenAIRE

    Battey, B.

    2016-01-01

    'Estuaries 1' can be viewed at https://vimeo.com/202629040 'Estuaries 1' is the first of the Estuaries series of audiovisual compositions, which explore the expressive potentials of the author's Variable-Coupled Map Networks and OptiNelder methods for generative music and image. It evokes an 'unstable stasis' through processes that are always on the edge of destabilisation.

  15. Estuaries 2

    OpenAIRE

    Battey, B.

    2017-01-01

    'Estuaries 2' is the second of the author's Estuaries series of audiovisual compositions, which explore the expressive potential of the authors Variable-Coupled Map Networks and OptiNelder methods for generative music and images. 'Estuaries 2' focuses on dialog between grid-based logic and all-over textures with random distributions,

  16. Bioaccumulation of heavy metals in fish and Ardeid at Pearl River Estuary, China.

    Science.gov (United States)

    Kwok, C K; Liang, Y; Wang, H; Dong, Y H; Leung, S Y; Wong, M H

    2014-08-01

    Sediment, fish (tilapia, Oreochromis mossambicus and snakehead, Channa asiatica), eggs and eggshells of Little Egrets (Egretta garzetta) and Chinese Pond Herons (Ardeola bacchus) were collected from Mai Po Ramsar site of Hong Kong, as well as from wetlands in the Gu Cheng County, Shang Hu County and Dafeng Milu National Nature Reserve of Jiangsu Province, China between 2004 and 2007 (n=3-9). Concentrations of six heavy metals were analyzed, based on inductively coupled plasma optical emission spectrometry (ICP-OES). Significant bioaccumulations of Cd (BAF: 165-1271 percent) were observed in the muscle and viscera of large tilapia and snakehead, suggesting potential health risks to the two bird species, as the fishes are the main preys of waterbirds. Significant (p<0.01) linear relationships were obtained between concentrations of Cd, Cr, Cu, Mn, Pb and Zn in the eggs and eggshells of various Ardeid species, and these regression models were used to extrapolate the heavy metal concentrations in the Ardeid eggs of Mai Po. Extrapolated concentrations are consistent with data in the available literature, and advocate the potential use of these models as a non-invasive sampling method for predicting heavy metal contamination in Ardeid eggs. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. [Distribution characteristics and source apportionment of dichloro-diphenyl-tricgloroethanes in Zhangiiang River Estuary of Fujian, China].

    Science.gov (United States)

    Luo, Dong-lian

    2014-12-01

    The concentration, distribution and transfer of dichloro-diphenyl-tricgloroethanes (DDTs) in the surface layer water, sediments and aquatic organisms from the Zhangjiang River Estuary were investigated using GC-ECD method. The possible sources were assessed based on the distribution and composition characteristics of DDTs together with the investigation results of dicofol. The results showed that the concentration of DDTs in surface layer water ranged from ND (not detected) to 20.1 ng x L(-1) with an average of 10.5 ng x L(-1) in dry period, from ND to 45.2 ng +/- L(-1) with an aver- age of 28.3 ng x L(-1) in wet period, and from ND to 18.8 ng x L(-1) with an average of 5.03 ng x L(-1) in level period. Concentration of DDTs in surface sediment (dry mass) ranged from 1.87 ng x g(-1) to 144 ng x g(-1) with an average of 17.3 ng x g(-1), and that in 11 species of aquatic organisms ranged from 1.09 ng x g(-1) to 432 ng x g(-1) with an average of 37.0 ng x g(-1). Compared to other areas, the residues of DDTs in the Zhangjiang River Estuary were at the medium level. The accumulation factors of DDTs in sediment and aquatic organisms were 1185 and 2534, respectively. The capacities for DDTs accumulation were in the order of fish>shellfish>shrimp>aquatic plants. The concentrations of DDTs showed downtrend along the Zhangjiang River, indicating that the residues of DDTs mainly came from terrigenous pollution rather than from the release of antifouling agent of ships. Based on the composition profile, DDTs mainly came from the early residues. However, the highest value of dicofol was recently detected both in the water and sediment of Y8 station, which suggested that new DDTs inputs at the Y8 station might be related to the recent usage of dicofol.

  18. Seasonal and spatial variability of appendicularian density and taxonomic composition in the Caravelas Estuary (Northeastern Brazil and adjacent coastal area

    Directory of Open Access Journals (Sweden)

    Pedro Freitas de Carvalho

    2010-02-01

    Full Text Available This study aimed to identify and assess the seasonal and spatial variations of the appendicularians in the Caravelas River estuary and the adjacent coastal area. Samples were taken during 12 campaigns over five years (2001 and 2003-2006. Ten species were identified; the most abundant were Oikopleura dioica, Oikopleura rufescens, and Oikopleura longicauda. These species represented more than 95% of the total numbers of appendicularians. The remaining species were less frequent and occurred in low densities. The mean density of appendicularians found at the coastal stations (804 ind.m-3. was higher than in the estuary (66 ind.m-3. However, the differences observed between the estuary and coastal stations were not significant (p=0.54. The samples taken during the dry season showed a higher mean density (587 ind.m-3 than in the rainy season (376 ind.m-3, and the differences between the seasons were statistically significant (p=0.004.Esse trabalho teve como objetivo identificar e avaliar as variações espaciais e sazonais das apendiculárias no estuário do rio Caravelas e área costeira adjacente (17º35' - 18º22' S e 39º8' - 39º55'W. As coletas foram realizadas em 12 campanhas durante cinco anos (2001 e 2003 - 2006. Foram identificadas dez espécies, sendo que Oikopleura dioica, O. rufescens e O. longicauda foram as mais abundantes. Estas três espécies representaram mais de 95% do total de apendiculárias coletadas. As outras espécies foram menos freqüentes e ocorreram em baixas densidades. A densidade média de apendiculárias encontrada nas estações e costeiras (804 ind.m-3 foi maior que na de estuário (158 ind.m-3. As diferenças encontradas entre as estações de estuário e costeiras não foram significativas (p=0,73. As campanhas realizadas durante o período seco apresentaram densidade média (587 ind.m-3 maior que do período chuvoso (376 ind.m-3. As diferenças entre os períodos chuvoso e seco foram estatisticamente

  19. Polybrominated diphenyl ethers in birds from Chongming Island, Yangtze estuary, China: insight into migratory behavior.

    Science.gov (United States)

    Huang, Kai; Lin, Kuangfei; Guo, Jie; Zhou, Xiaoyu; Wang, Junxia; Zhao, Jianhua; Zhou, Peng; Xu, Feng; Liu, Lili; Zhang, Wei

    2013-06-01

    Sum-PBDEs concentrations in shorebirds and Anatidae ducks muscles from Chongming Dongtan National Nature Reserve ranged from 21-324 to 14-159ngg(-1) lw, respectively. PBDEs were detected in muscles of all the studied species. Compared with flyways around the world, migratory waterbirds on the East Asian-Australasian flyway exhibited lower PBDEs burdens than those reported on Black Sea-Mediterranean flyway in Europe and Pacific, Atlantic, Mississippi flyway in North America. Residential Eurasian tree sparrow samples indicated few PBDE products were used in Chongming Island developed in the idea of world famous eco-island. There was no significant difference in PBDEs concentrations between shorebirds and ducks. However, PBDEs composition varied between them. BDE 209 (29-44%) contributed to sum-PBDEs more than BDE 47 (17-19%) in muscles of ducks, while BDE 47 was the predominant congener in shorebirds contributing 32-48%. Stable nitrogen and carbon isotopes and stomach content analysis indicated shorebirds and ducks had the same dietary composition, but showed different preference to bivalves, gastropods and crustaceans for shorebirds and aquatic plant material for ducks. Migratory species had inherent migratory routes and thus had exposure to PBDEs during their stay in breeding grounds, stopover sites and wintering grounds with high use of different commercial PBDE mixtures. Higher percentage of BDE 209 in ducks than shorebirds suggested that breeding ranges and wintering grounds of ducks comprise wetlands in inland and coastal China and Korea where decaBDEs pollution was serious in Asian-Pacific region. Our findings reveal the influence of migratory behavior on PBDEs distribution in migratory waterbirds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Composition profiles, levels, distributions and ecological risk assessments of trihalomethanes in surface water from a typical estuary of Bohai Bay, China.

    Science.gov (United States)

    Niu, Zhiguang; Li, Xiaonan; Zhang, Ying

    2017-04-15

    To characterize the spatiotemporal distribution and potential ecological risk for trihalomethanes (THMs) in the surface water of a river estuary, surface water samples were collected over five consecutive months (from March to July 2016) from four sites in the Haihe River estuary of Bohai Bay. The potential ecological risks of THMs were evaluated quantitatively based on a species sensitivity distribution (SSD) model. The results demonstrate that trichloromethane (TCM) was the predominant THM in surface water of the Haihe River estuary (2.93±1.98μg/L) followed by tribromomethane (TBM) (0.42±0.33μg/L), bromodichloromethane (BDCM) (0.14±0.06μg/L) and dibromochloromethane (DBCM) (0.09±0.10μg/L). The concentration of TCM was higher in summer than that in spring, while TBM displayed the opposite trend. The TCM concentration decreased from the estuary to the adjacent sea. However, the levels of TBM and DBCM in the adjacent sea were higher than those in the estuary. The ecological risks of THMs in surface water of Haihe River were notably low, and the ecological risks of THMs in freshwater were generally higher than those in seawater. Compared with other contaminants in water and surface sediment from rivers and coastal areas, the ecological risk levels of THMs in surface water can be considered low. This study is a contribution to the progress of ecological risk assessment of THMs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Tree cover changes in- and ouside protected areas in China

    DEFF Research Database (Denmark)

    Nüchel, Jonas; Bøcher, Peder Klith; Svenning, J.-C.

    Protected areas (PAs) are one of the main tools in the global conservation of biodiversity and ecosystems. This is also the case for China. However, only few studies have investigated protected areas´ efficiency in maintaining ecosystems and biodiversity. One way to investigate this is to look...... at tree cover changes inside the PAs and on the surrounding areas. Using MODIS Vegetation Continuous Fields we mapped tree-cover changes between 2000-2010 in- and outside PAs in China. The PAs were extracted from the World Database on Protected Areas. Our aim were to investigated the following four......) Does the efficiency of the PAs depend on general human pressures in the region? We used a paired t-test to investigate if there was a significant change in tree cover between the protected areas and the 10-km zones surrounding them. There were both negative and positive tree cover changes inside...

  2. Spatial variation and toxicity assessment for heavy metals in sediments of intertidal zone in a typical subtropical estuary (Min River) of China.

    Science.gov (United States)

    Sun, Zhigao; Li, Jiabing; He, Tao; Ren, Peng; Zhu, He; Gao, Hui; Tian, Liping; Hu, Xingyun

    2017-10-01

    Sediment samples were collected in five marshes (C1, Phragmites australis marsh; C2, P. australis and Cyperus malaccensis marsh; C3, C. malaccensis marsh; C4, Spartina alterniflora marsh; and C5, Cyperus compressus marsh) respectively along two typical transects (T1 and T2) extending from the vegetated marsh to the mudflat in a typical subtropical estuary (Min River) of China in July 2015 to investigate the spatial variation and toxicity of heavy metals (Pb, Cr, Cu, Zn, and Ni) in intertidal zone. Results showed that the concentrations of heavy metal in surface sediments of the two transects were in the order of Zn > Cr > Pb > Cu > Ni and slightly decreased from the land to the sea except for Pb and Zn. The levels of the five metals at C5 marsh were generally the lowest, while those of Pb, Cr, and Zn at C2 marsh were the highest. The vertical variations of Pb, Cr, and Zn concentrations in profiles differed among marshes or transects, and in most cases, there was no evidence of sediment organic matter (SOM) contributing to the sorption of significant amount of metals in sediments along the two transects, while grain composition was a primary factor controlling the spatial variations of metals. Both the vertical distributions of Cu and Ni levels among marshes or transects showed little fluctuation, which could be better explained by the effects of sulfur on the solubility and mobility of the two metals in profiles. Heavy metal levels in sediments of the Min River estuary were much higher compared with most estuaries in Asia, Europe, Africa, and South America. The sediments in intertidal zone of the Min River estuary were moderately polluted by the five metals, and particularly, Ni was identified as heavy metal of primary concern. Both Ni and Pb in sediments of the intertidal zone showed high potential toxicity and high contributions to the sum of the toxic units (ΣTUs). In future, the metal pollutions in intertidal zone of the Min River estuary might be more

  3. Amazonas estuary area: one of the last frontiers for giant oil and gas accumulations in the Brazilian offshore basins

    Energy Technology Data Exchange (ETDEWEB)

    Mello, M.R.; Silva, S.R.P.; Maciel, R.R.; Miranda, F.P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Mosmann, R.

    2000-07-01

    In most areas of the South Atlantic, exploration in deep-water has just begun. Geological data suggest that similar tectonic-stratigraphic evolution, organic-rich facies and oil types occurs across the South Atlantic petroleum provinces, allowing the application of a unified model for hydrocarbon provenance in counterpart basins. Such similarities, when interpreted in a palaeographic context, can help reveal details of unexplored petroleum systems. This paper, based in an integrated multidisciplinary approach and using technologies ranging from remote sensing to molecular geochemistry, suggests the Amazonas estuary area, as one of the most promising oil/gas-prone provinces to find giant oil and gas accumulations in the Brazilian continental margin. Throughout the tectonic-stratigraphic framework, regional facies variations of Upper Cretaceous and Tertiary source rocks are consistent with a marine carbonate and marine deltaic model for source rock deposition. The origin of the hydrocarbons, in the area, is related to Upper Cretaceous anoxic global events (Cenomanian to Turonian), and a huge fluvial marine deltaic complex that was formed during the Miocene. The Benue Through and Niger delta oil province are comparable petroleum system analogues. (author)

  4. Fish assemblages in a small temperate estuary on the Argentinian coast: spatial variation, environmental influence and relevance as nursery area

    Directory of Open Access Journals (Sweden)

    Agustín Solari

    2015-09-01

    Full Text Available AbstractThe effects of different environmental variables on the fish community structure were evaluated in a small temperate estuary. The biological and environmental data were collected bimonthly between 2007 and 2009 along the main estuarine axis. Multivariate analyses were applied (CLUSTER, SIMPER, CCA to determine the spatial structure of fish community and to estimate the environmental influence on it. A total of 48 species of "teleost" fishes were observed, with the families Characidae and Sciaenidae presenting the largest number of species, 90% of the catches being juveniles. The fish community was overwhelmingly dominated by one species (Micropogonias furnieri, 88.9%, and only four species contributed more than 1% of total catch (Odontesthes argentinensis5.4%, Brevoortia aurea 1.1%, Paralonchurus brasiliensis 1.1%, and Mugil platanus 1.0%. Estuarine and freshwater stragglers dominated in number of species, followed by freshwater migrants and marine migrants. Three areas with different fish assemblages, with distinctive species and functional guilds, were defined along the main axis. The occurrence and spatial spread of these areas were linked to spatial variation in salinity, which was consistently influenced by discharge from the Río de la Plata and local precipitation. The results highlight the importance of shallow environments as nursery areas and permit emphasis on their susceptibility to environmental changes.

  5. Functional diversity of benthic ciliate communities in response to environmental gradients in a wetland of Yangtze Estuary, China.

    Science.gov (United States)

    Xu, Yuan; Fan, Xinpeng; Warren, Alan; Zhang, Liquan; Xu, Henglong

    2018-02-01

    Researches on the functional diversity of benthic ecosystems have mainly focused on macrofauna, and studies on functional structure of ciliate communities have been based only on trophic- or size-groups. Current research was carried out on the changing patterns of classical and functional diversity of benthic ciliates in response to environmental gradients at three sites in a wetland in Yangtze Estuary. The results showed that changes of environmental factors (e.g. salinity, sediment grain size and hydrodynamic conditions) in the Yangtze Estuary induce variability in species composition and functional trait distribution. Furthermore, increased species richness and diversity did not lead to significant changes in functional diversity due to functional redundancy. However, salt water intrusion of Yangtze Estuary during the dry season could cause reduced functional diversity of ciliate communities. Current study provides the first insight into the functional diversity of ciliate communities in response to environmental gradients. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. About the Climate Ready Estuaries Program

    Science.gov (United States)

    The Climate Ready Estuaries program is a partnership between EPA and the National Estuary Programs to address climate change in coastal areas. It has helped coastal communities prepare for climate change since 2008.

  7. Nitrification and inorganic nitrogen distribution in a large perturbed river/estuarine system: the Pearl River Estuary, China

    Directory of Open Access Journals (Sweden)

    M. Dai

    2008-09-01

    Full Text Available We investigated the spatial distribution and seasonal variation of dissolved inorganic nitrogen in a large perturbed estuary, the Pearl River Estuary, based on three cruises conducted in winter (January 2005, summer (August 2005 and spring (March 2006. On-site incubation was also carried out for determining ammonium and nitrite oxidation rates (nitrification rates. We observed a year-round pattern of dramatic decrease in NH4+, increase in NO3, but insignificant change in NO2 in the upper estuary at salinity ~0–5. However, species and concentrations of inorganic nitrogen at upper estuary significantly changed with season. In winter, with low runoff, the most upper reach of the Pearl River Estuary showed relatively low rates of ammonia oxidation (0–5.4 μmol N L−1 d−1 and nitrite oxidation (0–5.2 μmol N L−1 d−1, accompanied by extremely high concentrations of ammonia (up to >800 μmol L−1 and nitrate (up to >300 μmol L−1. In summer, the upper estuary showed higher nitrification rates (ammonia oxidation rate ~1.5–33.1 μmol N L−1 d−1, nitrite oxidation rate ~0.6–32.0 μmol N L−1 d−1 with lower concentrations of ammonia (<350 μmol L−1 and nitrate (<120 μmol L−1. The Most Probable Number test showed relatively lower nitrifier abundance in summer at most sampling stations, indicating a greater specific nitrification rate per cell in the warm season. Temperature appeared to control nitrification rates to a large degree in different seasons. Spatial variability of nitrification rates appeared to be controlled by a combination of many other factors such as nutrient concentrations, nitrifier abundance and dissolved oxygen (DO concentrations. In addition to aerobic respiration, nitrification contributed significantly

  8. Carbon Sequestration in Reforested Areas in China Since 1970

    Science.gov (United States)

    Chen, J.; Liu, J.; Wang, S.; Sun, R.; Shi, X.; Tian, Q.; Xue, J.; Pan, J.; Kang, E.; Zhu, Q.; Zhou, Y.; Yang, L.; Liu, G.; Chen, M.; Thomas, S.; Bryan, R.; Yin, Y.; MacLaren, V.; Zhou, S.; Feng, X.; Wang, C.; Pan, J.

    2004-05-01

    Since July 2002, a 3-year Canada-China joint project was funded by the Canadian International Development Agency and the Chinese Academy of Sciences to assess the current status of China's forests and the impacts of forestry activities on carbon sequestration. From 1973 to 2001, China's total forested area increased from 122 Mha to 159 Mha, owing to large-scale reforestations for the main purpose of soil erosion control. In this project, four local forest sites in Changbaishan, Heihe, Liping and Xingguo in various regions are chosen for intensive assessments of forest and soil stocks. Ground-based measurements of leaf area index (LAI), net primary productivity (NPP), soil texture, vegetation and soil carbon stocks are used to calibrate models. High-resolution remote sensing images from ASTER and ETM are used to map LAI and NPP of these sites and for upscaling to the whole China based on MODIS and VEGETATION images. Remote sensing techniques and carbon cycle models (BEPS, InTEC) developed in Canada are being adapted to China's ecosystems. Preliminary results suggest that new reforested areas since 1970 are now actively sequester carbon, making the overall forested area as a carbon sink in the last few decades. Efforts are being made to reduce uncertainties in the estimation through incorporating new nation-wide datasets of forest age, soil texture and organic matter, nitrogen deposition, etc. At Changbaishan, Liping and Heihe, integrated assessments are being conducted to investigate the impacts of reforestation (Grain-to-Green) programs on the social and economic status of farmers as well as the ecological environment and land use options to maximize carbon sequestraton.

  9. Application of large capacity air gun in three-dimensional crustal structure exploration of the Pearl River estuary area

    Science.gov (United States)

    Zhang, Xiang; Gong, Xuan; Sun, Jinlong

    2017-06-01

    The air gun source has been widely used as an artificial source in seismic exploration of the sea area because of its simple operation, low risk, automatic continuous operation and almost no influence on the observation environment. In 2015, we carried out the 3-D crustal structural exploration project in the Pearl River estuary, 13 seismic sounding explorations were set up in the sea area, and activated air gun source for more than 12,000 times. Through records of ocean bottom seismograph (OBS) and fixed seismic stations, we found that seismic records of OBS can be clearly identified Pg, PmP, and other phases, the records of the fixed seismic stations can be clearly identified the air gun shot events. The results show that the energy of the air gun shot in this field exploration is quite good, and data can support the study of the three-dimensional structure of the crust in the sea by air gun shot records of seismometers.

  10. Radionulide analyses of ingested water from some estuaries within the coastal area of Akwa Ibom State, Nigeria.

    Science.gov (United States)

    Enyinna, P I; Uboh, U G

    2017-03-20

    Radionuclide analyses of ingested water from three selected estuaries within the coastal areas of Akwa Ibom State, Nigeria have been carried out. Fifteen water samples collected at strategic points from the estuaries were pre-treated and each placed on the sodium iodide NaI (Tl) -model 802 detector for 3600 s to obtain the gamma radiation count rate. The activity concentrations and other radiological risk parameters were computed. The effective dose rate of radiation due to ingested water (E.D.I.W.) ranged between 0.25 and 1.86 mSv yr-1, the effective equivalent dose rate due to absorbed radiation in air (Deq) ranged between 0.0065 and 0.0369 mSv yr-1 and the total equivalent dose rate of radiation ranged between 0.257 and 1.87 mSv yr-1. The E.D.I.W exceeded the International Commission on Radiological Protection (ICRP) permissible limit of 0.1 mSv yr-1 set for ingested radionuclides from food. Most surveyed points had their total equivalent dose rate of radiation greater than the ICRP permissible dose limit of 1 mSv yr-1 for radiation exposure from all internal and external sources. The annual gonadal dose equivalent ranged between 0.008 and 0.041 mSv yr-1 and are below the world average value of 0.3 mSv yr-1. The excess lifetime cancer risk ranged between 0.7 × 10-3 and 5.07 × 10-3 and are above the world average value of 0.29 × 10-3. The elevation of most of the radiation risk parameters over the standard limits shows that oil production activities may have raised the background radiation levels of the area. This research also revealed that computing only the Deq and neglecting the E.D.I.W would mean under estimating the radiation doses received by an impacted person by 97.4%-98.3%. Water consumed from these sources could enhance the radionuclide content and the percentage probabilities of developing cancer by impacted persons.

  11. Capacity of humic substances to complex with iron at different salinities in the Yangtze River estuary and East China Sea.

    Science.gov (United States)

    Yang, Rujun; Su, Han; Qu, Shenglu; Wang, Xuchen

    2017-05-03

    The iron binding capacities (IBC) of fulvic acid (FA) and humic acid (HA) were determined in the salinity range from 5 to 40. The results indicated that IBC decreased while salinity increased. In addition, dissolved iron (dFe), FA and HA were also determined along the Yangtze River estuary's increasing salinity gradient from 0.14 to 33. The loss rates of dFe, FA and HA in the Yangtze River estuary were up to 96%, 74%, and 67%, respectively. The decreases in dFe, FA and HA, as well as the change in IBC of humic substances (HS) along the salinity gradient in the Yangtze River estuary were all well described by a first-order exponential attenuation model: y(dFe/FA/HA, S) = a0 × exp(kS) + y0. These results indicate that flocculation of FA and HA along the salinity gradient resulted in removal of dFe. Furthermore, the exponential attenuation model described in this paper can be applied in the major estuaries of the world where most of the removal of dFe and HS occurs where freshwater and seawater mix.

  12. Diversity and spatial distribution of sediment ammonia-oxidizing crenarchaeota in response to estuarine and environmental gradients in the Changjiang Estuary and East China Sea.

    Science.gov (United States)

    Dang, Hongyue; Zhang, Xiaoxia; Sun, Jin; Li, Tiegang; Zhang, Zhinan; Yang, Guanpin

    2008-07-01

    Ammonia-oxidizing archaea (AOA) have recently been found to be potentially important in nitrogen cycling in a variety of environments, such as terrestrial soils, wastewater treatment reactors, marine waters and sediments, and especially in estuaries, where high input of anthropogenic nitrogen is often experienced. The sedimentary AOA diversity, community structure and spatial distribution in the Changjiang Estuary and the adjacent East China Sea were studied. Multivariate statistical analysis indicated that the archaeal amoA genotype communities could be clustered according to sampling transects, and the station located in an estuarine mixing zone harboured a distinct AOA community. The distribution of AOA communities correlated significantly with the gradients of surface-water salinity and sediment sorting coefficient. The spatial distribution of putative soil-related AOA in certain sampling stations indicated a strong impact of the Changjiang freshwater discharge on the marine benthic microbial ecosystem. Besides freshwater, nutrients, organic matter and suspended particles, the Changjiang Diluted Water might also contribute to the transport of terrestrial archaea into the seawater and sediments along its flow path.

  13. Historical evolution of mud deposition and erosion in intertidal areas of the Scheldt estuary (Belgium and SW Netherlands)

    OpenAIRE

    C. Wang; Vanlede, J.; Vandenbruwaene, W.; Y. Plancke; Temmerman, S.

    2015-01-01

    The mud dynamics in an estuary are recognized as an important element of estuarine functioning, because increasing suspended sediment concentrations may be both harmful for ecological functions (e.g., biomass production by phytoplankton) and deteriorative for human functions (e.g., by siltation of shipping channels). Considering the potential risk of increase in suspended sediment concentration in the Schelde estuary, this study aims to quantify the mud deposition/erosion in different time pe...

  14. Seasonal and spatial variations in rare earth elements and yttrium of dissolved load in the middle, lower reaches and estuary of the Minjiang River, southeastern China

    Science.gov (United States)

    Zhu, Xuxu; Gao, Aiguo; Lin, Jianjie; Jian, Xing; Yang, Yufeng; Zhang, Yanpo; Hou, Yuting; Gong, Songbai

    2017-09-01

    With the aim of elucidating the spatial and seasonal behaviors of rare earth elements (REEs), we investigated the dissolved REE concentrations of surface water collected during four seasons from middle, lower reaches and estuary of the Minjiang River, southeastern China. The results display that the REE abundances in Minjiang River, ranging from 3.3-785.9 ng/L, were higher than those of many of the major global rivers. The total REE concentrations (ΣREE) were seasonally variable, averaging in 5 937.30, 863.79, 825.65 and 1 065.75 ng/L during second highest flow (SHF), normal flow (NF), low flow (LF) and high flow (HF) season, respectively. The R (L/M) and R (H/M) ratios reveal the spatial and temporal variations of REE patterns, and particularly vary apparently in the maximum turbidity zone and estuary. REE patterns of dissolved loads are characterized by progressing weaker LREEs-enrichment and stronger HREEs-enrichment downstream from middle reaches to estuary during all four seasons. Comparing with NF and LF seasons, in which REE patterns are relatively flat, samples of SHF season have more LREE-enriched and HREE-depleted patterns that close to parent rocks, while samples of HF season are more LREEs-depleted and HREE-enriched. REE fractionations from the middle to lower reaches are stronger in the SHF and HF seasons than those in NF and LF seasons. Generally, spatial and seasonal variations in REE abundance and pattern are presumably due to several factors, such as chemical weathering, mixture with rainfall and groundwater, estuarine mixing, runoff, biological production and mountain river characters, such as strong hydrodynamic forces and steep slopes. The highest Gd/Gd* always occurs at north ports during all four seasons, where most of the large hospitals are located. This suggests Gd anomalies are depended on the density of modern medical facilities. Y/Ho ratios fluctuate and positively correlate to salinity in estuary, probably because of the geochemical

  15. Clay mineralogy and source-to-sink transport processes of Changjiang River sediments in the estuarine and inner shelf areas of the East China Sea

    Science.gov (United States)

    Zhao, Yifei; Zou, Xinqing; Gao, Jianhua; Wang, Chenglong; Li, Yali; Yao, Yulong; Zhao, Wancang; Xu, Min

    2018-02-01

    We examined the source-to-sink sediment transport processes from the Changjiang River to the estuarine coastal shelf area by analyzing the clay mineral assemblages in suspended sediment samples from the Changjiang River catchment and surface samples from the estuarine coastal shelf area following the impoundment of the Three Gorges Dam (TGD) in 2003. The results indicate that the clay mineral compositions throughout the study area are dominated by illite, with less abundant kaolinite and chlorite and scarce smectite. The clay minerals display distinct differences in the tributaries and exhibit obvious changes in the trunk stream compared with the periods before 2003, and the source of sediment has largely shifted to the mid- to lower reaches of the river after 2003. Spatially, the clay mineral assemblages in the estuarine area define two compositionally distinct provinces. Province I covers the mud area of the Changjiang River estuary and the Zhe-Min coastal region, where sediment is primarily supplied by the Changjiang River. Province II includes part of the Changjiang River estuary and the southeastern portion of the study area, where the sediment is composed of terrestrial material from the Changjiang River and re-suspended material from the Huanghe River carried by the Jiangsu coastal current. Moreover, the other smaller rivers in China (including the Oujiang and Minjiang rivers of mainland China and the rivers of West Taiwan) also contribut sediments to the estuarine and inner shelf areas. In general, the clay mineral assemblages in the Changjiang River estuarine area are have mainly been controlled by sediment supplied from upstream of the Changjiang River tributaries. However, since the completion of the TGD in 2003, the mid- to downstream tributaries have become the main source of sediments from the Changjiang catchment into the East China Sea. These analyses further demonstrate that the coastal currents and the decrease in the sediment load of the river

  16. Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

    Science.gov (United States)

    Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo; Bennike, Ole; Hübscher, Christian; Clausen, Ole Rønø

    2017-06-01

    High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels in the period 10.3-9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea-level rise. The estuary existed simultaneously with the occurrence and drainage of the Ancylus Lake. The drainage of this lake occurred through the Dana River (palaeo-Great Belt channel) into the southern Kattegat and then into the study area. The level of the Ancylus Lake in the Baltic Sea region dropped significantly at about 10.2 cal. ka BP at the same time as the estuary developed in the Kattegat region. One outcome of the present study is an enhanced understanding of the Ancylus Lake drainage path. No evidence of major erosion is seen, which indicates non-catastrophic continuous water flow from the south without major drainage events of the Ancylus Lake to the southern Kattegat. During the Littorina transgression, coastal estuarine conditions characterized the Hesselø Bay area where elongated ridges formed a bar system. As the Littorina transgression continued, back-stepping of the bar system and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area.

  17. Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

    Science.gov (United States)

    Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo; Bennike, Ole; Hübscher, Christian; Clausen, Ole Rønø

    2017-12-01

    High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels in the period 10.3-9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea-level rise. The estuary existed simultaneously with the occurrence and drainage of the Ancylus Lake. The drainage of this lake occurred through the Dana River (palaeo-Great Belt channel) into the southern Kattegat and then into the study area. The level of the Ancylus Lake in the Baltic Sea region dropped significantly at about 10.2 cal. ka BP at the same time as the estuary developed in the Kattegat region. One outcome of the present study is an enhanced understanding of the Ancylus Lake drainage path. No evidence of major erosion is seen, which indicates non-catastrophic continuous water flow from the south without major drainage events of the Ancylus Lake to the southern Kattegat. During the Littorina transgression, coastal estuarine conditions characterized the Hesselø Bay area where elongated ridges formed a bar system. As the Littorina transgression continued, back-stepping of the bar system and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area.

  18. Soil organic matter and soil acidity in Mangrove areas in the river Paraiba Estuary, Cabedelo, Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Renata Wilma Vasconcelos

    2014-08-01

    Full Text Available Mangrove ecosystems are of great environmental significance, because of their fragility and role in feeding and breeding various animal species. In northeastern Brazil, the disorderly occupation of estuarine areas and the urban sprawl have led to a considerable loss of the original area occupied by mangroves. In the municipality of Cabedelo, State of Paraíba, there are about 4,900 ha of remnant mangrove areas in the estuarine complex of the Paraíba River. However, information about the attributes of mangrove soils at this location is quite scarce. The aim of this study was to quantify the soil organic matter and soil acidity in mangroves located in the estuary of the Paraíba River, State of Paraíba, Brazil, in order to increase the database of soil attributes in this region. The study area is in local influence of the Restinga de Cabedelo National Forest (Flona, an environmental conservation unit of the Chico Mendes Institute for Biodiversity Conservation. For the choice of sampling points, we considered an area that receives direct influence of the eviction of domestic and industrial effluents. The soil of the study area is an “Organossolo Háplico” in Brazilian Soil Classification (Histosol, and was sampled at four point sites: one upstream of the effluent discharge (P1, one in the watercourse receiving effluent water (P2, one downstream of the effluent discharge (P3 and another near Flona (P4, at 0-20 and 20-40 cm, in four replications in time (28/08/2012 in the morning and afternoon, and 21/01/2013 in the morning and afternoon. Potential acidity, pH and soil organic matter (SOM were determined. No significant differences were detected in the potential acidity of the four collection sites, which ranged from 0.38 to 0.45 cmolc dm-3. Soil pH was greatest at point P4 (7.0 and lowest at point P1 (5.8. The SOM was highest at point P1 (86.4 % and lowest at P2 (77.9 %. The attributes related to soil acidity were not sensitive to indicate

  19. Area-intensive bottom culture of blue mussels Mytilus edulis in a micro-tidal estuary

    DEFF Research Database (Denmark)

    Dolmer, Per; Christensen, Helle Torp; Hansen, Benni Winding

    2012-01-01

    Dredge fishery for blue mussels Mytilus edulis (L.) impacts the benthic ecosystem, and substitution by area-intensive bottom culture production may reduce adverse effects on the ecosystem. Two different field studies in 2007 and 2009 tested the productivity of bottom culture of blue mussels...

  20. Flooding Mitigation of seawalls and river embankments to storm surges in the coastal areas of Guangdong Province, China

    Science.gov (United States)

    Wang, Xianwei; Wang, Xina

    2017-04-01

    The coastal areas of Guangdong Province, China are susceptible to the destructions of tropical cyclones and storm surges. The projected global warming, coastal subsidence and sea level rise together will bring about greater flooding risk to these areas. The seawall and river embankment have played a significant role in mitigating and preventing the coastal low-land areas from the impairment of storm surges flooding and wave runup. However, few risk assessment studies in this region consider the existence of seawall and river embankment and often overestimate the risk and potential economic loss and population affected due to storm surge flooding. This study utilizes a hydraulic model to simulate the overtop flooding and compare those without seawall and river embankment using several specific tropic storm events and extreme events of tropic storm surges in different return periods of 2, 10, 20, 50, 100, 200 and 500 years. Most seawalls are 4 or 5 meters plus another meter of wave levee above the local mean sea level. The river embankments are usually 4 or 5 meter higher than the local mean sea level as well and decrease from the outer estuary to the inner riverine. The modeling results considering seawall and river embankments and from real storm surges are in agreement with on-site survey and observations, while those without infusing seawall and river embankments overestimate the inundation condition and economic loss. Modeling results demonstrate that seawall and river embankment greatly reduce the flooding risk and prevent the low-land area from inundation for most tropic storm events, e.g., for extreme events less than 20 to 50 years, in the coastal areas of Guangdong Province, China. However, the seawall and river embankment may also cause catastrophic disasters once there is an engineering failure of seawalls and river embankment, especially once encountering with an extreme typhoon event, e.g., the 1969 super typhoon Viola in Shantou China and the 2005

  1. Digitisation of Scenic and Historic Interest Areas in China

    Science.gov (United States)

    Yang, C.; Lawson, G.; Sim, J.

    2015-08-01

    Digital documents have become the major information source for heritage conservation practice. More heritage managers today use electronic maps and digital information systems to facilitate management and conservation of cultural heritage. However, the social aspects of digital heritage have not been sufficiently recognised. The aim of this paper is to examine China's `Digital Scenic Area' project, a national program started in 2004, to reveal the political and economic powers behind digital heritage practice. It was found that this project was only conducted within the most popular tourist destinations in China. Tourism information was the main object but information about landscape cultures were neglected in this project. This project also demonstrated that digital management was more like a political or economic symbol rather than a tool for heritage conservation. However, using digital technologies are still considered by the local government as a highly objective way of heritage management. Selected as a typical Scenic Area in China, Slender West Lake in Yangzhou was investigated to identify heritage stakeholder's attitudes toward digital management and the request from local management practice.

  2. Strontium isotope record of seasonal scale variations in sediment sources and accumulation in low-energy, subtidal areas of the lower Hudson River estuary

    Science.gov (United States)

    Smith, J.P.; Bullen, T.D.; Brabander, D.J.; Olsen, C.R.

    2009-01-01

    Strontium isotope (87Sr/86Sr) profiles in sediment cores collected from two subtidal harbor slips in the lower Hudson River estuary in October 2001 exhibit regular patterns of variability with depth. Using additional evidence from sediment Ca/Sr ratios, 137Cs activity and Al, carbonate (CaCO3), and organic carbon (OCsed) concentration profiles, it can be shown that the observed variability reflects differences in the relative input and trapping of fine-grained sediment from seaward sources vs. landward sources linked to seasonal-scale changes in freshwater flow. During high flow conditions, the geochemical data indicate that most of the fine-grained sediments trapped in the estuary are newly eroded basin materials. During lower (base) flow conditions, a higher fraction of mature materials from seaward sources with higher carbonate content is trapped in the lower estuary. Results show that high-resolution, multi-geochemical tracer approaches utilizing strontium isotope ratios (87Sr/86Sr) can distinguish sediment sources and constrain seasonal scale variations in sediment trapping and accumulation in dynamic estuarine environments. Low-energy, subtidal areas such as those in this study are important sinks for metastable, short-to-medium time scale sediment accumulation. These results also show that these same areas can serve as natural recorders of physical, chemical, and biological processes that affect particle and particle-associated material dynamics over seasonal-to-yearly time scales. ?? 2009.

  3. Relevance of estuaries adjacent to megalopolis as modifiers of internal shelf areas

    Science.gov (United States)

    Wagener, Angela; Lazzzari, Leticia; Carreira, Renato; Farias, Cassia; Mauad, Cristiane

    2014-05-01

    Guanabara Bay located in the humid tropical region is a eutrophic estuarine system bordered by the second largest metropolitan area of Brazil. Human intervention resulted in water conditions ranging from complete anoxia in the polluted inner bay area to the adjacent, relatively pristine, open coastal area. In the present work the goals were to estimate nutrients and carbon fluxes between the bay and the adjacent coastal waters and to characterize by using stable isotopes, hydrocarbons and sterols the provenance of the exported/imported organic matter. Water samples were collected from three different depths over 25 hours cycles in the wet and dry seasons at a single station strategically positioned in the bay. Measurements included CTD, nutrients, chlorophylls, DOC, POC, PN, δ13C and δ15N, hydrocarbons and sterols in SPM. Most substances showed higher concentrations in ebb tide events and through statistical tools a significant difference between the campaigns was proved. The fluxes estimated on annual basis revealed the expressive exportation to the inner continental shelf of 1.27x104 Kmol DIN yr-1, 9.52x102 Kmol DIP yr-1, 2.65x104 tons DOC yr-1, 1.96x104 tons COP yr-1, 2.96x104 tons NP yr-1.

  4. Total Lightning Flash Activity Response to Aerosol over China Area

    Directory of Open Access Journals (Sweden)

    Pengguo Zhao

    2017-01-01

    Full Text Available Twelve years of measurements of aerosol optical depth (AOD, cloud fraction, cloud top height, ice cloud optical thickness and lightning flash density from 2001 to 2012 have been analyzed to investigate the effect of aerosols on electrical activity over an area of China. The results show that increasing aerosol loading inspires the convective intensity, and then increases the lightning flash density. The spatial distribution of the correlation between aerosol loading and electrical activity shows a remarkable regional difference over China. The high-correlation regions embody the positive aerosol microphysical effect on the intensity of the electrical activity, while the large-scale processes may play the main role in convection development and producing lightning in low-correlation regions.

  5. Benthic trophic status of sediments in a metropolitan area (Rio de la Plata estuary): Linkages with natural and human pressures

    Science.gov (United States)

    Venturini, Natalia; Pita, Ana Laura; Brugnoli, Ernesto; García-Rodríguez, Felipe; Burone, Leticia; Kandratavicius, Noelia; Hutton, Marisa; Muniz, Pablo

    2012-10-01

    We evaluated the benthic trophic status of the Montevideo coastal zone-Rio de la Plata estuary using the quantity and the biochemical composition of sedimentary organic matter as synthetic descriptors. The spatio-temporal patterns in the biochemical composition of sedimentary organic matter were related to the presence of some natural and human pressures. Biochemical features were analyzed correlatively with the type and proximity of certain impacts to investigate the usefulness of this biochemical approach for assessing the levels of natural and anthropogenic perturbations. Chlorophyll-a, phaeopigment and the biopolymeric carbon concentrations were similar to those reported in very productive, eutrophic and anthropised estuarine areas. Total proteins (PRT) and lipids (LIP) showed the highest concentrations in the inner portion of Montevideo Bay, decreasing towards the nearby coastal areas of Punta Carretas and Punta Yeguas. Total carbohydrates (CHO) presented the lowest values in the outer stations of Montevideo Bay, but similar and higher concentrations were recorded in the inner stations of the bay and the adjacent coastal zones. PRT:CHO ratios >1 were always observed for the inner stations of Montevideo Bay thus suggesting intense detritus mineralization and an increment in their protein content due to bacterial activity. The biopolymeric carbon showed the same spatial trend observed for PRT, LPD and the PRT: CHO ratios with highest concentrations in the inner bay than in Pta. Carretas and Pta. Yeguas. Elevated contributions of PRT and LIP in the inner Montevideo Bay may be associated with anthropogenic inputs of organic matter such as sewage, food industry and petroleum hydrocarbons. Conversely, high CHO contributions in the nearby coastal areas of Pta. Carretas and Pta. Yeguas seemed to be related to autochthonous primary production and CHO temporal variability with natural oscillations in the productivity of the system. Biochemical composition of organic

  6. Occurrence of intracellular and extracellular antibiotic resistance genes in coastal areas of Bohai Bay (China) and the factors affecting them.

    Science.gov (United States)

    Zhang, Yongpeng; Niu, Zhiguang; Zhang, Ying; Zhang, Kai

    2018-01-29

    Coastal areas are the transition zones between ocean and land where intracellular antibiotic resistance genes (iARGs) and extracellular antibiotic resistance genes (eARGs) could spread among marine organisms, and between humans and marine organisms. However, little attention has been paid to the combined research on iARGs and eARGs in marine environment. In this context, we collected water and sediment samples from the coastal areas of the Bohai Bay in China and performed molecular and chemical analyses. The results of quantitative real-time PCR (qPCR) showed that the relative abundance of eARGs was up to 4.3 ± 1.3 × 10 -1 gene copies/16S rRNA copies in the water samples and 2.6 ± 0.3 × 10 -3 gene copies/16S rRNA copies in the sediment samples. Also, the abundance of eARGs was significantly higher than that of iARGs. Furthermore, the average abundances of antibiotic resistance genes (ARGs, include iARGs and eARGs) were the highest in both the water and sediment samples from the estuaries. The results of liquid chromatography-mass spectrometry showed that the concentrations of antibiotics in estuaries and areas near the mariculture site were higher than that in the other sites. The class 1 integron gene (int1) and sul1 in the intracellular DNA were significantly correlated in the water samples. Moreover, significant correlation between int1 and sul2 in the extracellular DNA was also found in the sediment samples. The combination of sulfamerazine and tetracycline as well as the combination of sulfamethazine and dissolved oxygen can both explain the abundance of ARGs, implying the combined effects of multiple stresses on ARGs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Ichthyofauna in an estuary of the Mataripe area, Todos os Santos Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    June Ferraz Dias

    2011-03-01

    Full Text Available The community structure and dynamics as well as some biological parameters of selected species of the ichthyofauna of the Mataripe estuarine region affected by the Landulfo Alves Oil Refinery (RLAM were analyzed. Twenty stations were sampled with a gillnet in five different periods: August and December 2003, March and July/August 2004 and January 2005. Thirty-five actinopterygian species and one elasmobranch species were recorded, Oligoplites saurus, Diapterus rhombeus, Lutjanus synagris and Scomberomorus brasiliensis among them, on all the campaigns. A total of 1368 specimens, weighing 36.10 kg, were caught. The ichthyofauna total biomass was greater, in weight, on the eastern side of the study region, especially at the stations close to the shoals/reefs and the rocky bottom. A similar pattern was also observed for the diversity values. In general, low evenness and diversity were observed in the area studied, possibly as a result of the fishing gear used. D. rhombeus juveniles dominated in all but one of the samplings (July 2004, in which latter Cyclichthys spinosus was dominant. Carangids and species associated with consolidated bottoms were observed, although in small numbers, throughout the study period. In spite of the limitations imposed by the gear used for sampling, the estuarine area influenced by the RLAM was seen to play a role as a growth area for the great majority of species, especially the mojarra (D. rhombeus, but it offers no fishing potential due to the prevalence of young and small individuals. Evidence of imminent spawning was recorded for Pomadasys corvinaeformis in August 2003, and recent spawning in March 2004 for Oligoplites saurus. Further, mature individuals occurred in insufficient numbers to permit population level evaluation.A estrutura e dinâmica da ictiofauna amostrada na região estuarina de Mataripe sob a influência da Refinaria Landulpho Alves-Mataripe (RLAM foi analisada. Vinte estações foram amostradas com

  8. Assessment of Light Pollution Impact on Protected Areas in China

    Science.gov (United States)

    Jiang, W.; He, G.; Ni, Y.

    2017-09-01

    The Protected Areas (PAs) with natural, ecological and cultural value play important role in biological processes, biodiversity and ecosystem service. During the past years of rapid urban expansion in China, the spatial range and intensity of light pollution unprecedented increase. Historically, optical remote sensing and field survey data had been used to reveal that human activities impacted on PAs for individual areas and few papers documented the issue of light pollution impact on PAs at national scale. Here, time series night-time light satellite images of Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) were selected to assess the light pollution impacted on PAs in China. The method we proposed can be effectively applied to assess the impact of light pollution on PAs and the percent of dark PAs decreased by 35.38 % from 1992 to 2012 at nationwide. The trend of light pollution of most PAs in stable, however, light pollution of the local area is increase significantly, especially in northern Xinjiang, Gansu, Xizang, Yunnan, Jiangsu and Shandong. Considering the current status of light pollution encroach into PAs, two strategies of appropriate buffer zone and wide measured for light pollution are also recommend.

  9. Integrated Emergy and Economic Evaluation of Lotus-Root Production Systems on Reclaimed Wetlands Surrounding the Pearl River Estuary, China

    Science.gov (United States)

    Lotus (Neumbo nucifera, Gaertn) is the most important aquatic vegetable in China, with a cultivation history of over 3000 years. The emergy, energy, material, and money flows of three lotus root cultivation modes in Wanqingsha, Nansha District, Guangzhou, China were examined usin...

  10. Sedimentary BSi and TOC quantifies the degradation of the Changjiang Estuary, China, from river basin alteration and warming SST

    Science.gov (United States)

    Li, Maotian; Wang, Hong; Li, Yimiao; Ai, Wei; Hou, Lijun; Chen, Zhongyuan

    2016-12-01

    Environmental degradation in the Changjiang Estuary has recently become a global topic, given its proximity to Shanghai with a population >23 million. Intensification of human activities affecting the river basin is responsible for this degradation. Dam construction has cut off ca. 2/3 of the sediment flux to the sea, ca. 60% of the dissolved silicate load (DSi) has been retained in the reservoirs, while total phosphorous (TP) and total nitrogen (TN) transport to the sea are many times more than they were a few decades ago. Under such circumstances, details of the estuarine degradation remain poorly understood. This study uses sedimentary biological silicate (BSi) and total organic carbon (TOC) as environmental proxies to reveal the process-response of such degradation since the 1950s. Our results demonstrate the spatial differences of such degradation. The inner zone of the estuary used to be highly turbid, but presently has increasing diatom (BSi) and primary production (TOC), due to lower suspended sediment concentration (SSC) in relation to dam construction. In contrast, increasing riverine dissolved inorganic nitrate (DIN) and dissolved inorganic phosphorous (DIP) input (up to 2-5 times) and decreasing DSi provide a unique setting, with an excess in N and P, which catalyzes non-diatom algae in the less-turbid middle zone of the estuary. These are reflected by decreasing BSi and BSi/TOC since the 1950s, together with an increase of TOC of 20-40%. In the outer zone of the estuary, increasing DIN, DIP, and sea surface temperatures (SSTs), have resulted in the increase of diatom biomass by 15-20% and the growth of primary production by 30-60% since the 1950s. But the drastic decrease in DSi, Si/N, and Si/P depresses the ability of diatoms to develop, resulting in a reduction of 5-10% diatom proportion (BSi/TOC) since the 1930s. This study improves the understanding of the changing estuarine ecosystem in response to global change.

  11. Shifts in the pelagic ammonia-oxidizing microbial communities along the eutrophic estuary of Yong River in Ningbo City, China

    Directory of Open Access Journals (Sweden)

    Qiufang eZhang

    2015-10-01

    Full Text Available Aerobic ammonia oxidation plays a key role in the nitrogen cycle, and the responsible microorganisms diversities are regulated by environmental factors. Abundance and composition of ammonia-oxidizing archaea (AOA and ammonia-oxidizing bacteria (AOB were investigated in the surface waters along an environmental gradient of Yong River in Ningbo, China. Water samples were collected from three zones: freshwaters in urban canals, brackish waters in the downstream Yong River, and coastal water of Hangzhou Bay. Shifts in activity and diversity of the ammonia oxidizers occurred with changes in salinity, ammonium and oxygen. The AOA abundance was always higher than that of AOB and related to the ammonia oxidation activity. The ratios of AOA/AOB in the brackish and marine waters were significantly higher than those found in freshwaters. Both AOA and AOB showed similar community compositions in brackish and marine waters, but only 31 and 35% similarity, respectively, between these waters and the urban inland freshwaters. Most of AOA-amoA sequences from freshwater were affiliated with sequences obtained from terrestrial environments and those collected from brackish and coastal areas were ubiquitous in marine, coastal, and terrestrial ecosystems. All AOB from freshwaters belonged to Nitrosomonas, and those from brackish and marine waters mainly belonged to Nitrosospira.

  12. Spring habitat use by stocked one year old European sturgeon Acipenser sturio in the freshwater-oligohaline area of the Gironde estuary

    Science.gov (United States)

    Acolas, M. L.; Le Pichon, C.; Rochard, E.

    2017-09-01

    Post release habitat selection was studied on forty eight 10-month-old hatchery reared European sturgeon (mean fork length 31.0 cm ± 3.0) in the tidal part of their native catchment using acoustic telemetry. Most of the fish reached the oligohaline estuary within 2-4 days (70 km downstream the release site). Seventy four percent of the fish migrated rapidly downstream of the estuary into mesohaline waters while 26% selected habitat in the freshwater/oligohaline part of the estuary based on their linearity and residency indices. We focused on individual habitat use of these fish. The home range size (HR) was calculated using two methods: the kernel utilization distribution (KUD) which is driven by the maximum detection location density, and the Brownian Bridge (BB) approach which allows the time component of the trajectory path to be taken into account. The average 50% HR KUD was 5.6 ± 2.7 km2 (range 1.1-10.3 km2) and it was estimated to be 6 times larger using the 50% HR BB method (average reaching 31.9 ± 20.7 km2, range 5.2-77.8 km2). Habitat characterization (available prey, substrate and depth) in the studied area was described and the Ivlev electivity index was calculated using the habitat within the 50% HR BB for each individual. Despite the spatial use of different core areas among the fish tagged, we observed a convergence in habitat preference. For substrates, sturgeons showed avoidance of gravel and large rocks as well as fine and medium gravel. There was a significant preference for sand, silts and clay. For depth, they exhibited a preference firstly for the 5-8 m depth range and secondly for the 2-5 m range, a strong avoidance of depth range 8-20 m and a slight avoidance of shallow (0-2 m) and intertidal areas. For prey, individual variability was high. The most homogenous results were found for annelid polychaeta, with a slight preference for areas with this group of preys which are abundant in the saline estuary. For some individuals, a preference

  13. Crustal stress pattern in China and its adjacent areas

    Science.gov (United States)

    Hu, Xingping; Zang, Arno; Heidbach, Oliver; Cui, Xiaofeng; Xie, Furen; Chen, Jiawei

    2017-11-01

    During the update of the World Stress Map (WSM) database, we integrated the China stress database by strictly using the internationally developed quality ranking scheme for each individual stress data record. This effort resulted in a comprehensive and reliable dataset for the crustal stress of China and its adjacent areas with almost double the amount of data records from the WSM database release 2008, i.e., a total of 8228 data records with reliable A-C qualities in the region of 45-155° East and 0-60° North. We use this dataset for an analysis of the stress pattern for the orientation of maximum compressive horizontal stress (SHmax). In contrast to earlier findings that suggested that the mean SHmax orientation would be aligned with the direction of plate motion, we clearly see from our results that the plate boundary forces, as well as topography and faulting, are important control factors for the overall stress pattern. Furthermore, the smoothing results indicate that the SHmax orientation in China rotates clockwise from the west to the east, which results in a fan-shaped crustal stress pattern for the continental scale. The plate boundary forces around China, which are the Indian-Eurasian plate collision in the west and the Pacific plate subduction and the push from the Philippine plate in the east, can still be seen as the key driving processes and the first-order controls for the crustal stress pattern. The South-North seismic zone can be seen as the separation zone for the western and eastern plate boundary forces. Topographic variation and faulting activity, however, provide second-order changes, and lead to local variations and different inhomogeneity scales for the stress pattern. Due to differences in these factors, Northeast China and the central part of the Tibetan plateau have notably homogeneous stress patterns, while the South-North seismic zone, the Hindu Kush-Pamir region, and the Taiwan region have extremely inhomogeneous stress patterns

  14. Soil Fertility Map for Food Legumes Production Areas in China.

    Science.gov (United States)

    Li, Ling; Yang, Tao; Redden, Robert; He, Weifeng; Zong, Xuxiao

    2016-05-23

    Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and their patterns of distribution was constructed. The pH results indicated that soils were neutral to slightly alkaline overall. The soil organic matter (SOM) and the available nitrogen (AN) content were relatively low, while the available phosphorus (AP) and available potassium (AK) contents were from moderate to high. Production areas of food legumes (faba bean, pea, adzuki bean, mung bean and common bean) were clearly separated into 4 soil fertility type clusters. In addition, regions with SOM, AN, AP and AK deficiency, high acidity and high alkalinity were listed as target areas for further soil improvement. The potential was considered for biological nitrogen fixation to substitute for the application of mineral nitrogen fertiliser.

  15. Soil Fertility Map for Food Legumes Production Areas in China

    Science.gov (United States)

    Li, Ling; Yang, Tao; Redden, Robert; He, Weifeng; Zong, Xuxiao

    2016-05-01

    Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and their patterns of distribution was constructed. The pH results indicated that soils were neutral to slightly alkaline overall. The soil organic matter (SOM) and the available nitrogen (AN) content were relatively low, while the available phosphorus (AP) and available potassium (AK) contents were from moderate to high. Production areas of food legumes (faba bean, pea, adzuki bean, mung bean and common bean) were clearly separated into 4 soil fertility type clusters. In addition, regions with SOM, AN, AP and AK deficiency, high acidity and high alkalinity were listed as target areas for further soil improvement. The potential was considered for biological nitrogen fixation to substitute for the application of mineral nitrogen fertiliser.

  16. Rocky desertification treatment project in karst areas in South China

    Science.gov (United States)

    Zhou, Jinxing; Pang, Danbo; Wan, Long; Wu, Xiuqin; Wang, Genzhu

    2017-04-01

    Rocky desertification is one of the most severe ecological problems in karst areas of South China. Severe vegetation degradation, high soil erosion, high exposed bedrock and fast groundwater flow through karst conduits are typical characteristics in the rocky desertification areas. From 2008, the rocky desertification treatment project was conducted by the Chinese government to improve the local ecological environment. This paper has offered an overview of the rocky desertification treatment project, and the partitions for the rocky desertification treatment. Changes in the spatial and temporal distribution of different severity of rocky desertification were investigated. Diverse vegetation restoration modes and ecological engineering technology modes for rocky desertification management were introduced. We also discussed the vegetation restoration effects and the carbon absorbing effects by Chinese rocky desertification treatment project. Besides, the problems exist in the rocky desertification treatment were analyzed in our study. The new rocky desertification treatment project will be carried out from 2016 in China. We need continue to summarize the past experiences, and gain more achievements from the new project.

  17. Health literacy in rural areas of China: hypertension knowledge survey.

    Science.gov (United States)

    Li, Xia; Ning, Ning; Hao, Yanhua; Sun, Hong; Gao, Lijun; Jiao, Mingli; Wu, Qunhong; Quan, Hude

    2013-03-18

    We conducted this study to determine levels and correlates of hypertension knowledge among rural Chinese adults, and to assess the association between knowledge levels and salty food consumption among hypertensive and non-hypertensive populations. This face-to-face cross sectional survey included 665 hypertensive and 854 non-hypertensive respondents in the rural areas of Heilongjiang province, China. Hypertension knowledge was assessed through a 10-item test; respondents received 10 points for each correct answer. Among respondents, the average hypertension knowledge score was 26 out of a maximum of 100 points for hypertensive and 20 for non-hypertensive respondents. Hypertension knowledge was associated with marital status, education, health status, periodically reading books, newspapers or other materials, history of blood pressure measurement, and attending hypertension educational sessions. Hypertension knowledge is extremely low in rural areas of China. Hypertension education programs should focus on marginal populations, such as individuals who are not married or illiterate to enhance their knowledge levels. Focusing on educational and literacy levels in conjunction with health education is important given illiteracy is still a prominent issue for the Chinese rural population.

  18. Health Literacy in Rural Areas of China: Hypertension Knowledge Survey

    Directory of Open Access Journals (Sweden)

    Hude Quan

    2013-03-01

    Full Text Available We conducted this study to determine levels and correlates of hypertension knowledge among rural Chinese adults, and to assess the association between knowledge levels and salty food consumption among hypertensive and non-hypertensive populations. This face-to-face cross sectional survey included 665 hypertensive and 854 non-hypertensive respondents in the rural areas of Heilongjiang province, China. Hypertension knowledge was assessed through a 10-item test; respondents received 10 points for each correct answer. Among respondents, the average hypertension knowledge score was 26 out of a maximum of 100 points for hypertensive and 20 for non-hypertensive respondents. Hypertension knowledge was associated with marital status, education, health status, periodically reading books, newspapers or other materials, history of blood pressure measurement, and attending hypertension educational sessions. Hypertension knowledge is extremely low in rural areas of China. Hypertension education programs should focus on marginal populations, such as individuals who are not married or illiterate to enhance their knowledge levels. Focusing on educational and literacy levels in conjunction with health education is important given illiteracy is still a prominent issue for the Chinese rural population.

  19. ASEAN - China Free Trade Area : A quantitative study of Trade diversion and Trade creation effects on ASEAN - China trade flows

    OpenAIRE

    Duong Xuan, Vinh

    2011-01-01

    The Association of South-East Asian Nations (ASEAN) and China have a long history of trading with each other. They are economic partners as well as competitors for many years. In order to push their economic relationship to a higher level, in November 2002, ASEAN and China signed the initial framework agreement, determined on establishing the ASEAN - China Free Trade Area (ACFTA) among the eleven countries by 2010 for the ASEAN-6 (Brunei, Indonesia, Malaysia, Philippines, Singapore, Thailand)...

  20. n-Alkanes in sediments from the Yellow River Estuary, China: Occurrence, sources and historical sedimentary record.

    Science.gov (United States)

    Wang, Shanshan; Liu, Guijian; Yuan, Zijiao; Da, Chunnian

    2018-04-15

    A total of 21 surface sediments from the Yellow River Estuary (YRE) and a sediment core from the abandoned Old Yellow River Estuary (OYRE) were analyzed for n-alkanes using gas chromatography-mass spectrometry (GC-MS). n-Alkanes in the range C12-C33 and C13-C34 were identified in the surface sediments and the core, respectively. The homologous series were mainly bimodal distribution pattern without odd/even predominance in the YRE and OYRE. The total n-alkanes concentrations in the surface sediments ranged from 0.356 to 0.572mg/kg, with a mean of 0.434mg/kg on dry wt. Evaluation of n-alkanes proxies indicated that the aliphatic hydrocarbons in the surface sediments were derived mainly from a petrogenic source with a relatively low contribution of submerged/floating macrophytes, terrestrial and emergent plants. The dated core covered the time period 1925-2012 and the mean sedimentation rate was ca. 0.5cm/yr. The total n-alkanes concentrations in the core ranged from 0.0394 to 0.941mg/kg, with a mean of 0.180mg/kg. The temporal evolution of n-alkanes reflected the historical input of aliphatic hydrocarbons and was consistent with local and regional anthropogenic activity. In general, the investigation on the sediment core revealed a trend of regional environmental change and the role of anthropogenic activity in environmental change. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A multi-band semi-analytical algorithm for estimating chlorophyll-a concentration in the Yellow River Estuary, China.

    Science.gov (United States)

    Chen, Jun; Quan, Wenting; Cui, Tingwei

    2015-01-01

    In this study, two sample semi-analytical algorithms and one new unified multi-band semi-analytical algorithm (UMSA) for estimating chlorophyll-a (Chla) concentration were constructed by specifying optimal wavelengths. The three sample semi-analytical algorithms, including the three-band semi-analytical algorithm (TSA), four-band semi-analytical algorithm (FSA), and UMSA algorithm, were calibrated and validated by the dataset collected in the Yellow River Estuary between September 1 and 10, 2009. By comparing of the accuracy of assessment of TSA, FSA, and UMSA algorithms, it was found that the UMSA algorithm had a superior performance in comparison with the two other algorithms, TSA and FSA. Using the UMSA algorithm in retrieving Chla concentration in the Yellow River Estuary decreased by 25.54% NRMSE (normalized root mean square error) when compared with the FSA algorithm, and 29.66% NRMSE in comparison with the TSA algorithm. These are very significant improvements upon previous methods. Additionally, the study revealed that the TSA and FSA algorithms are merely more specific forms of the UMSA algorithm. Owing to the special form of the UMSA algorithm, if the same bands were used for both the TSA and UMSA algorithms or FSA and UMSA algorithms, the UMSA algorithm would theoretically produce superior results in comparison with the TSA and FSA algorithms. Thus, good results may also be produced if the UMSA algorithm were to be applied for predicting Chla concentration for datasets of Gitelson et al. (2008) and Le et al. (2009).

  2. Bioaccumulation and biomagnification of persistent organic pollutants in Indo-Pacific humpback dolphins (Sousa chinensis) from the Pearl River Estuary, China.

    Science.gov (United States)

    Gui, Duan; Yu, Riqing; He, Xuan; Tu, Qin; Chen, Laiguo; Wu, Yuping

    2014-11-01

    Indo-Pacific humpback dolphins (Sousa chinensis) are apex predators in the Pearl River Estuary waters (PRE) of China. PCBs, DDTs and other organochlorine pesticides (OCPs) (e.g., HCHs, HCB, mirex and dieldrin) were analysed in blubber samples of 45 dolphins and 10 prey fishes of S. chinensis collected from 2004 to 2013 in the PRE region to investigate the bioaccumulation and potential biomagnification of persistent organic pollutants (POPs). DDTs were the most abundant residue in the dolphins, with an average of 6,2700 ng g(-1) wet weight (ww), followed by PCBs (average: 1,790 ng g(-1) ww) and other OCPs including ∑HCHs, mirex, endrin, ∑chlordanes, HCB, dieldrin, aldrin, heptachlor, and pentachlorobenzene. The concentrations of PCBs and DDTs in male dolphins significantly increased with age and length. In contrast, female dolphins did not show obvious bioaccumulation trends with age and body length, possibly due to the lactational and parturitional transfer of these compounds. Compared with the POP residues in the prey fishes, the concentrations of PCBs, DDTs, and HCHs in the dolphin blubber increased by factors of 99, 212, and 5, respectively, whereas the residue levels of the other OCPs increased 2-185 times, indicating a potentially significant biomagnification in the top predators. The potential biomagnification factors calculated for most POPs were significantly higher than those in the cetacean species from other regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Short-chain chlorinated paraffins in marine organisms from the Pearl River Estuary in South China: Residue levels and interspecies differences.

    Science.gov (United States)

    Sun, Runxia; Luo, Xiaojun; Tang, Bin; Li, Zongrui; Huang, Liqian; Wang, Tao; Mai, Bixian

    2016-05-15

    There is limited information available on the bioaccumulation of short-chain chlorinated paraffins (SCCPs), a complicated group of persistent organic pollutants (POPs) candidates listed in the Stockholm Convention, in estuarine ecosystem. This study analyzed SCCPs in marine organisms (five fish and six invertebrates) from the Pearl River Estuary in South China. The concentrations of total SCCPs ranged from 210 to 21,000 ng · g(-1) lipid weight, with relatively higher levels in benthic invertebrates (shrimp, crabs and bivalves) than in non-benthic species (pelagic and mesopelagic fish and squid). SCCPs were biomagnified from prey fish (tapertail anchovy, Coilia mystus) to predator fish (Bombay duck, Harpadon nehereus), and the biomagnification factors (BMFs) of SCCP congeners ranged from 1.1 (C10H16Cl6) to 3.4 (C13H18Cl10). Species-specific homologue group patterns were also observed, with significantly lower proportions of C10 congeners in the shrimp, bivalves and Bombay duck than in the other species. Copyright © 2016. Published by Elsevier B.V.

  4. Response of gaseous carbon emissions to low-level salinity increase in tidal marsh ecosystem of the Min River estuary, southeastern China.

    Science.gov (United States)

    Hu, Minjie; Ren, Hongchang; Ren, Peng; Li, Jiabing; Wilson, Benjamin J; Tong, Chuan

    2017-02-01

    Although estuarine tidal marshes are important contributors to the emission of greenhouse gases into the atmosphere, the relationship between carbon dioxide (CO2), methane (CH4) emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO2 and CH4 from a freshwater marsh and a brackish marsh located in a subtropical estuary in southeastern China, as well as their magnitude. The duration of the study period was November 2013 to October 2014. Relevant to both the field and incubation experiments, the CO2 and CH4 emissions from the two marshes showed pronounced seasonal variations. The CO2 and CH4 emissions from both marshes demonstrated significant positive correlations with the air/soil temperature (pwater/tide water Cl- and SO42- (psalinity of less than 5‰. The findings of this study could have important implications for estimating the global warming contributions of estuarine marshes along differing salinity gradients. Copyright © 2016. Published by Elsevier B.V.

  5. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China.

    Science.gov (United States)

    Xiao, Rong; Bai, Junhong; Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui

    2015-06-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe-Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (pCu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. [Job burnout among physicians in ten areas of China].

    Science.gov (United States)

    Cui, Gui; Wang, Fang; Xu, Yan

    2013-12-17

    To explore the status of job burnout among Chinese physicians and identify the risk factors for hospital human resource management. A total of 510 physicians from 10 areas of China participated in the survey from July to October 2012. Among them, 84.9% reported medium or higher level of emotional exhaustion, 87.8% with moderate degree of depersonalization and 81.8% with at least moderate degree of diminished personal accomplishment. The degree of job burnout was higher among physicians who were unmarried (t = 2.12, P = 0.03; t = 2.06, P = 0.04) , under 10-year seniority (P = 0.03; P = 0.01) , working at tertiary hospitals (F = 2.34, P = 0.04) or emergency department (P burnout among physicians should raise great concerns. Individual's marriage status, length of service, degree of education, hospital class and affiliated department should be considered when identification and intervention of physicians' job burnout are implemented.

  7. Temporal and spatial variations of abundance of phycocyanin- and phycoerythrin-rich Synechococcus in Pearl River Estuary and adjacent coastal area

    Science.gov (United States)

    Jiang, Tao; Chai, Chao; Wang, Jifang; Zhang, Ling; Cen, Jingyi; Lu, Songhui

    2016-10-01

    Three surveys were carried out in Pearl River Estuary and adjacent coastal area in May, August, and November, 2013, to investigate the temporal and spatial variations of abundance of phycoerythrin-rich Synechococcus (PE-rich SYN) and phycocyanin-rich Synechococcus (PC-rich SYN). The effects of environmental factors on the alternation of the different Synechococcus groups were also elucidated. PE-rich SYN was detected in three surveys, whereas PC-rich SYN was detected in May and August, but not in November. The highest abundances of PE-rich SYN and PC-rich SYN were recorded in August and May, with mean values of 74.17×103 and 189.92×103 cells mL-1, respectively. From May to November, the relative abundance of PE-rich SYN increased, whereas that of PC-rich SYN declined. PE-rich and PC-rich SYN presented similar horizontal distributions with high abundance in the southern estuary in May, and in the western estuary in August. The abundances of PE-rich and PC-rich SYN were high at 27-32°C and salinity of 10-20. PC-rich SYN was not detected at < 24°C, and PC:PE-rich SYN decreased in abundance with salinity increase. When less than 20 mg L-1, suspended particulate matter (SPM) was helpful for Synechococcus growth. PE-rich SYN decreased in abundance when the concentration of dissolved inorganic nitrogen increased in May and November, and the concentration of phosphate increased in November. However, PC-rich SYN abundance and nutrients showed no correlation. Principal component analysis and regression analysis indicated that PE-rich SYN significantly correlated with the principal components that were affected by environmental factors.

  8. Sustainable development of agriculture in karst areas, South China

    Directory of Open Access Journals (Sweden)

    Linhua Song

    1999-01-01

    Full Text Available The exposed carbonate rocks aged from Sinian to Mid-Triassic Periods cover an area of 500,000 Km2 in south-west China. In karst areas with spectacular landscapes characterized by magnificent tower karst and conical karst, rare surface drainage systems and prevalent subsurface drainage systems, the environment is ecologically very fragile. The rapid increase of population, over deforested and cultivated lands, worsted the ecological system, causing a higher frequency of draught, flood and various disasters, backward economic development, low living standard of the people. In order to improve the sustainability of the agriculture the experience shows that the following operations should be adopted: (1 serious control of the population increase, emigration, extra labours and improvement of the environmental education of the local inhabitants; (2 terracing of the slopes (shi jala di as to improve the cultivated land quality, to preserve the water, soil and fertiliser and ameliorate the effective utilisation of the land; (3 development of new rural energies such as the solar energy and gas energy, and expansion of the saving-fuel stoves to reduce the load of bio-energy; (4 reforestation and bounding the hills and mountains; the ecological, economic and fuel forests model has been developed in fengcong-depression areas: the tree species with high ecological, economical and energetic characteristics, should be chosen, such as the bamboo, wild grapes, Sapium rotundifolium etc.; (5 better utilisation of the ram water and karst water resource to solve the water supply problems. The karst landscape is well developed in the 500,000 km2 carbonate terrain in Yunnan, Guizhou, Guangxi, west Hunan and south Sichuan provinces in south-west China, where 100 million habitants live (Song, 1997. The large population and its high density, serious deforestation, over-cultivation and fragile ecological system make the environmental problems very serious and about 30

  9. Swartkops estuary

    CSIR Research Space (South Africa)

    Baird, D

    1988-01-01

    Full Text Available The Swartkops estuary has been an object of study for many years and research results obtained during the past 30 years were considered at a symposium in 1987. This report documents the proceedings of this symposium as well as conclusions...

  10. Global Warming: The Instability of Desert Climate is Enhancing in the Northwest Area in China: A Case Study in the Desert Area in Northwestern China

    OpenAIRE

    Zhao-Feng Chang; Shu-Juan Zhu; Fu-Gui Han; Sheng-Nnian Zhong; Qiang-Qiang Wang; Jian-Hui Zhang

    2013-01-01

    To disclose the relation between the sandstorms change and the temperature changes, a case study in the desert area in northwestern china is investigated. The results showed that: the instability of climate in Minqin desert area is enhancing in the arid desert region in northwest China. Mainly as follows: Variation the annual extreme maximum temperature increasing. Variation of extreme minimum temperature also an increasing trend. Average visibility of sandstorms significantly reduced and the...

  11. Seasonal changes of polycyclic aromatic hydrocarbons in response to hydrology and anthropogenic activities in the Pearl River estuary, China.

    Science.gov (United States)

    Liu, Feng; Niu, Lixia; Chen, Hui; Li, Ping; Tian, Feng; Yang, Qingshu

    2017-04-15

    The behaviours of PAHs (containing 2-6 aromatic rings) in the Pearl River estuary were examined each month in 2011. This study was designed to investigate the abundance of 16 priority PAHs and their response to the seasonal dynamics of anthropogenic activities and hydrological cycles. Monthly mean concentrations of ∑ 16 PAHs in water and suspended particulate matter (SPM) were 88.31ng/L and 252.31ng/L respectively, with higher concentrations in the wet season (April to September). Heavy precipitation in the wet season resulted in relatively increased PAH input via riverine discharges and atmospheric deposition. Seasonal variations in suspended sediment concentration (SSC), temperature and salinity have considerably affected the PAH phase association. Higher SSC in the wet season contributed to higher concentration of the PAHs in SPM, and higher temperature and lower salinity facilitated desorption from SPM. The PAH sources were largely attributed to vehicular emissions, coal combustion and coke ovens. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Soil As Levels and Bioaccumulation in Suaeda salsa and Phragmites australis Wetlands of the Yellow River Estuary, China

    Directory of Open Access Journals (Sweden)

    Junjing Wang

    2015-01-01

    Full Text Available Little information is available on As contamination dynamics in the soil-plant systems of wetlands. Total arsenic (As in soil and plant samples from Suaeda salsa and Phragmites australis wetlands was measured in the Yellow River Estuary (YRE in summer and autumn of 2007 to investigate the seasonal changes in As concentrations in different wetlands. The results showed that soil As levels greatly exceeded the global and regional background values. As levels in soil and the roots and stems of both types of plants were much higher in summer than in autumn, whereas leaf As showed higher level in autumn. Soil sulfur was the main factor influencing As levels in Suaeda salsa wetlands, whereas soil porosity was the most important factor for Phragmites australis wetlands. The contamination factor (CF showed moderately to considerably polluted levels of As in both wetland soils. Plant roots and leaves of Suaeda salsa had higher As concentrations and biological concentration factors (BCFs than stems, while the leaves and stems of Phragmites australis showed higher As levels and BCFs than roots. Compared to Phragmites australis, Suaeda salsa generally showed higher translocation factor (TF, while TF values for both plant species were higher in summer than in autumn.

  13. Macrobenthic assemblages of the Changjiang River estuary (Yangtze River, China) and adjacent continental shelf relative to mild summer hypoxia

    Science.gov (United States)

    Liao, Yibo; Shou, Lu; Tang, Yanbin; Zeng, Jiangning; Gao, Aigen; Chen, Quanzhen; Yan, Xiaojun

    2017-05-01

    To assess the effects of hypoxia, macrobenthic communities along an estuarine gradient of the Changjiang estuary and adjacent continental shelf were analyzed. This revealed spatial variations in the communities and relationships with environmental variables during periods of reduced dissolved oxygen (DO) concentration in summer. Statistical analyses revealed significant differences in macrobenthic community composition among the three zones: estuarine zone (EZ), mildly hypoxic zone (MHZ) in the continental shelf, and normoxic zone (NZ) in the continental shelf (Global R =0.206, P =0.002). Pairwise tests showed that the macrobenthic community composition of the EZ was significantly different from the MHZ (pairwise test R =0.305, P =0.001) and the NZ (pairwise test R =0.259, P =0.001). There was no significant difference in macrobenthic communities between the MHZ and the NZ (pairwise test R =0.062, P =0.114). The taxa included small and typically opportunistic polychaetes, which made the greatest contribution to the dissimilarity between the zones. The effects of mild hypoxia on the macrobenthic communities are a result not only of reduced DO concentration but also of differences in environmental variables such as temperature, salinity, and nutrient concentrations caused by stratification.

  14. Geometry analysis for landscape fragmentation in coastal areas of China

    Science.gov (United States)

    Zhang, Tianhai; Yu, Ning; Mu, Hongdu; Tuo, Tao

    2017-08-01

    In recent years, the continuous expansion of urban-transport networks in China has aggravated the fragmentation of regional landscapes and led to the degradation of multiple ecological functions. In this study, Geographic Information System (GIS) techniques, patch size of fragmentation geometry were used to identify and monitor spatial distribution patterns of landscape fragmentation due to urban-transport networks in Fujian Province. This network has caused serious damage to regional ecological functions, and risks to the persistence of animal populations and biodiversity. This analysis revealed that the smallest patch class (0-15 km2) occurred with a much greater frequency than all other larger patch sizes. In the coastal cities of Xiamen, Zhangzhou and Quanzhou, the percentage of the number of patches less than 300 km2 was higher than in the western cities of Nanping, Sanming and Longyan, and the percentage of the area of patches less than 300 km2 was also higher. Based on a holistic identification of the structure of the network and its landscape division, we found that: Fujian Province has a spatial pattern of landscape fragmentation, with less fragmentation in western and northern regions, and most fragmentation in southern and eastern regions. Coastal regions and areas close to the main transport routes were more seriously fragmented and contained most of the small patches.

  15. Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China

    National Research Council Canada - National Science Library

    Du, Buyun; Li, Ping; Feng, Xinbin; Qiu, Guangle; Zhou, Jun; Maurice, Laurence

    2016-01-01

    To evaluate the mercury (Hg) exposure level of children located in a Hg mining area, total Hg concentrations and speciation were determined in hair and urine samples of children in the Wanshan Hg mining area, Guizhou Province, China...

  16. China, A Country Study. Area Handbook Series. Third Edition.

    Science.gov (United States)

    Bunge, Frederica M., Ed.; Shinn, Rinn-Sup, Ed.

    Basic facts are given about the social, economic, political, and military institutions of China. The handbook, which is one of a continuing series designed for those interested in foreign affairs, is a revision of one published in 1972. The 1981 edition focuses on historical antecedents and China's new modernization strategies. Arranged into 14…

  17. Fractionation, transfer, and ecological risks of heavy metals in riparian and ditch wetlands across a 100-year chronosequence of reclamation in an estuary of China

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Rong [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); School of Nature Conservation, Beijing Forestry University, Beijing 100083 (China); Bai, Junhong, E-mail: junhongbai@163.com [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China); Lu, Qiongqiong; Zhao, Qingqing; Gao, Zhaoqin; Wen, Xiaojun; Liu, Xinhui [State Key Laboratory of Water Environment Stimulation, School of Environment, Beijing Normal University, Beijing 100875 (China)

    2015-06-01

    The effect of reclamation on heavy metal concentrations and the ecological risks in ditch wetlands (DWs) and riparian wetlands (RWs) across a 100-year chronosequence in the Pearl River Estuary of China was investigated. Concentrations of 4 heavy metals (Cd, Cu, Pb, and Zn) in soil and plant samples, and sequential extracts of soil samples were determined, using inductively coupled plasma atomic absorption spectrometry. Results showed that heavy metal concentrations were higher in older DW soils than in the younger ones, and that the younger RW soils contained higher heavy metal concentrations compared to the older ones. Although the increasing tendency of heavy metal concentrations in soil was obvious after wetland reclamation, the metals Cu, Pb, and Zn exhibited low or no risks to the environment based on the risk assessment code (RAC). Cd, on the other hand, posed a medium or high risk. Cd, Pb, and Zn were mainly bound to Fe–Mn oxide, whereas most of Cu remained in the residual phase in both ditch and riparian wetland soils, and the residual proportions generally increased with depth. Bioconcentration and translocation factors for most of these four heavy metals significantly decreased in the DWs with older age (p < 0.05), whereas they increased in the RWs with younger age (p < 0.05). The DW soils contained higher concentrations of heavy metals in the organic fractions, whereas there were more carbonate and residual fractions in the RW soils. The non-bioavailable fractions of Cu and Zn, and the organic-bound Cd and Pb significantly inhibited plant growth. - Highlights: • Heavy metals in ditch wetland accumulated with increasing reclamation history. • Heavy metals exist in the Fe–Mn oxides and residual fractions in both wetlands. • Cd posed a medium to high environmental risk while low risk for other metals. • Long reclamation history caused lower BCFs and TFs in DWs and higher levels in RWs. • RW soils contained more heavy metals in the carbonate

  18. [A Contrastive Study on Salt-alkaline Resistance and Removal Efficiency of Nitrogen and Phosphorus by Phragmites australis and Typha angustifolia in Coastal Estuary Area].

    Science.gov (United States)

    Chen, You-yuan; Sun, Ping; Chen, Guang-lin; Wang, Ning-ning

    2015-04-01

    The salt and alkali contents were so high that the ecological landscape was depressed in water body of a coastal estuary area. Screening some plants which could not only tolerate saline-alkaline but also effectively remove nitrogen and phosphorus was therefore in urgent need. The tolerance range and removal rate of nitrogen and phosphorus by Phragmites australis and Typha angustifolia under salt and pH stress were investigated by hydroponic experiments. The results showed that Phragmites australis could tolerate at least 10 per thousand salinity and pH 8.5, while Typha angustifolia tolerated 7.5 per thousand salinity and pH 8.0. Combined with the change of the growth and physiological indexes (relative conductivity, proline, chlorophyll and root activity), the salt resistance of Phragmites australis was stronger than that of Typha angustifolia. Under salt stress, the removal rate of ammonia nitrogen of Phragmites australis was higher. The removal rates of nitrate nitrogen and phosphorus of Typha angustifolia were 2.5% and 7.3% higher than those of Phragmites australis in average, respectively, because of the high biomass of Typha angustifolias. The total nitrogen removal rate was equivalent. Under pH stress, the removal rate of ammonia nitrogen and total phosphorus of Phragmites australis was a little higher than that of Typha angustifolia. However, Typha angustifolia had a higher removal rate of total nitrogen, which was 8.2% higher than that of Phragmites australis. All the analysis showed that both Phragmites australis and Typha angustifolia could be used as alternative plants to grow and remove nitrogen and phosphorus in the high salt-alkaline water body in coastal estuary area.

  19. Perception of Air Pollution in the Jinchuan Mining Area, China : A Structural Equation Modeling Approach

    NARCIS (Netherlands)

    Li, Zhengtao; Folmer, Henk; Xue, Jianhong

    Studies on the perception of air pollution in China are very limited. The aim of this paper is to help to fill this gap by analyzing a cross-sectional dataset of 759 residents of the Jinchuan mining area, Gansu Province, China. The estimations suggest that perception of air pollution is

  20. Seasonal influence of scallop culture on nutrient flux, bacterial pathogens and bacterioplankton diversity across estuaries off the Bohai Sea Coast of Northern China.

    Science.gov (United States)

    He, Yaodong; Sen, Biswarup; Shang, Junyang; He, Yike; Xie, Ningdong; Zhang, Yongfeng; Zhang, Jianle; Johnson, Zackary I; Wang, Guangyi

    2017-11-15

    In this study, we investigated the environmental impacts of scallop culture on two coastal estuaries adjacent the Bohai Sea including developing a quantitative PCR assay to assess the abundance of the bacterial pathogens Escherichia coli and Vibrio parahaemolyticus. Scallop culture resulted in a significant reduction of nitrogen, Chlorophyll a, and phosphorous levels in seawater during summer. The abundance of bacteria including V. parahaemolyticus varied significantly across estuaries and breeding seasons and was influenced by nitrate as well as nutrient ratios (Si/DIN, N/P). Bacterioplankton diversity varied across the two estuaries and seasons, and was dominated by Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes. Overall, this study suggests a significant influence of scallop culture on the ecology of adjacent estuaries and offers a sensitive tool for monitoring scallop contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The physico-chemical characteristics of Imo River Estuary in ...

    African Journals Online (AJOL)

    The physicochemical characteristics of Imo River Estuary were studied from April to September, 2011 to assess the water quality. The estuary is located at the coastal part of Ikot Abasi Local Government Area of Akwa Ibom State in southeastern Nigeria. Sampling was done monthly at fishing grounds in the estuary ...

  2. The filtering capacity of selected Eastern Cape estuaries, South Africa

    African Journals Online (AJOL)

    Four Eastern Cape estuaries, the Kromme, Gamtoos, Swartkops and Sundays Estuaries have a permanent connection to the adjacent ocean, but differ in the amount of freshwater inflows as well as in the land-use patterns in their respective catchment areas. The nutrient loading to the four estuaries in terms of phosphate, ...

  3. China.

    Science.gov (United States)

    1983-12-01

    This discussion of China focuses on the following: the people; geography; history (early history, 20th century China, the People's Republic of China; the "Great Leap Forward" and the Sino Soviet Split, the Cultural Revolution, and Mao's death and present directions); government (state structure, Chinese Communist Party, and legal system); education; economy; foreign relations; defense; and relations between China and the US. As of 1982, China's population totaled just over 1.008 billion with an annual growth rate of 1.5%. Life expectancy is 68 years. Government authorities endorsed birth control in the 1950s, played it down in 1958, and began to promote it again in 1962. The present family planning program began in the early 1970s and has become more fully mobilized since 1979. The largest ethnic group is the Han Chinese, who constitute 93.3% of the total population. The People's Republic of China, located in eastern Asia, is almost as large as the European continent. 2/3 of China's area is mountainous or semidesert; only about 1/10 is cultivated. China is the oldest continuous major world civilization with records dating back about 3500 years. Mao's death in September 1976 removed a towering figure from Chinese politics and set off a scramble for succession. The post 11th Party Congress leadership has emphasized economic development and renounced the mass political movements of prior years. Important educational reforms were made in early 1978. Since 1979, the Chinese leadership has moved toward more pragmatic positions in almost all fields. The Chinese government has always been subordinate to the Chinese Communist Party (CCP), its role being to implement party policies. The primary instruments of state power are the State Council, an executive body corresponding to a cabinet, and the NPC, a legislative body. China has made impressive progress in primary education since 1949. About 93% of eligible children are enrolled in 1st grade, though only 65% finish primary

  4. Polycyclic aromatic hydrocarbons in surface sediment of typical estuaries and the spatial distribution in Haihe river basin.

    Science.gov (United States)

    Liu, Jing L; Zhang, Jing; Liu, Feng; Zhang, Lu L

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) with carcinogenic and mutagenic characteristics have been detected in many estuaries and bays around the world. To detect the contaminated level in typical estuaries in Haihe river basin, China, a comprehensive survey of 16 PAHs in surface sediment has been conducted and an ecological risk assessment has been taken. It showed that Haihe river estuary had the highest concentration, ranging from 92.91 to 15886.00 ng g(-1). And Luan river estuary has the lowest polluted level, ranging from 39.55 to 328.10 ng g(-1). PAHs in sediment were dominated by low and mid molecular weight PAHs in all the sampling sites. Most of the sampling sites in all sampling seasons indicated a rarely happened ecological risk of ΣPAHs, while the S6 in Haihe river estuary was in an occasionally anticipated risk. To illustrate the spatial distribution pattern of PAHs in surface sediment in Haihe river basin, the results were compared with previous research of the research team. Based on data of the comparison, it had been revealed that Haihe river had the most serious PAHs pollution, with an average concentration of 5884.86 ng g(-1), and showed the highest contamination level in all four ecological units. The ΣPAHs concentration showed in a rank of reservoir > estuary > rural area > city.

  5. [Preliminary studies on the occurrence of antibiotic resistance genes in typical aquaculture area of the Pearl River Estuary].

    Science.gov (United States)

    Liang, Xi-Mei; Nie, Xiang-Ping; Shi, Zhen

    2013-10-01

    Traditional and quantitative PCR techniques were used to determine the occurrence and quantities of ARGs, including three types of genes resistant to sulfonamide, seven for tetracycline resistance and one for quinolone resistance, as well as one integron gene in typical aquaculture of the Pearl River Estuary. The results showed that all genes except for tetW were detectable in the aquaculture environment, and sull, sul2 and int1 were the most frequently detected genes (detectable percentage, 100% ). Relative abundances of ARGs increased with the prolongation of rearing time under the same aquaculture pattern, suggesting a cumulative effect. Moreover, the occurrences of ARGs in the ponds were different with different aquaculture patterns, indicating that the aquaculture pattern might play an important role in the abundances and distributions of ARGs. Relative abundances of intl, as a horizontal mobile genetic element, were significantly correlated to the levels of sull and the total ARGs (P aquaculture substantially increased the abundances of ARGs probably owning to the induction of horizontal gene transfer of ARGs among bacteria.

  6. Level and ecological risk of four common metals in surface water along the Qinhuangdao coastal areas, China

    Science.gov (United States)

    Wang, Liping; Lei, Kun; Qiao, Yanzhen; Hao, Chenlin

    2017-01-01

    Heavy metals have been a widespread environmental contamination. Due to their associated ecological risk, the presence in water environment has attracted broad attention to public. Here 4 most common metals including copper (Cu), lead (Pb), cadmium (Cd) and zinc (Zn) were determined in surface water along the Qinhuangdao coastal areas, China. And their ecological risk was assessed using species sensitivity distribution (SSD) method. Total 12 stations were designed near the main estuary in the study area. The results showed that the concentrations of Cu, Pb, Cd and Zn of surface water were in the range of 847.81-1602.81µg/L, 0.42-1.59µg/L, 1.82-7.99µg/L and 26.9 -59.36µg/L, respectively. According to the National Seawater Quality Standard of China (GB3097-1997), Cu concentration in each station was much higher than the standard value of IV level (50µg/L), thus Cu could not even met the lowest level of water quality. In contrast, Pb met the I or II level of water quality, Cd and Zn met the II or III level. The HC5 (hazardous concentration for 5% of species) of each metal was obtained from their corresponding SSD curve. In case of Cu and Zn, the concentration at all sites exceeded their HC5 values, suggesting both of them had adverse effect on the aquatic organism, especially Cu. While Pb concentration at all sites was much lower than its HC5 value, thus Pb had no negative effect on aquatic life. In case of Cd, the concentration at 5 sites was higher than its HC5 value, and the other 7 sites was lower than its HC5 value, suggesting that adverse effect only occur at partial region in the study area. The RQ (risk quotient) value of Cu varied between 1355.41 and 2621.28, far larger than 1, indicating that 100% of sites had a much higher risk. The RQ of Zn varied between 6.06 and 13.88 (>1) indicating that Zn had a high risk in the study area. In case of Cd, the RQ ranged from 0.94 to 4.41 and about 92% of sites were larger than 1, suggesting that Cd had a high risk

  7. Effects of freshwater input on trace element pollution in salt marsh soils of a typical coastal estuary, China

    Science.gov (United States)

    Bai, Junhong; Zhao, Qingqing; Lu, Qiongqiong; Wang, Junjing; Reddy, K. Ramesh

    2015-01-01

    Freshwater input is an important pathway for the restoration of degraded coastal wetlands, however, little information is available on the negative effects of freshwater inputs on salt marsh soils in restored wetlands. Soil profile samples to a depth of 70 cm were collected in both degraded wetland (DW) and freshwater restored wetland (RW) in the Yellow River Delta of China to analyze the trace element pollution effects of freshwater input on coastal wetland soils. Heavy metals (i.e. Cd, Cr, Cu, Ni, Pb and Zn) and arsenic (As) concentrations were determined using the inductively coupled plasma atomic absorption spectrometry to investigate their distributions, sources and ecotoxicity in marsh soils from both wetlands. Our results showed that these trace elements had moderate spatial variability in both DW and RW soils. The concentrations of As, Cr, Pb and Cd in all soil layers were generally higher in RW soils than those in DW soils (p wetlands, however, As and Zn in DW or As, Zn and Ni in RW might have another similar origin. The enrichment factor (EF) values for Cu, Ni and Pb in both wetlands indicated minimal enrichment levels, whereas both As and Cd were significantly enriched with EF values 3 or 6 times greater than 1.5, implying a significant natural or anthropogenic origin. As and Ni exceeded the effect range low (ERL) and threshold effect level (TEL) in both wetlands, even As exceeded the probable effect level (PEL) in RW soils. Cr, Cu and Cd were grouped into TELs-PELs, moreover, Cr concentrations in RW soils exceeded the ERL. However, both Pb and Zn concentrations were below the TELs in both wetlands. Generally, The toxic unit in more than 85% of DW or RW soil samples showed low toxicity with higher contribution of As and Ni. It is necessary to monitor and control trace elements in the freshwater supplied to restored wetlands in coastal wetland restoration projects.

  8. Remediation of Legacy Arsenic Mining Areas in Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Ian H. von Lindern

    2011-01-01

    Conclusions. The success of the demonstration project was recognized and has provided direction and momentum for a wider effort by the Province to address mining pollution and water contamination challenges. It demonstrates the success of using known techniques for environmental remediation in the US, with local partners in China responding to their communities’ health and environmental problems.

  9. Persistent organic pollutant residues in the sediments and mollusks from the Bohai Sea coastal areas, North China: an overview.

    Science.gov (United States)

    Zhang, Peng; Song, Jinming; Yuan, Huamao

    2009-04-01

    The Bohai Sea costal area is one of the most developed zones of China and the sewage water from populous and developed cities, including Beijing, Tianjin, Qinhuangdao and Dalian is discharged into the Bohai Sea. Additionally, its semi-enclosed characteristic restricts water exchange, which leads to high accumulation of pollutants in the environment. This overview presents the residues of 6 classes of Persistent Organic Pollutants (POPs), including PAHs, DDTs, HCHs, PCBs and PCDD/Fs, in the sediments and mollusks of the Bohai Sea through analyzing previous literatures. In the sediments, the highest PAH concentrations were detected in the vicinities of Qinhuangdao, while the northeast corner of the Bohai Bay possessed the highest levels of DDTs and PCBs. The investigations on HCHs and PCDD/Fs distributions on the whole sea scale have not been reported. In mollusks, PAH concentrations were in the same order of magnitude in the whole Bohai Sea, so were DDTs, HCHs and PCBs, while the outlier maximum values of PCDDs and PCDFs occurred in Yingkou. In general, the POPs residues in mollusks collected from Shandong Province were higher than the other areas. The compositions of DDTs, HCHs and PCBs in sediments indicated their recent usage. By comparing POP concentrations in sediments with the recommended criterions, it was shown that some individual PAH compounds occasionally associated with adverse biological effects in the vicinities of the Liaodong Bay and Qinhuangdao, and the Liaohe River Estuary were heavily contaminated with DDTs, but PCBs were all below the thresholds. In order to reveal the transference and transformation of POPs in the environment, further studies concerning with their behavior, fate and bioaccumulation in the different trophic levels should be programmed. Moreover, laws and regulations should be enforced to ban the illegal usage of POPs-containing pesticides to guarantee health of the environment and human.

  10. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

    estuarine system, the Pearl River Estuary, China. J. Geophys. Res., 114, G03013, doi: 10.1029/2008JG000905. Hunt, C.W., J.E. Salisbury, D. Vandemark, and W. McGillis (2010). Contrasting carbon dioxide inputs and exchange in three adjacent New England...

  11. The Study of Airline Merger and Acquisition in the Great China Area

    Science.gov (United States)

    Shon, Zhengyi

    2003-01-01

    The Asian financial crisis in the late 20 th century has some long lasting effect on the air transportation industry in Asia, especially in the Great China Area. Starting from 1998, airlines in both China and Taiwan suffered some serious financial losses due to the diminishing travel demand caused by the economic recession. Airlines were forced to cut price to attract passengers and hence crashed the market discipline. A number of airline mergers and acquisitions were then driven by the markets and the governments. After China and Taiwan have both entered the World Trade Organization, some mega-merging cases were finalized in late 2002 for better fitting the world's aviation competitions. This paper reviews the nine merging and acquiring cases in the Great China Area in the past 5 years. Almost all the airlines in the area were involved. The new groups of airlines and the survival airlines are introduced. Market response to the airline mergers will also be examined. A general look over the performance of the new airlines will be discussed. And the future of the market will also be analyzed. Finally, the practices and the impacts of current inter-state mergers in the Great China Area will be examined. The study has expected a highly concentrated domestic market in both China and Taiwan. Each of the market will be dominated by three major airline groups of their own. Cross-holding equity within these 6 leading aviation groups would also be possible after further deregulations.

  12. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River Estuary, China.

    Science.gov (United States)

    Song, Yuze; Yu, Pan; Li, Bailin; Pan, Yingjie; Zhang, Xiaojun; Cong, Jian; Zhao, Yinying; Wang, Hua; Chen, Lanming

    2013-09-30

    The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. This study constitutes the first investigation of ICEs-positive Vibrio spp. in the Yangze River Estuary, China

  13. The mosaic accessory gene structures of the SXT/R391-like integrative and conjugative elements derived from Vibrio spp. isolated from aquatic products and environment in the Yangtze River estuary, China

    Science.gov (United States)

    2013-01-01

    Background The emergence, resurgence and spread of human food-borne pathogenic Vibrios are one of the major contributors to disease burden and mortality particularly in developing countries with disputable sanitary conditions. Previous research on pathogenic Vibrio cholerae and Vibrio parahaemolitycus derived from clinical samples has proposed links between acquisition of virulence and multiple drug resistance traits and intercellular transmissibility of mobile genetic elements in the environment. To date, very few information is available on environmental Vibrio isolates. In this study, we characterized eleven Vibrio strains bearing the SXT/R391-like integrative and conjugative elements (ICEs) derived from aquatic products and environment in the Yangtze River Estuary, China. Results The eleven Vibrio strains were isolated in 2010 to 2011, and taxonomically identified, which included six Vibrio cholerae, three Vibrio parahaemolyticus, one Vibrio alginolyticus and one Vibrio natriegens. Most of the strains displayed strong resistance phenotypes to ampicillin, mercury and chromium. The majority of their ICEs, which belong to S and R exclusion system groups, contain ICEs-chromosome junction sequences and highly conserved core-genes required for ICE transfer. However, comparative sequence analysis uncovered interesting diversity in their mosaic accessory gene structures, which carry many novel genes that have not been described in any known ICEs to date. In addition, antibiotic resistance was transmitted by ICEVchChn6 and ICEVpaChn1 from V. cholerae, V. parahaemolyticus to E. coli MG1655 via conjugation, respectively. Our data also revealed that the ICEs characterized in this study are phylogenetically distant from most of the SXT/R391 ICEs reported previously, which may represent a novel cluster likely shaped by the ecological environment in the Yangtze River Estuary, China. Conclusions This study constitutes the first investigation of ICEs-positive Vibrio spp. in the

  14. Modelling Phytoplankton Dynamics in Estuaries

    NARCIS (Netherlands)

    Liu, B.

    2017-01-01

    In estuaries, which are the transition areas between rivers and coastal waters, the spatial and temporal distribution of phytoplankton cell number density (P) is determined by local specific growth and loss, advection by currents, mixing by turbulence, and sinking if the density of phytoplankton is

  15. [Regional differences in adults' tea drinking pattern: findings from China Kadoorie Biobank study in 10 areas in China].

    Science.gov (United States)

    Li, Xia; Lyu, Jun; Guo, Yu; Bian, Zheng; Yu, Canqing; Zhou, Huiyan; Tan, Yunlong; Pei, Pei; Chen, Junshi; Chen, Zhengming; Li, Liming

    2015-11-01

    To describe the gender and regional differences in adults' tea drinking pattern found in China Kadoorie Biobank (CKB) survey, involving half million adults, in 10 areas in China. The baseline survey of CKB was conducted in 5 urban areas and 5 rural areas in China during 2004-2008. The information on tea drinking of 512 891 adults aged 30-79 years was collected and analyzed. The overall prevalence of regular tea drinking (i.e., weekly) was 50.7% in males and 21.3% in females. Among 10 areas, Hunan reported the highest regular tea drinking prevalence (74.3% in males, 76.6% in females), while Henan reported the lowest regular tea drinking prevalence (5.5% in males, 1.0% in females). Most regular tea drinkers consumed green tea except those from Zhejiang and Haikou. Hunan reported the highest tea consumption per time (3.8 g in males, 3.1 g in females), per day (6.2 g in males, 4.1 g in females) and per week (38.4 g in males, 25.0 g in females). The adults' tea drinking pattern i.e. frequency, type, amount of tea and preferred concentration of tea water, varied greatly among the 10 regions covered by CKB study.

  16. Climate Ready Estuaries Partner Projects Map

    Science.gov (United States)

    CRE partners with the National Estuary Program to develop climate change projects in coastal U.S. areas, such as bays and harbors; to develop adaptation action plans, identify climate impacts and indicators, and more. This map shows project locations.

  17. Molecular Fingerprint and Dominant Environmental Factors of Nitrite-Dependent Anaerobic Methane-Oxidizing Bacteria in Sediments from the Yellow River Estuary, China

    National Research Council Canada - National Science Library

    Yan, Pengze; Li, Mingcong; Wei, Guangshan; Li, Han; Gao, Zheng

    2015-01-01

    ...), which connects the carbon and nitrogen global nutrient cycles. In the present study, M. oxyfera-like bacteria sequences were successfully recovered from Yellow River Estuary sediments using specific primers for 16S rRNA and pmoA genes. A M...

  18. Climate Ready Estuaries

    Science.gov (United States)

    Information on climate change impacts to different estuary regions, tools and resources to monitor changes, and information to help managers develop adaptation plans for risk management of estuaries and coastal communities.

  19. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis) in the Pearl River Estuary, China.

    Science.gov (United States)

    Wang, Zhi-Tao; Nachtigall, Paul E; Akamatsu, Tomonari; Wang, Ke-Xiong; Wu, Yu-Ping; Liu, Jian-Chang; Duan, Guo-Qin; Cao, Han-Jiang; Wang, Ding

    2015-01-01

    A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  20. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis in the Pearl River Estuary, China.

    Directory of Open Access Journals (Sweden)

    Zhi-Tao Wang

    Full Text Available A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis. Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  1. Observations of atmospheric Hg species and depositions in remote areas of China

    Directory of Open Access Journals (Sweden)

    Feng X.

    2013-04-01

    Full Text Available From September 2007, we conducted continuous measurements of speciated atmospheric mercury (Hg and atmospheric mercury depositions at five remote sites in China. Four of these sites were involved in the Global Mercury Observation System (GMOS as ground-based stations. These stations were located in the northwest, southwest, northeast, and east part of China, respectively, which represent the regional atmospheric Hg budgets in different areas of China. The preliminary results showed that mean TGM concentrations were in the range of 1.60 – 2.88 ng m-3, with relatively higher levels observed at sites in Eastern China and Southwestern China and lower levels at sites in Northeastern and Northwestern China. TGM concentrations at remote sites of China were also higher than those reported from background sites in North America and Europe, and this is corresponding very well with the Chinese great anthropogenic Hg emissions. Gaseous oxidized mercury (GOM and particulate bounded mercury (PBM were in the ranges of 3.2 – 7.4 pg m−3 and 19.4 – 43.5 pg m-3, respectively. The preliminary result on precipitation showed mean precipitation THg concentrations were in the range of 2.7 – 18.0 ng L-1.

  2. Analysis of the Possibility and Limitation of Criminal Mediation in Rural Areas in China

    Directory of Open Access Journals (Sweden)

    Hao Guo

    2014-04-01

    Full Text Available With the development in the theory and practice in the area of criminal law in China, a lot of creative views have been put into legal practice. Criminal mediation, which is cropping up in both practice and theory becomes a hot subject under discussion in the field of legislation. The newly modified criminal law formally prescribes the criminal mediation, which has been recognized in the level of law-making. It has become a basic policy in the procedure of law suit. This thesis emphasizes the possibility of criminal mediation in rural areas in China, discussing the disadvantages of the current criminal justice mode, the advantages of criminal mediation and the tradition in rural areas in China. Additionally, it attempts to set up the limitation of criminal mediation, based on the principle of law, principle of equality, principle of utility and principle of justice.

  3. Comparative study of physico-chemical parameters of drinking water from some longevity and non-longevity areas of China.

    Science.gov (United States)

    Du, Yajun; Luo, Kunli; Hussain, Rahib

    2017-06-01

    There is an obvious regional longevity phenomenon in China and many longevity counties are located in South China. This study was carried out to find the characteristics of elemental contents of drinking water in longevity areas in South China and the differences to non-longevity areas in China. A total of 128 drinking water samples were collected from longevity areas in South China (n = 40), non-longevity areas in South China (n = 74) and non-longevity areas in North China (n = 14) and 46 parameters of water were determined or calculated. The results showed that drinking water in longevity areas of South China had a high ratio of sum concentration of essential micro-elements in sum concentration of micro-elements (SCME) and a low ratio of sum concentration of hazardous micro-elements in SCME. The concentration of total hardness (TH) and strontium in drinking water was 157.82 mg/L and 82.1 μg/L, respectively, and they were 14.61 mg/L, 7.45 μg/L and 291.69 mg/L, 748.65 μg/L in the non-longevity areas of South and North China, respectively. The study concluded that drinking water containing 157.82 mg/L TH and 82.1 μg/L strontium in South China may be optimum to human health.

  4. From blue to black: Anthropogenic forcing of carbon and nitrogen influx to mangrove-lined estuaries in the South China Sea.

    Science.gov (United States)

    Lee, S Y

    2016-08-30

    Southeast Asia is the global centre of mangrove development but human activities have dramatically reduced mangrove area in the region. An analysis is made of the shift in carbon and nitrogen influxes into the South China Sea (SCS) resulting from three anthropogenic nutrient sources: domestic sewage discharge, fertilizer use in rice agriculture and environmental loss from mariculture, between 1997 and 2010. Anthropogenic C and N influxes were, respectively, 1.81× and 1.43× those in 1997, with coastal aquaculture contributing most to the increase. In contrast, fringing mangroves provided ~44% of the C but only ~3% of the N from anthropogenic sources in 2010. In 1997, influx from mangroves was 113% and 6% of anthropogenic influx for C and N, respectively. This dominance by relatively labile anthropogenic nutrients over mangrove sources would change nearshore trophodynamics, with negative implications for the resilience of mangroves and nutrient-intolerant systems such as corals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. CO2 emissions from a temperate drowned river valley estuary adjacent to an emerging megacity (Sydney Harbour)

    Science.gov (United States)

    Tanner, E. L.; Mulhearn, P. J.; Eyre, B. D.

    2017-06-01

    The Sydney Harbour Estuary is a large drowned river valley adjacent to Sydney, a large urban metropolis on track to become a megacity; estimated to reach a population of 10 million by 2100. Monthly underway surveys of surface water pCO2 were undertaken along the main channel and tributaries, from January to December 2013. pCO2 showed substantial spatio-temporal variability in the narrow high residence time upper and mid sections of the estuary, with values reaching a maximum of 5650 μatm in the upper reaches and as low as 173 μatm in the mid estuary section, dominated by respiration and photosynthesis respectively. The large lower estuary displayed less variability in pCO2 with values ranging from 343 to 544 μatm controlled mainly by tidal pumping and temperature. Air-water CO2 emissions reached a maximum of 181 mmol C m-2 d-1 during spring in the eutrophic upper estuary. After a summer high rainfall event nutrient-stimulated biological pumping promoted a large uptake of CO2 transitioning the Sydney Harbour Estuary into a CO2 sink with a maximum uptake of rate of -10.6 mmol C m-2 d-1 in the mid-section of the estuary. Annually the Sydney Harbour Estuary was heterotrophic and a weak source of CO2 with an air-water emission rate of 1.2-5 mmol C m-2 d-1 (0.4-1.8 mol C m-2 y-1) resulting in a total carbon emission of around 930 tonnes per annum. CO2 emissions (weighted m3 s-1 of discharge per km2 of estuary surface area) from Sydney Harbour were an order of magnitude lower than other temperate large tectonic deltas, lagoons and engineered systems of China, India, Taiwan and Europe but were similar to other natural drowned river valley systems in the USA. Discharge per unit area appears to be a good predictor of CO2 emissions from estuaries of a similar climate and geomorphic class.

  6. Spatial risk for gender-specific adult mortality in an area of southern China

    Directory of Open Access Journals (Sweden)

    Ochiai Rion

    2007-07-01

    Full Text Available Abstract Background Although economic reforms have brought significant benefits, including improved health care to many Chinese people, accessibility to improved care has not been distributed evenly throughout Chinese society. Also, the effects of the uneven distribution of improved healthcare are not clearly understood. Evidence suggests that mortality is an indicator for evaluating accessibility to improved health care services. We constructed spatially smoothed risk maps for gender-specific adult mortality in an area of southern China comprising both urban and rural areas and identified ecological factors of gender-specific mortality across societies. Results The study analyzed the data of the Hechi Prefecture in southern in China. An average of 124,204 people lived in the area during the study period (2002–2004. Individual level data for 2002–2004 were grouped using identical rectangular cells (regular lattice of 0.25 km2. Poisson regression was fitted to the group level data to identify gender-specific ecological factors of adult (ages 15– Conclusion We found a disparity in mortality rates between rural and urban areas in the study area in southern China, especially for adult men. There were also differences in mortality rates between poorer and wealthy populations in both rural and urban areas, which may in part reflect differences in health care quality. Spatial influences upon adult male versus adult female mortality difference underscore the need for more research on gender-related influences on adult mortality in China.

  7. Areas of potential suitability and survival of Dendroctonus valens in China under extreme climate warming scenario.

    Science.gov (United States)

    He, S Y; Ge, X Z; Wang, T; Wen, J B; Zong, S X

    2015-08-01

    The areas in China with climates suitable for the potential distribution of the pest species red turpentine beetle (RTB) Dendroctonus valens LeConte (Coleoptera: Scolytidae) were predicted by CLIMEX based on historical climate data and future climate data with warming estimated. The model used a historical climate data set (1971-2000) and a simulated climate data set (2010-2039) provided by the Tyndall Centre for Climate Change (TYN SC 2.0). Based on the historical climate data, a wide area was available in China with a suitable climate for the beetle in which every province might contain suitable habitats for this pest, particularly all of the southern provinces. The northern limit of the distribution of the beetle was predicted to reach Yakeshi and Elunchun in Inner Mongolia, and the western boundary would reach to Keerkezi in Xinjiang Province. Based on a global-warming scenario, the area with a potential climate suited to RTB in the next 30 years (2010-2039) may extend further to the northeast. The northern limit of the distribution could reach most parts of south Heilongjiang Province, whereas the western limit would remain unchanged. Combined with the tendency for RTB to spread, the variation in suitable habitats within the scenario of extreme climate warming and the multiple geographical elements of China led us to assume that, within the next 30 years, RTB would spread towards the northeast, northwest, and central regions of China and could be a potentially serious problem for the forests of China.

  8. A review on the establishment and research in hydrological experimental areas (catchments) in plain areas in China and abroad

    Science.gov (United States)

    Yang, Hai; Wang, Chuanhai; Hua, Wenjuan

    2017-04-01

    This paper reviewed some specific conceptions of hydrological experimental areas (catchments) while found that the traditional definition of 'catchment' may be difficult to meet in plain areas. According to the review of development history and current situation of hydrological experimental areas (catchments) in plain areas in China, 4 stages were shown besides the recent 10 years, i.e., 'golden stage(1952-1966)', 'backward stage(1966-1986)', 'short recovery stage(1986-1989)' and 'stagnant stage(1986-2006)'. It gets new impetus since 2006 with some investigation work promoted by the government. Furthermore, some historic problems during establishing experimental areas (catchments) in plain areas were revealed based on the document literature and a few meaningful lessons were drawn from the past. It was also the first time to collect and classify the details of both 11 representative experimental areas in China and abroad, after that a brief comparison about the measurement level and research directions was made between two regions. Additionally, we took the experimental research work in the plain of Taihu Lake Basin as example and introduced the particular research goals and the corresponding establishing process, including how to design the experimental area, eg, size, location, land use type, arranging the measurement instruments et al. We hope such case can provide a reference for newly-building, recovering and extending hydrological experimental areasin plain areas in the future. Finally, this paper prospected the future development in establishment and research in hydrological experimental areas (catchments) in plain areas. It may be more common to see the cooperation between model scientists and field experts. Because of the comprehensive goals in water problems, researchers from various fields would work together in the future experimental research work. Scale study and modelling in plain areas will be a promising branch after some typical experimental areas

  9. Integrating priority areas and ecological corridors into national network for conservation planning in China.

    Science.gov (United States)

    Liang, Jie; He, Xinyue; Zeng, Guangming; Zhong, Minzhou; Gao, Xiang; Li, Xin; Li, Xiaodong; Wu, Haipeng; Feng, Chunting; Xing, Wenle; Fang, Yilong; Mo, Dan

    2018-01-11

    Considering that urban expansion and increase of human activities represent important threats to biodiversity and ecological processes in short and long term, developing protected area (PA) network with high connectivity is considered as a valuable conservation strategy. However, conservation planning associated with the large-scale network in China involves important information loopholes about the land cover and landscape connectivity. In this paper, we made an integrative analysis for the identification of conservation priority areas and least-cost ecological corridors (ECs) in order to promote a more representative, connected and efficient ecological PA network for this country. First, we used Zonation, a spatial prioritization software, to achieve a hierarchical mask and selected the top priority conservation areas. Second, we identified optimal linkages between two patches as corridors based on least-cost path algorithm. Finally, we proposed a new framework of China's PA network composed of conservation priority and ECs in consideration of high connectivity between areas. We observed that priority areas identified here cover 12.9% of the region, distributed mainly in mountainous and plateau areas, and only reflect a spatial mismatch of 19% with the current China's nature reserves locations. From the perspective of conservation, our result provide the need to consider new PA categories, specially located in the south (e.g., the middle-lower Yangtze River area, Nanling and Min-Zhe-Gan Mountains) and north regions (e.g., Changbai Mountains), in order to construct an optimal and connected national network in China. This information allows us better opportunities to identify the relative high-quality patches and draft the best conservation plan for the China's biodiversity in the long-term run. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Distribution and sources of polycyclic aromatic hydrocarbons in sediments from rivers of Pearl River Delta and its nearby South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Luo, X.J.; Chen, S.J.; Mai, B.X.; Zeng, Y.P.; Sheng, G.Y.; Fu, J.M. [Chinese Academy of Science, Guangzhou (China). State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry

    2005-07-15

    Polycyclic aromatic hydrocarbons (PAHs) are measured in surface sediments from rivers and estuary of Pearl River Delta and its nearby South China Sea. Total PAH concentration varied from 255.9 - 16 670.3 ng/g and a moderate to low level compare to relevant areas worldwide. The PAH concentration in sediments was: highest in the rivers of the Pearl River Delta, next highest in the estuary and lowest in theSouth China Sea. The most significant PAH contamination was at Guangzhou channel of Zhujiang river. A decrease trend for PAHs concentration with distance from estuary to open sea can be sees in South China Sea. Coal and biomass combustion is the major source of PAHs in nearshore of South China Sea, and petroleum combustion is the main source of pyrolytic PAHs in rivers and estuary of Pearl River Delta according to PAHs diagnostic ratios. Petroleum PAHs are revealed have a high contribution to PAHs in Xijiang River, estuary and some stations in Zhujiang River. A comparison of data from study in 1997 with data from present study indicates that there is no clear change in the PAH concentration over time but the source of PAHs in Pearl River Delta have been change from a main coal combustion to petroleum combustion and being reflect in the sediments in rivers and estuary of Pearl River Delta where there have high sedimentation rate.

  11. Collaborative Potential between National Estuary Programs ...

    Science.gov (United States)

    Estuaries are among the most productive ecosystems in the world, providing unique habitat for freshwater and marine species as well as valuable social and economic benefits. The wealth of ecosystem goods and services from estuaries has led to growth and development of human communities in adjacent areas and an increase in human activities that can adversely affect water quality and critical habitat. Managing for sustainable estuaries requires a balance of environmental concerns with community social and economic values. This has created an opportunity to leverage Environmental Protection Agency (EPA) scientific knowledge and tools with National Estuary Program (NEP) planning and management expertise to address environmental challenges in important estuarine ecosystems. The non-regulatory National Estuary Program (NEP) was outlined in the Clean Water Act to provide stakeholders an opportunity to monitor and manage ‘nationally significant’ estuaries. Currently there are 28 estuaries in the NEP, broadly distributed across the Atlantic, Pacific and Gulf Coasts, and in Puerto Rico. The local NEP management conferences must address a variety of environmental issues, from water quality and natural resources to coastal and watershed development. While the underlying objectives of each NEP are quite similar, each has unique landscapes, land uses, waterbodies, habitats, biological resources, economies and social culture. Consequently, the effects and severity of anthr

  12. Influences of population pressure change on vegetation greenness in China's mountainous areas.

    Science.gov (United States)

    Li, Wei; Li, Xiubin; Tan, Minghong; Wang, Yahui

    2017-11-01

    Mountainous areas in China account for two-thirds of the total land area. Due to rapid urbanization, rural population emigration in China's mountainous areas is very significant. This raises the question to which degree such population emigration influences the vegetation greenness in these areas. In this study, 9,753 sample areas (each sample measured about 64 square kilometers) were randomly selected, and the influences of population emigration (population pressure change) on vegetation greenness during 2000-2010 were quantitatively expressed by the multivariate linear regression (MLR) model, using census data under the condition of controlling the natural elements such as climatic and landform factors. The results indicate that the vegetation index in the past 10 years has presented an increasing overall trend, albeit with local decrease in some regions. The combined area of the regions with improved vegetation accounted for 81.7% of the total mountainous areas in China. From 2000 to 2010, the rural population significantly decreased, with most significant decreases in the northern and central areas (17.2% and 16.8%, respectively). In China's mountainous areas and in most of the subregions, population emigration has significant impacts on vegetation change. In different subregions, population decrease differently influenced vegetation greenness, and the marginal effect of population decrease on vegetation change presented obvious differences from north to south. In the southwest, on the premise of controlling other factors, a population decrease by one unit could increase the slope of vegetation change by 16.4%; in contrast, in the southeastern, northern, northeastern, and central area, the proportion was about 15.5%, 10.6%, 9.7%, and 7.5%, respectively, for improving the trend of NDVI variation.

  13. The etiology of esophageal cancer in high- and low- risk areas of Jiangsu province, China

    NARCIS (Netherlands)

    Wu, M.

    2011-01-01

        [Background]Esophageal cancer (EC) remains one of the most common and fatal malignancies worldwide. The geographic variation in EC occurrence is striking, and China is an area with one of the highest incidences of EC. A number of epidemiological studies

  14. Reflections on the Difficulties of Educational Development in Minority Areas of Western China

    Science.gov (United States)

    Jian, Wang

    2017-01-01

    At present, the development of education in western China's rural and ethnic minority areas faces problems including the management of boarding schools, the education of left-behind children, and changing the functions of schools. Resolving these problems requires not only changing traditional ways of thinking, but also placing minority education…

  15. Patterns of alien plant invasion across coastal bay areas in southern China

    Science.gov (United States)

    Hai Ren; Qinfeng Guo; Hong Liu; Jing Li; Qianmei Zhang; Hualin Xu; Fanghong Xu

    2014-01-01

    An understanding of the ways in which levels of invasions by alien species are correlated with environmental factors is helpful to manage the negative impacts of these invasive species. Two tropical coastal areas in South China, Shenzhen Bay and Leizhou Bay, are national nature reserves, but they are threatened by invasive plants. Here, we investigated the level of...

  16. A foraminiferal testimony for the reduced adverse effects of mining in Zuari Estuary, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Panchang, R.; Nigam, R.; Baig, N.; Nayak, G.N.

    with the TSM data collected over the years, which has considerably decreased. The foraminiferal data, TSM data and reduction in mining activities in the catchment area of the Zuari Estuary suggest an improvement in the environmental health of the estuary...

  17. Selection of strategic replacement areas for CBM exploration and development in China

    Directory of Open Access Journals (Sweden)

    Longyi Shao

    2015-03-01

    Full Text Available At present, the increase in proved reserves and production of coalbed methane (CBM in China depends mainly on several CBM bases in the southern Qinshui Basin and in the eastern margin of the Ordos Basin. Therefore, it is urgent to find new batches of exploration and development strategic replacement areas. For this purpose, we investigated the resources, reservoir properties, preservation conditions, and development conditions of CBM in China, and put forward eight general factors and four critical factors that can be used in establishing selection criteria of strategic replacement areas for affecting the CBM exploration and development in China. The eight general factors are resource abundance, coalbed thickness, gas content, original permeability, burial depth, hydrogeological conditions, coalbed depositional environment, and landforms, and the four critical factors include genetic type, stability type, later reservoir reformation, and damage degree of coal structure. Comparison shows that the low-rank coal area in the northwestern area, the northeastern medium-low rank coal area, and the southwestern medium-high rank and structurally-complex coal area are the major replacement areas for CBM following the northern area of China. Key factors affecting CBM enrichment in each of the three key areas, respectively, are: a genetic type and stability of coal seams, b genetic type and reconstruction of the reservoir by volcanic intrusion, and c stability of coal seams and damage degree of coal structure. Based on these factors, a system for selection and evaluation of strategic replacement areas for CBM development was established. Fifteen blocks in the above three areas were evaluated by using multi-layered fuzzy mathematics, selecting eight favorable areas and seven relatively favorable areas that contain 1.8 trillion m3 of predicted CBM geological resources. The eight favorable areas include the Wucaiwan-Dajing coal exploration area in the Zhundong

  18. The English Education in Primary Schools in Minor Ethnic Areas in Western China--Taking Leshan City as an Example

    Science.gov (United States)

    Bing, Wang

    2016-01-01

    As we all know, China is a country with many ethnic minorities mainly living in the northeastern and southwestern China. The English education in the primary schools in these areas is an important issue. The article analyzes the status quo of English education in primary schools in minor ethnic areas, taking the Leshan city, a western one as an…

  19. Quantitative risk analysis and prediction of potential distribution areas of common lantana (Lantana Camara in China

    Directory of Open Access Journals (Sweden)

    XiangRong Lui

    2011-04-01

    Full Text Available The ornamental hybrid shrub, Lantana camara L. (lantana, is a serious environmental weed and has been targeted for the biologist. This paper used such approaches as Analytic Hierarchy Process (AHP, fuzzy decision, etc., to analyze and predict potential distribution areas of common lantana in 147 sites of China. Based on ecological properties of common lantana, we chose 5 climate ecological factors, i.e., mean annual temperature, mean temperature from March to May in a year, elevation, days with temperature greater than 25C and annual precipitation. The results showed that common lantana will continue to spread forward north China (Hunan, Hubei, etc..

  20. Adaptive Effectiveness of Irrigated Area Expansion in Mitigating the Impacts of Climate Change on Crop Yields in Northern China

    National Research Council Canada - National Science Library

    Tianyi Zhang; Jinxia Wang; Yishu Teng

    2017-01-01

    .... Here, we assess the effects of irrigated area expansion on crop yields based on county-level data during 1980-2011 in northern China and estimate climate impacts under irrigated area scenarios in the 2030s...

  1. Learning Lessons from Estuaries

    Science.gov (United States)

    Schnittka, Christine

    2006-01-01

    There is something that draws all people to the sea and especially to the fertile estuaries that nuzzle up to its shores. An estuary serves as both a nursery and a grave for sea creatures. If life evolved from some primordial sea, it may well have been an estuary--a place where ocean and rivers meet and fresh and salty waters mingle in the…

  2. Air Pollutants, Climate, and the Prevalence of Pediatric Asthma in Urban Areas of China.

    Science.gov (United States)

    Zhang, Juanjuan; Dai, Jihong; Yan, Li; Fu, Wenlong; Yi, Jing; Chen, Yuzhi; Liu, Chuanhe; Xu, Dongqun; Wang, Qiang

    2016-01-01

    Background. Prevalence of childhood asthma varies significantly among regions, while its reasons are not clear yet with only a few studies reporting relevant causes for this variation. Objective. To investigate the potential role of city-average levels of air pollutants and climatic factors in order to distinguish differences in asthma prevalence in China and explain their reasons. Methods. Data pertaining to 10,777 asthmatic patients were obtained from the third nationwide survey of childhood asthma in China's urban areas. Annual mean concentrations of air pollutants and other climatic factors were obtained for the same period from several government departments. Data analysis was implemented with descriptive statistics, Pearson correlation coefficient, and multiple regression analysis. Results. Pearson correlation analysis showed that the situation of childhood asthma was strongly linked with SO2, relative humidity, and hours of sunshine (p climate, at least in terms of children, plays a major role in explaining regional differences in asthma prevalence in China.

  3. Assessing Collembola biodiversity under human influence at Three Gorges Area, China.

    Science.gov (United States)

    Huang, Cheng; Wang, Tianle; Luo, Yongzheng; Chen, Shi; Kim, Ke Chung

    2013-04-01

    In this study we comprehensively assessed Collembola biodiversity at Three Gorges Area, one of most diverse habitat regions in China. In total, 3,796 Collembola specimens comprising 9 families, 45 genera, and 103 species (including 14 new species and new records in China) were collected from three primary sampling areas: one nature reserve and two rural and urban areas representing different degrees of human influence. Each sampling area was further divided into nine sampling sites associated with different habitats and altitudes. Analyses of biodiversity data showed that individual abundance was highest in the nature reserve followed by mildly human influenced areas, and then highly influenced areas, and species richness was lowest in highly influenced areas. Hence, we suggest Collembola biodiversity is systematically lost after urbanization. In the nature reserve, altitude significantly influenced both the species richness and individual abundance, whereas in rural and urban areas, both altitude and the human-altered environmental gradient were influential. We also measured sampling efficiency and estimated potential species richness in these areas. This study serves as both a fundamental survey of Collembola biodiversity, as well as an assessment of human/environmental influence on the Collembola community, and can provide further insight into protecting the soil integrity of the Three Gorges Area.

  4. Modelling Suspended Sediment Transport in Monsoon Season: A Case Study of Pahang River Estuary, Pahang, Malaysia

    Science.gov (United States)

    Zakariya, Razak; Ahmad, Zuhairi; Saad, Shahbudin; Yaakop, Rosnan

    2013-04-01

    Sediment transport based on 2-dimensional real time model was applied to Pahang River estuary, Pahang, Malaysia and has been evaluated and verified with time series of tidal elevation, flow and suspended sediment load. Period of modelling was during highest high tide and lowest low tide in Northeast Monsoon (NE) which happened in December 2010 and Southwest Monsoon (SW) in July 2011. Simulated model outputs has been verify using Pearson's coefficient and has showed high accuracy. The validated model was used to simulate hydrodynamic and sediment transport of extreme conditions during both monsoon seasons. Based on field measurement and model simulation, tidal elevation and flow velocity, freshwater discharge of Pahang River were found to be higher during NE Monsoon. Based on the fluxes, the estuary also showed 'ebb-dominant' characteristic during highest high tide and lowest low tide in NE monsoon and normal ebbing-flooding characteristics during SW monsoon. In the Pahang River estuary, inflow and outflow patterns were perpendicular to the open boundary with circular flow formed at the shallow area in the middle of estuary during both monsoons. Referring to sea water intrusion from the river mouth, both seasons show penetration of more than 9 km (upstream input boundary) during higher high water tide. During higher lower water tide, the water intrusion stated varies which 5.6km during NE monsoon and 7.8km during SW monsoon. Regarding to the times lap during high tide, the sea water takes 2.8 hours to reach 9km upstream during NE monsoon compared to 1.9 hour during SW monsoon. The averages of suspended sediment concentration and suspended sediment load were higher during Northeast monsoon which increased the sedimentation potentials.Total of suspended sediment load discharged to the South China Sea yearly from Pahang River is approximately 96727.5 tonnes/day or 3.33 tonnes/km2/day which 442.6 tonnes/day during Northeast Monsoon and 25.3 tonnes/day during Southwest

  5. First identification of a possible nursery area for diadromous Coilia nasus in the Poyang Lake nearly 1000 km away from the Yangtze River Estuary

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2015-11-01

    Full Text Available Estuarine tapertail anchovy Coilia nasus is a small-sized anadromous species in the Yangtze River, China. It is probably the most expensive fish in the world with price as high as $1000/kg and even $9600 for a single extremely large individual with a total length of 45.3 cm and body weight of 0.325 kg in the Jiangsu section of the river in 2012. However, when and where C. nasus spawn along the Yangtze River has still remained a mystery so far. In our field surveys of 2014 and 2015, some highly mature female and male C. nasus with stage V or VI gonads were firstly collected in the water region around Xingzi County in the Poyang Lake, which is nearly 1000 km away from the mouth of the Yangtze River. Although previous studies believed that all C. nasus in the Poyang Lake were freshwater residents, the otolith microchemistry signatures of the present study determined with EPMA and LA-ICPMS further clearly demonstrated that these fish were anadromous individuals. The findings indicated that the C. nasus migrated over nearly 1000 km upstream, with an extremely strong migration ability, passing through the lower reaches of the Yangtze River from the adjacent Yellow sea (even from the areas nearly straight line for as far as ca. 300 km off the Chinese coast line or East China Sea (Figure 1. The aforementioned evidence strongly suggests that the water region around Xingzi County in the Poyang Lake is a possible spawning/nursery area for anadromous C. nasus. It will be critical to ensure the protection of this region of the Poyang Lake being free from the environmental destruction of anthropogenic activities, especially hydraulic structure (especially dam construction and sand mining.

  6. Risk factors of bicycle traffic injury among middle school students in chaoshan rural areas of china.

    Science.gov (United States)

    Lin, Zhen-Bin; Ji, Yan-Hu; Xiao, Qing-Yu; Luo, Li-Bo; Li, Li-Ping; Choi, Bernard

    2017-01-26

    Bicycle injuries are a leading cause of accidental death among children in the world, and bicycle-related injuries are also very common in China, thus to find out bicycle injury risk factors is imperative. This study aims to identify the cyclist-, bicycle- and road-related risk factors of bicycle injury, to develop health education programs as an intervention and to provide a scientific basis for establishing policies against bicycle injury. We selected two middle schools randomly among seven schools in Chaoshan rural areas,where the main means of transportation for students from home to school was bicycle. The subjects were middle school students from 7th to 9th grades from Gucuo Middle School and Hefeng Middle School. Cyclists were surveyed through questionnaires about bicycle injury in the past 12 months. Multivariable logistic analysis showed that compared with a combination-type road、 motor lane and a non-intact road were both risk factors of bicycle injuries. This was followed by riding with fatigue, non-motor lane and inattentive riding. Bicycle injuries are frequent in China. Three risk factors on bicycle traffic injury among middle school students in Chaoshan rural areas of China were identified. This study provides important data to develop intervention strategies for China and other developing countries.

  7. Long-term monitoring of atmospheric total gaseous mercury (TGM) at a remote site in Mt. Changbai area, northeastern China

    OpenAIRE

    X. W. Fu; X. Feng; L. H. Shang; S. F. Wang; H. Zhang

    2012-01-01

    Total gaseous mercury (TGM) was continuously monitored at a remote site (CBS) in the Mt. Changbai area, northeastern China biennially from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60 ± 0.51 ng m−3, which is lower than those reported from remote sites in eastern, southwestern and western China, indicating a relatively low regional anthropogenic mercury (Hg) emission intensity in northeastern China. Measurements at a site in ...

  8. Two years of measurements of atmospheric total gaseous mercury (TGM) at a remote site in Mt. Changbai area, Northeastern China

    OpenAIRE

    X. W. Fu; X. Feng; L. H. Shang; S. F. Wang; H. Zhang

    2012-01-01

    Total gaseous mercury (TGM) was continuously monitored at a remote site (CBS) in Mt. Changbai area, Northeastern China from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60±0.51 ng m−3, which is lower than those reported from remote sites in Eastern, Southwestern, and Western China, indicating a relatively lower regional anthropogenic mercury (Hg) emission intensity in Northeastern China. Measurements at a site in the vicinity (...

  9. Structure, distribution, and evolution history of the Early Holocene erosional mud ridge system on the inner East China Sea shelf near the Yangtze River estuary

    Science.gov (United States)

    Feng, Zhibing; Liu, Baohua; Zhao, Yuexia; Li, Xishuang; Dada, Olusegun A.; Jiang, Li; Si, Shaokun

    2017-04-01

    Utilizing the collected high-resolution seismic dataset and accompanying borehole and bathymetric data, we systematically evaluated the morphology, architecture, sedimentology, and evolution of erosional mud ridges within the inner East China Sea (ECS) shelf. We identified 20 mud ridges, i.e., seismic reflection profile crossings of exposed or buried mud ridges, which are 3.0-30.1 km in width and 2.5-17.3 m in height. The mud ridges are composed predominantly of gray clayey silt, and on seismic profiles contain parallel to subparallel reflectors. They formed around 10-12 ka BP within an estuarine environment. Scouring features of some mud ridges on the eastern part of the study area can be recognized. Consideration of the relative positions of mud ridges, together with the topographical features, enables us to map four linear mud ridges (LMRs). The SE-NW oriented LMRs are > 50 km in length, 3.0-9.5 km in width and running parallel to each other. They also display asymmetric shapes, with steeper slopes to the SW. The eastern segments of some LMRs are exposed on the present seafloor whereas other segments are mainly overlain by the mid- and late Holocene strata. Since the LMRs share similarities with the modern tidal sand ridges in shape and orientation, we hypothesize that they are formed under a uniform tidal current. Seismic data highlight that the internal reflectors of sand ridges consist of dipping clinoforms and are significantly different from LMRs, a feature which is largely due to the difference in grain-size composition of sediments between the inner and mid-outer ECS shelf. The mid- to outer ECS shelf is capped by coarser-grained sediments (i.e., medium to fine-grained), which were reworked and deposited at locations near the erosional areas under a polycyclic tidal current, thus forming multiphase sand ridges. However, fine-grained sediments (i.e., silty clay and clayey silt) overlain on the inner ECS shelf with light mass were carried far away from the

  10. The Mtata River estuary

    African Journals Online (AJOL)

    1989-02-28

    Feb 28, 1989 ... A survey of the fish fauna of Transkei estuaries. Part Three: The Mtata River estuary. E.E. Plumstead* and J.F. Prinsloo. Department of Zoology, University of Transkei, Private Bag X1 001, Unitra, Umtata, Republic of Transkei. H.J. Schoonbee. Department of Zoology, Rand Afrikaans University, P.O. Box 524, ...

  11. The Hudson River estuary

    National Research Council Canada - National Science Library

    Levinton, J.S; Waldman, J.R

    2006-01-01

    ... emphasis on important issues specific to the Hudson, such as the effect of power plants and high concentrations of PCBs. The chapters are written by specialists at a level that is accessible to students, teachers, and the interested layperson. The Hudson River Estuary is a unique scientifi c biography of a major estuary, with relevance to the s...

  12. The impact of husbands' gender equity awareness on wives' reproductive health in rural areas of China.

    Science.gov (United States)

    Ying, Cui; Li, Yang; Hui, Han

    2011-02-01

    The aim of this study was to investigate the effect of husbands' gender equity awareness on wives' reproductive health in rural areas of China. A qualitative study of 1919 wives aged from 18 to 69 years and their husbands was conducted in rural China. Data were collected through 3838 structured interviews. We quantified "belief in gender equity" based on responses to 7 specific statements and graded the responses according to a system scoring the strength of the overall belief (a total score 19 or higher, strong; 15-18, moderate; and 14 or less, weak). Data were recorded by bi-input with EpiData 3.1 after being carefully checked. χ(2) tests and logistic regression were performed in this study. Only 20.0% of the husbands demonstrated strong convictions about gender equity. Husbands' gender equity awareness is related to wives' receiving any prenatal care, the number of prenatal visits to a healthcare provider, having a hospital delivery of a newborn, and having gynecological examination one time per year. Raising husbands' gender awareness on wives' reproductive health and reducing female illiteracy were very necessary. The whole community should participate actively in the progress of reproductive health promotion. China's Health System requires an integration of its various sectors, including family planning, maternal and child care in resource sharing, and service delivery. Obstetricians & gynecologists. After completing this CME activity, physicians should be better able to evaluate the impact of husbands' gender equity awareness on wives' reproductive health in rural areas of China; assess how raising husbands' gender awareness on wives' reproductive health and reducing female illiteracy will improve wives' reproductive health; and analyze how China's Health System can integrate its various sectors, including family planning, maternal, and childcare in resource sharing, and service delivery, to improve wives' reproductive health.

  13. Investigation on actual dietary life conditions of elementary school children in urban areas of China

    OpenAIRE

    邱, 昱; 中山, 玲子

    2016-01-01

    To clarify the dietary life of children in urban areas of China, we have conducted this research to investigate the daily habits, dietary awareness and dietary behavior of children in Guangzhou. A questionnaire was conducted among 814 parents of children at two public elementary schools in 2015. The dietary habits were related to the school year and gender of child. Students of lower grades showed better eating habits, better exercise, life rhythm regularly. However, the percentage of upper g...

  14. China’s Out of Area Naval Operations: Case Studies, Trajectories, Obstacles, and Potential Solutions

    Science.gov (United States)

    2010-12-01

    blue water,20 out of area navigation exercises (to Zengmu Reef , the southernmost islets in the South China Sea). The fleet was organized around the... mines , and serve as reconnaissance for the task force. The Gulf of Aden deployments each enjoyed the use of two helicopters, a woefully inadequate...War, and Spanish- American War, thus cutting off access to coal , supplies, and repair facilities during hostilities.72 The political repercussions of

  15. A new species of Metaeuchromius (Lepidoptera, Crambidae from the Tibetan glacier area of China

    Directory of Open Access Journals (Sweden)

    Weichun Li

    2015-01-01

    Full Text Available Metaeuchromius glacialis Li, sp. n. is described from the Tibetan glacier area of China. The new species is similar to M. circe Bleszynski by the distal projection of costa exceeding the apex of valva, and the phallus with strong spine-like cornuti in the male genitalia. Images of male adult, tympanal and scent organs as well as genitalia of the new species are provided.

  16. Assessment of heavy metal pollution in wetland soils from the young and old reclaimed regions in the Pearl River Estuary, South China.

    Science.gov (United States)

    Bai, Junhong; Xiao, Rong; Cui, Baoshan; Zhang, Kejiang; Wang, Qinggai; Liu, Xinhui; Gao, Haifeng; Huang, Laibin

    2011-03-01

    Soils were sampled in three types of wetlands from the young (A) and old (B) reclaimed regions of the Pearl River Estuary. They were analyzed for total concentrations of heavy metals to investigate their distributions and pollution levels in both regions. Results showed that most heavy metals in ditch and riparian wetlands did not significantly differ from those in reclaimed wetlands in A region, while significantly lower for Cd, Cu, Pb, and Zn in reclaimed wetlands in B region, suggesting higher effects of long-term reclamation. Iron, Cr and Cu were identified as metal pollutants of primary concern and had higher contributions to the total toxic units compared to other metals. Almost all metals exceeded their lowest effect levels and Fe and Cr even exceeded the severe effect levels. Multivariate analysis shows that Fe and Mn are controlled by parent rocks and other metals mainly originate from anthropogenic source. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Proceedings of a Maritimes Science Advisory Process to develop a framework for monitoring the Musquash Estuary Marine Protected Area (MPA) and Administered Intertidal Area (AIA), 9-10 December 2010, St. Andrews, New Brunswick: Compte rendu d'une réunion du Processus de consultation scientifique de la Région des Maritimes concernant l'établissement d'un cadre de surveillance de la zone de protection marine (ZPA) de l'estuaire du MPO et de la zone intertidale administrée par le MPO, les 9 et 10 décembre 2010, St. Andrews (Nouveau-Brunswick)

    National Research Council Canada - National Science Library

    Kennedy, E; Curran, K

    2011-01-01

    ... agencies, attended the meeting. The meeting was held to review the proposed indicators, strategies, and protocols for monitoring the Musquash Estuary Marine Protected Area and intertidal area administered by DFO...

  18. Influences of hydrological regime on heavy metal and salt ion concentrations in intertidal sediment from Chongming Dongtan, Changjiang River estuary, China

    Science.gov (United States)

    Zhao, Jiale; Gao, Xiaojiang; Yang, Jin

    2017-11-01

    The tidal flat along the Changjiang (Yangtze) River estuary has long been reclaimed for the agricultural purposes, with the prevailing hydrological conditions during such pedogenic transformations being of great importance to their successful development. In this study, samples of surface sediment from Chongming Dongtan, situated at the mouth of the Changjiang River estuary, were collected and analyzed in order to understand how hydrological management can influence the concentrations of heavy metals and salt ions in pore water, and chemical fractionation of heavy metals during the reclamation process. We performed a series of experiments that simulated three different hydrological regimes: permanent flooding (R1), alternative five-day periods of wetting and drying (R2), continuous field capacity (R3). Our results exhibited good Pearson correlations coefficients between heavy metals and salt ions in the pore water for both R1 and R2. In particular, the concentrations of salt ions in the pore water decreased in all three regimes, but showed the biggest decline in R2. With this R2 experiment, the periodic concentration patterns in the pore water varied for Fe and Mn, but not for Cr, Cu, Pb and Zn. Neither the fractionation of Ni nor the residual fractions of any metals changed significantly in any regime. In R1, the reducible fractions of heavy metals (Cr, Cu, Zn and Pb) in the sediment decreased, while the acid extractable fractions increased. In R2, the acid extractable and the reducible fractions of Cr, Cu, Zn and Pb both decreased, as did the oxidizable fraction of Cu. These data suggest that an alternating hydrological regime can reduce both salinity and the availability of heavy metals in sediments.

  19. Variation of Archaeal Populations Along a Salinity Gradient in the Pearl River Estuary, China: Implications for Synergy Between Different Metabolic Processes

    Science.gov (United States)

    Zhang, C.

    2016-02-01

    Marine archaea mainly include marine group I (MGI) that function as chemolithoautotrophs growing on ammonia and marine group II (MGII) that live heterotrophically. In this study, we quantified the abundance of MGI (represented by archaeal amoA gene) and MGII (16S rRNA gene) using qPCR in the water column of different salinities (A: 0.8‰; B: 18.1‰; C: 23.9‰: D: 31‰) in the Pearl River Estuary over a 12-month period. The results showed that the abundance of MG II in site C (8.5±10.1×107 copies/L) was significantly higher than the other three sites (A: 3.5±8.8×105 copies/L; B: 2.7±4.5×107 copies/L; D: 2.2±4.4×107 copies/L) in all seasons, indicating the perennial blooming of MGII that might be due to the optimal combination of available organic carbon and salinity at this site. We also observed that the correlation between MGI and MGII became better toward the marine water and was significant at site D (R2: A, 0.06; B, 0.1; C, 0.24; D, 0.64), indicating the potential functional relationship between them with increasing salinity. This allows us to hypothesize that the growth of MGI in the coastal site is more dependent on release of ammonia from organic matter degradation by MGII and other heterotrophic organisms. The Pearl River Estuary may be an ideal environment for testing this hypothesis, which may provide insight into the mechanisms of carbon cycle performed by different archaea in continental margin systems.

  20. Abundance, distribution and bioavailability of major and trace elements in surface sediments from the Cai River estuary and Nha Trang Bay (South China Sea, Vietnam)

    Science.gov (United States)

    Koukina, S. E.; Lobus, N. V.; Peresypkin, V. I.; Dara, O. M.; Smurov, A. V.

    2017-11-01

    Major (Si, Al, Fe, Ti, Mg, Ca, Na, K, S, P), minor (Mn) and trace (Li, V, Cr, Co, Ni, Cu, Zn, As, Sr, Zr, Mo, Cd, Ag, Sn, Sb, Cs, Ba, Hg, Pb, Bi and U) elements, their chemical forms and the mineral composition, organic matter (TOC) and carbonates (TIC) in surface sediments from the Cai River estuary and Nha Trang Bay were first determined along the salinity gradient. The abundance and ratio of major and trace elements in surface sediments are discussed in relation to the mineralogy, grain size, depositional conditions, reference background and SQG values. Most trace-element contents are at natural levels and are derived from the composition of rocks and soils in the watershed. A severe enrichment of Ag is most likely derived from metal-rich detrital heavy minerals such as Ag-sulfosalts. Along the salinity gradient, several zones of metal enrichment occur in surface sediments because of the geochemical fractionation of the riverine material. The parts of actually and potentially bioavailable forms (isolated by four single chemical reagent extractions) are most elevated for Mn and Pb (up to 36% and 32% of total content, respectively). The possible anthropogenic input of Pb in the region requires further study. Overall, the most bioavailable parts of trace elements are associated with easily soluble amorphous Fe and Mn oxyhydroxides. The sediments are primarily enriched with bioavailable metal forms in the riverine part of the estuary. Natural (such as turbidities) and human-generated (such as urban and industrial activities) pressures are shown to influence the abundance and speciation of potential contaminants and therefore change their bioavailability in this estuarine system.

  1. The effects of the 2010 flood on the composition and abundance of the terrestrial organic matter in sediments along the inner-shelf off the Changjiang Estuary, China

    Science.gov (United States)

    Li, X.; Bianchi, T. S.; Allison, M. A.; Chapman, P.; Yang, G.

    2011-12-01

    Surface sediments were collected within the primary depositional pathway along the inner-shelf off the Changjiang Estuary in winter 2009 and fall 2010 - before and after the 2010 flood in the Changjiang River. Multiple proxies (stable isotopes, lignin-phenols, pigments, cutins) were analyzed to examine the influence of this flooding event on the composition and abundance of river-derived terrestrial organic matter in sediments off the Changjiang Estuary. Elemental and stable isotope analyses showed significantly higher molar C/N ratios and enriched δ13C signatures for 2010 samples, which likely reflected inputs of C4 vascular plant materials. Post-flood concentrations of lignin-phenols were significantly lower in concentration than pre-flood concentrations in 2009. Lignin-phenol acid/aldehyde (Ad/Al) ratios, the lignin degradation index, showed significantly more degraded lignin post-flood in 2010 than that in 2009, which suggests greater inputs of lignins that were likely associated more with degraded soils, due to enhanced erosion from the flood, than surface plant litter. This was also in good agreement with higher inputs of another lignin soil proxy, the 3,5-Bd (3,5-dihydroxybenzoic acid) /V. Lignin-phenol source plots showed no significant differences in pre-and post flood sources, with sources largely consisting of a mixture of woody and non-woody gymnosperm and angiosperm inputs. Short lived radionuclides such as 7Be, 234Th analysis showed no apparent short-term sediment accumulation. The lack of evidence for new sediments deposited to the inner shelf after the flood was likely influenced in part, by the effects of extensive upstream damming on the Changjiang, especially the more recently constructed Three Gorges Dam.

  2. Can Information and Counseling Help Students from Poor Rural Areas Go to High School? Evidence from China

    Science.gov (United States)

    Loyalka, Prashant; Liu, Chengfang; Song, Yingquan; Yi, Hongmei; Huang, Xiaoting; Wei, Jianguo; Zhang, Linxiu; Shi, Yaojiang; Chu, James; Rozelle, Scott

    2013-01-01

    To sustain its economic growth in the coming years, China will have to increase the country's supply of skilled labor by enabling its workforce to attain to higher levels of formal education. Unfortunately, when children in poor, rural areas today grow up, they may not be able to enjoy China's future economic prosperity because of their low levels…

  3. Education for Sustainable Development in Ethnic Autonomous Areas of China: A Comparison of Two Curriculum Initiatives and Their Educational Implications

    Science.gov (United States)

    Khoo, Yishin

    2015-01-01

    This paper examines the educational implications of two curriculum initiatives in China that have produced curricular materials promoting education for sustainable development (ESD) in minority-populated ethnic autonomous areas in China. The two curriculum projects present distinctive discourses, conceptions, models, frameworks and scopes of ESD…

  4. State of rare earth elements in different environmental components in mining areas of China.

    Science.gov (United States)

    Liang, Tao; Li, Kexin; Wang, Lingqing

    2014-03-01

    China has relatively abundant rare earth elements (REEs) reserves and will continue to be one of the major producers of REEs for the world market in the foreseeable future. However, due to the large scale of mining and refining activities, large amounts of REEs have been released to the surrounding environment and caused harmful effects on local residents. This paper summarizes the data about the contents and translocation of REEs in soils, waters, atmosphere, and plants in REE mining areas of China and discusses the characteristics of their forms, distribution, fractionation, and influencing factors. Obviously high concentrations of REEs with active and bioavailable forms are observed in all environmental media. The mobility and bioavailability of REEs are enhanced. The distribution patterns of REEs in soils and water bodies are all in line with their parent rocks. Significant fractionation phenomenon among individual members of REEs was found in soil-plant systems. However, limited knowledge was available for REEs in atmosphere. More studies focusing on the behavior of REEs in ambient air of REE mining areas in China are highly suggested. In addition, systematic study on the translocation and circulation of REEs in various media in REEs mining areas and their health risk assessment should be carried out. Standard analytical methods of REEs in environments need to be established, and more specific guideline values of REEs in foods should also be developed.

  5. Risk analysis and evaluation of agricultural drought disaster in the major grain-producing areas, China

    Directory of Open Access Journals (Sweden)

    Zongtang Xie

    2016-09-01

    Full Text Available The analysis and evaluation of agricultural drought risk can assist in reducing regional disasters and agricultural drought losses. Because of the uncertainties and incomplete agricultural drought information, this paper employed an information diffusion technology and information matrix to identify a drought disaster risk distribution and to quantify the relationship between the annual drought-affected rate and the grain production losses in China's major grain-producing areas. From the assessment results, provincial drought disaster risk spatial distribution maps for each major grain-producing area in China were obtained. These risk patterns showed that the probability of drought fell when the annual drought-covered rate and the annual drought-affected rate increased, and that the high risk areas were located primarily in China's northern and central provinces. These results can provide the basis for the development of effective drought mitigation strategies which would be able to inform possible drought situations and allow for easier decision-making on drought resistance strategies. The fuzzy relationship between the annual drought-affected rate and the drought-caused grain production losses provides vital information for the development of disaster compensation plans. Furthermore, the results of this study indicated that the proposed methods had superior detection stability and higher precision. We hope that by conducting such agricultural drought risk analysis, the results are able to provide the basis for the development of drought mitigation strategies to reduce future losses.

  6. mysidacea of the mtentu river estuary, transkei, south africa

    African Journals Online (AJOL)

    The Mtentu River has a straight open tidal estuary flowing between steep grassy or indigenous forest. covered slopes. Total high-water surface area is about 0,3 kin·. The zooplankton was studied by periodic sampling over a period of thirteen months. Some physical characteristics of the estuary are presented. The seasonal ...

  7. Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

    Directory of Open Access Journals (Sweden)

    Jizhong Shao

    2016-04-01

    Full Text Available Based on the Great Western Development Strategy and the requirement for sustainable development in the west of China, rural affordable housing, energy conservation, and environmental protection are becoming development standards in the construction field. This paper mainly explores an innovative, sustainable, residential construction method for rural areas in western China, particularly the integration of solar energy technology with modern prefabricated building techniques, formally named solar energy block-based construction. The conscious approach of using volumetric blocks provides superior adaptability and expansibility in integration with a steel structure, thereby reducing the construction time and cost. Allowing a wide variety of configurations and styles in the building layout, this approach can be customized to the end-user’s precise location and climate, making rural residential buildings much more flexible and modern. To take advantage of adequate solar energy resource in western China, the blocks are associated with active and passive solar energy technologies, thereby reducing pollution, mitigating global warming, and enhancing sustainability. Therefore, we concluded that solar energy block-based construction could bring significant benefits to the environment, economy, and society. It could also promote sustainable development in the rural regions of western China.

  8. Model simulation of tide-induced currents in Gauthami-Godavari estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Sridevi, B.; Murty, T.V.R.; Sadhuram, Y.; Sarma, V.V.S.S.; Naidu, V.S.; Prasad, K.V.S.R.

    –Godavari estuary Estuaries are often surrounded by pro- tected ecosystems, and harbour signifi- cant human populations which exploit the area for leisure and tourism. Studies on Indian estuaries can be found in Qasim1. Several studies2–11 reported various... controlled by Low Dam at Dowleiswaram, where it bifurcates into two channels as Vasishta and Gauthami Godavari estuary (Figure 1)18,19. Discharge was maximal in August, and virtually no or negligible discharge between January and May19. Mixing...

  9. The effects of a solar eclipse on photo-oxidants in different areas of China

    Directory of Open Access Journals (Sweden)

    J.-B. Wu

    2011-08-01

    Full Text Available This study investigates the effects of the total solar eclipse of 22 July 2009 on surface ozone and other photo-oxidants over China. A box model was used to study the sensitivity of ozone to the limb darkening effect during an eclipse event, and to show that the impact on ozone is small (less than 0.5 %. In addition, the regional model WRF-Chem was applied to study the effects of the eclipse on meteorological and chemical parameters, focusing on different regions in China. Chemical and meteorological observations were used to validate the model and to show that it can capture the effects of the total solar eclipse well. Model calculations show distinct differences in the spatial distributions of meteorological and chemical parameters with and without the eclipse. The maximum impacts of the eclipse occur over the area of totality, where there is a decrease in surface temperature of 1.5 °C and decrease in wind speed of 1 m s−1. The maximum impacts on atmospheric pollutants occur over parts of north and east China where emissions are greater, with an increase of 5 ppbv in NO2 and 25 ppbv in CO and a decrease of 10 ppbv in O3 and 4 ppbv in NO. This study also demonstrates the effects of the solar eclipse on surface photo-oxidants in different parts of China. Although the sun was obscured to a smaller extent in polluted areas than in clean areas, the impacts of the eclipse in polluted areas are greater and last longer than they do in clean areas. In contrast, the change in radical concentrations (OH, HO2 and NO3 in clean areas is much larger than in polluted areas mainly because of the limited source of radicals in these areas. The change in radical concentrations during the eclipse reveals that nighttime chemistry dominates in both clean and polluted areas. As solar eclipses provide a natural opportunity to test more thoroughly our understanding of atmospheric chemistry, especially that

  10. Carbonate platforms in the Reed Bank area, South China Sea: seismic characteristics, development and controlling factors

    Science.gov (United States)

    Ding, W.

    2013-12-01

    We identify the seismic characteristics about the carbonate platform and other types of reefs in the Reed Bank area, South China Sea, based on a more than 220 km long multi-channel seismic reflection profile. From the Late Oligocene to Early Miocene Carbonate platforms were well developed featured with high-amplitude continuous reflections at the top and low-amplitude parallel reflections within. Reefal carbonate build-ups continued in structural highs almost up to the Middle Miocene, and even to present in the Reed Bank. The development of carbonate platforms and reefs were controlled by the tectonics and sea level changes in the study area synthetically. During the drifting stage of SCS the Reed Bank area was in a relatively stable condition. An everlasting shallow marine environment and low sediments input favored the formation of carbonate platforms. A sudden thermal subsidence after the cessation of SCS's opening in Early Miocene and the continue rising of sea level made the carbonate platform drown and die. Reed Bank basin is a very promising area for further exploration work. Keywords: carbonate platform, Reed Bank area, Tectonic subsidence, controlling factors, South China Sea Fig 1. Model of hydrocarbon accumulation and transfer with carbonate platform and reef reservoir in the deep water area of the Reed Bank basin. Fig 2 Tectonic subsidence in the Reed Bank Basin

  11. Projecting environmental suitable areas for malaria transmission in China under climate change scenarios.

    Science.gov (United States)

    Hundessa, Samuel; Li, Shanshan; Liu, De Li; Guo, Jinpeng; Guo, Yuming; Zhang, Wenyi; Williams, Gail

    2018-04-01

    The proportion of imported malaria cases in China has increased over recent years, and has presented challenges for the malaria elimination program in China. However, little is known about the geographic distribution and environmental suitability for malaria transmission under projected climate change scenarios. Using the MaxEnt model based on malaria presence-only records, we produced environmental suitability maps and examined the relative contribution of topographic, demographic, and environmental risk factors for P. vivax and P. falciparum malaria in China. The MaxEnt model estimated that environmental suitability areas (ESAs) for malaria cover the central, south, southwest, east and northern regions, with a slightly wider range of ESAs extending to the northeast region for P. falciparum. There was spatial agreement between the location of imported cases and area environmentally suitable for malaria transmission. The ESAs of P. vivax and P. falciparum are projected to increase in some parts of southwest, south, central, north and northeast regions in the 2030s, 2050s, and 2080s, by a greater amount for P. falciparum under the RCP8.5 scenario. Temperature and NDVI values were the most influential in defining the ESAs for P. vivax, and temperature and precipitation the most influential for P. falciparum malaria. This study estimated that the ESA for malaria transmission in China will increase with climate change and highlights the potential establishment of further local transmission. This model should be used to support malaria control by targeting areas where interventions on malaria transmission need to be enhanced. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Increase of Elderly Population in the Rainstorm Hazard Areas of China.

    Science.gov (United States)

    Liang, Pujun; Xu, Wei; Ma, Yunjia; Zhao, Xiujuan; Qin, Lianjie

    2017-08-26

    In light of global warming, increased extreme precipitation events have enlarged the population exposed to floods to some extent. Extreme precipitation risk assessments are of great significance in China and allow for the response to climate change and mitigation of risks to the population. China is one of the countries most influenced by climate change and has unique national population conditions. The influence of extreme precipitation depends on the degree of exposure and vulnerability of the population. Accurate assessments of the population exposed to rising rainstorm trends are crucial to mapping extreme precipitation risks. Studying the population exposed to rainstorm hazard areas (RSHA) at the microscale is extremely urgent, due to the local characteristics of extreme precipitation events and regional diversity of the population. The spatial distribution of population density was mapped based on the national population census data from China in 1990, 2000 and 2010. RSHA were also identified using precipitation data from 1975-2015 in China, and the rainstorm tendency values were mapped using GIS in this paper. The spatial characteristics of the rainstorm tendencies were then analyzed. Finally, changes in the population in the RSHA are discussed. The results show that the extreme precipitation trends are increasing in southeastern China. From 1990 to 2010, the population in RSHA increased by 110 million, at a rate of 14.6%. The elderly in the region increased by 38 million at a rate of 86.4%. Studying the size of the population exposed to rainstorm hazards at the county scale can provide scientific evidence for developing disaster prevention and mitigation strategies from the bottom up.

  13. Ecotourism Environmental Protection Measures and Their Effects on Protected Areas in China

    Directory of Open Access Journals (Sweden)

    Ling-en Wang

    2014-09-01

    Full Text Available Ecological and environmental protection is the core content of ecotourism development. A quantitative evaluation of the effects of ecotourism environmental protection (hereinafter referred to as EEP measures on protected areas is conducive to a deeper understanding of the key issues related to ecotourism development in China, thus providing the theoretical basis for formulating the relevant national policies of sustainable ecotourism development in China. This paper first discusses the evaluation index system and then establishes an index evaluation model of EEP measures and their effects on protected areas. Using surveys of more than 1110 protected areas in 27 provinces (autonomous regions or municipalities, we evaluated the EEP measures and their effects from a quantitative and spatial perspective. The completeness of EEP measures for Chinese protected areas was moderately effective, and the implementation status of the protection measures varied with the protection region. The effectiveness of EEP measures in different provinces and regions showed significant differences. The effectiveness decreased from east to west. The evaluation index values of the environmental protection measures displayed a high correlation with the effects of environmental protection on protected areas. The ecological protection measures should be further improved and strengthened according to their regional differences during ecotourism development.

  14. Phylogeography of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae in southern China and some surrounding areas.

    Directory of Open Access Journals (Sweden)

    Jian Peng

    2017-08-01

    Full Text Available Angiostrongylus cantonensis is of increasing public health importance as the main zoonotic pathogen causing eosinophilic meningitis or meningoencephalitis, which has been documented all over the world. However, there are very limited studies about its phylogeography and spread pattern. In the present study, the phylogeography of A. cantonensis in southern China (including Taiwan and partial areas of Southeast Asia were studied based on the sequences of complete mitochondrial cytochrome b (Cytb gene. A total of 520 individuals of A. cantonensis obtained from 13 localities were sequenced for the analyses and grouped into 42 defined haplotypes. The phylogenetic tree (NJ tree and BI tree revealed a characteristic distribution pattern of the four main lineages, with detectable geographic structure. Genetic differentiation among populations was significant, but demographic expansion could not be detected by either neutrality tests or mismatch distribution analysis, which implied a low gene flow among the local populations in different regions where the samples were collected. Two unique lineages of the A. cantonensis population in Taiwan were detected, which suggests its multiple origin in the island. Populations in Hekou (China and Laos showed the highest genetic diversities, which were supported by both genetic diversity indices and AMOVA. These results together infer that the area around Thailand or Hekou in Yunnan province, China are the most likely origins of Angiostrongylus cantonensis.

  15. Effect of experimental crude oil contamination on abundance, mortality and resettlement of representative mud flat organisms in the mesohaline area of the elbe estuary

    Science.gov (United States)

    Van Bernem, K. H.

    After repeated experimental contamination with small doses of the crude oils Arabian light, Kuwait crude and Iranian light on a silty mud flat in the Elbe estuary, neither an increased mortality nor emigration was found in Macoma balthica or Nereis diversicolor. Oligochaetes increased in abundance. The entire population of Corophium volutator tried to leave the contaminated sediment. Most specimens came into contact with the oil coating of the sediment and were killed. Twelve weeks after the beginning of the contaminations the original community structure had reestablished. Different effects between the 3 crude oils tested were not significant.

  16. [Study on status of nutrition in children under three years old in rural area in China].

    Science.gov (United States)

    Cui, Ying; Yang, Li; Zhao, Yan-Xia; Wu, Qi; Tian, Xiao-Bo

    2008-03-01

    To understand the nutrition status of children under three years in rural area of western China and to explore the influencing factors so as to provide reasonable suggestions for policy making. Use PPS sampling method to investigate the 13,532 children under three years old. Height and weight were used as nutritional indexes. The prevalence of stunting (height for age Z-score Z-score Z-score influencing factors of malnutrition. Under-6-month children who were not taken care by their mothers showed higher risk of stunting. Over-6-month children stunting had significant relationship with age, gender, sibling order, nationality,maternal educational level,special cooking for children and residential region. Underweight of over-6-month children significantly related to age, nationality, and maternal educational level, yolk supply during 6-8 month old and living region. Malnutrition was really prevalent among children in China,suggesting that intervention should be done according to the influencing factors.

  17. Chinese Grand Strategy: How Anti-Access/Area Denial (A2/AD) Fits in China’s Plan

    Science.gov (United States)

    2014-04-01

    This includes the selection of targets exactly as is described in the Intermediate Developmental Education (IDE) schools for the U.S. military... inequality . China and the party are more dependent on the continued viability of the global system than at any time in the past, and the clear trajectory...Philippines, Malaysia , and Brunei all actively disputing some area of the South China Sea. There are several reasons for the intense competition as the area

  18. Estimating Hydrologic Fluxes, Crop Water Use, and Agricultural Land Area in China using Data Assimilation

    Science.gov (United States)

    Smith, Tiziana; McLaughlin, Dennis B.; Hoisungwan, Piyatida

    2016-04-01

    Crop production has significantly altered the terrestrial environment by changing land use and by altering the water cycle through both co-opted rainfall and surface water withdrawals. As the world's population continues to grow and individual diets become more resource-intensive, the demand for food - and the land and water necessary to produce it - will continue to increase. High-resolution quantitative data about water availability, water use, and agricultural land use are needed to develop sustainable water and agricultural planning and policies. However, existing data covering large areas with high resolution are susceptible to errors and can be physically inconsistent. China is an example of a large area where food demand is expected to increase and a lack of data clouds the resource management dialogue. Some assert that China will have insufficient land and water resources to feed itself, posing a threat to global food security if they seek to increase food imports. Others believe resources are plentiful. Without quantitative data, it is difficult to discern if these concerns are realistic or overly dramatized. This research presents a quantitative approach using data assimilation techniques to characterize hydrologic fluxes, crop water use (defined as crop evapotranspiration), and agricultural land use at 0.5 by 0.5 degree resolution and applies the methodology in China using data from around the year 2000. The approach uses the principles of water balance and of crop water requirements to assimilate existing data with a least-squares estimation technique, producing new estimates of water and land use variables that are physically consistent while minimizing differences from measured data. We argue that this technique for estimating water fluxes and agricultural land use can provide a useful basis for resource management modeling and policy, both in China and around the world.

  19. Consumption-based Total Suspended Particulate Matter Emissions in Jing-Jin-Ji Area of China

    Science.gov (United States)

    Yang, S.; Chen, S.; Chen, B.

    2014-12-01

    The highly-industrialized regions in China have been facing a serious problem of haze mainly consisted of total suspended particulate matter (TSPM), which has attracted great attention from the public since it directly impairs human health and clinically increases the risks of various respiratory and pulmonary diseases. In this paper, we set up a multi-regional input-output (MRIO) model to analyze the transferring routes of TSPM emissions between regions through trades. TSPM emission from particulate source regions and sectors are identified by analyzing the embodied TSPM flows through monetary flow and carbon footprint. The track of TSPM from origin to end via consumption activities are also revealed by tracing the product supply chain associated with the TSPM emissions. Beijing-Tianjin-Hebei (Jing-Jin-Ji) as the most industrialized area of China is selected for a case study. The result shows that over 70% of TSPM emissions associated with goods consumed in Beijing and Tianjin occurred outside of their own administrative boundaries, implying that Beijing and Tianjin are net embodied TSPM importers. Meanwhile, 63% of the total TSPM emissions in Hebei Province are resulted from the outside demand, indicating Hebei is a net exporter. In addition, nearly half of TSPM emissions are the by-products related to electricity and heating supply and non-metal mineral products in Jing-Jin-Ji Area. Based on the model results, we provided new insights into establishing systemic strategies and identifying mitigation priorities to stem TSPM emissions in China. Keywords: total suspended particulate matter (TSPM); urban ecosystem modeling; multi-regional input-output (MRIO); China

  20. Decentralization and Polycentricity: Spatial Changes of Employment in Beijing Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    Yongqiang Lv

    2017-10-01

    Full Text Available Decentralization and polycentric spatial structure strategies are important ways to alleviate urban disease in China. However, whether the urban spatial structure is meeting expectations is still unknown. Taking the Beijing Metropolitan Area as a case, the author adopted a non-parametric method to identify the subcenters, then an employment density model was used to analyze the spatial changes of employment and the employment centers’ impacts on the urban spatial structure. The results show that the Beijing Metropolitan Area was undergoing processes of employment decentralization, the monocentric structure was obvious throughout this time, but the polycentric model prevailed. The spatial structure of the Beijing Metropolitan Area was characterized as depicting “all centers aggregation” and the spatial structure of the central district of Beijing can be described as “subcenter agglomeration” between 2004 and 2013. The spatial structure became increasingly polycentric in the Beijing Metropolitan Area, but became more scattered in the central district.

  1. Biodeposition, respiration, and excretion rates of an introduced clam Mercenaria mercenaria in ponds with implications for potential competition with the native clam Meretrix meretrix in Shuangtaizi estuary, China

    Science.gov (United States)

    Zhang, Anguo; Yuan, Xiutang; Hou, Wenjiu; Li, Xiaodong; Zhao, Kai; Chen, Weixin; Su, Xiurong

    2016-05-01

    This study aimed to evaluate the potential impacts of an introduced clam Mercenaria mercenaria on estuarine ecosystem, and implications for the niche competition with a native clam Meretrix meretrix. The biodeposition, respiration, and excretion rates of M. mercenaria were determined seasonally using a sediment trap and a closed respirator in field. The biodeposition rates of M. mercenaria were 0.06-0.37 g/ (ind.·d), and the respiration rates were 0.31-14.66 mg/(ind.·d). The ammonia and phosphate excretion rates were 0.18-36.70 and 1.44-14.87 μg/(ind.·d), respectively. The hard clam M. mercenaria may discharge dry deposits up to 2.1×105 t, contribute 18.3 t ammonia and 9.0 t phosphate to culture ponds, and consume 7.9×103 t O2 from ponds annually. It suggested that the hard clam M. mercenaria might play an important role in pelagic-benthic coupling in pond ecosystem through biodeposition and excretion. A comparison of the key physiological parameters of the introduced clam M. mercenaria and the native clam Meretrix meretrix suggested that M. mercenaria had a niche similar to that of Meretrix meretrix in Shuangtaizi estuary and might have a potential competition with Meretrix meretrix for habitat and food if M. mercenaria species escaped from the culture pond or artificially released in estuarine ecosystem.

  2. Eighty-year sedimentary record of heavy metal inputs in the intertidal sediments from the Nanliu River estuary, Beibu Gulf of South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Xia Peng, E-mail: pengxia@fio.org.c [College of Marine Geo-science, Ocean University of China, Qingdao 266100 (China); First Institute of Oceanography, State Oceanic Administration, Qingdao 266061 (China); Meng Xianwei, E-mail: mxw@fio.org.c [First Institute of Oceanography, State Oceanic Administration, Qingdao 266061 (China); Yin Ping [Qingdao Institute of Marine Geology, China Geological Survey, Qingdao 266071 (China); Cao Zhimin [College of Marine Geo-science, Ocean University of China, Qingdao 266100 (China); Wang Xiangqin [First Institute of Oceanography, State Oceanic Administration, Qingdao 266061 (China)

    2011-01-15

    {sup 210}Pb analysis in the sediment core C11 was used to reconstruct the historical fluxes of Hg, Cu, Pb, Zn, Cd, Cr and As in the Nanliu River estuary during the last {approx}81 year. The {sup 210}Pb{sub xs}-derived sedimentation rates, molar C/N ratios, enrichment factors and excess fluxes indicated that the natural inputs prevailed till the early 1990s. When the erosion related to land-use modifications enhanced, it promoted higher accumulation rates of the sedimentary material. In the recent sediments they were found a moderate enrichment of Cd and Hg (maximum 3.5- and 2.8-fold corresponding to the local background levels, respectively) and a slight enrichment of Cr, Zn, As and Pb (maximum 1.3-, 1.3-, 1.3- and 1.2-fold, respectively). The excess metal fluxes also showed a consistently increasing tread since the early 1990s, which could be associated with the intensive use of phosphate fertilizers and the combustion of fossil fuels derived from human activities. - The enrichment factor was successfully used to identify the different sources of heavy metals derived from natural, maricultural and agricultural inputs.

  3. Creating new path for Old Industrial Areas: A Case Study on Dalian city, China

    Directory of Open Access Journals (Sweden)

    Yimei Yin and Zhigao Liu

    2012-01-01

    Full Text Available The formation of new industries has recently been widely studied, but little research attention has been paid to the formation of new industries in old industrial districts, especially in transitional countries such as China. Based on fieldwork and rereading historical archives, this paper uses an example of Dalian tourism cluster to contribute to understanding the emergence of new economy in old industrial areas in a transitional country. The Section 2 of this paper will provide the theoretical framework from evolutionary economics for my empirical study. In Section 3, this paper will discuss the main characteristics of the decline of old industrial areas in Northeast China and the significances of developing new economy to revitalizing old industry areas. Section 4 will introduce the transitional history of Dalian economy from a high industrial region to a new economy city and also provides descriptive information about the development process of Dalian tourism industry. In Section 5, this paper will probe into the dynamics of the Dalian tourism cluster, from viewpoints of co-evolution and co-adaptation of firm, technology and institutions. Finally, we will give some policy suggestions of how to foster and promote new industries in old industrial areas, especially for transitional countries.

  4. Evaluation of soil contamination indices in a mining area of Jiangxi, China.

    Directory of Open Access Journals (Sweden)

    Jin Wu

    Full Text Available There is currently a wide variety of methods used to evaluate soil contamination. We present a discussion of the advantages and limitations of different soil contamination assessment methods. In this study, we analyzed seven trace elements (As, Cd, Cr, Cu, Hg, Pb, and Zn that are indicators of soil contamination in Dexing, a city in China that is famous for its vast nonferrous mineral resources in China, using enrichment factor (EF, geoaccumulation index (Igeo, pollution index (PI, and principal component analysis (PCA. The three contamination indices and PCA were then mapped to understand the status and trends of soil contamination in this region. The entire study area is strongly enriched in Cd, Cu, Pb, and Zn, especially in areas near mine sites. As and Hg were also present in high concentrations in urban areas. Results indicated that Cr in this area originated from both anthropogenic and natural sources. PCA combined with Geographic Information System (GIS was successfully used to discriminate between natural and anthropogenic trace metals.

  5. Projecting future climate change impacts on heat-related mortality in large urban areas in China.

    Science.gov (United States)

    Li, Ying; Ren, Ting; Kinney, Patrick L; Joyner, Andrew; Zhang, Wei

    2018-02-12

    Global climate change is anticipated to raise overall temperatures and has the potential to increase future mortality attributable to heat. Urban areas are particularly vulnerable to heat because of high concentrations of susceptible people. As the world's largest developing country, China has experienced noticeable changes in climate, partially evidenced by frequent occurrence of extreme heat in urban areas, which could expose millions of residents to summer heat stress that may result in increased health risk, including mortality. While there is a growing literature on future impacts of extreme temperatures on public health, projecting changes in future health outcomes associated with climate warming remains challenging and underexplored, particularly in developing countries. This is an exploratory study aimed at projecting future heat-related mortality risk in major urban areas in China. We focus on the 51 largest Chinese cities that include about one third of the total population in China, and project the potential changes in heat-related mortality based on 19 different global-scale climate models and three Representative Concentration Pathways (RCPs). City-specific risk estimates for high temperature and all-cause mortality were used to estimate annual heat-related mortality over two future twenty-year time periods. We estimated that for the 20-year period in Mid-21st century (2041-2060) relative to 1970-2000, incidence of excess heat-related mortality in the 51 cities to be approximately 37,800 (95% CI: 31,300-43,500), 31,700 (95% CI: 26,200-36,600) and 25,800 (95% CI: 21,300-29,800) deaths per year under RCP8.5, RCP4.5 and RCP2.6, respectively. Slowing climate change through the most stringent emission control scenario RCP2.6, relative to RCP8.5, was estimated to avoid 12,900 (95% CI: 10,800-14,800) deaths per year in the 51 cities in the 2050s, and 35,100 (95% CI: 29,200-40,100) deaths per year in the 2070s. The highest mortality risk is primarily in cities

  6. Penobscot Estuary (Maine) Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's NEFSC collects fisheries data from the Penobscot Estuary using several types of fishing gear. The data is used to determine species presence, relative...

  7. Patterns and socioeconomic influences of tobacco exposure in tobacco cultivating rural areas of Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Cai Le

    2012-10-01

    Full Text Available Abstract Background This study describes the patterns and socioeconomic influences of tobacco use among adults in tobacco-cultivating regions of rural southwest China. Methods A cross-sectional survey was conducted in 8681 adults aged ≥18 years in rural areas of Yunnan Province, China from 2010 to 2011. A standardized questionnaire was administered to obtain data about participants’ demographic characteristics, individual socioeconomic status, ethnicity, self-reported smoking habits, and exposure to secondhand smoke (SHS. The socioeconomic predictors of current smoking, nicotine addiction, and SHS exposure were analyzed using multivariate logistic regression. Results The prevalence rates of tobacco use were much higher in men compared with women (current smoking 68.5% vs. 1.3%; and nicotine dependence 85.2% vs. 72.7%. However, the rate of SHS exposure was higher in women compared with men (76.6% vs. 70.5%. Tobacco farmers had higher prevalence rates of current smoking, nicotine dependence, and SHS exposure compared with participants not engaged in tobacco farming (P Conclusions This study suggests that tobacco control efforts in rural southwest China must be tailored to address tobacco-cultivating status and socioeconomic factors.

  8. Identifying the Areas Benefitting from the Prevention of Wind Erosion by the Key Ecological Function Area for the Protection of Desertification in Hunshandake, China

    Directory of Open Access Journals (Sweden)

    Yu Xiao

    2017-10-01

    Full Text Available Research on the spatial flow of ecosystem services can help to identify the spatial relationships between service-providing areas (SPAs and service-benefitting areas (SBAs. In this study, we used the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT model to stimulate the flow paths of the wind erosion prevented by ecosystems in Hunshandake, China. By interpolating these paths, the SBAs were identified, and their benefits in terms of land cover, population, and Gross Domestic Product (GDP were determined. The results indicated that the flow paths mostly extended to the eastern part of the study area, and the estimated cover of the SBAs was 39.21% of the total area of China. The grid cells through which many (≥10% of the trajectories passed were mainly located in the western part of north-eastern China and the eastern part of northern China. The benefitting population accounted for 74.51% of the total population of China, and the GDP was 67.11% of the total in 2010. Based on this research, we described a quantitative relationship between the SPAs and the SBAs and identified the actual beneficiaries. This work may provide scientific knowledge that can be used by decision makers to develop management strategies, such as ecological compensation to mitigate damage from sandstorms in the study area.

  9. Influences of coal mining water irrigation on the maize losses in the Xingdong Mine area, China.

    Science.gov (United States)

    Sun, Yuzhuang; Ling, Pei; Li, Yanheng; Li, Qingxue; Sun, Quande; Wang, Jinxi

    2014-02-01

    In 2008, a maize underproduction disaster occurred in the Xianyu village after irrigation using the coal mining water from the Xingdong Mine, China. This disaster resulted in about 40 hectare maize underproduction and 20 hectare total loss of the maize yields. In order to study the reason, a total of 25 soil, water and plant samples were taken from the study area. These samples were analysed by inductively coupled plasma mass spectrometry and ion chromatography. The results indicate that the contents of both water-soluble fluorine and total fluorine are very high and resulting of maize underproduction and total loss of production. The possible pollution sources of fluorine in the study area could be from the coal mine water used for irrigation and glass chemical factory near the study area.

  10. Research on the Identity Construction of the Disabled Elderly in Rural Areas of China

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2014-04-01

    Full Text Available The identity construction is a very important aspect among the problems of the disabled elderly in rural areas of China. Based on the method of case study and theoretical analysis, this research studies the contents and the process of the identity construction of the disabled elderly in rural areas. It suggests that the identity consists of three elements: personal identity, group identity and social identity, and the characteristics of which include the “high recognition on the disability”, the “core construction of the disability”, the “daily expenses orientation” and the “de-certification of the identity construction”. The mechanism of the construction is supported by three different system types: the basic system, the consolidation system and the maintenance system. The results of the construction demonstrate the features of the identity of “triple-weakness” and “muddling along” of the disabled elderly in rural areas.

  11. Sugar-sweetened beverages and school students' hypertension in urban areas of Nanjing, China.

    Science.gov (United States)

    Qin, Zhenzhen; Xu, Fei; Ye, Qing; Zhou, Hairong; Li, Chao; He, Jing; Wang, Zhiyong; Hong, Xin; Hou, Xiangyu

    2018-02-06

    Literature showed that sugar-sweetened beverages (SSBs) could increase the risk of developing hypertension in school students, but there is no reported evidence from China yet, so this study aims to investigate the association of the SSBs consumption and school students' hypertension in urban areas of Nanjing, China. A cross-sectional survey was conducted among primary and junior high school students selected from 32 primary schools and 16 junior high schools using a multi-stage random sampling method, with a total number of 10,091 participants involved. The mean age of Grade 4 is 9.04 ± 0.38, while the mean age of Grade 7 is 12.03 ± 0.41. Blood pressure was measured and SSBs consumption was reported using a validated questionnaire. The overall prevalence of hypertension was 4.5% among the participants. After adjustment for school, parental education, physical activity, diet intake including meat and snacks, participants who had an experience of SSBs intake were at a higher risk of developing hypertension (odds ratio (OR) = 1.40, 95% confidence interval (CI) = 1.15, 1.70) compared with those who had no experience of SSBs intake. A significant association between the consumption of SSBs and hypertension was observed among the students who were at a healthy weight (OR = 1.78, 95% CI = 1.20, 2.65), as well as who were overweight or obese (OR = 1.28, 95% CI = 1.01, 1.61). SSBs may play a contributing role in developing childhood hypertension in this population in China, which is of important implications for future population-based childhood hypertension intervention in China and other countries.

  12. Investigations into Salmonella contamination in feed production chain in Karst rural areas of China.

    Science.gov (United States)

    Yang, Shenglin; Wu, Zongfen; Lin, Wei; Xu, Longxin; Cheng, Long; Zhou, Lin

    2017-01-01

    In order to understand the status of Salmonella contamination of feed production chain in Karst rural areas, southwest of China, a total of 1077 feed samples including animal feed materials and feed products were randomly collected from different sectors of feed chain covering feed mills, farms, and feed sales in nine regions of Karst rural areas between 2009 and 2012, to conduct Salmonella test. The different positive rates with Salmonella contamination were detected, the highest was 4.7 % in 2009, the lowest was 0.66 % in 2011, while 4.3 % in 2010, 2.8 % in 2012, respectively. Twelve types of feed including concentrate, complete, self-made, and feed ingredients were inspected. Salmonella contamination mainly concentrated on animal protein material such as meat meal, meat and bone meal, feather meal, blood meal, and fish meal. No Salmonella contamination was detected in feed yeast, microbial protein, rapeseed, and soybean meal. Salmonella contamination existed in each sector of feed production chain. This investigation provided a basic reference for feed production management and quality control in feed production chain in Karst rural areas of China.

  13. Human inorganic mercury exposure, renal effects and possible pathways in Wanshan mercury mining area, China.

    Science.gov (United States)

    Li, Ping; Du, Buyun; Chan, Hing Man; Feng, Xinbin

    2015-07-01

    Rice can accumulate methylmercury (MeHg) and rice consumption is the main route of MeHg exposure for the local population in Guizhou, China. However, inorganic Hg (IHg) load in human body is not comprehensively studied in highly Hg polluted areas such as Hg mining areas. This study is designed to evaluate human IHg exposure, related renal effects and possible pathways in Wanshan Hg mining area, Guizhou, Southwest China. Residents lived within 3 km to the mine waste heaps showed high Urine Hg (UHg) concentrations and the geometrical means (Geomean) of UHg were 8.29, 5.13, and 10.3 μg/g Creatinine (Cr) at site A, D, and E, respectively. It demonstrated a gradient of UHg concentrations with the distance from the pollution sources. A significantly positive correlation between paired results for UHg concentrations and serum creatinine (SCr) was observed in this study, but not for UHg and blood urea nitrogen (BUN). There are significant increases of SCr in two quartiles with high UHg concentrations. The results indicated that human IHg exposure may cause impairment of renal function. By calculation of Probable Daily Intake from different routes, we found that dietary intake is the main pathway of IHg exposure for the local population, rather than inhalation of Hg vapor. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Prevalence of Pre-Diabetes and Its Associated Risk Factors in Rural Areas of Ningbo, China

    Directory of Open Access Journals (Sweden)

    Ming Zhao

    2016-08-01

    Full Text Available Objective: The aims of the study were to investigate the prevalence of pre-diabetes and explore its associated risk factors in rural areas of Ningbo, China. Methods: A cross-sectional survey was conducted with 4583 adult residents in rural areas of Ningbo, China between March and May 2013. The survey used a multi-stage, stratified, cluster sampling method. Data collected included demographics and medical history, anthropometric measurements, blood pressure, blood lipid, and plasma glucose. After at least 10 h of overnight fasting, participants underwent an oral glucose tolerance test (OGTT to identify pre-diabetes. Univariate and multivariate logistic regression analyses were used to evaluate the associated risk factors for pre-diabetes, and to estimate the effect of interaction between the factors. Results: There were 1307 survey participants having pre-diabetes (28.52% and the age-standardized prevalence was 30.53%. Multivariate logistic regression results showed that overweight/obesity, hypertension, and higher triglycerides were the risk factors for developing pre-diabetes. There were positive interactions between overweight/obesity and triglycerides, and also between hypertension and triglycerides on the multiplicative scale, suggesting that they synergistically influenced the development of pre-diabetes. Conclusions: The rural areas in Ningbo had a high prevalence of pre-diabetes. Overweight and obesity, hypertension, and elevated triglycerides were the major risk factors. There is a need of early intervention for preventing pre-diabetes.

  15. Noise monitoring and adverse health effects in residents in different functional areas of Luzhou, China.

    Science.gov (United States)

    Han, Zhi-Xia; Lei, Zhang-Heng; Zhang, Chun-Lian; Xiong, Wei; Gan, Zhong-Lin; Hu, Ping; Zhang, Qing-Bi

    2015-03-01

    The purpose of the study was to investigate the noise pollution situation and the resulting adverse effect on residents' health in Luzhou, China, to provide data for noise pollution prevention policies and interventions. Four different functional areas (commercial, construction, residential, and transportation hub areas) were chosen to monitor noise level for 3 months. The survey was performed by questionnaire on the spot on randomly selected individuals; it collected data on the impact of noise on residents' health (quality of sleep, high blood pressure, subjective feeling of nervous system damage, and attention) as well as the knowledge of noise-induced health damage, the degree of adaptation to noise, and their solutions. The noise levels of residential, commercial, transportation, and construction areas exceeded the national standards (P health hazards associated with noise; 64.57% of residents have adapted to the current noise environment. Most of them have to close the doors and windows to reduce noise. The noise pollution situation in Luzhou, China, is serious, especially the traffic noise pollution. Residents pay less attention to it and adopt single measures to reduce the noise. We should work toward the prevention and control of traffic noise and improve the residents' awareness to reduce the adverse health effects of noise. © 2014 APJPH.

  16. Chiritopsis longzhouensis, a New Species of Gesneriaceae from Limestone Areas in Guangxi, China

    Directory of Open Access Journals (Sweden)

    Bo Pan

    2010-11-01

    Full Text Available A new species of Gesneriaceae, Chiritopsis longzhouensis B. Pan & W. H. Wu from limestone areas in Guangxi, China, is described and illustrated. The new species is similar to C. jingxiensis Yan Liu, W. B. Xu & H. S. Gao in the corolla shape, but differs in its leaf blade 2-4 × 1.3-2.5 cm, appressed pilose on both surfaces, Cymes 5-10, 1-3-branched, each 5-25-flowered, filaments geniculate about 1 mm above base, sparsely glandular-puberulent, staminodes 3.

  17. Energy policies for sustainable livelihoods and sustainable development of poor areas in China

    Energy Technology Data Exchange (ETDEWEB)

    Fan Jie [Key Laboratory of Regional Sustainable Development Modeling, Chinese Academy of Sciences, Beijing 100101 (China); Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Liang Yutian; Tao Anjun [Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Sheng Kerong [Shandong University of Technology, Shandong 255049 (China); Ma Hailong [Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Graduate University, Chinese Academy of Sciences, Beijing 100049 (China); Xu Yong; Wang Chuansheng [Key Laboratory of Regional Sustainable Development Modeling, Chinese Academy of Sciences, Beijing 100101 (China); Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Sun Wei, E-mail: sunw@igsnrr.ac.c [Key Laboratory of Regional Sustainable Development Modeling, Chinese Academy of Sciences, Beijing 100101 (China); Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China)

    2011-03-15

    Focusing on the sustainable livelihoods of rural households and regional sustainable development, this research takes Yan'an at the upper reaches of Yellow River and Zhaotong at mid-upper reaches of the Yangtze River as the study areas, extracts the central affecting factors of energy consumption and characteristic indexes of energy zoning based on 1560 rural household questionnaires of 85 villages in 4 counties (districts) and database analysis of socio-economic development, conducts energy zoning for the poor areas in China, and puts forward specific supporting policies for each type of zone. The research finds that (1) the study areas are found to have the following energy consumption characteristics: low per capita energy consumption (merely 1/4 of the national average), with energy consumption for non-production purposes taking up the main part (more than 70%), high proportion of non-commercial energy, i.e. firewood, straw, etc. (more than 45%), low utilization rate of such new energy resources as biogas, solar energy, etc. (lower than 2% in high mountain regions), remarkable differentiation of vertical and horizontal zonality, etc. (2) Physical conditions like temperature and topography, socio-economic factors, i.e. income of rural households, energy endowment, transportation conditions, and institutional factors like policy support are the major affecting factors of energy consumption and characteristic indexes of energy policy zoning. (3) According to the characteristic index evaluation and matrix classification of both the suitability for energy development and types of regional energy endowment, the poor areas in China can be divided into three energy policy-oriented zones, i.e. network-based centralized energy supply zone, diversified energy utilization zone, and new energy utilization zone. - Research highlights: {yields}Energy consumption characteristics of the study areas are as follows: low per capita energy consumption, high proportion of non

  18. Prevalence and determinants of metabolic syndrome among adults in a rural area of Northwest China.

    Directory of Open Access Journals (Sweden)

    Yaling Zhao

    Full Text Available To evaluate the prevalence and determinants of metabolic syndrome (MetS among adults in a rural area of Northwest China.A population-based cross-sectional study was conducted in 2010 among adults aged 18 to 80 years in rural areas of Hanzhong, in Northwest China. Interview, physical and clinical examinations, and fasting blood glucose and lipid measurements were completed for 2990 adults. The definitions of MetS proposed by the Third Report of the National Cholesterol Education Program Expert Panel (Adults Treatment Panel III, ATP III and the International Diabetes Federation (IDF, and the modified ATP III definition for Asian population were used and compared. Proportions were adjusted for age and sex.The prevalence of MetS was 7.9%, 10.8% and 15.1% according to ATP III, IDF and modified ATP III criteria, respectively. Agreement between ATP III and IDF criteria and that between ATP III and modified ATP III criteria were moderate (Kappa = 0.52 and 0.64, respectively, whereas agreement between IDF and modified ATP III criteria was good (Kappa = 0.83. The prevalence of MetS increased with age, and was higher in women than in men (10.4% versus 5.4%, 13.6% versus 8.1% and 17.4% versus 12.8%, according to ATP III, IDF and modified ATP III criteria, respectively. The most common MetS component was high blood pressure. Having family history of hypertension, lack of physical activity, high economical level, overweight and obesity were positively associated with MetS.MetS is prevalent among rural adults in Northwest China and high blood pressure is the most common MetS component. Prevention and treatment of hypertension and MetS should be a public health priority to reduce cardiovascular diseases in rural areas of Northwest China. More attention should be given to the elderly, women, people with family history of hypertension and obese people who are at high risk of MetS.

  19. Particulate air pollution from combustion and construction in coastal and urban areas of China.

    Science.gov (United States)

    Chen, Bing; Chen, Jinsheng; Zhao, Jinping; Zhang, Fuwang

    2011-11-01

    In China, the areas that are undergoing rapid urban growth are faced with increasingly more complicated air pollution problems. Sources of air pollution need to be identified and their contributions quantified. In this study, PM2.5 (particulate matter with aerodynamic diameters areas in Xiamen (the downtown area, an industrial park, a suburb, and one remote site). The contributions of carbonaceous aerosols to PM2.5 and PM2.5-10 were 20-30% and 10-20%, respectively, indicating that finer particles contained more carbonaceous aerosols. The EC concentrations in PM2.5 at the downtown, industrial, suburb, and remote sites were 2.16 +/- 0.61, 2.05 +/- 0.45, 1.69 +/- 0.54, and 0.65 +/- 0.43 microg m-3, respectively, showing a decrease from the urban and industrial hotspots to the surrounding areas. These data show that carbonaceous aerosols emitted from the combustion of fossil fuels in urban and industrial hotspots influence air quality at the regional scale. Higher levels of PM2.5 and PM2.5-10 were observed at the suburb site compared to the urban and industrial sites. Peak EC concentrations in PM2.5 were observed during the morning and evening rush hours. However, peak PM2.5 levels at the suburb site were observed around noon, which coincides with construction work hours, instead of the morning and evening rush hours when emissions from combustion dominated. These findings indicate that both fuel combustion and construction have exacerbated air pollution in coastal and urban areas in China.

  20. Medical abortion service in rural areas of Henan Province, China: a provider survey.

    Science.gov (United States)

    Ji, Ning; Zhou, You; Zhang, Ying; He, Dian; Pang, Cheng; Xi, Maomao; Cheng, Yimin

    2013-03-01

    The aim of this study was to explore the knowledge, attitudes and practices on medical abortion of abortion service providers in rural areas of China. A cross-sectional study via self-administered questionnaire was conducted among 362 abortion service providers from family planning service centers (FPSC) and hospitals in rural areas of Henan Province, China, between November 2009 and May 2010. Most of the providers were female (99.4%) and obstetricians/gynecologists (63.3%). The knowledge score achieved ranged from 9.4 to 78.1 points, with both the median and the mode of 56.3 points. Of the 52.2% (189/362) of providers having a preference on abortion method, 30.2% (57/189) preferred medical abortion, while 69.8% (132/189) preferred surgical abortion. In total, 50.7% (174/343) of the providers indicated the provision of medical abortion should be expanded, with the three biggest challenges in its further expansion being increased complications/failures, poor client knowledge/awareness, and problems with drug/equipment supplies. Of all the providers, 81.7% and 92.2% reported they had experience in providing medical abortion and surgical abortion, respectively. Medical abortion providers were mainly experienced in misoprostol with oral (81.8%)/vaginal (79.6%) prostaglandin (misoprostol/gemeprost). Knowledge on medical abortion of providers working in rural China was at a moderate level. Providers preferred surgical abortion to medical abortion. Providers have more experience in providing surgical abortion than medical abortion. Efforts should be made to overcome the perceived challenges in future expansion of medical abortion. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.

  1. Solar radiation and its penetration in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Bhattathiri, P.M.A.; Abidi, S.A.H.

    The Cochin Backwater which is an estuarine area on the west coast of India receives maximum solar radiation from December to March and minimum from June to September. During the monsoon months the estuary becomes highly turbid as a result...

  2. Implications of genetics and current protected areas for conservation of 5 endangered primates in China.

    Science.gov (United States)

    Liu, Zhijin; Liu, Guangjian; Roos, Christian; Wang, Ziming; Xiang, ZuoFu; Zhu, Pingfen; Wang, Boshi; Ren, Baoping; Shi, Fanglei; Pan, Huijuan; Li, Ming

    2015-12-01

    Most of China's 24-28 primate species are threatened with extinction. Habitat reduction and fragmentation are perhaps the greatest threats. We used published data from a conservation genetics study of 5 endangered primates in China (Rhinopithecus roxellana, R. bieti, R. brelichi, Trachypithecus francoisi, and T. leucocephalus); distribution data on these species; and the distribution, area, and location of protected areas to inform conservation strategies for these primates. All 5 species were separated into subpopulations with unique genetic components. Gene flow appeared to be strongly impeded by agricultural land, meadows used for grazing, highways, and humans dwellings. Most species declined severely or diverged concurrently as human population and crop land cover increased. Nature reserves were not evenly distributed across subpopulations with unique genetic backgrounds. Certain small subpopulations were severely fragmented and had higher extinction risk than others. Primate mobility is limited and their genetic structure is strong and susceptible to substantial loss of diversity due to local extinction. Thus, to maximize preservation of genetic diversity in all these primate species, our results suggest protection is required for all sub-populations. Key priorities for their conservation include maintaining R. roxellana in Shennongjia national reserve, subpopulations S4 and S5 of R. bieti and of R. brelichi in Fanjingshan national reserve, subpopulation CGX of T. francoisi in central Guangxi Province, and all 3 T. leucocephalus sub-populations in central Guangxi Province. © 2015 Society for Conservation Biology.

  3. Perception of Air Pollution in the Jinchuan Mining Area, China: A Structural Equation Modeling Approach

    Directory of Open Access Journals (Sweden)

    Zhengtao Li

    2016-07-01

    Full Text Available Studies on the perception of air pollution in China are very limited. The aim of this paper is to help to fill this gap by analyzing a cross-sectional dataset of 759 residents of the Jinchuan mining area, Gansu Province, China. The estimations suggest that perception of air pollution is two-dimensional. The first dimension is the perceived intensity of air pollution and the second is the perceived hazardousness of the pollutants. Both dimensions are influenced by environmental knowledge. Perceived intensity is furthermore influenced by socio-economic status and proximity to the pollution source; perceived hazardousness is influenced by socio-economic status, family health experience, family size and proximity to the pollution source. There are no reverse effects from perception on environmental knowledge. The main conclusion is that virtually all Jinchuan residents perceive high intensity and hazardousness of air pollution despite the fact that public information on air pollution and its health impacts is classified to a great extent. It is suggested that, to assist the residents to take appropriate preventive action, the local government should develop counseling and educational campaigns and institutionalize disclosure of air quality conditions. These programs should pay special attention to young residents who have limited knowledge of air pollution in the Jinchuan mining area.

  4. Perception of Air Pollution in the Jinchuan Mining Area, China: A Structural Equation Modeling Approach.

    Science.gov (United States)

    Li, Zhengtao; Folmer, Henk; Xue, Jianhong

    2016-07-21

    Studies on the perception of air pollution in China are very limited. The aim of this paper is to help to fill this gap by analyzing a cross-sectional dataset of 759 residents of the Jinchuan mining area, Gansu Province, China. The estimations suggest that perception of air pollution is two-dimensional. The first dimension is the perceived intensity of air pollution and the second is the perceived hazardousness of the pollutants. Both dimensions are influenced by environmental knowledge. Perceived intensity is furthermore influenced by socio-economic status and proximity to the pollution source; perceived hazardousness is influenced by socio-economic status, family health experience, family size and proximity to the pollution source. There are no reverse effects from perception on environmental knowledge. The main conclusion is that virtually all Jinchuan residents perceive high intensity and hazardousness of air pollution despite the fact that public information on air pollution and its health impacts is classified to a great extent. It is suggested that, to assist the residents to take appropriate preventive action, the local government should develop counseling and educational campaigns and institutionalize disclosure of air quality conditions. These programs should pay special attention to young residents who have limited knowledge of air pollution in the Jinchuan mining area.

  5. Water Sources and Their Protection from the Impact of Microbial Contamination in Rural Areas of Beijing, China

    OpenAIRE

    Hairong Li; Wuyi Wang; Yonghua Li; Bixiong Ye; Linsheng Yang

    2013-01-01

    Bacterial contamination of drinking water is a major public health problem in rural China. To explore bacterial contamination in rural areas of Beijing and identify possible causes of bacteria in drinking water samples, water samples were collected from wells in ten rural districts of Beijing, China. Total bacterial count, total coliforms and Escherichia coli in drinking water were then determined and water source and wellhead protection were investigated. The bacterial contamination in drink...

  6. Climate Ready Estuaries Progress Reports

    Science.gov (United States)

    Climate Ready Estuaries has supported adaptation activities in National Estuary Programs since 2008. In 2012, the program partnered with 23 NEPs, completed a pilot project with water utilities, and held workshops. Download annual reports from 2009-2012.

  7. Rare earth elements in human hair from a mining area of China.

    Science.gov (United States)

    Wei, Binggan; Li, Yonghua; Li, Hairong; Yu, Jiangping; Ye, Bixiong; Liang, Tao

    2013-10-01

    Rare earth minerals have been mined for more than 50 years in Inner Mongolia of China. In the mining area rare earth elements (REE) may be significantly accumulated in humans. Therefore, the aim of this paper is to characterize the REE concentrations in hair of local residents. REE concentrations in hair of 118 subjects were determined. The results showed that the mean concentrations of the determined REE in the hair of both females and males were usually higher from mining area than from control area. The mean concentrations of all the fifteen REE were much higher in hair of males than in hair of females from mining area. This suggested that males might be more sensitive to REE than females. In addition, the mean contents of the REE in hair of miners, particularly light REE (La, Ce, Pr and Nd), were usually much higher than the values in hair of non-miners from both mining area and control area, indicating that the miners were exposed to higher concentrations of REE in occupational environment. Among age groups, the relationships between REE concentrations and age groups showed that more and more concentrations of light REE accumulated in body of both females and males with age until 60 years, while heavy REE concentrations decreased with age in males who were exposed to low concentrations of heavy REE. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Health risk assessment of rare earth elements in cereals from mining area in Shandong, China.

    Science.gov (United States)

    Zhuang, Maoqiang; Wang, Liansen; Wu, Guangjian; Wang, Kebo; Jiang, Xiaofeng; Liu, Taibin; Xiao, Peirui; Yu, Lianlong; Jiang, Ying; Song, Jian; Zhang, Junli; Zhou, Jingyang; Zhao, Jinshan; Chu, Zunhua

    2017-08-29

    To investigate the concentrations of rare earth elements in cereals and assess human health risk through cereal consumption, a total of 327 cereal samples were collected from rare earth mining area and control area in Shandong, China. The contents of 14 rare earth elements were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The medians of total rare earth elements in cereals from mining and control areas were 74.22 μg/kg and 47.83 μg/kg, respectively, and the difference was statistically significant (P rare earth elements concentrations (109.39 μg/kg and 77.96 μg/kg for mining and control areas, respectively) and maize had the lowest rare earth elements concentrations (42.88 μg/kg and 30.25 μg/kg for mining and control areas, respectively). The rare earth elements distribution patterns for both areas were characterized by enrichment of light rare earth elements. The health risk assessment demonstrated that the estimated daily intakes of rare earth elements through cereal consumption were considerably lower than the acceptable daily intake (70 μg/kg bw). The damage to adults can be neglected, but more attention should be paid to the effects of continuous exposure to rare earth elements on children.

  9. Solar Lighting Technologies for Highway Green Rest Areas in China: Energy Saving Economic and Environmental Evaluation

    Directory of Open Access Journals (Sweden)

    Xiaochun Qin

    2015-01-01

    Full Text Available In this paper, taking Lushan West Sea highway green rest area in Jiangxi Province of China as the case study, the suitable types, applicability, advantages, and effective methods of solar lighting technologies for highway rest area were determined based on the analysis of characteristics of highway green rest area. It was proved that solar lighting technologies including the natural light guidance system, solar LED lighting, and maximizing natural light penetration were quite suitable for highway rest area in terms of lighting effects and energy and economic efficiency. The illuminance comparison of light guidance system with electrical lighting was made based on the on-site experiment. Also, the feasibility of natural light guidance system was well verified in terms of the lighting demand of the visitor centre in the rest area by the illuminance simulation analysis. The evaluation of the energy saving, economic benefits, and environmental effects of solar lighting technologies for highway rest area was, respectively, made in detail. It was proved that the application of solar technology for green lighting of highway rest facilities not only could have considerable energy saving capacity and achieve high economic benefits, but also make great contributions to the reduction of environment pollution.

  10. Renewable energy policy in remote rural areas of Western China. Implementation and socio-economic benefits

    Energy Technology Data Exchange (ETDEWEB)

    Shyu, Chian-Woei

    2010-05-19

    Electricity is essential for rural development. In 2005, 1.6 billion people, around a quarter of the world's population, living mostly in rural areas of developing countries, had no access to electricity. In general, remote rural areas in developing countries have little prospect of having access to grid-based electricity, which usually only extends to densely populated urban areas, where a large customer base justifies heavy expenditure for electricity infrastructure. One option for electrification in remote rural areas is to decentralize electricity systems based on renewable energy sources. However, such an option is not universally agreed upon. This dissertation examines a renewable energy-based rural electrification program, the 'Township Electrification Program', launched by the Chinese government in 2002. The Program was implemented in 1013 non-electrified townships in remote rural areas of 11 western provinces, providing electricity for 300,000 households and 1.3 million people. And at the time of research, the Program was known as the world's largest renewable energy-based rural electrification program in terms of investment volume ever carried out by a country. Two townships, Saierlong Township in Qinghai Province and Namcuo Township in Tibet Autonomous Region, were selected as cases for an in-depth examination of rural electrification practices in remote rural areas of western China. Both qualitative (interviews, observations, mapping, and transition walk) and quantitative (household survey) methods were applied in the field to collect data. The main findings of the study are summarized as follows: First, political leaders' concern over the unequal economic development of eastern and western China, as well as rural and urban areas, was the main factor triggering inclusion of the policy issue, electricity access in remote rural areas of western China, in the government's policy agenda. Second, like other energy policies, the

  11. Heavy metals in sea cucumber juveniles from coastal areas of Bohai and Yellow seas, north China.

    Science.gov (United States)

    Jiang, Haifeng; Tang, Shizhan; Qin, Dongli; Chen, Zhongxiang; Wang, Jinlong; Bai, Shuyan; Mou, Zhenbo

    2015-05-01

    The study was undertaken to assess the contents of heavy metals (Cu, Zn, Cr, Pb, Cd, As and Hg) in sea cucumber (Apostichopus japonicus) juveniles from coastal areas of Bohai and Yellow seas in northern China. Sea cucumber juveniles were collected from twenty commercial hatcheries distributed in five coastal cities. The mean concentrations obtained for heavy metals in mg/kg were as follows: Cu (0.179), Zn (2.634), Cr (0.108), Pb (0.065), Cd (0.161), As (0.372), Hg (0.034). All the mean concentrations were below the maximum residual limits set by Chinese legislation, but As in 10 % samples exceeded the safety threshold. Significant differences in contents of Cr, Pb and Hg were found among the five investigated areas. Overall, the heavy metal levels in sea cucumber juveniles were relatively low and more attention should be paid to toxic metals Pb, Cd, As and Hg in future routine monitoring program.

  12. A model for community health service development in depressed rural areas in China

    Directory of Open Access Journals (Sweden)

    Zhaokang Yuan

    2012-12-01

    Full Text Available Abstract Background To introduce a model of community health service organization (as implemented in urban areas to less developed rural areas in China and evaluate the impact of this model on health care utilization. Methods The intervention involved developing leadership at county level, training rural health practitioners, providing clinical management guidelines and standards, encouraging clinic improvements and providing access to subsidies for public health work. We chose 7 townships and 49 administrative villages in Chongyi County as the intervention sites; 3 townships and 9 administrative villages in Luxi County as the comparison sites. Officers from county health bureaus and postgraduates from School of Public Health, Nanchang University visited each township hospital and village clinic in field together and made observations and interviewed clinic staff. Results There was little change in health facilities or workforce in the two areas. However, there was an increase in the use of public health services at township and village level in the intervention sites in Chongyi. In these, the proportion of clinics which had developed a child health (under the age of 3 management system, maternal postpartum visit and chronic disease management increased from 53%, 51% and 47% to 78%, 73%, and 71% respectively. There was no significant change in the comparison sites. Conclusions The trial demonstrated that it was feasible to implement a model of community health service delivery that was adapted to depressed rural areas because it required little organizational change, additional funding or personnel. The model had a positive impact on the provision of public health programs, a finding which has implications for efforts to improve access to primary health care in rural China.

  13. Transport pathway and source area for Artemisia pollen in Beijing, China

    Science.gov (United States)

    Qin, Xiaoxin; Li, Yiyin; Sun, Xu; Meng, Ling; Wang, Xiaoke

    2017-12-01

    Artemisia pollen is an important allergen responsible for allergic rhinitis in Beijing, China. To explore the transport pathways and source areas of Artemisia pollen, we used Burkard 7-day traps to monitor daily pollen concentrations in 2016 in an urban and suburban locality. Backward trajectories of 24- and 96-h and their cluster analysis were performed to identify transport pathways of Artemisia pollen using the HYSPLIT model on 0.5° × 0.5° GADS meteorological data. The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were calculated to further identify the major potential source areas at local, regional, and long-range scales. Our results showed significant differences in Artemisia pollen concentration between urban and suburban areas, attributed to differences in plant distribution and altitude of the sampling locality. Such differences arisen from both pollen emission and air mass movements, hence pollen dispersal. At local or regional scales, source area of northwestern parts of Beijing City, Hebei Province and northern and northwestern parts of Inner Mongolia influenced the major transport pathways of Artemisia pollen. Transport pathway at a long-range scale and its corresponding source area extended to northwestern parts of Mongolia. The regional-scale transport affected by wind and altitude is more profound for Artemisia pollen at the suburban than at the urban station.

  14. Analysis of the Network of Protected Areas in China Based on a Geographic Perspective: Current Status, Issues and Integration

    Directory of Open Access Journals (Sweden)

    Mengtian Cao

    2015-11-01

    Full Text Available With the continued growth of protected areas (PAs in China in terms of the number, coverage and varieties of protected objects, how to efficiently manage the protected areas to ensure both resource protection and environmental protection has become a crucial research question. By applying a geographic perspective in an analysis of the development and evolution of protected areas in China, this paper presents the results of an analysis focused on the status and the types of current approaches to the management of natural protected areas to reveal the problems that exist in their management and to further explore an integration strategy for the protected area network. It proposes that the future management of protected areas should prioritize their legal status, the sustainable livelihood of individuals living in close proximity to them, and the establishment of a unified database to achieve grid and information management of the protected areas.

  15. Evaluating the Effect of a Novel Molluscicide in the Endemic Schistosomiasis Japonica Area of China

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    Jing Xia

    2014-10-01

    Full Text Available Oncomelania hupensis is the sole intermediate host snail of Schistosoma japonicum in China. Snail control by molluscicide remains one of the most effective measures of schistosomiasis japonica control. A 50% wettable powder of niclosamide ethanolamine salt (WPN is widely used for snail control in China. However, WPN is costly and toxic to fish. A novel molluscicide named LDS, the salt of quinoid-2′, 5-dichloro-4′-nitrosalicylanilide from niclosamide, has been developed. To evaluate the effects of large-scale field application of LDS on field snail control, tests were conducted in 15 counties of Hubei Province, China. Active adult snails, were immersed in 0.2, 0.4, and 0.6 g/m3 of 10% LDS, 1.0 g/m3 of 50% WPN was used as the molluscicide control, and then the mortality rates of snails were investigated after 1, 2, and 3 days. In addition, four active concentrations of 10% LDS (0.4, 0.6, 0.8 and 1.0 g/m2 were applied by spraying and powdering in the field. 1.0 g/m2 of 50% WPN was used as the molluscicide control, and then the mortality rates of snails were observed after 1, 3, and 7 days. The results indicated that 0.4 g/m3 LDS applied by the immersion or 0.6 g/m2 LDS applied by spraying and powdering achieved the same molluscicidal effect as that of WPN, regardless of exposure time. By using different methods, the snail mortality rates in the molluscicide groups were related to exposure time and concentration, respectively. LDS costs less than WPN; thus, LDS is suitable and applicable for use as a molluscicide in schistosomiasis japonica epidemic areas.

  16. Genetic heterogeneity of oesophageal cancer in high-incidence areas of southern and northern China.

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    Zhang Guohong

    Full Text Available BACKGROUND AND OBJECTIVE: Oesophageal cancer is one of the most common and deadliest cancers worldwide. Our previous population-based study reported a high prevalence of oesophageal cancer in Chaoshan, Guangdong Province, China. Ancestors of the Chaoshan population migrated from the Taihang Mountain region of north-central China, which is another high-incidence area for oesophageal cancer. The purpose of the present study was to obtain evidence of inherited susceptibility to oesophageal cancer in the Chaoshan population, with reference to the Taihang Mountain population, with the eventual goal of molecular identification of the disease genes. METHODS: We conducted familial correlation, commingling, and complex segregation analyses of 224 families from the Chaoshan population and 403 families from the Taihang population using the FPMM program of S.A.G.E. version 5.3.0. A second analysis focused on specific families having large numbers of affected individuals or early onset of the disease. RESULTS: For the general population, moderate sib-sib correlation was noticed for esophageal cancer. Additionally, brother-brother correlation was even higher. Commingling analyses indicated that a three-component distribution model best accounts for the variation in age of onset of oesophageal cancer, and that a multifactorial model provides the best fit to the general population data. An autosomal dominant mode and a dominant or recessive major gene with polygenic inheritance were found to be the best models of inherited susceptibility to oesophageal cancer in some large families. CONCLUSIONS: The current results provide evidence for inherited susceptibility to oesophageal cancer in certain high-risk groups in China, and support efforts to identify the susceptibility genes.

  17. [Analysis on the epidemiological features of human brucellosis in northern and southern areas of China, 2015-2016].

    Science.gov (United States)

    Shi, Y J; Lai, S J; Chen, Q L; Mu, D; Li, Y; Li, X X; Yin, W W; Yu, H J

    2017-04-10

    Objective: To analyze the epidemiological characteristics of human brucellosis in northern and southern areas of China, and to develop national strategies for brucellosis prevention and control. Methods: Individual data on human brucellosis was collected from the National Notifiable Infectious Disease Reporting Information System to describe the situation of brucellosis in China during 2015-2016. Epidemiological features of the disease in northern and southern areas of China were analyzed. Results: A total of 104 125 cases were reported in mainland China during 2015-2016, with an average incidence rate as 3.81/100 000. The overall incidence rate from the northern provinces was 7.77/100 000 in 2016, a 18.6 % decrease from 2015 (9.55/100 000), whereas the incidence rate in the southern provinces was 0.27/100 000 in 2016, with an increase of 28.6 % than 0.21/100 000 in 2015. 90.0 % of the newly infected counties mainly distributed in southern China. As for the locations of reporting cases, most of them were in the same counties in the northern areas (52.3 % ) while most cases in the southern areas (59.6 % ) were imported from other counties. The median age of the cases was 48 ( IQR: 38-58) years, with male-to-female ratios as 2.7∶1 in the north and 2.2∶1 in the south. Majority of the cases were occupation-related, from both the northern (86.8 % ) and southern (62.7 % ) areas. Human brucellosis occurred every month throughout the year but with an obvious seasonal increase between March and July. Conclusions: Different epidemiological features of human brucellosis appeared in both northern and southern areas of China. The disease was seen endemic in the northern and dispersal in the southern provinces. Appropriate strategies for brucellosis prevention and control should be developed, according to the different epidemiological characteristics in the northern or southern areas.

  18. The needs of the science teachers of Shenyang area, Northeast China

    Science.gov (United States)

    Zhao, Chao

    Purpose of the study. The purpose of this research was to survey those individuals teaching science in the middle schools of the Shenyang area, Northeast China. Specifically, the study attempted to differentiate between rural and nonrural teachers with respect to demographic differences, problem areas, instructional activities, and perceived needs. Procedure. A 100-item survey was used to collect data for this study. The sample consisted of 224 science teachers (Rural 114, nonrural 110) who taught at least science class in 1996--97 academic year in a middle school of Shenyang area, Northeast China. Frequencies and percentages presented the needs of the teachers. The differences between rural and nonrural groups were analyzed by Chi Square statistics. Findings. Almost three quarters (74.9%) of returns were younger than 41, and 43.9% of returns held no degree. Significant differences were fond between rural and nonrural groups according to age, classroom experience, school enrollment, lab activities, motivating students to learn science, using science test data bank, peer tutoring and evaluating your own instructional effectiveness as a science teacher. Rural and nonrural teachers shared 10 of 14 greatest needs. Conclusions. Teacher in-service program designers need to establish academic training programs which lead to entry level degrees and certificates and improve young teacher's instructional skills. Increased efforts should be given to meet the perceived needs addressed in this study in order to improve teachers' teaching and students' learning. Lack of person energy or motivation and program fail to meet teachers' needs were considered as barriers of attending inservice programs.

  19. Geographic signatures of North American West Coast estuaries

    Science.gov (United States)

    Emmett, Robert; Llansó, Roberto; Newton, Jan; Thom, Ron; Hornberger, Michelle; Morgan, Cheryl; Levings, Colin; Copping, Andrea; Fishman, Paul

    2000-01-01

    West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources.

  20. Comprehensive molecular etiology analysis of nonsyndromic hearing impairment from typical areas in China

    Directory of Open Access Journals (Sweden)

    Kang Dongyang

    2009-09-01

    Full Text Available Abstract Background Every year, 30,000 babies are born with congenital hearing impairment in China. The molecular etiology of hearing impairment in the Chinese population has not been investigated thoroughly. To provide appropriate genetic testing and counseling to families, we performed a comprehensive investigation of the molecular etiology of nonsyndromic deafness in two typical areas from northern and southern China. Methods A total of 284 unrelated school children with hearing loss who attended special education schools in China were enrolled in this study, 134 from Chifeng City in Inner Mongolia and the remaining 150 from Nangtong City in JiangSu Province. Screening was performed for GJB2, GJB3, GJB6, SLC26A4, 12S rRNA, and tRNAser(UCN genes in this population. All patients with SLC26A4 mutations or variants were subjected to high-resolution temporal bone CT scan to verify the enlarged vestibular aqueduct. Results Mutations in the GJB2 gene accounted for 18.31% of the patients with nonsyndromic hearing loss, 1555A>G mutation in mitochondrial DNA accounted for 1.76%, and SLC26A4 mutations accounted for 13.73%. Almost 50% of the patients with nonsyndromic hearing loss in these typical Chinese areas carried GJB2 or SLC26A4 mutations. No significant differences in mutation spectrum or prevalence of GJB2 and SLC26A4 were found between the two areas. Conclusion In this Chinese population, 54.93% of cases with hearing loss were related to genetic factors. The GJB2 gene accounted for the etiology in about 18.31% of the patients with hearing loss, SLC26A4 accounted for about 13.73%, and mtDNA 1555A>G mutation accounted for 1.76%. Mutations in GJB3, GJB6, and mtDNA tRNAser(UCN were not common in this Chinese cohort. Conventionally, screening is performed for GJB2, SLC26A4, and mitochondrial 12S rRNA in the Chinese deaf population.

  1. Air Pollutants, Climate, and the Prevalence of Pediatric Asthma in Urban Areas of China

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    Juanjuan Zhang

    2016-01-01

    Full Text Available Background. Prevalence of childhood asthma varies significantly among regions, while its reasons are not clear yet with only a few studies reporting relevant causes for this variation. Objective. To investigate the potential role of city-average levels of air pollutants and climatic factors in order to distinguish differences in asthma prevalence in China and explain their reasons. Methods. Data pertaining to 10,777 asthmatic patients were obtained from the third nationwide survey of childhood asthma in China’s urban areas. Annual mean concentrations of air pollutants and other climatic factors were obtained for the same period from several government departments. Data analysis was implemented with descriptive statistics, Pearson correlation coefficient, and multiple regression analysis. Results. Pearson correlation analysis showed that the situation of childhood asthma was strongly linked with SO2, relative humidity, and hours of sunshine (p<0.05. Multiple regression analysis indicated that, among the predictor variables in the final step, SO2 was found to be the most powerful predictor variable amongst all (β=-19.572, p < 0.05. Furthermore, results had shown that hours of sunshine (β = -0.014, p < 0.05 was a significant component summary predictor variable. Conclusion. The findings of this study do not suggest that air pollutants or climate, at least in terms of children, plays a major role in explaining regional differences in asthma prevalence in China.

  2. Safety evaluation of signalized intersections with left-turn waiting area in China.

    Science.gov (United States)

    Jiang, Xinguo; Zhang, Guopeng; Bai, Wei; Fan, Wenbo

    2016-10-01

    In recent years the metropolitans in China have seen the surging installations of the left-turn waiting area (LWA) at the signalized intersections. The design allows the left-turning vehicles to enter the intersection at the onset of the through green phase (of the same approach) and wait for the exclusive left-turn signal at the LWA. The LWA layout can effectively reduce the probability of stranded and queue overflow of the left-turn vehicles, but no study is conducted yet to assess the safety performance of the signalized intersections with LWA. The paper adopts the traffic conflict technique (represented by post-encroachment time), compares the discrepancy of conflict types between intersections with LWA and without, and develops the severity models to identify the contributing factors for the left-turn conflicts. Results demonstrate that the left-turn volume, driving outside the LWA, running red light, the presence of secondary conflicts, and the rear-end conflicts significantly increase the severities of traffic conflicts at the LWA. The findings serve to provide recommendations to revise the current design standard of the LWA (GB5768-2009) and consequently improve the safety operations of signalized intersections with LWA in China. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Gas hydrate saturation from acoustic impedance and resistivity logs in the shenhu area, south china sea

    Science.gov (United States)

    Wang, X.; Wu, S.; Lee, M.; Guo, Y.; Yang, S.; Liang, J.

    2011-01-01

    During the China's first gas hydrate drilling expedition -1 (GMGS-1), gas hydrate was discovered in layers ranging from 10 to 25 m above the base of gas hydrate stability zone in the Shenhu area, South China Sea. Water chemistry, electrical resistivity logs, and acoustic impedance were used to estimate gas hydrate saturations. Gas hydrate saturations estimated from the chloride concentrations range from 0 to 43% of the pore space. The higher gas hydrate saturations were present in the depth from 152 to 177 m at site SH7 and from 190 to 225 m at site SH2, respectively. Gas hydrate saturations estimated from the resistivity using Archie equation have similar trends to those from chloride concentrations. To examine the variability of gas hydrate saturations away from the wells, acoustic impedances calculated from the 3 D seismic data using constrained sparse inversion method were used. Well logs acquired at site SH7 were incorporated into the inversion by establishing a relation between the water-filled porosity, calculated using gas hydrate saturations estimated from the resistivity logs, and the acoustic impedance, calculated from density and velocity logs. Gas hydrate saturations estimated from acoustic impedance of seismic data are ???10-23% of the pore space and are comparable to those estimated from the well logs. The uncertainties in estimated gas hydrate saturations from seismic acoustic impedances were mainly from uncertainties associated with inverted acoustic impedance, the empirical relation between the water-filled porosities and acoustic impedances, and assumed background resistivity. ?? 2011 Elsevier Ltd.

  4. Temporal patterns of cotton Fusarium and Verticillium wilt in Jiangsu coastal areas of China.

    Science.gov (United States)

    Li, Xiaogang; Zhang, Ya'nan; Ding, Changfeng; Xu, Wenhua; Wang, Xingxiang

    2017-10-03

    Cotton diseases caused by soil-borne pathogenic fungi present a major constraint to cotton production not only in China but also worldwide. A long-term field inventory was made of the prevalence of Fusarium and Verticillium wilt of cotton in the Jiangsu coastal area of China from 2000 to 2014. Various factors (crop varieties, rotation and weather) were analyzed to explore the dynamics of these diseases in cotton. The results showed that the prevalence of Fusarium and Verticillium wilt increased before 2005 and that Verticillium wilt remained at a high incidence over most of the past 10 years, while Fusarium wilt began to gradually decrease after 2005. The dynamics of Fusarium and Verticillium wilt were closely associated with the introduced cotton varieties and the intensive cropping history. In addition, weather conditions occurring during some of the years appeared to coincide with a substantial variation in the wilt diseases. Our study highlighted epidemiological dynamics of Fusarium and Verticillium wilt in a long-term survey.

  5. Trends in the prevalence of hypertension in island and coastal areas of china: a systematic review with meta-analysis.

    Science.gov (United States)

    Chen, Xin; Wei, Wei; Zou, Safeng; Wu, Xiaomei; Zhou, Bo; Fu, Lingyu; Wang, Hailong; Shi, Jingpu

    2014-12-01

    With the economic development in recent years, there has been a dramatic increase in the prevalence of hypertension in some coastal cities of China; however, the number of reports regarding the prevalence of hypertension based on a nationwide study of island and coastal areas of China is limited. We estimated the prevalence and described the trends of hypertension during the last 3 decades in these specific areas. Authoritative databases were searched for cross-sectional studies reporting the prevalence of hypertension in island and coastal areas of China published in the past 3 decades, and 37 studies that involved 760,428 individuals representing 22 different locations were identified and included in our analysis. The estimated prevalence of hypertension was 9.8% (95% confidence interval (CI) = 6.3%-14.9%) in the 1980s, 18.5% (95% CI = 13.6%-24.8%) in the 1990s, and 30.0% (95% CI = 26.7%-33.6%) in the 2000s (χ(2) for trend: P = 0.00). In the 2000s, adjusted prevalence estimate of hypertension was 21.6% according to the national standard population composition in 1990, and the pooled prevalence estimate for the northern region in coastal areas of China was significantly higher than the southern region (36.2% vs. 26.2%; P = 0.002). Thus, the prevalence of hypertension in the island and coastal areas of China appears to have increased 21.5% in the last 3 decades; the increasing trend was observed in men and women. Our findings highlight the urgent need for public health strategies with more emphasis on improvement of primary health care in the island and coastal areas of China. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Risk factors for breast cancer in women residing in urban and rural areas of eastern China.

    Science.gov (United States)

    Wang, Feng; Yu, LiXiang; Wang, Fei; Liu, LiYuan; Guo, MingMing; Gao, DeZong; Zhang, Qiang; Li, YuYang; Li, Liang; Fu, QinYe; Yu, ZhiGang

    2015-12-01

    To investigate breast cancer risk factors in Chinese women residing in urban and rural areas of eastern China using a large-scale cross-sectional survey. In this multistage, stratified cluster sampling epidemiological survey, information on demographic characteristics, diet and lifestyle variables were gathered using a carefully designed questionnaire. Multivariate logistic regression analysis and subgroup analyses of the data were performed, including separate analyses of data from women residing in urban and rural areas. A total of 122,058 women were included in the survey. Age, body mass index, number of miscarriages, family history of breast cancer and menopausal status were found to be risk factors for breast cancer, while the consumption of soya bean products was a protective factor. Among women residing in urban areas, high or moderate intake of soya bean products and red meat were protective factors. Among women residing in rural areas, obesity and a high intake of milk were identified as risk factors for breast cancer, while a moderate intake of soya bean products was a protective factor. This type of data is crucial for understanding the risk factors for breast cancer and could facilitate the development and targeting of effective intervention strategies, with the ultimate aim of breast cancer prevention. © The Author(s) 2015.

  7. [Study on the characteristics of Tsutsugamushi disease in the epidemic areas of south islands in China].

    Science.gov (United States)

    Wang, Shan-shan; Huang, Jia-liang; Su, Jian-xin; Xi, Yun-zhen; Wang, Yan; Li, Min-min

    2007-10-01

    To study the increasing incidence and the characteristics of Tsutsugamushi disease in the areas of Nan Peng Lie islands, Nan Ao island, Wan Shan archipelago, Nao Zhou island and Lei Zhou peninsula, located in the southern part of China and to develop strategies for preventive measures. Both epidemiological investigation, isolation and gene identification of Orientia tsutsugamushi, as well as pilot preventive measures were carried out. These islands belonged to the epidemic area of south subtropical zone of Tsutsugamushi disease. The main host was Rattus norvegicu and the overall rates of infection on Orientia tsutsugamushi were 22.78%-33.75%. The main biological vector was Leptotrombidium (Leptotrombidium) deliens and the rates of infection on Orientia tsutsugamushi were 40.00%-75.00%. 25 strains of Orientia tsutsugamushi had been isolated from Rattus norvegicu and Leptotrombidium (Leptotrombidium) deliens. Results showed that the isolated strains of Orientia tsutsugamushi were 15 Karp, 8 Kato, 2 Yonchon. Results from serological studies showed that the positive rate of anti-Orientia tsutsugamushi antibodies was high, in both residents and soldiers stationed in these islands. On these islands, rats and biological vectors were killed. Results showed that these measures had positive impact in reducing the incidence. Islands from the southern part of the country belonged to the epidemic area of Tsutsugamushi disease. People visiting this areas should be under protection.

  8. Research history and prospecting potential of gold deposits in Dongchuan Area, Yunnan, China

    Science.gov (United States)

    Huang, Chaowen; Zhang, Shugen

    2017-03-01

    The Dongchuan area in China is part of the Sichuan-Yunnan-Guizhou polymetallic metallogenic field and contains extensive ore-deposits. Although gold was first discovered in the area in the 1990s, gold exploration and research are currently limited; only five areas have currently been identified as containing gold deposits with reserves of more than 20 tons. However, the area is believed to have considerable prospecting potential. Gold deposits mainly occurring in the wall of the rock mass have been found in the upper-middle section of the Pingdingshan Group to the lower-bottom section of the Yinming Group in relation to the intrusive action and development of sodium diorite. It has been determined that the core of the anticline complex and its nearby fault zone are the major ore hosting structures and that gold-deposit prospecting should be conducted around the N-S compressive shear zone. In this study, sites are determined that have certain characteristics accompanied by a high degree of rock formation and complete assemblages of lithological composition; these are considered to be locations conducive to the prospecting of gold deposits.

  9. [Status and influencing factors of polychlorinated biphenyls (PCBs) pollution in the coastal areas in China].

    Science.gov (United States)

    Liu, Min-Xia; Yang, Yu-Yi; Li, Qing-Xiao; Wang, Jun

    2013-08-01

    This review focused on the distribution, pollution status, sources and influencing factors of PCBs in the coastal areas (seawater, surface sediments and biota) in China. A few main points are listed as follows: (1) For coastal seawater, concentrations of PCBs were increasing from the north to the south and the highest concentrations of PCBs were observed in the developed east coastal areas. The concentrations of PCBs in most coastal areas were higher than the seawater standard of U. S. EPA (30 ng x L(-1)), indicating that there was a high potential risk. (2) Only a small part of surface sediments had PCBs concentrations higher than the ISQG (interim sediment quality guideline) and ERL (effects range-low) values, suggesting little probability of causing biological adverse effects and potential risk in surface sediments. (3) High-molecular-weight PCBs (4, 5 and 6 chlorinated biphenyl) were bio-accumulated in marine biota. The concentrations of PCBs in organisms were generally lower than 2000 ng x g(-1), which may have negligible effects on human health. (4) The main sources of PCBs were wastewater discharged from factories and the leakage of dismantling PCBs from electronic wastes. Factors influencing the concentrations and distribution of PCBs in the coastal areas included distance from land, flow exchange situation, water-carrying capacity, season, sediment particle size and total organic carbon content.

  10. [Factors that related to the depressive symptoms among elderly in urban and rural areas of China].

    Science.gov (United States)

    Yang, Z; Chen, R; Hu, X; Ren, X H

    2017-08-10

    Objective: The aim of this research was to study the prevalence and differences of depressive symptoms and related factors in elderly in both urban and rural areas so as to develop relative strategies on this issue. Methods: Ten-question-version of the Center Epidemiologic Studies-Depression scale (CES-D) was applied to score the depressive status. Data used in this research was from the 2013 China Health and Retirement Longitudinal Study (CHARLS). Binary logistic regressions method was applied to examine the influential factors related to depression symptoms. Results: In the elderly population, the mean score on depressive symptoms was 8.3±5.9, with a prevalence as 26.8%. The incidence rates on 'Elderly depression' in urban and rural areas were 16.4% and 30.0% respectively. The prevalence of depressive symptoms was relatively low (Pareas. Age and alcohol consumption appeared factors that influencing the depressive symptoms of the elderly in rural areas, while the average income was an influencing factor on the elderly in urban areas. Incidence of depression was relatively low in age ≥75 years group in rural areas. However, elderly in the rural areas with abstinence of alcohol intake showed higher incidence of depressive symptoms (Pareas. Conclusions: Incidence of depression appeared high among the elderly and even higher in the rural areas. Strategies would include the following points: to strengthen the construction of urban-rural integration, improving and strengthening the rural pension insurance system, upgrading the urban social assistance for low-income elderly, strengthening the psychological consultation service of primary medical institutions and actively developing the three-tier levels related to the prevention of chronic diseases.

  11. [Studies on multiple factor intervention in stroke of ten areas in northeast, north China and Shanghai].

    Science.gov (United States)

    Wang, G; Guo, Z; Wang, Y

    1996-03-01

    In order to explore the ways to prevent from the disease, 4,793 subjects aged over 40 at high risk of stroke from a total population of 250,000 in communities with high incidence of it were studied with multiple factor intervention, by oral administration of "Nao An" capsules as a major measure in 10 areas of north and northeast China, as well as Shanghai, during 1990 to 1993. Three years after intervention, incidence of stroke decreased by 49.17% in the population, with reduction of systolic and diastolic blood pressure, levels of blood sugar, cholesterol and triglyceride. Lowering of stroke incidence correlated positively with that of blood pressure in the population. It suggests stroke can be prevented effectively by concentrated efforts in comprehensive intervention in individuals at high risk.

  12. Road traffic injuries among middle school students in a rural area of China.

    Science.gov (United States)

    Jaung, Michael S; Yu, Songlin; Stallones, Lorann; Xiang, Huiyun

    2009-06-01

    Injuries resulting from road traffic crashes are a major and growing public health problem worldwide, disproportionately affecting vulnerable road users in developing countries. However, research on road traffic injuries in developing countries has been limited. We studied road traffic injuries among middle school students in a rural area of China. We surveyed 1551 students in Hunan province using a hard-copy survey questionnaire. The survey was conducted at two middle schools with the cooperation of teachers and school officials. The questionnaire gathered data including sociodemographics, school activities, and sleep patterns along with road traffic injuries among middle students during a 3-month recall period in 2006. Road traffic injuries were defined as injuries incurred as a result of a road traffic collision involving at least one vehicle in motion on a public or private road that resulted in at least one person being injured. There were 56 road traffic injuries reported by the surveyed students yielding a rate of 3.6 percent over the 3-month period. The greatest percentage of those injuries involved a motorcycle (80%). Nearly two fifths of injuries resulted in a period of activity restriction lasting one day or more (39%). The multivariable logistic regression analysis indicated that there were statistically significant associations between the assignment of extra homework by parents (odds ratio [OR] = 3.78, 95% confidence intervals [CI] = 1.49-9.60, p-value factor (OR = 2.03, 95% CI = 0.78-5.28, p-value = 0.06). School-related stress and sleep disturbance were identified as possible risk factors for road traffic injuries among students in a rural area of China. Further research is warranted in order to develop prevention strategies to address these preventable injuries.

  13. Spatial distributions of airborne di-carbonyls in urban and rural areas in China

    Science.gov (United States)

    Lui, K. H.; Dai, Wen-Ting; Chan, C. S.; Ho, Steven Sai Hang; Cao, Jun-Ji; Lee, S. C.; Ho, K. F.

    2017-04-01

    Gaseous glyoxal and methylglyoxal concentrations were characterized in nine cities of China during 2010-2011. The average summer (winter) glyoxal and methylglyoxal concentrations were 36.4-178.4 (12.3-241.4) and 67.8-359.4 (28.4-530.0) ng/m3, respectively. In summer, the highest average glyoxal concentration was in Guangzhou (GZ), while the lowest was in Shanghai (SH). In winter, Xiamen (XM) showed the highest average methylglyoxal concentration and Yantai (YT) reported the lowest. Both di-carbonyls showed distinct seasonal variations. The maximum average methylglyoxal concentration was approximately twice as much as glyoxal, which is consistent with the results of other studies. Glyoxal-to-methylglyoxal ratios showed that there was a consistent direct source of emissions in remote areas such as Qinghai Lake and Lhasa in both seasons (r ≥ 0.9). Pearson's correlation analysis suggested possible similar sources formation (R ≥ 0.7) for the two di-carbonyls in winter. Multiple linear regression analyses demonstrated that every 1 °C temperature increase could lead to a > 2% increase in the concentration of the di-carbonyls in both seasons. There was a greater percentage gain for glyoxal in winter than in summer for the same temperature increase. The northeast monsoon occurs in winter, and for every 1 ms- 1 increase in wind speed, > 20% of the di-carbonyls can be transferred out of China. This study is useful to understand about the secondary organic aerosol formation in the areas, the statistical analysis can provide information about the relationships between these carbonyls in atmosphere.

  14. Proposed biodiversity conservation areas: gap analysis and spatial prioritization on the inadequately studied Qinghai Plateau, China

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    Renqiang Li

    2018-01-01

    Full Text Available Global biodiversity priorities are primarily addressed through the establishment or expansion of conservation areas (CAs. Spatial prioritization of these CAs can help minimize biodiversity loss by accounting for the uneven distribution of biodiversity and conservation considerations (e.g., accessibility, cost, and biodiversity threats. Furthermore, optimized spatial priorities can help facilitate the judicious use of limited conservation resources by identifying cost effective CA designs. Here, we demonstrate how key species and ecosystems can be incorporated into systematic conservation planning to propose the expansion and addition of new CAs in the biodiversity-unique and data-poor region of Qinghai Plateau, China. We combined species distribution models with a systematic conservation planning tool, MARXAN to identify CAs for biodiversity on Qinghai Plateau. A set of 57 optimal CAs (273,872 km2, 39.3 % of this Province were required to achieve the defined conservation targets in Qinghai Province. We also identified 29 new CAs (139,216 km2, 20% of Qinghai Province outside the existing nature reserve (NRs that are necessary to fully achieve the proposed conservation targets. The conservation importance of these 29 new CAs was also indicated, with 10 labeled as high priority, 11 as medium priority, and 8 as low priority. High priority areas were more abundant in the eastern and southeastern parts of this region. Our results suggest that many species remain inadequately protected within the Qinghai Plateau, with conservation gaps in eastern and northwestern regions. The proposed more representative and effective CAs can provide useful information for adjusting the existing NRs and developing the first National Park in China.

  15. B-Vitamin Levels in Human Milk among Different Lactation Stages and Areas in China.

    Science.gov (United States)

    Ren, Xiangnan; Yang, Zhenyu; Shao, Bing; Yin, Shi-An; Yang, Xiaoguang

    2015-01-01

    To determine the contents of B-vitamins in human milk in China, we analyzed 1778 human milk samples from the sample bank of the National High Technique R & D Program (863 Projects) which was a cross-sectional survey and covered 6419 human milk samples from healthy lactating mothers who were at different stages of lactation (0-330 days postpartum) in 11 provinces of China. The contents of free forms of six B-vitamins in these human milk samples were analyzed by using UPLC-MS/MS. The median concentrations of free form of 6 B-vitamins in colostrums, transitional milk, 15-180 d mature milk and 181-330 d mature milk were respectively as follows: thiamin 5.0 µg/L, 6.7 µg/L, 21.1 µg/L and 40.7 µg/L; riboflavin 29.3 µg/L, 40.6 µg/L, 33.6 µg/L and 29.6 µg/L; niacin 470.7 µg/L, 661.3 µg/L, 687.0 µg/L and 571.3 µg/L; vitamin B-6 4.6 µg/L, 16.1 µg/L, 62.7 µg/L and 80.7 µg/L; flavin adenine dinucleotide (FAD) 808.7 µg/L, 1162.8 µg/L, 1023.9 µg/L and 1057.2 µg/L; pantothenic acid 1770.9 µg/L, 2626.8 µg/L, 2213.0 µg/L and 1895.5 µg/L. The contents of 6 B-vitamins varied significantly among the different lactation stages and different areas (coastal area vs inland area, rural area vs urban area). The present study indicated that the concentrations of B-vitamins in colostrum were generally much lower than those in transitional milk and mature milk. Further studies are warranted for their roles and significance on B-vitamins in colostrum in nutrition and metabolism of neonates.

  16. B-Vitamin Levels in Human Milk among Different Lactation Stages and Areas in China

    Science.gov (United States)

    Ren, Xiangnan; Yang, Zhenyu; Shao, Bing; Yin, Shi-an; Yang, Xiaoguang

    2015-01-01

    To determine the contents of B-vitamins in human milk in China, we analyzed 1778 human milk samples from the sample bank of the National High Technique R & D Program (863 Projects) which was a cross-sectional survey and covered 6419 human milk samples from healthy lactating mothers who were at different stages of lactation (0–330 days postpartum) in 11 provinces of China. The contents of free forms of six B-vitamins in these human milk samples were analyzed by using UPLC-MS/MS. The median concentrations of free form of 6 B-vitamins in colostrums, transitional milk, 15–180 d mature milk and 181-330 d mature milk were respectively as follows: thiamin 5.0 µg/L, 6.7 µg/L, 21.1 µg/L and 40.7 µg/L; riboflavin 29.3 µg/L, 40.6 µg/L, 33.6 µg/L and 29.6 µg/L; niacin 470.7 µg/L, 661.3 µg/L, 687.0 µg/L and 571.3 µg/L; vitamin B-6 4.6 µg/L, 16.1 µg/L, 62.7 µg/L and 80.7 µg/L; flavin adenine dinucleotide (FAD) 808.7 µg/L, 1162.8 µg/L, 1023.9 µg/L and 1057.2 µg/L; pantothenic acid 1770.9 µg/L, 2626.8 µg/L, 2213.0 µg/L and 1895.5 µg/L. The contents of 6 B-vitamins varied significantly among the different lactation stages and different areas (coastal area vs inland area, rural area vs urban area). The present study indicated that the concentrations of B-vitamins in colostrum were generally much lower than those in transitional milk and mature milk. Further studies are warranted for their roles and significance on B-vitamins in colostrum in nutrition and metabolism of neonates. PMID:26186707

  17. B-Vitamin Levels in Human Milk among Different Lactation Stages and Areas in China.

    Directory of Open Access Journals (Sweden)

    Xiangnan Ren

    Full Text Available To determine the contents of B-vitamins in human milk in China, we analyzed 1778 human milk samples from the sample bank of the National High Technique R & D Program (863 Projects which was a cross-sectional survey and covered 6419 human milk samples from healthy lactating mothers who were at different stages of lactation (0-330 days postpartum in 11 provinces of China. The contents of free forms of six B-vitamins in these human milk samples were analyzed by using UPLC-MS/MS. The median concentrations of free form of 6 B-vitamins in colostrums, transitional milk, 15-180 d mature milk and 181-330 d mature milk were respectively as follows: thiamin 5.0 µg/L, 6.7 µg/L, 21.1 µg/L and 40.7 µg/L; riboflavin 29.3 µg/L, 40.6 µg/L, 33.6 µg/L and 29.6 µg/L; niacin 470.7 µg/L, 661.3 µg/L, 687.0 µg/L and 571.3 µg/L; vitamin B-6 4.6 µg/L, 16.1 µg/L, 62.7 µg/L and 80.7 µg/L; flavin adenine dinucleotide (FAD 808.7 µg/L, 1162.8 µg/L, 1023.9 µg/L and 1057.2 µg/L; pantothenic acid 1770.9 µg/L, 2626.8 µg/L, 2213.0 µg/L and 1895.5 µg/L. The contents of 6 B-vitamins varied significantly among the different lactation stages and different areas (coastal area vs inland area, rural area vs urban area. The present study indicated that the concentrations of B-vitamins in colostrum were generally much lower than those in transitional milk and mature milk. Further studies are warranted for their roles and significance on B-vitamins in colostrum in nutrition and metabolism of neonates.

  18. Risk factors for infectious diseases in backyard poultry farms in the Poyang Lake area, China.

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    Yong Wang

    Full Text Available Emergence and transmission of infectious diseases have an enormous impact on the poultry industry and present a serious threat to the health of humans and wild birds. Noncommercial poultry operations, such as backyard poultry facilities in China, are potential sources of virus exchange between commercial poultry and wild birds. It is particularly critical in wetland areas where backyard poultry have close contact with commercial poultry and migratory birds, therefore increasing the risk of contracting infectious diseases. To evaluate the transmission risks, a cross-sectional study was undertaken in the Poyang Lake area, China, involving 309 residents in the backyard poultry farms in three counties (Region A, B, and C of Jiangxi Province. We examined the backyard poultry population, poultry species, presence of poultry deaths from infectious diseases, food sources, and biosecurity practices. Region B ranked highest for biosecurity while region C ranked lowest. The risks of infectious diseases were assessed by adjusted odds ratio based on multivariate logistic regression analysis. Potential risk factors in the three regions of the study site were compared. In Region A, significant factor was contact of poultry with wild birds (OR: 6.573, 95% CI: 2.148-20.115, P=0.001. In Region B, the most significant factor was contact of poultry with neighboring backyard waterfowls (OR: 3.967, 95% CI: 1.555-10.122, P=0.004. In Region C, significant factors were poultry purchase from local live bird markets (OR: 3.740, 95% CI: 1.243-11.255, P=0.019, and contact of poultry with wild birds (OR: 3.379, 95% CI: 1.058-10.791, P=0.040. In summary, backyard poultry was significantly affected by neighboring commercial poultry and close contact with wild birds. The results are expected to improve our understanding of the transmission risks of infectious diseases in a typical backyard poultry environment in rural China, and address the need to improve local farming

  19. Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China.

    Science.gov (United States)

    Du, Buyun; Li, Ping; Feng, Xinbin; Qiu, Guangle; Zhou, Jun; Maurice, Laurence

    2016-11-08

    To evaluate the mercury (Hg) exposure level of children located in a Hg mining area, total Hg concentrations and speciation were determined in hair and urine samples of children in the Wanshan Hg mining area, Guizhou Province, China. Rice samples consumed by these same children were also collected for total mercury (THg) and methyl-mercury (MeHg) analysis. The geometric mean concentrations of THg and MeHg in the hair samples were 1.4 (range 0.50-6.0) μg/g and 1.1 (range 0.35-4.2) μg/g, respectively, while the geometric mean concentration of urine Hg (UHg) was 1.4 (range 0.09-26) μg/g Creatinine (Cr). The average of the probable daily intake (PDI) of MeHg via rice consumption was 0.052 (0.0033-0.39) µg/kg/day, which significantly correlated with the hair MeHg concentrations (r = 0.55, p exposure for children in this area. Furthermore, 18% (26/141) of the PDIs of MeHg exceeded the USEPA Reference Dose (RfD) of 0.10 µg/kg/day, indicating that children in this area are at a high MeHg exposure level. This paper for the first time evaluates the co-exposure levels of IHg and MeHg of children living in Wanshan mining area, and revealed the difference in exposure patterns between children and adults in this area.

  20. Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China

    Directory of Open Access Journals (Sweden)

    Buyun Du

    2016-11-01

    Full Text Available To evaluate the mercury (Hg exposure level of children located in a Hg mining area, total Hg concentrations and speciation were determined in hair and urine samples of children in the Wanshan Hg mining area, Guizhou Province, China. Rice samples consumed by these same children were also collected for total mercury (THg and methyl-mercury (MeHg analysis. The geometric mean concentrations of THg and MeHg in the hair samples were 1.4 (range 0.50–6.0 μg/g and 1.1 (range 0.35–4.2 μg/g, respectively, while the geometric mean concentration of urine Hg (UHg was 1.4 (range 0.09–26 μg/g Creatinine (Cr. The average of the probable daily intake (PDI of MeHg via rice consumption was 0.052 (0.0033–0.39 µg/kg/day, which significantly correlated with the hair MeHg concentrations (r = 0.55, p < 0.01, indicating that ingestion of rice is the main pathway of MeHg exposure for children in this area. Furthermore, 18% (26/141 of the PDIs of MeHg exceeded the USEPA Reference Dose (RfD of 0.10 µg/kg/day, indicating that children in this area are at a high MeHg exposure level. This paper for the first time evaluates the co-exposure levels of IHg and MeHg of children living in Wanshan mining area, and revealed the difference in exposure patterns between children and adults in this area.

  1. Assessing the impact of human activities on British Columbia's estuaries.

    Science.gov (United States)

    Robb, Carolyn K

    2014-01-01

    The world's marine and coastal ecosystems are under threat and single-sector management efforts have failed to address those threats. Scientific consensus suggests that management should evolve to focus on ecosystems and their human, ecological, and physical components. Estuaries are recognized globally as one of the world's most productive and most threatened ecosystems and many estuarine areas in British Columbia (BC) have been lost or degraded. To help prioritize activities and areas for regional management efforts, spatial information on human activities that adversely affect BC's estuaries was compiled. Using statistical analyses, estuaries were assigned to groups facing related threats that could benefit from similar management. The results show that estuaries in the most populated marine ecosections have the highest biological importance but also the highest impacts and the lowest levels of protection. This research is timely, as it will inform ongoing marine planning, land acquisition, and stewardship efforts in BC.

  2. Caledonian granitoids in the Jinxiu area, Guangxi, South China: Implications for their tectonic setting

    Science.gov (United States)

    Li, Xiaofeng; Yu, Yong; Wang, Chunzeng

    2017-02-01

    Jinxiu area is tectonically located between the Cathaysia and Yangtze blocks of South China. The area has three granitic plutons, Dajin, Boquan, and Lingzu plutons. Geochemically the plutons are high-K calc-alkaline, depleted in Ba, Sr, P, and Ti and rich in Pb, with decoupled Nb and Ta, and show non-island-arc magmatic affinity. Biotite monzogranite samples collected from the Dajin, Boquan, and Lingzu plutons yield zircon SHRIMP 206Pb/238U ages of 419.0 ± 5.0 Ma, 436.0 ± 4.0 Ma, and 446.1 ± 8.2 Ma, respectively, indicating that the plutons were emplaced during the Late Ordovician to Late Silurian of the Caledonian time. The granodiorite within the Lingzu biotite monzogranite pluton yields a zircon 206Pb/238U age of 174.5 ± 1.9 Ma, indicating a superimposed Late Jurassic magmatic event. The monzogranites and their enclaves show εNd(t) values of - 14.7 to - 11.1 and - 8.0 respectively and TDM2 values of 2.1-2.4 Ga and 1.8 Ga, respectively, demonstrating that the magmas were derived from re-melted Paleoproterozoic continental crust. Based on geochronology and geochemistry of the granitic plutons, as well as regional stratigraphy and paleontology, it is concluded that any existence of oceanic crust and oceanic subduction was unlikely in the Jinxiu area and vicinity during the Paleozoic Caledonian Ordovician-Silurian time.

  3. Seismic Hazard and Risk Assessments for Beijing-Tianjin-Tangshan, China, Area

    Science.gov (United States)

    Xie, F.; Wang, Z.; Liu, J.

    2011-01-01

    Seismic hazard and risk in the Beijing-Tianjin-Tangshan, China, area were estimated from 500-year intensity observations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 ?? 0.1??. Second, we performed a statistical analysis on the digitized intensity data, determined an average b value (0.39), and derived the intensity-frequency relationship (hazard curve) for each cell. Finally, based on a Poisson model for earthquake occurrence, we calculated seismic risk in terms of a probability of I ??? 7, 8, or 9 in 50 years. We also calculated the corresponding 10 percent probability of exceedance of these intensities in 50 years. The advantages of assessing seismic hazard and risk from intensity records are that (1) fewer assumptions (i. e., earthquake source and ground motion attenuation) are made, and (2) site-effect is included. Our study shows that the area has high seismic hazard and risk. Our study also suggests that current design peak ground acceleration or intensity for the area may not be adequate. ?? 2010 Birkh??user / Springer Basel AG.

  4. Trace Elements in Soils and Selected Agricultural Plants in the Tongling Mining Area of China.

    Science.gov (United States)

    Ding, Ziwei; Li, Yang; Sun, Qingye; Zhang, Haojie

    2018-01-25

    The quality and safety of agricultural products from metal mining areas are of wide concern. In order to investigate the contents and health risks of trace elements in fruit vegetables planted in metal mining areas, 440 samples of fruit vegetables from 117 vegetable plots were collected from Tongling mining area. Trace element contents in fruit vegetables and soil were measured. The results indicated that the total concentration of trace elements in some of the soil samples exceeded the Grade II national standard in China. Transfer factor (TF) of Cd was the highest (8.360), followed by Zn, Cu, As, and Pb. Estimated daily intake (EDI) of the trace elements, except Cd, were generally below the maximum tolerable daily intake (MTDI). The target hazard quotient (THQ) of Zn for children was more than 1 in some vegetables, suggesting potential health hazards for child population. Total target hazard quotient (TTHQ) of Cu and Zn were also more than 1 through consumption of all vegetables, indicating significant health risks. For both adults and children, hazard index (HI) was more than 1 for the consumption of vegetables. The findings reveal the health risks associated with the consumption of trace elements through the intake of selected vegetables in the population of Tongling.

  5. Situation of Diabetes and Related Disease Surveillance in Rural Areas of Jilin Province, Northeast China

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    Rui Wang

    2016-05-01

    Full Text Available Background: Several studies have investigated the prevalence and awareness of diabetes mellitus (DM in China, but little is known about the situation of DM in the northeastern rural areas. Our present study investigated the prevalence, awareness and associated characteristics of DM in rural areas of Jilin Province, aiming to suggest more efforts for the prevention and control of DM. Methods: A multistage stratified random cluster sampling design was used in this cross-sectional study which took place in 2012. Data were collected by face-to-face interviews and physical examinations. Rao-Scott Chi-square test, t test and multivariate logistic regression analysis were used. Results: The estimated prevalence of DM in rural areas of Jilin province was 7.2%. DM was positively associated with age, Body mass index (BMI, hypotension, dyslipidemia and was high in participants with a family history of diabetes and those who exercise frequently, but low for high education level and married participants. 69.0% participants with DM were aware of their diabetes status, 88.2% of whom received treatment and 34.4% of whom had received treatment controlled their DM status. Conclusions: We observed a high prevalence and low awareness status of DM among the rural residents in Jilin Province, but the rate of effective control in those who have received treatment was considerable. The low rate of disease surveillance should draw health authority’s attention.

  6. The prevalence of dementia in urban and rural areas of China.

    Science.gov (United States)

    Jia, Jianping; Wang, Fen; Wei, Cuibai; Zhou, Aihong; Jia, Xiangfei; Li, Fang; Tang, Muni; Chu, Lan; Zhou, Youlong; Zhou, Chunkui; Cui, Yong; Wang, Qi; Wang, Weishan; Yin, Peng; Hu, Nan; Zuo, Xiumei; Song, Haiqing; Qin, Wei; Wu, Liyong; Li, Dan; Jia, Longfei; Song, Juexian; Han, Ying; Xing, Yi; Yang, Peijie; Li, Yuemei; Qiao, Yuchen; Tang, Yi; Lv, Jihui; Dong, Xiumin

    2014-01-01

    The Chinese population has been aging rapidly and the country's economy has experienced exponential growth during the past three decades. The goal of this study was to estimate the changes in the prevalence of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) among elderly Chinese individuals and to analyze differences between urban and rural areas. For the years 2008 to 2009, we performed a population-based cross-sectional survey with a multistage cluster sampling design. Residents aged 65 years and older were drawn from 30 urban (n = 6096) and 45 rural (n = 4180) communities across China. Participants were assessed with a series of clinical examinations and neuropsychological measures. Dementia, AD, and VaD were diagnosed according to established criteria via standard diagnostic procedures. The prevalence of dementia, AD, and VaD among individuals aged 65 years and older were 5.14% (95% CI, 4.71-5.57), 3.21% (95% CI, 2.87-3.55), and 1.50% (95% CI, 1.26-1.74), respectively. The prevalence of dementia was significantly higher in rural areas than in urban ones (6.05% vs. 4.40%, P dementia and AD was found in rural areas than in urban ones, and education might be an important reason for the urban-rural differences. Copyright © 2014. Published by Elsevier Inc.

  7. Impact factors on expansion of built-up areas in Zhejiang Province, China

    Science.gov (United States)

    Liu, Dong; Zhu, Qiankun; Li, Yan; Gong, Fang

    2017-10-01

    Built-up areas are the results of human activities. Not only are they the real reflection of human and society activities, but also one of the most important input parameters for the simulation of biogeochemical cycle. Therefore, it is very necessary to map the distribution of built-up areas and monitor their changes by using new technologies and methods at high spatiotemporal resolution. By combining technologies of GIS (Geographic Information System) and RS (Remote Sensing), this study mainly explored the expansion and driving factors of built-up areas at the beginning of the 21st century in Zhejiang Province, China. Firstly, it introduced the mapping processes of LULC (Land Use and Land Cover) based on the method which combined object-oriented method and binary decision tree. Then, it analyzed the expansion features of built-up areas in Zhejiang from 2000 to 2005 and 2005 to 2010. In addition to these, potential driving factors on the expansion of built-up areas were also explored, which contained physical geographical factors, railways, highways, rivers, urban centers, elevation, and slop. Results revealed that the expansions of built-up areas in Zhejiang from 2000 to 2005 and from 2005 to 2010 were very obvious and they showed high levels of variation in spatial heterogeneity. Except those, increased built-up areas with distance to railways, highways, rivers, and urban centers could be fitted with power function (y = a*xb ), with minimum R2 of 0.9507 for urban centers from 2000 to 2005; the increased permillages of built-up areas to mean elevation and mean slop could be fitted with exponential functions (y = a*ebx), with minimum R2 of 0.6657 for mean slop from 2005 to 2010. Besides, government policy could also impact expansion of built-up areas. In a nutshell, a series of conclusions were obtained through this study about the spatial features and driving factors of evolution of built-up areas in Zhejiang from 2000 to 2010.

  8. Spatiotemporal variations and regional differences of extreme precipitation events in the Coastal area of China from 1961 to 2014

    Science.gov (United States)

    Wang, Xiaoli; Hou, Xiyong; Wang, Yuandong

    2017-11-01

    Coastal area of China (CAC) is of high ecological vulnerability and extremely sensitive to global climate change. Based on daily precipitation dataset of 156 station records, spatial and temporal variations of extreme precipitation events from 1961 to 2014 in the coastal area of China were investigated using a set of mathematical and statistical methods including trend analysis, R/S analysis, wavelet analysis, Mann-Kendall test, accumulative anomaly analysis and Pettitt test. Results revealed that there was a generally insignificant upward and downward tendency of extreme precipitation events in the southern and northern coastal area, respectively. Persistent of tendency suggested that trends of extreme precipitation events in Huabei, Huanghuai, Jiangnan and Huanan coastal areas would continue but trends in Dongbei and Jianghuai coastal areas would mostly present contrary to the past in the future. Multi-year averages of all extreme precipitation indices except consecutive dry days (CDD) varied largely in the coastal area of China, generally highest in Huanan coastal area and lowest in Huabei coastal area. The primary period of extreme precipitation indices varied from 2- to 7-year in the sub-regions. The abrupt change of extreme precipitation indices occurred mainly in the 1990s and the 1970s in the CAC.

  9. An epidemiological analysis of paediatric burns in urban and rural areas in south central China.

    Science.gov (United States)

    Zhou, Bo; Zhou, Xiao; Ouyang, Li-zhi; Huang, Xiao-yuan; Zhang, Pi-hong; Zhang, Ming-hua; Ren, Li-cheng; Liang, Peng-fei

    2014-02-01

    This study aims to analyse the epidemiology of paediatric burns in south central China, illustrate the differences between rural and urban areas, and discern prevention measures to reduce paediatric burns. Data were obtained from all paediatric patients admitted to Department of Burns unit of Xiangya Hospital during 2009-2012. A retrospective review was performed, including cause of burn, pre-hospital treatment, place of burn occurrence, anatomical areas involved, extent of burn, date of injury, number of operations, complications, length of hospital stay, hospitalisation cost and cure rate. A total of 278 hospitalised paediatric patients were admitted in this study. The majority (56.47%) were 1-3 years old. Rural patients accounted for 67.99% in total; the ratio of boys to girls was 2.05. Scalding with hot fluids was the most common cause of burns in children (62.59%), followed by flame (17.63), fireworks (9.71%), electricity (5.76%) and other factors such as contact and chemical (4.32%). The living room was the location with the highest frequency of burns in children (53.24%). Burns were more likely to happen in winter and the upper extremities were the most involved anatomic site (53.24%). Total burn surface area (TBSA) ranging from 0% to 9% accounted for 55.4% in total. Rural patients underwent more operations and had longer and costlier hospital stays than urban patients. Compared with treatment in urban areas, rural burn patients received less first-aid treatment, underwent more surgery, had more complications and longer and more costly hospital stays. This finding strongly suggests that it is necessary to make more efforts to prevent burns, especially in rural areas. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  10. Apparent source levels and active communication space of whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis in the Pearl River Estuary and Beibu Gulf, China

    Directory of Open Access Journals (Sweden)

    Zhi-Tao Wang

    2016-02-01

    Full Text Available Background. Knowledge of species-specific vocalization characteristics and their associated active communication space, the effective range over which a communication signal can be detected by a conspecific, is critical for understanding the impacts of underwater acoustic pollution, as well as other threats. Methods. We used a two-dimensional cross-shaped hydrophone array system to record the whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis in shallow-water environments of the Pearl River Estuary (PRE and Beibu Gulf (BG, China. Using hyperbolic position fixing, which exploits time differences of arrival of a signal between pairs of hydrophone receivers, we obtained source location estimates for whistles with good signal-to-noise ratio (SNR ≥10 dB and not polluted by other sounds and back-calculated their apparent source levels (ASL. Combining with the masking levels (including simultaneous noise levels, masking tonal threshold, and the Sousa auditory threshold and the custom made site-specific sound propagation models, we further estimated their active communication space (ACS. Results. Humpback dolphins produced whistles with average root-mean-square ASL of 138.5 ± 6.8 (mean ± standard deviation and 137.2 ± 7.0 dB re 1 µPa in PRE (N = 33 and BG (N = 209, respectively. We found statistically significant differences in ASLs among different whistle contour types. The mean and maximum ACS of whistles were estimated to be 14.7 ± 2.6 (median ± quartile deviation and 17.1± 3.5 m in PRE, and 34.2 ± 9.5 and 43.5 ± 12.2 m in BG. Using just the auditory threshold as the masking level produced the mean and maximum ACSat of 24.3 ± 4.8 and 35.7 ± 4.6 m for PRE, and 60.7 ± 18.1 and 74.3 ± 25.3 m for BG. The small ACSs were due to the high ambient noise level. Significant differences in ACSs were also observed among different whistle contour types. Discussion. Besides shedding some light for evaluating appropriate noise

  11. Apparent source levels and active communication space of whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in the Pearl River Estuary and Beibu Gulf, China.

    Science.gov (United States)

    Wang, Zhi-Tao; W L Au, Whitlow; Rendell, Luke; Wang, Ke-Xiong; Wu, Hai-Ping; Wu, Yu-Ping; Liu, Jian-Chang; Duan, Guo-Qin; Cao, Han-Jiang; Wang, Ding

    2016-01-01

    Background. Knowledge of species-specific vocalization characteristics and their associated active communication space, the effective range over which a communication signal can be detected by a conspecific, is critical for understanding the impacts of underwater acoustic pollution, as well as other threats. Methods. We used a two-dimensional cross-shaped hydrophone array system to record the whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in shallow-water environments of the Pearl River Estuary (PRE) and Beibu Gulf (BG), China. Using hyperbolic position fixing, which exploits time differences of arrival of a signal between pairs of hydrophone receivers, we obtained source location estimates for whistles with good signal-to-noise ratio (SNR ≥10 dB) and not polluted by other sounds and back-calculated their apparent source levels (ASL). Combining with the masking levels (including simultaneous noise levels, masking tonal threshold, and the Sousa auditory threshold) and the custom made site-specific sound propagation models, we further estimated their active communication space (ACS). Results. Humpback dolphins produced whistles with average root-mean-square ASL of 138.5 ± 6.8 (mean ± standard deviation) and 137.2 ± 7.0 dB re 1 µPa in PRE (N = 33) and BG (N = 209), respectively. We found statistically significant differences in ASLs among different whistle contour types. The mean and maximum ACS of whistles were estimated to be 14.7 ± 2.6 (median ± quartile deviation) and 17.1± 3.5 m in PRE, and 34.2 ± 9.5 and 43.5 ± 12.2 m in BG. Using just the auditory threshold as the masking level produced the mean and maximum ACSat of 24.3 ± 4.8 and 35.7 ± 4.6 m for PRE, and 60.7 ± 18.1 and 74.3 ± 25.3 m for BG. The small ACSs were due to the high ambient noise level. Significant differences in ACSs were also observed among different whistle contour types. Discussion. Besides shedding some light for evaluating appropriate noise exposure

  12. [Pollution characteristics and health risk assessment of atmospheric VOCs in the downtown area of Guangzhou, China].

    Science.gov (United States)

    Li, Lei; Li, Hong; Wang, Xue-Zhong; Zhang, Xin-Min; Wen, Chong

    2013-12-01

    The measurements of 31 kinds of VOCs in the ambient air of a site were carried out in the downtown of Guangzhou by online method from November 5, 2009 to November 9, 2009. The ambient level and composition characteristics, temporal variation characteristics, sources identification, and chemical reactivity of VOCs were studied, and the health risk of VOCs in the ambient air in the study area was assessed by using the international recognized health risk assessment method. Results showed that the mean and the range of the mass concentrations of 31 VOCs were 114.51 microg x m(-3) and 29.42-546.06 microg x m(-3), respectively. The mass concentrations of 31 VOCs, and those of alkanes, alkenes, and aromatics all showed a changing trend of higher in the morning and in the evening, and lower at noontime. Vehicular exhaust, gasoline and liquefied petroleum gas evaporates were the main sources of VOCs with the volatilization of paints and solvents being important emission sources. Toluene, trans-2-butene, m/p-xylene, i-butane, and 1,3,5-trimethylbenzene were the key reactive species among the 31 VOCs. Vehicular exhaust and gasoline evaporation were the main sources of VOCs leading to the formation of ozone. Health risk assessment showed that n-hexane, 1,3-butadiene, benzene, toluene, ethylbenzene, m/p-xylene and o-xylene had no appreciable risk of adverse non-cancer health effect on the exposed population, but 1, 3-butadiene and benzene had potential cancer risk. By comparing the corresponding data about health risk assessment of benzene compounds in some cities in China, it is concluded that benzene can impose relatively high cancer risk to the exposed populations in the ambient air of some cities in China. Therefore, strict countermeasures should be taken to further control the pollution of benzene in the ambient air of cities, and it is imperative to start the related studies and develop the atmospheric environmental health criteria and national ambient air quality

  13. High concentration hydrate in disseminated forms obtained in Shenhu area, north slope of South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.; Wu, N.; Zhang, G.; Liang, J.; Lu, J. [Guangzhou Marine Geology Survey, Guangzhou (China); Zhang, H. [China Geological Survey, Beijing (China); Su, X. [China Univ. of Geosciences, Beijing (China); Schultheiss, P.; Holland, M. [Geotek, Daventry (United Kingdom); Rose, K. [National Energy Technology Laboratory, Morgantown, WV (United States)

    2008-07-01

    The geological and tectonic settings, the temperature and pressure regimes, and the methane-generating potential from the thick organic-rich sediments of the north slope of the South China Seas are all favorable properties for gas hydrate formation. The Guangzhou Marine Geological Survey (GMGS) has been performing geological, geophysical and geochemical investigations for gas hydrate in the northern South China Sea since 2001. In order to determine the nature and distribution of gas hydrates, a gas hydrate drilling expedition was initiated in the Shenhu area of the north slope of the South China Sea in April and June of 2007. The purpose of the expedition was to detect gas hydrates and quantify its nature, distribution and concentration. The study involved the use of different observation and measurement techniques to provide multiple lines of evidence for gas hydrate. Pressure cores provided benchmark spot measurements of actual methane concentration, gas hydrate concentration, and background chlorinity. In order to detect the presence of dissociating/dissociated gas hydrate throughout the hole, infrared imaging of non-pressurized cores were utilized. Porewater freshening analysis from chlorinity variations was employed to quantify the gas hydrate at the centimeter scale. Gas hydrate saturations from the pressure and non-pressurized cores within the cored intervals were then compared to the resistivity, acoustic, and other well logs for a complete hydrate picture of the borehole. The expedition also involved the collection of samples from both non-pressure and pressure cores that were likely to contain gas hydrate and preserved them in liquid nitrogen. The paper discussed the general operations and strategy; coring plan; preservation of gas hydrate samples in liquid nitrogen; core temperature measurement; porewater sampling, porewater analysis, and gas hydrate from porewater freshening. Other procedures that were discussed included gas sampling and analyses

  14. Molecular detection of spotted fever group Rickettsia in Dermacentor silvarum from a forest area of northeastern China

    NARCIS (Netherlands)

    W.-C. Cao (Wuchun); L. Zhan (Lin); S.J. de Vlas (Sake); B.-H. Wen (Bo-Hai); H. Yang (Honghui); J.H. Richardus (Jan Hendrik); J.D.F. Habbema (Dik)

    2008-01-01

    textabstractIn total, 676 Dermacentor silvarum Olenev (Acari: Ixodidae) from a forest area of Jilin Province in northeastern China were examined by polymerase chain reaction for the presence of spotted fever group (SFG) Rickettsia. The overall positive rate was 10.7%, with a 95% confidence interval

  15. Comparative analysis of different underlying surfaces using a high-resolution assimilation dataset in semi-arid areas in China

    Science.gov (United States)

    Ruan, Jinshuai; Wen, Xiaohang; Fan, Guangzhou; Li, Deqin; Hua, Wei; Wang, Bingyun; Zhang, Yi; Zhang, Mingjun; Wang, Chao; Wang, Lei

    2017-11-01

    To study the land surface and atmospheric meteorological characteristics of non-uniform underlying surfaces in the semi-arid area of Northeast China, we use a "High-Resolution Assimilation Dataset of the water-energy cycle in China (HRADC)". The grid points of three different underlying surfaces were selected, and their meteorological elements were averaged for each type (i.e., mixed forest, grassland, and cropland). For 2009, we compared and analyzed the different components of leaf area index (LAI), soil temperature and moisture, surface albedo, precipitation, and surface energy for various underlying surfaces in Northeast China. The results indicated that the LAI of mixed forest and cropland during the summer is greater than 5 m2 m-2 and below 2.5 m2 m-2 for grassland; in the winter and spring seasons, the Green Vegetation Fraction (GVF) is below 30%. The soil temperature and moisture both vary greatly. Throughout the year, the mixed forest is dominated by latent heat evaporation; in grasslands and croplands, the sensible heat flux and the latent heat flux are approximately equal, and the GVF contributed more to latent heat flux than sensible heat flux in the summer. This study compares meteorological characteristics between three different underlying surfaces of the semi-arid area of Northeast China and makes up for the insufficiency of purely using observations for the study. This research is important for understanding the water-energy cycle and transport in the semi-arid area.

  16. Structural and Metamorphic Evolution of the Archaean High-pressure Granulite in Datong-Huaian Area, North China

    NARCIS (Netherlands)

    Zhang, J.

    2001-01-01

    The Archaean granulite terrain in the Datong-Huaian area, north China, comprises a basement complex of fe lsic and mafic granulite (TTG gneiss), overlain by a sedimentary sequence dominated by metapelite and metapsammite (khondalite series). Both lithological associations are separated by

  17. Identification of sources of elevated concentrations of polycyclic aromatic hydrocarbons in an industrial area in Tianjin, China

    NARCIS (Netherlands)

    Jiao, W.T.; Lu, Y.L.; Li, J.; Han, Jingyi; Wang, T.Y.; Luo, W.; Shi, Y.J.; Wang, G.

    2009-01-01

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector in 105 topsoil samples from an industrial area around Bohai Bay, Tianjin in the North of China. Results demonstrated that concentrations of PAHs in 104

  18. Pathogenetic effects of salted pork in an area of China with high-risk for stomach cancer

    OpenAIRE

    Yuan, Yuan; Lin, Hui-Zhi; Zhang, Yin-Chang; Wang, Xuan-Jie; Wu, Yie-Qiu; Gao, Hua; Wang, Lan; Liu, Yan-Hou; Lu, Fang; Lou, Su-Qing

    1997-01-01

    AIM: To study the pathogenetic effects of salted pork (SP) (a special food in Zhuanghe City, a region of northern China that is a high-risk area for stomach cancer) on stomach cancer, and a provide scientific basis for the primary prevention of stomach cancer in this high-risk region.

  19. On the Urban-Rural Differences in Classroom Environment in Compulsory Education in the Eastern Coastal Developed Areas of China

    Science.gov (United States)

    Sun, Furong; Xie, Limin

    2008-01-01

    Totally 789 students from 18 schools (9 primary schools and 9 junior high schools) at a medium managed level from Shanghai, Wenzhou, and Aojiang, which are located in the Eastern coastal developed areas of China were investigated with the questionnaire of Hong Kong Classroom Environment Scale in this study. The result indicates that the actual…

  20. Massive Endoscopic Screening for Esophageal and Gastric Cancers in a High-Risk Area of China

    Science.gov (United States)

    Xu, Kun; Lü, Lingshuang; Peng, Xianzhen; Wang, Min; Xu, Guisheng; Hua, Zhaolai; Wang, Jianping; Xue, Hengchuan; Wang, Jianming; Lu, Cheng

    2015-01-01

    Objective This study aims to describe the findings from a massive endoscopic screening program in a high-risk area of China and to evaluate the prognosis of patients diagnosed through endoscopic screening compared with those diagnosed at usual hospital visits because of illness. Methods In 2006, an early detection and treatment program was initiated in Yangzhong county, China. Local residents aged 40–69 years were eligible for free endoscopic screening. Endoscopic examination was performed with Lugol’s iodine staining, followed by biopsies. Patients diagnosed with esophageal or gastric cancer were referred for treatment and followed to assess their long-term survival status. Results From 2006 through 2012, we screened 12453 participants, including 5334 (42.8%) men and 7119 (57.2%) women. The average age was 52.8±8.0 years. We detected 166 patients with upper digestive tract cancers, including 106 cancers in the esophagus (detection rate: 0.85%) and 60 cancers in the stomach (detection rate: 0.48%). Of these patients, 98.11% with esophageal cancer and 100% with gastric cancer were defined as at the early stage. In the process of follow-up, 17 patients died from cancer-related causes, and the median survival time was greater than 85 months. The overall survival rates for 1, 3 and 5 years were 98.0%, 90.0% and 89.0%, respectively. A significant positive effect was observed for the long-term survival of patients diagnosed through massive endoscopic screening. Conclusions In a high-risk population, massive endoscopic screening can identify early stage carcinoma of esophageal and gastric cancers and improve patients’ prognosis through early detection and treatment. PMID:26699332

  1. Assessment of agricultural drought in rainfed cereal production areas of northern China

    Science.gov (United States)

    Li, Rui; Tsunekawa, Atsushi; Tsubo, Mitsuru

    2017-02-01

    Agricultural drought assessment is an important tool for water management in water-scarce regions such as Inner Mongolia and northeastern China. Conventional methods have difficulty of clarifying long-term influences of drought on regional agricultural production. To accurately evaluate regional agricultural drought, we assessed the performance of drought indices by constructing a new assessment framework with three components: crop model calibration and validation, drought index calculation, and index assessment (standard period setting, mean value and agreement assessments). The Environmental Policy Integrated Climate (EPIC) model simulated well of county-level wheat and maize yields in the nine investigated counties. We calculated a major crop-specific index yield reduction caused by water stress (WSYR) in the EPIC crop model, by relating potential and rainfed yields. Using 26 agricultural drought cases, we compared WSYR with two meteorological drought indices: precipitation (P) and aridity index (AI). The results showed that WSYR had greater agreement (85 %) than either the precipitation (65 %) or aridity index (68 %). The temporal trend of the indices over the period 1962-2010 was tested using three approaches. The result via WSYR revealed a significant increase in the trend of agricultural drought in drought-prone counties, which could not be shown by the precipitation and aridity indices. Total number of dry year via WSYR from 1990s to 2000s increases more sharply than via P or AI. As shown by WSYR, the number of dry years in northeastern China and Inner Mongolia is generally increasing, particularly after the 2000s, in the western part of the study area. The study reveals the usefulness of the framework for drought index assessment and indicates the potential of WSYR and possible drought cases for drought classification.

  2. Uppermost Permian to Lower Triassic Conodont Zonation from Enshi area, western Hubei Province, South China

    Science.gov (United States)

    Lyu, Z.; Zhao, L.; Chen, Z. Q.; Ma, D.; Yan, P.; Zhan, P.

    2015-12-01

    The Permian-Triassic transition witnessed the largest biotic turnover of Earth life during the Phanerozoic history. Ecosystems in sea and on land have also experienced the most protected restoration following the end-Permian mass extinction. These biocrises were also associated with climatic and environmental extremes through the latest Permian to Middle Triassic. In order to uncover the links among these extreme events, we need to establish high-resolution biochronostratigraphy, which offers precise timescales for reconstructing event sequences and probing the possible causes. Of these, conodont biostratigraphy is an operational tool in enhancing stratigraphic resolution. Although their ancestors and phylogeny remain unclear, conodonts are a rapid evolutionary lineage and extremely abundant in the Triassic marine carbonate successions. Here, we present recent study results of the Lower Triassic conodont zonation from the Ganxi and Jianshi areas, western Hubei Province, South China, which were situated on a carbonate ramp at the southern northern margin of the Upper Yangtze Platform. Therein, the uppermost Permian to Lower Triassic successions are well exposed and yield abundant conodonts. A total of nine conodont zones was established: (1) Clarkina yini-Clarkina zhangi Zone, (2) Hindeodus changxingensis Zone, (3) Hindeodus parvus Zone, (4) Isarcicella staeschei Zone, (5) Clarkina planata Zone, (6) Neoclarkina discrete Zone, (7) Neospathodus dieneri Zone, (8) Novispathodus waageni Zone, and (9) Triassospathodus homeri Zone. The Ns. dieneri M1, Ns. dieneri M2 and Ns. dieneri M3 subzones have also been distinguished from the Ns. dieneri Zone. Both Nv. waageni eowaageni subzones and Nv. waageni waageni subzones are also recognizable from the Nv. waageni Zone. The first occurrence of H. parvus marks the Permian-Triassic boundary(PTB), while the first occurrence of Nv. waageni eowaageni defines the Induan-Olenekian boundary. These conodont zones correlate well with

  3. Assessment of tsunami hazard for coastal areas of Shandong Province, China

    Science.gov (United States)

    Feng, Xingru; Yin, Baoshu

    2017-04-01

    Shandong province is located on the east coast of China and has a coastline of about 3100 km. There are only a few tsunami events recorded in the history of Shandong Province, but the tsunami hazard assessment is still necessary as the rapid economic development and increasing population of this area. The objective of this study was to evaluate the potential danger posed by tsunamis for Shandong Province. The numerical simulation method was adopted to assess the tsunami hazard for coastal areas of Shandong Province. The Cornell multi-grid coupled tsunami numerical model (COMCOT) was used and its efficacy was verified by comparison with three historical tsunami events. The simulated maximum tsunami wave height agreed well with the observational data. Based on previous studies and statistical analyses, multiple earthquake scenarios in eight seismic zones were designed, the magnitudes of which were set as the potential maximum values. Then, the tsunamis they induced were simulated using the COMCOT model to investigate their impact on the coastal areas of Shandong Province. The numerical results showed that the maximum tsunami wave height, which was caused by the earthquake scenario located in the sea area of the Mariana Islands, could reach up to 1.39 m off the eastern coast of Weihai city. The tsunamis from the seismic zones of the Bohai Sea, Okinawa Trough, and Manila Trench could also reach heights of >1 m in some areas, meaning that earthquakes in these zones should not be ignored. The inundation hazard was distributed primarily in some northern coastal areas near Yantai and southeastern coastal areas of Shandong Peninsula. When considering both the magnitude and arrival time of tsunamis, it is suggested that greater attention be paid to earthquakes that occur in the Bohai Sea. In conclusion, the tsunami hazard facing the coastal area of Shandong Province is not very serious; however, disasters could occur if such events coincided with spring tides or other

  4. Hair mercury concentrations and associated factors in an electronic waste recycling area, Guiyu, China

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Wenqing [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Chen, Yaowen [Central Laboratory of Shantou University, Shantou 515063, Guangdong (China); Huang, Yue; Wang, Xiaoling [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Zhang, Gairong [Central Laboratory of Shantou University, Shantou 515063, Guangdong (China); Luo, Jiayi [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Wu, Kusheng, E-mail: kswu@stu.edu.cn [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China)

    2014-01-15

    Objective: Toxic heavy metals are released to the environment constantly from unregulated electronic waste (e-waste) recycling in Guiyu, China, and thus may contribute to the elevation of mercury (Hg) and other heavy metals levels in human hair. We aimed to investigate concentrations of mercury in hair from Guiyu and potential risk factors and compared them with those from a control area where no e-waste processing occurs. Methods: A total of 285 human hair samples were collected from three villages (including Beilin, Xianma, and Huamei) of Guiyu (n=205) and the control area, Jinping district of Shantou city (n=80). All the volunteers were administered a questionnaire regarding socio-demographic characteristics and other possible factors contributed to hair mercury concentration. Hair mercury concentration was analyzed by hydride generation atomic fluorescence spectrometry (AFS). Results: Our results suggested that hair mercury concentrations in volunteers of Guiyu (median, 0.99; range, 0.18–3.98 μg/g) were significantly higher than those of Jinping (median, 0.59; range, 0.12–1.63 μg/g). We also observed a higher over-limit ratio (>1 μg/g according to USEPA) in Guiyu than in Jinping (48.29% vs. 11.25%, P<0.001). Logistic regression model showed that the variables of living house also served as an e-waste workshop, work related to e-waste, family income, time of residence in Guiyu, the distance between home and waste incineration, and fish intake were associated with hair mercury concentration. After multiple stepwise regression analysis, in the Guiyu samples, hair mercury concentration was found positively associated with the time residence in Guiyu (β=0.299, P<0.001), and frequency of shellfish intake (β=0.184, P=0.016); and negatively associated with the distance between home and waste incineration (β=−0.190, P=0.015) and whether house also served as e-waste workshop (β=−0.278, P=0.001). Conclusions: This study investigated human mercury exposure

  5. Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Kang Xu

    2015-09-01

    Full Text Available Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3 in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰ and δ18O (−7.91‰ to −5.07‰ suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration.

  6. Sediment reallocations due to erosive rainfall events in the Three Gorges Reservoir Area, Central China

    Science.gov (United States)

    Stumpf, Felix; Goebes, Philipp; Schmidt, Karsten; Schindewolf, Marcus; Schönbrodt-Stitt, Sarah; Wadoux, Alexandre; Xiang, Wei; Scholten, Thomas

    2017-04-01

    Soil erosion by water outlines a major threat to the Three Gorges Reservoir Area in China. A detailed assessment of soil conservation measures requires a tool that spatially identifies sediment reallocations due to rainfall-runoff events in catchments. We applied EROSION 3D as a physically based soil erosion and deposition model in a small mountainous catchment. Generally, we aim to provide a methodological frame that facilitates the model parametrization in a data scarce environment and to identify sediment sources and deposits. We used digital soil mapping techniques to generate spatially distributed soil property information for parametrization. For model calibration and validation, we continuously monitored the catchment on rainfall, runoff and sediment yield for a period of 12 months. The model performed well for large events (sediment yield>1 Mg) with an averaged individual model error of 7.5%, while small events showed an average error of 36.2%. We focused on the large events to evaluate reallocation patterns. Erosion occurred in 11.1% of the study area with an average erosion rate of 49.9Mgha 1. Erosion mainly occurred on crop rotation areas with a spatial proportion of 69.2% for 'corn-rapeseed' and 69.1% for 'potato-cabbage'. Deposition occurred on 11.0%. Forested areas (9.7%), infrastructure (41.0%), cropland (corn-rapeseed: 13.6%, potatocabbage: 11.3%) and grassland (18.4%) were affected by deposition. Because the vast majority of annual sediment yields (80.3%) were associated to a few large erosive events, the modelling approach provides a useful tool to spatially assess soil erosion control and conservation measures.

  7. Summertime ozone formation in Xi'an and surrounding areas, China

    Directory of Open Access Journals (Sweden)

    T. Feng

    2016-04-01

    Full Text Available In this study, the ozone (O3 formation in China's northwest city of Xi'an and surrounding areas is investigated using the Weather Research and Forecasting atmospheric chemistry (WRF-Chem model during the period from 22 to 24 August 2013, corresponding to a heavy air pollution episode with high concentrations of O3 and PM2.5. The model generally performs well compared to measurements in simulating the surface temperature, relative humidity, and wind speed and direction, near-surface O3 and PM2.5 mass concentrations, and aerosol constituents. High aerosol concentrations in Xi'an and surrounding areas significantly decrease the photolysis frequencies and can reduce O3 concentrations by more than 50 µg m−3 (around 25 ppb on average. Sensitivity studies show that the O3 production regime in Xi'an and surrounding areas is complicated, varying from NOx to VOC (volatile organic compound-sensitive chemistry. The industrial emissions contribute the most to the O3 concentrations compared to biogenic and other anthropogenic sources, but neither individual anthropogenic emission nor biogenic emission plays a dominant role in the O3 formation. Under high O3 and PM2.5 concentrations, a 50 % reduction in all the anthropogenic emissions only decreases near-surface O3 concentrations by about 14 % during daytime. The complicated O3 production regime and high aerosol levels pose a challenge for O3 control strategies in Xi'an and surrounding areas. Further investigation regarding O3 control strategies will need to be performed, taking into consideration the rapid changes in anthropogenic emissions that are not reflected in the current emission inventories and the uncertainties in the meteorological field simulations.

  8. A hybrid fuzzy weight of evidence method in landslide susceptibility analysis on the Wuyuan area, China

    Science.gov (United States)

    Hong, Haoyuan; Ilia, Ioanna; Tsangaratos, Paraskevas; Chen, Wei; Xu, Chong

    2017-08-01

    The present study proposed a hybrid fuzzy weight of evidence model for constructing a landslide susceptibility map in the Wuyuan area, China, where disastrous landslide events have occurred. The model combines the knowledge of experts obtained through a fuzzy logic approach and a hybrid weight of evidence method. The estimated knowledge-based fuzzy membership value of each environmental variable is combined with data-based conditional probabilities to derive fuzzy posterior probabilities and landslide susceptibility. The developed model was compared with a landslide susceptibility map produced using the data-driven weight of evidence method, based on 510 landslide and non-landslide sites. The sites were identified by analyzing airborne imagery, field investigation and previous studies. Landside susceptibility for these sites was analyzed using 10 geo-environmental variables: slope, aspect, lithology, soil, rainfall, plan curvature, the normalized difference vegetation index, distance to roads, distance to rivers and distance to faults. The resultant hybrid fuzzy weight of evidence method showed high predictive power, with the area under the success and predictive curves being 0.770 and 0.746, respectively. Additional analyses showed that the developed model could work effectively even with limited data.

  9. Grain-Size Analysis of Debris Flow Alluvial Fans in Panxi Area along Jinsha River, China

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    Wen Zhang

    2015-11-01

    Full Text Available The basic geometric parameters of 236 debris flow catchments were determined by interpreting SPOT5 remote sensing images with a resolution of 2.5 m in a 209 km section along the Jinsha River in the Panxi area, China. A total of 27 large-scale debris flow catchments were selected for detailed in situ investigation. Samples were taken from two profiles in the deposition zone for each debris flow catchment. The φ value gradation method of the grain size was used to obtain 54 histograms with abscissa in a logarithmic scale. Five types of debris flows were summarized from the outline of the histogram. Four grain size parameters were calculated: mean grain size, standard deviation, coefficient of skewness, and coefficient of kurtosis. These four values were used to evaluate the features of the histogram. The grain index that reflects the transport (kinetic energy information of debris flows was defined to describe the characteristics of the debris-flow materials. Furthermore, a normalized grain index based on the catchment area was proposed to allow evaluation of the debris flow mobility. The characteristics of the debris-flow materials were well-described by the histogram of grain-size distribution and the normalized grain index.

  10. Topography and Data Mining Based Methods for Improving Satellite Precipitation in Mountainous Areas of China

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    Ting Xia

    2015-07-01

    Full Text Available Topography is a significant factor influencing the spatial distribution of precipitation. This study developed a new methodology to evaluate and calibrate the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA products by merging geographic and topographic information. In the proposed method, firstly, the consistency rule was introduced to evaluate the fitness of satellite rainfall with measurements on the grids with and without ground gauges. Secondly, in order to improve the consistency rate of satellite rainfall, genetic programming was introduced to mine the relationship between the gauge rainfall and location, elevation and TMPA rainfall. The proof experiment and analysis for the mean annual satellite precipitation from 2001–2012, 3B43 (V7 of TMPA rainfall product, was carried out in eight mountainous areas of China. The result shows that the proposed method is significant and efficient both for the assessment and improvement of satellite precipitation. It is found that the satellite rainfall consistency rates in the gauged and ungauged grids are different in the study area. In addition, the mined correlation of location-elevation-TMPA rainfall can noticeably improve the satellite precipitation, both in the context of the new criterion of the consistency rate and the existing criteria such as Bias and RMSD. The proposed method is also efficient for correcting the monthly and mean monthly rainfall of 3B43 and 3B42RT.

  11. Gas Hydrate System of Shenhu Area, Northern South China Sea: Geochemical Results

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    Nengyou Wu

    2011-01-01

    Full Text Available The drilling recovered high-concentration methane hydrates (maximum 26–48% in a disseminated form in silty clay sediments in Shenhu area of Pearl River Mouth Basin, South China Sea. Combining the geochemical data, the gas hydrate-bearing sediments are 10 m to 43 m in thickness and located just above the base of the gas hydrate stability zone. The methane content is 96.10–99.91% with small amount of ethane and propane. The baseline chlorinity of pore waters shows 10% lower than that of shallow sediments below and inside the gas hydrate zone. The methane/ethane ratios are higher than 1000 above the gas hydrate zone and less than 1000 at the interval of gas hydrate zone. The depth of sulphate methane interface varies from site to site as 17 to 27 mbsf. These results show that the methane of gas hydrate was mainly originated from microbial activity and the upward methane flux is minor. This is evidenced by the δC13CH4 values of headspace gases from the gravity piston cores and released gases from pressure cores, which range from −74.3‰  PDB to −46.2‰  PDB, with the majority less than −55%‰  PDB. The hydrate deposit is a distributed gas hydrate system in Shenhu area.

  12. Human hair mercury levels in the Wanshan mercury mining area, Guizhou Province, China.

    Science.gov (United States)

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Li, Guanghui

    2009-12-01

    The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province, Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 μg/g and 1.9 ± 0.9 μg/g for T-Hg and Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 μg/g and 1.2 ± 0.5 μg/g for T-Hg and Me-Hg, respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents, respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the Wanshan Hg mining area.

  13. Prevalence of age-related cataract in high-selenium areas of China.

    Science.gov (United States)

    Li, Tuo; He, Tao; Tan, Xiaodong; Yang, Shurong; Li, Jiazhang; Peng, Zuoquan; Li, Hongyan; Song, Xiusheng; Wu, Qingsong; Yang, Fanglie; Xing, Yiqiao

    2009-04-01

    The objective of this study was to determine the prevalence of age-related cataract in high-selenium areas of China. This is a cross-sectional study of 1,522 persons aged 50 years and more who were selected as a representative sample from the Enshi prefecture in Hubei province. All lenses were graded and classified for opacities by slit lamp after papillary dilation, using the Lens Opacification Classification System II. The age-related cataract patients were 418 cases (33.28%). The prevalence of age-related cataract was 37.2% in women and 26.0% in men. The prevalence of nuclear cataract was 23.7%; cortical cataract was 22.4% and posterior subcapsule cataract was 5.2%. The prevalence of cataract of the 50-59 group was 13.41%; 60-69 group was 42.15%; 70 and over group was 61.9%. The prevalence of age-related cataract in high-selenium areas has not significantly increased; to some extent, the high selenium intake will not become a risk factor for the increase of cataract incidence.

  14. [Reproductive expectation and gender preferences of parents in poverty areas of China].

    Science.gov (United States)

    Du, Li-rong; Ding, Zong-yi

    2004-12-01

    The reproductive goals of married couples living in impoverished areas of China affect survival rates and quality of life of female children in those areas. The goal of this study was to collect information on parents' attitudes toward reproduction, gender preferences/prejudices, and to collect relevant socioeconomic and demographic data. Random sample families were enrolled from 3 poverty counties. Sample size included parents of 1800 children from birth to 6 years old. The children were divided into 6 age groups at one-year interval. Baseline data were collected and a questionnaire (endorsed by UNICEF) was used to evaluate reproductive expectations and gender preferences of parents. (1) The success of the One Child Family program has lead to a decreased overall birthrate. (2) The gender ratio (boys:girls) of the 3 counties studied was 100:87-100:95-100:97. No gender imbalance was found in this study. (3) The "Boy Preference" was still expressed by both fathers (69.0%) and mothers (65.7%). Approximately 40% of fathers and 37% of mothers interviewed expressed that only a male child would be acceptable. (4) Approximately 65% of both fathers and mothers recognize that girls are more likely to care for aging parents. Government initiatives have encouraged small families, yet in this region gender ratio of newborns is still normal. More educational and social programs are needed to influence perceptions regarding gender and to eliminate the suboptimal status/poorly perceived value of girls in many societies.

  15. Probabilistic Analysis of Drought Spatiotemporal Characteristics in the Beijing-Tianjin-Hebei Metropolitan Area in China

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    Wanyuan Cai

    2015-03-01

    Full Text Available The temporal and spatial characteristics of meteorological drought have been investigated to provide a framework of methodologies for the analysis of drought in the Beijing-Tianjin-Hebei metropolitan area (BTHMA in China. Using the Reconnaissance Drought Index (RDI as an indicator of drought severity, the characteristics of droughts have been examined. The Beijing-Tianjin-Hebei metropolitan area was divided into 253 grid-cells of 27 × 27km and monthly precipitation data for the period of 1960–2010 from 33 meteorological stations were used for global interpolation of precipitation using spatial co-ordinate data. Drought severity was assessed from the estimated gridded RDI values at multiple time scales. Firstly, the temporal and spatial characteristics of droughts were analyzed, and then drought severity-areal extent-frequency (SAF annual curves were developed. The analysis indicated that the frequency of moderate and severe droughts was about 9.10% in the BTHMA. Using the SAF curves, the return period of selected severe drought events was assessed. The identification of the temporal and spatial characteristics of droughts in the BTHMA will be useful for the development of a drought preparedness plan in the region.

  16. Geochemical modeling of groundwater in southern plain area of Pengyang County, Ningxia, China

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    Pei-yue Li

    2010-09-01

    Full Text Available The purpose of this paper is to examine the evolution mechanisms of a hydrochemical field and to promote its benefits to the living standards of local people and to the local economy in the southern plain area of Pengyang County, in Ningxia, China. Based on understanding of the hydrogeological conditions in Pengyang County, the chemical evolution characteristics of groundwater in the plain area were analyzed. PHREEQC geochemical modeling software was used to perform hydrochemical modeling of water-rock interaction and to quantitatively analyze the evolution processes and the formation mechanisms of the local groundwater. Geochemical modeling was performed for two groundwater paths. The results showed that, along path 1, Na+ adsorption played the leading role in the precipitation process and its amount was the largest, up to 6.08 mmol/L; cation exchange was significant along path 1, while along simulated path 2, albite accounted for the largest amount of dissolution, reaching 9.06 mmol/L, and the cation exchange was not significant. According to the modeling results, along the groundwater flow path, calcite and dolomite showed oversaturated status with a precipitation trend, while the fluorite and gypsum throughout the simulated path were not saturated and showed a dissolution trend. The total dissolved solids (TDS increased and water quality worsened along the flow path. The dissolution reactions of albite, CO2, and halite, the exchange adsorption reaction of Na+, and the precipitation of sodium montmorillonite and calcite were the primary hydrogeochemical reactions, resulting in changes of hydrochemical ingredients.

  17. Analysis on Imbalance of Family Intergenerational Exchange in China Rural Area

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    Liguo Liu

    2014-04-01

    Full Text Available In China rural area, intergenerational exchange on supporting each other between parents and offspring is uneven. Parents pay much more than the return they’ll get when they’re old, which mainly relates to the utilities of children. In countryside, the utilities of children (especially sons manifest in following aspects: continuing the family line, emotional comfort, laborer and supporting for old age. To some extent, these factors influence the rural intergenerational injustice respectively and together. From the prospective of trend of social and economic development, the caring of the retired will be taken by social insurance system; the intergeneration exchange on supporting each other between parents and offspring will no longer be a social issue, but in the vast rural areas, the influence of traditional culture family lineage is still powerful. The need of caring of the old becomes so weak that emotional effect becomes much more urgent. The weak status of the old generation bring the fathers’ generation in a weak social status, which seriously affect the living conditions of the old generations. Therefore, when focusing the caring issue in the country, besides that we should ensure the old be cared materially, what matters most is keep the balance between the exchanging two sides

  18. Neogene seismites and seismic volcanic rocks in the Linqu area, Shandong Province, E China

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    Tian H.S.

    2014-07-01

    Full Text Available The Yishu Fault Zone runs through the centre of Shandong Province (E China; it is a deep-seated large fault system that still is active. Two volcanic faulted basins (the Shanwang and Linqu Basins in the Linqu area, west of the fault zone, are exposed to rifting, which process is accompanied by a series of tectonic and volcanic earthquakes with a magnitude of 5-8. Lacustrine sediments in the basins were affected by these earthquakes so that seismites with a variety of soft-sediment deformation structures originated. The seismites form part of the Shanwang Formation of the Linqu Group. Semi-consolidated fluvial conglomerates became deformed in a brittle way; these seismites are present at the base of the Yaoshan Formation. Intense earthquakes triggered by volcanic activity left their traces in the form of seismic volcanic rocks associated with liquefied-sand veins in the basalt/sand intercalations at the base of the Yaoshan Formation. These palaeo-earthquake records are dated around 14-10 Ma; they are responses to the intense tectonic extension and the basin rifting in this area and even the activity of the Yishu Fault Zone in the Himalayan tectonic cycle.

  19. Impacts of China's Three Gorges Dam Project on net primary productivity in the reservoir area.

    Science.gov (United States)

    Xu, Xibao; Tan, Yan; Yang, Guishan; Li, Hengpeng; Su, Weizhong

    2011-10-15

    China's Three Gorges Dam Project (TGP) is the world's largest hydroelectric power project, and as a consequence the reservoir area is at risk of ecological degradation. This study uses net primary productivity (NPP) as an important indicator of the reservoir ecosystem's productivity to estimate the impacts of the TGP in the local resettlement region of the Three Gorges Reservoir Area (TGRA) over the 2000-2010 period. The modeling method is based upon the Carnegie Ames Stanford Approach (CASA) terrestrial carbon model and uses Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data for modeling simulation. The results demonstrate that total NPP in the resettlement region decreased by 8.0% (632.8Gg) from 2000 to 2010. The impact of the TGP on NPP is mainly mediated by land-use change brought about by the large-scale inundation of land and subsequent massive resettlement of both rural and urban residents. Nearby resettlement, land inundation, and relocation of old urban centers and affiliated urban dwellers are responsible for 54.3%, 28.0%, and 5.8% respectively of total NPP reduction in the resettlement region over the study period. The major national ecological projects implemented in the TGRA since 1998 have played a key role in offsetting the negative impacts of the TGP on NPP in the region. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Research on Ore-controlling factors and Metallogenic Prognosis of Dongchuan Copper Mining Area, Yunnan, China

    Science.gov (United States)

    Wang, Tianguo; Liu, Jishun; Huang, Chaowen

    2017-03-01

    Dongchuan is a famous copper producing area in China, where has good geological condition to form many copper deposits with local characteristics. This article summarizes the metallogenic regularities of Dongchuan copper deposits based on the previous works, research findings and the latest research advances. The study suggests that the Dongchuan copper-ore area has a good metallogenic background and immense prospecting potential. Copper ore is mainly found in Yinmin Formation, Luoxue Formation, Heishan Formation, Daqiaodi Formation, and in the Sinian-aged basement, and its occurrence is closely related to volcanic magmatism. The discussions regarding prospecting directions of Dongchuan copper ore were conducted based on the metallogenic regularity research, the results shows that further expanding of the exploration activities from the existing ore-bodies would be carried out; the breakthrough points focus on the Pingdingshan Formation, Qinglongshan Formation, and Daqiaodi Formation strata; at the same tine, more attention should be paid to the new types of deposits, such as Yanziya-type or hydrothermal deposits.

  1. Juvenile salmon usage of the Skeena River estuary.

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    Charmaine Carr-Harris

    Full Text Available Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years, Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the

  2. Vector capacity of Anopheles sinensis in malaria outbreak areas of central China

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    Pan Jia-Yun

    2012-07-01

    Full Text Available Abstract Background Both falciparum and vivax malaria were historically prevalent in China with high incidence. With the control efforts, the annual incidence in the whole country has reduced to 0.0001% except in some areas in the southern borders after 2000. Despite this, the re-emergence or outbreak of malaria was unavoidable in central China during 2005–2007. In order to understand the role of the vector in the transmission of malaria during the outbreak period, the vector capacity of An. sinensis in Huanghuai valley of central China was investigated. Findings The study was undertaken in two sites, namely Huaiyuan county of Anhui province and Yongcheng county of Henan province. In each county, malaria cases were recorded for recent years, and transmission risk factors for each study village including anti-mosquito facilities and total number of livestock were recorded by visiting each household in the study sites. The specimens of mosquitoes were collected in two villages, and population density and species in each study site were recorded after the identification of different species, and the blood-fed mosquitoes were tested by ring precipitation test. Finally, various indicators were calculated to estimate vector capacity or dynamics, including mosquito biting rate (MBR, human blood index (HBI, and the parous rates (M. Finally, the vector capacity, as an important indicator of malaria transmission to predict the potential recurrence of malaria, was estimated and compared in each study site. About 93.0% of 80 households in Huaiyuan and 89.3% of 192 households in Yongcheng had anti-mosquito facilities. No cattle or pigs were found, only less than 10 sheep were found in each study village. A total of 94 and 107 Anopheles spp. mosquitos were captured in two study sites, respectively, and all of An. sinensis were morphologically identified. It was found that mosquito blood-feeding peak was between 9:00 pm and 12:00 pm. Man biting rate of

  3. Hydro- and sediment dynamics in the estuary zone of the Mekong Delta: case study Dinh An estuary.

    Science.gov (United States)

    Tran, Anh Tuan; Thoss, Heiko; Gratiot, Nicolas; Dussouillez, Philippe; Brunier, Guillaume; Apel, Heiko

    2017-04-01

    The Mekong River is the tenth largest river in the world, covers an area of 795,000 km2, 4400km in length, the main river flows over the six countries including: China, Myanmar, Thailand, Laos, Cambodia and Vietnam. Its water discharge is 470 km3year-1 and the sediment discharge is estimated about 160 million ton year-1. The sediment transported by the Mekong River is the key factor in the formation and development of the delta. It is a vital factor for the stability of the coastline and river banks. Furthermore it compensates land subsidence by floodplain deposition, and is the major natural nutrient source for agriculture and aquaculture. However, only a few studies were conducted to characterize and quantify sediment properties and process in the Delta. Also the morphodynamic processes were hardly studied systematically. Hence, this study targets to fill some important and open knowledge gaps with extensive field works that provide important information about the sediment properties and hydrodynamic processes in different seasons Firstly three field survey campaigns are carried out along a 30 km section of the Bassac River from the beginning of Cu Lao Dung Island to Dinh An estuary in 2015 and 2016. During the field campaign, the movement of the salt wedge and the turbidity were monitored by vertical profiles along the river, as well as discharge measurements by ADCP were carried out at three cross sections continuously for 72 hours. The extension of the salt wedge in the river was determined, along with mixing processes. The movement and dynamics observed under different flow conditions indicate that sediment was pumped during low flow upwards the river, while during high flow net transport towards the sea dominated. Also a distinct difference in the sediment properties in the different seasons was observed, with a general tendency towards a higher proportion of coarser particles in the high flow season. These quantitative results give insights into the

  4. A socio-ecological survey in Jalantai Area, Alxa League, Inner Mongolia, China

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    Lorenzo Orioli

    2015-12-01

    Full Text Available This article concerns with new and traditional practises in agriculture in Alxa League in the Inner Mongolia of China. For such a purpose, the DISPAA Department of University of Florence (Italy collaborated with the University of Tuscia (Italy, which has been one of the Italian executives for the Beijing Wind Dust Control Project under the framework of the Sino-Italian Cooperation Programme on Environmental Protection. In the context of ADAM Project, the Inner Mongolia was indicated as a potential hot-spot due to the combination of climatic change, human activities and the general phenomenon of desertification, which is an ongoing process in this area. During the past centuries, arid and semi-arid general environmental characteristics of Inner Mongolia’s landscape have conditioned the main course of economic development in rural areas. Into the Alxa League, a sub-case study situated around Jarantai City in the Alxa Left Banner was selected. During 2005-06, the work analysed the agricultural activities of the local rural population to evaluate if these might be able to cope with desertification and, more in general, with climatic change impacts. In particular, field surveys were implemented among local peasants, which were old herders or new farmers immigrated in the area, following a non-structured interview approach where the length of the interview was calibrated on the characteristics of the single interviewed. The interviews showed that soil fertility and water requirement (e.g. water drawdown and high evaporation rate that cause superficial salt crust formation are yet the main constraints to social and economic development of agriculture.

  5. The Built Environment and Walking Activity of the Elderly: An Empirical Analysis in the Zhongshan Metropolitan Area, China

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    Yi Zhang

    2014-02-01

    Full Text Available Policies and interventions involving the built environment have become a promising opportunity for the promotion of walking as a sustainable transportation mode. Among voluminous literature, few studies were found that examined the association between the built environment and walking among the elderly in China. This study investigated the relationship between the built environment and the walking activity of the elderly based on data collected in Zhongshan Metropolitan Area, China. The results suggest that abundant sidewalks, dense bus stops, easily accessible commercial establishments, and ample green land space are potentially effective to enhance walking among the elderly, albeit to varied degrees. The compact urban form, which is considered as walkability in the western context, may not necessarily play a positive role in Zhongshan’s context. The findings provide insights into the policy-making to promote sustainable transportation modes and the design of interventions on health promotion of the elderly in China.

  6. Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

    Science.gov (United States)

    Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

    2017-10-06

    Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

  7. Ship Emission Inventories in Estuary of the Yangtze River Using Terrestrial AIS Data

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    Xin Yao

    2016-12-01

    Full Text Available Estuary forms a transition zone between inland river and open sea. In China, the estuary of the Yangtze River plays a vital role in connecting the inland and oversea shipping, and witnesses heavy vessel traffic in the recent decades. Nowadays, more attentions have been directed to the issue of ship pollution in busy waterways. In order to investigate the ship emission inventory, this paper presents an Automatic Identification System(AIS based method. AIS data is the realistic data of vessel traffic including dynamic information (position, speed, course, etc. and static information (ship type, dimensions, name, etc.. According to ship dimensions, the power of engines is estimated for different ship types. By using AIS based bottom-up approach, ship emission inventories and shares of air pollutants and GHGs (Greenhouse gases are developed. Spatial distribution of ship emissions is illustrated in the form of heat map. As a case study, the emission inventories are analyzed using AIS data of 2010 in the estuary, and following results are made:(1 shares of the emission are cruise ships 6.59%, bulk carriers 5.16%, container ships 52.96%, tankers 15.16%, fishing ships 9.16%, other ships 10.97%; (2 CO2 is the dominant part of the emission. (3 Areas of highest emission intensity are generally clustered around the South Channel, the North Channel and ports in the vicinity. The proposed method is promising because it is derived from the AIS data which contains not only real data of individual ship but also vessel traffic situation in the study area. It can server as a reference for other researchers and policy makers working in this field.

  8. [Survey of economic burden of hepatitis B-related diseases in 12 areas in China].

    Science.gov (United States)

    Ma, Q S; Liang, S; Xiao, H W; Zhang, S X; Zhuang, G H; Zou, Y H; Tan, H Z; Liu, J C; Zhang, Y H; Xu, A Q; Zhang, L; Feng, X X; Hu, D S; Wang, F Z; Cui, F Q; Liang, X F

    2017-07-10

    Objective: Less surveys on the economic burden of hepatitis B (HB)-related diseases have been conducted in China, so the socioeconomic harm caused by the diseases is not clear and the key parameters for economic evaluation of hepatitis B prevention and treatment are lacking. This study aimed to analyze the direct, indirect and intangible expenditures of hospitalized patients with HB-related diseases during hospitalization and during a year in different areas of China. Methods: The hospitals for infectious diseases and the large general hospitals in 12 areas in China were selected in the study. All the inpatients with HB-related diseases were surveyed by cluster sampling of consecutive cases. The direct expenditure included direct medical cost and direct non-medical cost. The indirect expenditure, including work loss of patients and caregivers, were calculated by using human capital method for urban and rural populations in 12 areas. The intangible expenditure were reflected by willing to pay and stochastic tournament. The influencing factors of direct and indirect costs were identified by stepwise linear multi-variation regression analysis. Results: A total of 27 hospitals in 12 areas were included in the survey. A total of 4 718 cases were surveyed, the overall response rate was 77.7%. The average hospital stay was 29.2 days (27-34) and the hospitalization expenditure was averagely 16 832.80 yuan (RMB) per case, in which the highest proportion (61.2%) was medicine fees [10 365.10 yuan (RMB)]. The average direct expenditure and indirect expenditure were consistent with the severity of illness, which were 18 336.10 yuan (RMB) and 4 759.60 yuan (RMB) respectively, with the ratio of 3.85 ∶ 1. The direct medical expenditure [17 434.70 yuan (RMB)] were substantially higher than the direct non-medical expenditure [901.40 yuan (RMB)]. It was found that the hospitalization expenses was highest in direct medical expenditure and the transportation expenses was highest in

  9. Contamination and restoration of an estuary affected by phosphogypsum releases

    Energy Technology Data Exchange (ETDEWEB)

    Villa, M., E-mail: mvilla@us.es [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mosqueda, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Hurtado, S. [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla CITIUS, Av. Reina Mercedes 4B, E41012-Sevilla (Spain); Mantero, J.; Manjon, G. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain); Perianez, R. [E.U.I.T.A., Universidad de Sevilla, Departamento de Fisica Aplicada III, Carretera de Utrera, Km. 1, 41013 Sevilla (Spain); Vaca, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21007-Huelva (Spain); Garcia-Tenorio, R. [E. T. S. Arquitectura, Universidad de Sevilla, Departamento de Fisica Aplicada II, Av. Reina Mercedes, 2. 41012-Sevilla (Spain)

    2009-12-15

    The Huelva Estuary in Huelva, Spain, has been one of the most studied environmental compartments in the past years from the point of view of naturally occurring radioactive material (NORM) releases. It has been historically affected by waste releases, enriched in radionuclides from the U-decay series, from factories located in the area devoted to the production of phosphoric acid and phosphate fertilizers. Nevertheless, changes in national regulations forced a new waste management practice in 1998, prohibiting releases of phosphogypsum into the rivers. The input of natural radionuclides from phosphate factories to rivers was drastically reduced. Because of this there was a unique opportunity for the study of the response of a contaminated environmental compartment, specifically an estuary affected by tidal influences, after the cessation of the contaminant releases to, in this case, the Huelva Estuary (henceforth referred to as the Estuary). To investigate the environmental response to this new discharge regime, the specific activities of radionuclides {sup 226}Ra and {sup 210}Pb in water and sediment samples collected in four campaigns (from 1999 to 2005) were determined and compared with pre-1998 values. From this study it is possible to infer the most effective mechanisms of decontamination for the Estuary. Decontamination rates of {sup 210}Pb and {sup 226}Ra in the sediments and water have been calculated using exponential fittings and corresponding half-lives have been deduced from them. The cleaning half-life in the whole area of the Estuary is about 6 and 3.5 years for {sup 226}Ra and {sup 210}Pb respectively. The observed trend clearly shows that contamination of the Estuary by natural radionuclides is now decreasing and radioactive levels in waters and sediments are approaching the natural background references. This work attempts to evaluate whether it can be expected that the decontamination of the enhanced levels of natural radioactivity in the Estuary

  10. Research on the Placement of the Ecological Shelter Zone in the Three Gorges Reservoir Area, China

    Science.gov (United States)

    Shan, N.; Ruan, X.

    2011-12-01

    The Three Gorges Dam is built on the middle reaches of Yangtze River (Changjiang) in south-central China, which is the world's third longest river. The Three Gorges Reservoir Region (TGRR), including the entire inundated area and 19 administrative units (counties and cities) on both sides of the river, is regarded as an environmentally sensitive area. The total area of the TGRR is approximately 58000 km2. As the Three Gorges Dam fully operated, for the flood control, the water level should be kept in the range between 145 m and 175 m and the reservoir surface water area(over 1080 km2)at a water level of 175 m, with a length of 600 km. Many of cities, villages and farms have been submerged. Moreover, as a result of reservoir operation, the water-level alternation of the reservoir is opposite to the nature, which is low water level (145m) in summer and high water level (175m) in winter. The Hydro-Fluctuation Belt, with a height of 30m, will become a new pollution source due to the riparian being flooded and the submerged areas may still contain trace amounts of toxic or radioactive materials. The environmental impacts associated with large scale reservoir area often have significant negative impacts on the environment. It affects forest cover, species in the area, some endangered, water quality, increase the likelihood of earthquakes and mudslides in the area. To solve these problems, it is necessarily to construct the Ecological Shelter Zone (ESZ) along with the edge of the reservoir area. The function of the ESZ is similar to the riparian zone in reducing flood damage, improving water quality, decreasing the levels of the nonpoint source pollution load and soil erosion and rebuilding the migration routes of plant and wildlife. However, the research of the ESZ is mainly focused on rivers at field scale by now, lack of research method on reservoir at the watershed scale. As the special nature of the Three Gorges Reservoir, the construction of the ESZ in the TGRA is

  11. Geology and geochemistry of telluride-bearing Au deposits in the Pingyi area, Western Shandong, China

    Science.gov (United States)

    Hu, H.-B.; Mao, J.-W.; Niu, S.-Y.; Li, Y.-F.; Li, M.-W.

    2006-07-01

    Telluride-bearing gold deposits of the Pingyi area, western Shandong, China, are located on the southeastern margin of the North China Craton. There are two main types of deposits: (i) mineralized cryptoexplosive breccia, e.g., Guilaizhuang; and (ii) stratified, finely-disseminated mineralization hosted in carbonate rocks, e.g., Lifanggou and Mofanggou deposits. In Guilaizhuang, the cryptoexplosive breccia is formed within rocks of the Tongshi complex and Ordovician dolomite. The mineralization is controlled by an E-W-trending listric fault. Stratified orebodies of the Lifanggou and Mofanggou deposits are placed along a NE-trending, secondary detachment zone. They are hosted within dolomitic limestone, micrite and dolomite of the Early-Middle Cambrian Changqing Group. The mineralization in the ore districts is considered to be related to the Early Jurassic Tongshi magmatic complex that formed in a continental arc setting on the margin of the North China Craton. The host rocks are porphyritic and consist predominantly of medium- to fine-grained diorite and pyroxene (hornblende)-bearing monzonite. SHRIMP U-Pb zircon dating of diorites give a 206Pb/238U weighted mean age of 175.7 ± 3.8 Ma. This is interpreted as representing the crystallization age of the Tongshi magmatic complex. Considering the contact relationships between the magmatic and host sedimentary rocks, as well as the genetic link with the deposits, we conclude that this age is relevant also for the formation of mineralization in the Pingyi area. We hence consider that the deposits formed in the Jurassic. The principal gold minerals are native gold, electrum and calaverite. Wall-rock alteration comprises pyritization, fluoritization, silicification, carbonatization and chloritization. Fluid inclusion studies indicate that all the analyzed inclusions are of two-phase vapor-liquid NaCl-H2O type. Homogenization temperatures of the fluid inclusions vary from 103 °C to 250 °C, and the ice melting

  12. [Atmospheric emission of PCDD/Fs from secondary aluminum metallurgy industry in the southwest area, China].

    Science.gov (United States)

    Lu, Yi; Zhang, Xiao-Ling; Guo, Zhi-Shun; Jian, Chuan; Zhu, Ming-Ji; Deng, Li; Sun, Jing; Zhang, Qin

    2014-01-01

    Five secondary aluminum metallurgy enterprises in the southwest area of China were measured for emissions of PCDD/Fs. The results indicated that the emission levels of PCDD/Fs (as TEQ) were 0.015-0.16 ng x m(-3), and the average was 0.093 ng x m(-3) from secondary aluminum metallurgy enterprises. Emission factors of PCDD/Fs (as TEQ) from the five secondary aluminum metallurgy enterprises varied between 0.041 and 4.68 microg x t(-1) aluminum, and the average was 2.01 microg x t(-1) aluminum; among them, PCDD/Fs emission factors from the crucible smelting furnace was the highest. Congener distribution of PCDD/F in stack gas from the five secondary aluminum metallurgies was very different from each other. Moreover, the R(PCDF/PCDD) was the lowest in the enterprise which was installed only with bag filters; the R(PCDF/PCDD) were 3.8-12.6 (the average, 7.7) in the others which were installed with water scrubbers. The results above indicated that the mechanism of PCDD/Fs formation was related to the types of exhaust gas treatment device. The results of this study can provide technical support for the formulation of PCDD/Fs emission standards and the best available techniques in the secondary aluminum metallurgy industry.

  13. Risk assessment of drought disaster in typical area of corn cultivation in China

    Science.gov (United States)

    Zhang, Qi; Zhang, Jiquan; Wang, Chunyi

    2017-05-01

    This study assesses the risk of corn drought disaster in China under current climate conditions and builds a predictable relationship between drought disaster risk and yield losses. Two regions, Jilin and Henan, have been selected to represent two typical areas of corn cultivation. Risk is assessed from the aspects of hazard and vulnerability. Hazard presented as drought frequency and intensity. The sensitivity of corn to droughts that happened in different corn-growing stages and regional irrigation ability are used to reflect vulnerability. The results show that drought hazard and sensitivity in Jilin are much more serious than Henan, and irrigation ability is better in Henan. As a result, the drought disaster risk in Jilin is high; corn faces severe drought stress. The average corn yield loss rates during 1978-2010 in Jilin and Henan were 9.94 and 6.91 %, respectively. The correlation between corn yield losses and drought disaster risk is significant ( r = 0.711). The results can help to guide future agriculture planning and drought adaptation polices.

  14. Heavy metal contamination in surface sediments of representative reservoirs in the hilly area of southern China.

    Science.gov (United States)

    Wang, Xiaolong; Zhang, Lu; Zhao, Zhonghua; Cai, Yongjiu

    2017-12-01

    A study on the characteristics of heavy metals in surface sediments of typical reservoirs in the hilly area of southern China was carried out. The results showed that contents of heavy metals had great temporal and spatial heterogeneity among studied reservoirs. Zn, Pb, and As presented significant enrichment ratio in reservoirs of Dou Shui (DS) and Feng Tang (FT), as well as Ti in reservoirs of DZ and GT. The content of Cd in reservoir of FT reservoirs was characterized with high health risk with the significantly highest value of 52.43 mg/kg. Furthermore, Pb was identified with high health risk in reservoirs of SFM, Ouyang Hai (OYH), FT, and DS, and As was in OYH and ZX. Multivariate statistical analysis suggested high consistency in the variations of Cr, Ni, and Cu; moreover, Cd, Zn, and Pb were characterized with great homogeneity in their sources. In addition, agricultural activities might exert less effect on variations of heavy metals in studied reservoirs, considered that there was a weak relationship between heavy metals and nutrients. These results could improve our understanding of the spatial variations of heavy metals and their potential sources in reservoirs in this ecologically fragile region.

  15. Poverty and biodiversity in rural areas based on two investigations in Pujiang County, China.

    Science.gov (United States)

    Fang, Bin

    2009-04-01

    This study presents an integrated framework for the analysis of options of agricultural development and natural resource management at the ecosystem level. Pujiang County in Zhejiang Province, China, is used as a case-study area. The IMGLP model is applied to maximize regional agricultural economic surplus and labor market conditions in Pujiang. The consequences of four poverty reduction strategies (intensification of production, diversification toward livestock production, land expansion, and exit from agriculture) are determined for a set of regional poverty and biodiversity indicators. Diversification seems to be the most promising poverty reduction strategy, but requires an efficient use of animal manure in cropping systems to avoid environmental problems. Improved nutrient management in cropping systems is effective in reducing the regional nitrogen surplus, but less effective in increasing per capita income. The exit strategy is beneficial for reducing poverty and achieving biodiversity, but may have important social consequences that are not addressed in this study. Further reduction of rural poverty is hampered by labor constraints during the harvesting period for high-value crops such as vegetables and fruits. These constraints can be overcome by intensive research and development in the field of agricultural mechanization.

  16. Conservation of Terrestrial Vertebrates in a Global Hotspot of Karst Area in Southwestern China.

    Science.gov (United States)

    Luo, Zhenhua; Tang, Songhua; Jiang, Zhigang; Chen, Jing; Fang, Hongxia; Li, Chunwang

    2016-05-26

    The karst area of southwest China (KASC) is the largest piece of karst landscape on the earth and a global biodiversity hot-spot with high concentrations of endemic species. Although a number of nature reserves (NRs) have been established across the region, the representativeness of biodiversity of the NR system is still unknown. Based on comprehensive literature and field surveys, and intensive consultations with zoologists and wildlife managers, we compiled distributions of 1,204 terrestrial vertebrate species and 271 NRs in KASC. We found Jinxiu, Mengla, Hekou, and Jinghong have the richest amphibian species; Jinxiu has the highest species richness of reptiles; Jinghong, Menghai, and Mengla have the largest numbers of avian species; whereas, Mengla, Longzhou, and Ningming have the greatest mammalian diversity in the region. Gap analysis among NR system, species richness pattern, and five biogeographic indicators found insufficient representation of the NR system on territorial vertebrate diversity. The conservation effectiveness in Guizhou Province was much lower than that in Guangxi and Yunnan Provinces. Under-representation and over-representation simultaneously occurred in many of the ecoregions, elevation classes, vegetation types, landcover categories, and human disturbance intensity gradients. For conservation of terrestrial vertebrates in KASC, several suggestions were presented in this study.

  17. Dynamics and anthropogenic impacts of multiple karst flow systems in a mountainous area of South China

    Science.gov (United States)

    Luo, Mingming; Chen, Zhihua; Criss, Robert E.; Zhou, Hong; Huang, He; Han, Zhaofeng; Shi, Tingting

    2016-12-01

    The Xiangxi River basin, South China, is a steep terrane with well-developed karst features and an important Cambrian-Ordovician aquifer. Meteoric water in this mountainous area features a mean δ18O elevation gradient of -2.4 ‰/km. This gradient was used to estimate mean recharge elevations of 760 m for Shuimoxi (SMX) spring, 1,060 m for Xiangshuidong (XSD) spring, and 1,430 m for drill hole ZK03, indicating multiple flow paths in the Cambrian-Ordovician karst aquifer. Mean residence times of 230 and 320 days and ˜2 years were estimated for these features, respectively, using the damped running average model that predicts the isotopic variations in groundwater from those in precipitation. Groundwater in the regional karst flow system has the longest residence time, the highest recharge elevation, the longest flow paths, the lowest addition of anthropogenic components, and the greatest amount of water-rock interaction as indicated by its higher dissolved solids, Mg2+ concentrations and Mg/Ca ratios than the springs. In contrast, the local and shallow karst flow systems respond rapidly to recharge events. Artificial tracer tests prove that these shallow karst systems can also quickly transmit anthropogenic contaminants, indicating that they are highly vulnerable to human impacts, which include the enrichment of NO3 -. The intensity of water-rock interaction and groundwater vulnerability are mainly determined by the structure and dynamics of the multiple karst flow systems.

  18. Radionuclides in mushrooms and soil-to-mushroom transfer factors in certain areas of China.

    Science.gov (United States)

    Tuo, Fei; Zhang, Jing; Li, Wenhong; Yao, Shuaimo; Zhou, Qiang; Li, Zeshu

    2017-12-01

    Activity concentrations of 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K in 64 mushroom samples collected in China from Yunnan, Fujian and Heilongjiang Provinces, were measured. Gamma-ray emissions were determined by using high-purity germanium (HPGe) γ spectrometry. The range of concentrations (Bq kg -1 dry weight) for 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K in all investigated mushroom samples were from 0.12 to 12, 0.05 to 7.5, 0.14 to 14, MDC(mushrooms showed some variation between species sampled at the same site. To calculate soil to mushroom transfer factors, levels of radionuclide in 15 paired soil samples and mushrooms were also investigated. The median transfer factors for 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K were 8.32 × 10 -2 , 3.03 × 10 -2 , 6.69 × 10 -2 , 0.40 and 1.19, respectively. The results were compared with values of other areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Preliminary discussion on gas hydrate reservoir system of Shenhu Area, North Slope of South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Wu, N.; Yang, S.; Liang, J.; Wang, H.; Fu, S. [Guangzhou Marine Geological Survey, Guangzhou (China); Zhang, H. [China Geological Survey, Beijing (China); Su, X. [China Univ. of Geosciences, Beijing (China)

    2008-07-01

    Gas hydrate is a type of ice-like solid substance formed by the combination of certain low-molecular-weight gases such as methane, ethane, and carbon dioxide with water. Gas hydrate primarily occurs naturally in sediments beneath the permafrost and the sediments of the continental slope with the water depth greater than 300 m. Marine gas hydrate geological systems are important because they may be sufficiently concentrated in certain locations to be an economically viable fossil fuel resource. However, gas hydrates can cause geo-hazards through large-scale slope destabilization and can release methane, a potential greenhouse gas, into the environment. This paper discussed the hydrate drilling results from a geological and geophysical investigation of the gas hydrate reservoir system of the Shenhu Area, located in the north slope of South China Sea. The paper identified the basic formation conditions, and discussed the pore-water geochemical features of shallow sediments and their inflected gas sources, gas hydrate distribution and seismic characteristics. It was concluded that the gas hydrate was heterogeneously distributed in space, and mainly distributed in certain ranges above the bottom of the gas hydrate stability zone. It was also concluded that methane gas that formed hydrate was likely from in-situ micro-biogenic methane. Last, it was found that distributed and in-situ micro-biogenic methane resulted in low methane flux, and formed the distributed pattern of gas hydrate system with the features of differential distribution and saturation. 34 refs., 2 tabs., 3 figs.

  20. A Novel Selenocystine-Accumulating Plant in Selenium-Mine Drainage Area in Enshi, China

    Science.gov (United States)

    Yuan, Linxi; Zhu, Yuanyuan; Lin, Zhi-Qing; Banuelos, Gary; Li, Wei; Yin, Xuebin

    2013-01-01

    Plant samples of Cardamine hupingshanesis (Brassicaceae), Ligulariafischeri (Ledeb.) turcz (Steraceae) and their underlying top sediments were collected from selenium (Se) mine drainage areas in Enshi, China. Concentrations of total Se were measured using Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS) and Se speciation were determined using liquid chromatography/UV irradiation-hydride generation-atomic fluorescence spectrometry (LC-UV-HG-AFS). The results showed that C. hupingshanesis could accumulate Se to 239±201 mg/kg DW in roots, 316±184 mg/kg DW in stems, and 380±323 mg/kg DW in leaves, which identifies it as Se secondary accumulator. Particularly, it could accumulate Se up to 1965±271 mg/kg DW in leaves, 1787±167 mg/kg DW in stem and 4414±3446 mg/kg DW in roots, living near Se mine tailing. Moreover, over 70% of the total Se accumulated in C. hupingshanesis were in the form of selenocystine (SeCys2), increasing with increased total Se concentration in plant, in contrast to selenomethionine (SeMet) in non-accumulators (eg. Arabidopsis) and secondary accumulators (eg. Brassica juncea), and selenomethylcysteine (SeMeCys) in hyperaccumulators (eg. Stanleya pinnata). There is no convincing explanation on SeCys2 accumulation in C. hupingshanesis based on current Se metabolism theory in higher plants, and further study will be needed. PMID:23750270

  1. Quartz in ash, and air in a high lung cancer incidence area in China.

    Science.gov (United States)

    Downward, George S; Hu, Wei; Rothman, Nat; Reiss, Boris; Tromp, Peter; Wu, Guoping; Wei, Fusheng; Xu, Jun; Seow, Wei Jie; Chapman, Robert S; Lan, Qing; Vermeulen, Roel

    2017-02-01

    Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung cancer rates in the nation, irrespective of gender or smoking status. Previous studies have shown that smoky coal contains approximately twice as much quartz when compared to alternative fuels in the area, although it is unclear how the quartz in coal relates to household air pollution. Samples of ash and fine particulate matter (PM 2.5 ) were collected from 163 households and analysed for quartz content by Fourier transformed infrared spectroscopy (FT-IR). Additionally, air samples from 12 further households, were analysed by scanning electron microscopy (SEM) to evaluate particle structure and silica content. The majority (89%) of household air samples had undetectable quartz levels (quartz in smoky coal went on to form part of the ash. These findings indicate that the quartz within smoky coal does not become adequately airborne during the combustion process to cause significant lung cancer risk, instead going on to form part of the ash. The identification of fibre-like particles in air samples is an interesting finding, although the clinical relevance of this finding remains unclear. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Levels and profiles of Dechlorane Plus in a major E-waste dismantling area in China.

    Science.gov (United States)

    Xiao, Ke; Wang, Pu; Zhang, Haidong; Shang, Hongtao; Li, Yingming; Li, Xinghong; Ren, Daiwei; Chen, Weihai; Zhang, Qinghua

    2013-10-01

    Dechlorane Plus (DP) is a high-production volume, chlorinated flame retardant comprising two major isomers, syn- and anti-DP. In this study, levels of DP were measured in soil and earthworm samples in farmland from a typical E-waste dismantling area in China. The concentrations of total DP ranged from 0.17 to 1,990 ng g(-1) dw in soil samples and 3.43 to 89.2 ng g(-1) lw in earthworm samples. Higher DP levels were found in some main E-waste dismantling sites than those in other sites. The ratios of anti-DP to total DP (f anti) ranged from 0.57 to 0.80 in soil samples and 0.47 to 0.81 in earthworm samples, respectively. The f anti in most samples in this study was in the range of the reported technical DP values. These results showed that improper E-waste dismantling activities could result in the emission of DP. Most earthworm samples showed very low BSAFs (biota-to-soil accumulation factors) for total DP. The values of BSAF were in the range of 0.0007-1.85, with an average value of 0.23. This study presents the first report of the DP in earthworms, which would be useful for ecological risk assessment of DP in terrestrial ecosystem.

  3. Comparison of Sexual Knowledge, Attitude, and Behavior between Female Chinese College Students from Urban Areas and Rural Areas: A Hidden Challenge for HIV/AIDS Control in China

    Directory of Open Access Journals (Sweden)

    Min Chen

    2016-01-01

    Full Text Available Currently, research in sexual behavior and awareness in female Chinese college students (FCCSs is limited, particularly regarding the difference and the influencing factors between students from rural areas and urban areas. To fill the gap in available data, a cross-sectional study using anonymous questionnaires was conducted among 3193 female students from six universities located in Beijing, Shanghai, and Guangzhou, China, from February to June, 2013. Of the 2669 respondents, 20.6% and 20.9% of the students from urban and rural areas, respectively, reported being sexually experienced. The proportion of students who received safe-sex education prior to entering university from rural areas (22.4%, 134/598 was lower (P<0.0001 than the proportion from urban areas (41.8%, 865/2071. Sexual behavior has become increasingly common among FCCSs, including high-risk sexual behavior such as unprotected commercial sex. However, knowledge concerning human immunodeficiency virus (HIV/acquired immune deficiency syndrome (AIDS transmission and the risks is insufficient, particularly for those from rural areas, which is a challenge for HIV/AIDS control in China. The Chinese government should establish more specific HIV/AIDS prevention policies for Chinese young women, strengthen sex education, and continue to perform relevant research.

  4. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China.

    Science.gov (United States)

    Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

    2015-12-15

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33-521mg/L) in NO3(-) concentrations. Elevated nitrate concentrations, in addition to seawater intrusion in the Daweijia well field, both attributable to anthropogenic activities, may impact future water-management practices. Chemical and stable isotopic (δ(18)O, δ(2)H) analysis, (3)H and CFCs methods were applied to provide a better understanding of the relationship between the distribution of groundwater mean residence time (MRT) and nitrate transport, and to identify sources of nitrate concentrations in the complex coastal aquifer systems. There is a relatively narrow range of isotopic composition (ranging from -8.5 to -7.0‰) in most groundwater. Generally higher tritium contents observed in the wet season relative to the dry season may result from rapid groundwater circulation in response to the rainfall through the preferential flow paths. In the well field, the relatively increased nitrate concentrations of groundwater, accompanied by the higher tritium contents in the wet season, indicate the nitrate pollution can be attributed to domestic wastes. The binary exponential and piston-flow mixing model (BEP) yielded feasible age distributions based on the conceptual model. The good inverse relationship between groundwater MRTs (92-467years) and the NO3(-) concentrations in the shallow Quaternary aquifers indicates that elevated nitrate concentrations are attributable to more recent recharge for shallow groundwater. However, there is no significant relationship between the MRTs (8-411years) and the NO3(-) concentrations existing in the carbonate aquifer system, due to the complex hydrogeological conditions, groundwater age distributions and the range of contaminant source areas. Nitrate in the groundwater system without denitrification effects could accumulate and be transported for tens of years, through the complex carbonate

  5. Soil TPH concentration estimation using vegetation indices in an oil polluted area of eastern China.

    Directory of Open Access Journals (Sweden)

    Linhai Zhu

    Full Text Available Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m(-2 to 5.3 g m(-2 with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg(-1 to 652 mg kg(-1. The modified chlorophyll absorption ratio index (MCARI best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R(2 = 0.73 and accuracy of prediction (RMSE = 104.2 mg kg(-1. For other vegetation indices and red edge parameters, the R(2 and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg(-1 to 106.8 mg kg(-1 respectively. The traditional broadband normalized difference vegetation index (NDVI, one of the broadband multispectral vegetation indices (BMVIs, produced a prediction (R(2 = 0.70 and RMSE = 110.1 mg kg(-1 similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable.

  6. Soil TPH Concentration Estimation Using Vegetation Indices in an Oil Polluted Area of Eastern China

    Science.gov (United States)

    Zhu, Linhai; Zhao, Xuechun; Lai, Liming; Wang, Jianjian; Jiang, Lianhe; Ding, Jinzhi; Liu, Nanxi; Yu, Yunjiang; Li, Junsheng; Xiao, Nengwen; Zheng, Yuanrun; Rimmington, Glyn M.

    2013-01-01

    Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis) around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m−2 to 5.3 g m−2 with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg−1 to 652 mg kg−1. The modified chlorophyll absorption ratio index (MCARI) best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R2 = 0.73) and accuracy of prediction (RMSE = 104.2 mg kg−1). For other vegetation indices and red edge parameters, the R2 and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg−1 to 106.8 mg kg−1 respectively. The traditional broadband normalized difference vegetation index (NDVI), one of the broadband multispectral vegetation indices (BMVIs), produced a prediction (R2 = 0.70 and RMSE = 110.1 mg kg−1) similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable. PMID:23342066

  7. Detection of the Coupling between Vegetation Leaf Area and Climate in a Multifunctional Watershed, Northwestern China

    Directory of Open Access Journals (Sweden)

    Lu Hao

    2016-12-01

    Full Text Available Accurate detection and quantification of vegetation dynamics and drivers of observed climatic and anthropogenic change in space and time is fundamental for our understanding of the atmosphere–biosphere interactions at local and global scales. This case study examined the coupled spatial patterns of vegetation dynamics and climatic variabilities during the past three decades in the Upper Heihe River Basin (UHRB, a complex multiple use watershed in arid northwestern China. We apply empirical orthogonal function (EOF and singular value decomposition (SVD analysis to isolate and identify the spatial patterns of satellite-derived leaf area index (LAI and their close relationship with the variability of an aridity index (AI = Precipitation/Potential Evapotranspiration. Results show that UHRB has become increasingly warm and wet during the past three decades. In general, the rise of air temperature and precipitation had a positive impact on mean LAI at the annual scale. At the monthly scale, LAI variations had a lagged response to climate. Two major coupled spatial change patterns explained 29% and 41% of the LAI dynamics during 1983–2000 and 2001–2010, respectively. The strongest connections between climate and LAI were found in the southwest part of the basin prior to 2000, but they shifted towards the north central area afterwards, suggesting that the sensitivity of LAI to climate varied over time, and that human disturbances might play an important role in altering LAI patterns. At the basin level, the positive effects of regional climate warming and precipitation increase as well as local ecological restoration efforts overwhelmed the negative effects of overgrazing. The study results offer insights about the coupled effects of climatic variability and grazing on ecosystem structure and functions at a watershed scale. Findings from this study are useful for land managers and policy makers to make better decisions in response to climate

  8. Knowledge, attitudes and practices (KAP relating to avian influenza in urban and rural areas of China

    Directory of Open Access Journals (Sweden)

    Cheng Xiaowen

    2010-02-01

    Full Text Available Abstract Background Studies have revealed that visiting poultry markets and direct contact with sick or dead poultry are significant risk factors for H5N1 infection, the practices of which could possibly be influenced by people's knowledge, attitudes and practices (KAPs associated with avian influenza (AI. To determine the KAPs associated with AI among the Chinese general population, a cross-sectional survey was conducted in China. Methods We used standardized, structured questionnaires distributed in both an urban area (Shenzhen, Guangdong Province; n = 1,826 and a rural area (Xiuning, Anhui Province; n = 2,572 using the probability proportional to size (PPS sampling technique. Results Approximately three-quarters of participants in both groups requested more information about AI. The preferred source of information for both groups was television. Almost three-quarters of all participants were aware of AI as an infectious disease; the urban group was more aware that it could be transmitted through poultry, that it could be prevented, and was more familiar with the relationship between AI and human infection. The villagers in Xiuning were more concerned than Shenzhen residents about human AI viral infection. Regarding preventative measures, a higher percentage of the urban group used soap for hand washing whereas the rural group preferred water only. Almost half of the participants in both groups had continued to eat poultry after being informed about the disease. Conclusions Our study shows a high degree of awareness of human AI in both urban and rural populations, and could provide scientific support to assist the Chinese government in developing strategies and health-education campaigns to prevent AI infection among the general population.

  9. Chemical composition of fog water in Nanjing area of China and its related fog microphysics

    Science.gov (United States)

    Lu, Chunsong; Niu, Shengjie; Tang, Lili; Lv, Jingjing; Zhao, Lijuan; Zhu, Bin

    2010-07-01

    Fog samples were collected at Pancheng in the Nanjing area of China during December 2006 and December 2007. Fog droplet spectra, surface meteorological elements and visibility were also measured during the same period. The data from PM 10, SO 2 and NO 2 measurements were obtained from the air quality monitoring networks of Nanjing. The total ionic concentration (TIC) and electrical conductivity (EC) in fog samples, and the local pollutant emissions were one or two orders of magnitude higher than those found in Europe or South America for instance. Pollutants were expected to be mainly from local sources, including factories, plants, freeways, soil sources, house construction, and biomass burning. Advection also contributed to pollution levels in radiation-advection fogs. The scavenging of NH 3 and coarse particles by fog droplets was the main cause for the high mean pH value of 5.9. In-phase temporal evolution of TIC, [SO 42-], [NO 3-], SO 2, NO 2, PM 10 and S/LWC (S: the surface area of fog droplets per unit volume of air; LWC: liquid water content) was found to be due to the interaction of air pollutants and fog droplets, change of air mass due to advection, and so on. S/LWC seemed to be a better indicator for describing the relationship between TIC and microphysics with respect to LWC. A formula between TIC and S/LWC was derived and the related parameters were discussed. Depositions of chemical species in fog cases were estimated and the result showed that deposition was efficient.

  10. Soil TPH concentration estimation using vegetation indices in an oil polluted area of eastern China.

    Science.gov (United States)

    Zhu, Linhai; Zhao, Xuechun; Lai, Liming; Wang, Jianjian; Jiang, Lianhe; Ding, Jinzhi; Liu, Nanxi; Yu, Yunjiang; Li, Junsheng; Xiao, Nengwen; Zheng, Yuanrun; Rimmington, Glyn M

    2013-01-01

    Assessing oil pollution using traditional field-based methods over large areas is difficult and expensive. Remote sensing technologies with good spatial and temporal coverage might provide an alternative for monitoring oil pollution by recording the spectral signals of plants growing in polluted soils. Total petroleum hydrocarbon concentrations of soils and the hyperspectral canopy reflectance were measured in wetlands dominated by reeds (Phragmites australis) around oil wells that have been producing oil for approximately 10 years in the Yellow River Delta, eastern China to evaluate the potential of vegetation indices and red edge parameters to estimate soil oil pollution. The detrimental effect of oil pollution on reed communities was confirmed by the evidence that the aboveground biomass decreased from 1076.5 g m(-2) to 5.3 g m(-2) with increasing total petroleum hydrocarbon concentrations ranging from 9.45 mg kg(-1) to 652 mg kg(-1). The modified chlorophyll absorption ratio index (MCARI) best estimated soil TPH concentration among 20 vegetation indices. The linear model involving MCARI had the highest coefficient of determination (R(2) = 0.73) and accuracy of prediction (RMSE = 104.2 mg kg(-1)). For other vegetation indices and red edge parameters, the R(2) and RMSE values ranged from 0.64 to 0.71 and from 120.2 mg kg(-1) to 106.8 mg kg(-1) respectively. The traditional broadband normalized difference vegetation index (NDVI), one of the broadband multispectral vegetation indices (BMVIs), produced a prediction (R(2) = 0.70 and RMSE = 110.1 mg kg(-1)) similar to that of MCARI. These results corroborated the potential of remote sensing for assessing soil oil pollution in large areas. Traditional BMVIs are still of great value in monitoring soil oil pollution when hyperspectral data are unavailable.

  11. Dietary intake of mercury by children and adults in Jinhu area of China.

    Science.gov (United States)

    Sun, Jinfang; Wang, Cannan; Song, Xiaoyun; Wu, Yongning; Yuan, Baojun; Liu, Pei

    2011-06-01

    Dietary intakes of mercury by children and adults in Jinhu area of China were determined using a duplicate diet approach. A total of 176 duplicate diet portions were collected from 60 individuals in November and December of 2007. Mercury levels in duplicate samples were measured by atomic fluorescence spectrometry. The daily mercury intakes (median and range) from consumption days without fish or shellfish for children and adults were 0.13 (0.05-0.78) μg(kg(bw))(-1) day(-1) and 0.07 (0.04-0.18) μg(kg(bw))(-1) day(-1), respectively, which were significantly lower than those from consumption days with fish or shellfish for both children and adults whose daily intakes (median and range) were 0.16 (0.11-0.84) μg(kg(bw))(-1) day(-1) and 0.09 (0.05-0.46) μg(kg(bw))(-1) day(-1), respectively. The exposure level of children was significantly higher than that of adults. The 50th and 99th percentile of the usual mercury intake from all consumption days for children were 0.14 and 0.22 μg(kg(bw))(-1) day(-1) and for adults were 0.09 and 0.14 μg(kg(bw))(-1) day(-1), where the between-person variance in dietary mercury intake for children and adults were 0.038 and 0.036, respectively. Comparing with the provisional tolerable weekly intake (PTWI) divided into daily intake (PTDI) of 0.57 μg(kg(bw))(-1) day(-1), it is concluded that the average daily intakes and the usual intakes to mercury can be considered safe for both children and adults in Jinhu area by the duplicate diet study. But the maximum daily intakes for children exceeding the PTDI deserve a close attention. Copyright © 2011 Elsevier GmbH. All rights reserved.

  12. Co-infection of HIV and intestinal parasites in rural area of China

    Directory of Open Access Journals (Sweden)

    Tian Li-Guang

    2012-02-01

    Full Text Available Abstract Background Intestinal parasite infections (IPIs are among the most significant causes of illness and disease of socially and economically disadvantaged populations in developing countries, including rural areas of the People's Republic of China. With the spread of the human immunodeficiency virus (HIV among rural Chinese populations, there is ample scope for co-infections and there have been increasing fears about their effects. However, hardly any relevant epidemiological studies have been carried out in the country. The aim of the present survey was to assess the IPI infection status among a representative sample of HIV-positive Chinese in rural Anhui province, and compare the findings with those from a cohort of non-infected individuals. Methods A case control study was carried out in a rural village of Fuyang, Anhui province, China. Stool samples of all participants were examined for the presence of intestinal parasites. Blood examination was performed for the HIV infection detection and anemia test. A questionnaire was administered to all study participants. Results A total of 302 HIV positive and 303 HIV negative individuals provided one stool sample for examination. The overall IPI prevalence of intestinal helminth infections among HIV positives was 4.3% (13/302 while it was 5.6% (17/303 among HIV negatives, a non-significant difference. The prevalence of protozoa infections among HIV positives was 23.2% while the rate was 25.8% among HIV negatives. The species-specific prevalences among HIV positives were as follows: 3.6% for hookworm, 0.7% for Trichuris trichiura, zero for Ascaris lumbricoides, 0.3% for Clonorchis sinensis, 1.3% for Giardia intestinalis, 16.2% for Blastocystis hominis, 1.7% for Entamoeba spp. and 8.3% for Cryptosporidium spp.. Cryptosporidium spp. infections were significantly more prevalent among HIV positives (8.3% compared to the HIV negative group (3.0%; P Cryptosporidium spp. was significantly more

  13. Sources, Ages, and Alteration of Organic Matter in Estuaries.

    Science.gov (United States)

    Canuel, Elizabeth A; Hardison, Amber K

    2016-01-01

    Understanding the processes influencing the sources and fate of organic matter (OM) in estuaries is important for quantifying the contributions of carbon from land and rivers to the global carbon budget of the coastal ocean. Estuaries are sites of high OM production and processing, and understanding biogeochemical processes within these regions is key to quantifying organic carbon (Corg) budgets at the land-ocean margin. These regions provide vital ecological services, including nutrient filtration and protection from floods and storm surge, and provide habitat and nursery areas for numerous commercially important species. Human activities have modified estuarine systems over time, resulting in changes in the production, respiration, burial, and export of Corg. Corg in estuaries is derived from aquatic, terrigenous, and anthropogenic sources, with each source exhibiting a spectrum of ages and lability. The complex source and age characteristics of Corg in estuaries complicate our ability to trace OM along the river-estuary-coastal ocean continuum. This review focuses on the application of organic biomarkers and compound-specific isotope analyses to estuarine environments and on how these tools have enhanced our ability to discern natural sources of OM, trace their incorporation into food webs, and enhance understanding of the fate of Corg within estuaries and their adjacent waters.

  14. Hydro-morphological modelling of small, wave-dominated estuaries

    Science.gov (United States)

    Slinger, Jill H.

    2017-11-01

    Small, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary.

  15. Planning of Green Space Ecological Network in Urban Areas: An Example of Nanchang, China.

    Science.gov (United States)

    Li, Haifeng; Chen, Wenbo; He, Wei

    2015-10-15

    Green space plays an important role in sustainable urban development and ecology by virtue of multiple environmental, recreational, and economic benefits. Constructing an effective and harmonious urban ecological network and maintaining a sustainable living environment in response to rapid urbanization are the key issues required to be resolved by landscape planners. In this paper, Nanchang City, China was selected as a study area. Based on a series of landscape metrics, the landscape pattern analysis of the current (in 2005) and planned (in 2020) green space system were, respectively, conducted by using FRAGSTATS 3.3 software. Considering the actual situation of the Nanchang urban area, a "one river and two banks, north and south twin cities" ecological network was constructed by using network analysis. Moreover, the ecological network was assessed by using corridor structure analysis, and the improvement of an ecological network on the urban landscape was quantitatively assessed through a comparison between the ecological network and green space system planning. The results indicated that: (1) compared to the green space system in 2005, the planned green space system in 2020 of the Nanchang urban area will decline in both districts (Changnan and Changbei districts). Meanwhile, an increase in patch density and a decrease in mean patch size of green space patches at the landscape level implies the fragmentation of the urban green space landscape. In other words, the planned green space system does not necessarily improve the present green space system; (2) the ecological network of two districts has high corridor density, while Changnan's ecological network has higher connectivity, but Changbei's ecological network is more viable from an economic point of view, since it has relatively higher cost efficiency; (3) decrease in patch density, Euclidean nearest neighbor distance, and an increase in mean patch size and connectivity implied that the ecological network

  16. Multivariate and geostatistical analyzes of metals in urban soil of Weinan industrial areas, Northwest of China

    Science.gov (United States)

    Li, Xiaoping; Feng, Linna

    2012-02-01

    An investigation on spatial distribution, possible pollution sources, and affecting factors of heavy metals in the urban soils of Weinan (China) was conducted using geographic information system (GIS) technique and multivariate statistics. The results indicated that the levels of 10 heavy metals (Pb, Cr, Ba, Zn, V, Mn, Co, Cu, Ni and As) distribution measured by wavelength dispersive X-ray fluorescence spectrometry (WDXRF) in urban soil of Weinan were As varied from 2.60 to 11.50 mg kg -1, Co was 8.00-14.50 mg kg -1, Cr from 74.90 to 157.00 mg kg -1, Cu from 14.60 to 34.70 mg kg -1, Ba from 413.00 to 1137.60 mg kg -1, Mn from 431.30 to 653.70 mg kg -1, Ni from 20.80 to 35.8 mg kg -1, Pb from 19.00 to 89.50 mg kg -1, V from 63.80 to 89.50 mg kg -1, Zn from 44.50 to 196.80 mg kg -1, respectively. The mean enrichment factors (EFs) decreased in the order of Pb > Cr > Ba > Cu > Zn > Ni > V > Mn > Co > As, indicating Ba, Cu, Pb, Cr and Zn were significant enriched in the study areas. Spatial distribution maps of heavy metal contents, based on geostatistical analysis and GIS mapping, indicated that Pb and Cr had similar patterns of spatial distribution, likewise, between Ba, Cu and Zn, and among As, Co, Mn, V as well. Multivariate statistical analysis (correlation analysis, principal component analysis, and clustering analysis) showed distinctly different associations among the studied metals, suggesting that the heavy metals, Ba, Cu, Pb, Cr and Zn were associated with anthropic activities (industrial sources, combined with coal combustion as well as traffic factor), whereas Mn, V, Co, As and Ni in study area mainly controlled by parent materials and therefore had natural sources. A comprehensive environmental management strategy should be concerned by the local government to address soil pollution in urban areas.

  17. Planning of Green Space Ecological Network in Urban Areas: An Example of Nanchang, China

    Directory of Open Access Journals (Sweden)

    Haifeng Li

    2015-10-01

    Full Text Available Green space plays an important role in sustainable urban development and ecology by virtue of multiple environmental, recreational, and economic benefits. Constructing an effective and harmonious urban ecological network and maintaining a sustainable living environment in response to rapid urbanization are the key issues required to be resolved by landscape planners. In this paper, Nanchang City, China was selected as a study area. Based on a series of landscape metrics, the landscape pattern analysis of the current (in 2005 and planned (in 2020 green space system were, respectively, conducted by using FRAGSTATS 3.3 software. Considering the actual situation of the Nanchang urban area, a “one river and two banks, north and south twin cities” ecological network was constructed by using network analysis. Moreover, the ecological network was assessed by using corridor structure analysis, and the improvement of an ecological network on the urban landscape was quantitatively assessed through a comparison between the ecological network and green space system planning. The results indicated that: (1 compared to the green space system in 2005, the planned green space system in 2020 of the Nanchang urban area will decline in both districts (Changnan and Changbei districts. Meanwhile, an increase in patch density and a decrease in mean patch size of green space patches at the landscape level implies the fragmentation of the urban green space landscape. In other words, the planned green space system does not necessarily improve the present green space system; (2 the ecological network of two districts has high corridor density, while Changnan’s ecological network has higher connectivity, but Changbei’s ecological network is more viable from an economic point of view, since it has relatively higher cost efficiency; (3 decrease in patch density, Euclidean nearest neighbor distance, and an increase in mean patch size and connectivity implied that the

  18. Energy potential of municipal solid waste incineration in urban areas of China.

    NARCIS (Netherlands)

    Zheng, Ling

    2006-01-01

    This study aims to evaluate the energy potential of municipal solid waste (MSW) incineration in Chinese cities from 1996 to 2020. In China, with improving the standard of living recently, the extreme increase of the municipal solid waste generation (MSWG)

  19. Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

    DEFF Research Database (Denmark)

    Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo

    2017-01-01

    High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal enviro...... and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area....

  20. Polybrominated diphenyl ethers in water, sediment, soil, and biological samples from different industrial areas in Zhejiang, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junxia; Lin, Zhenkun [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035 (China); Lin, Kuangfei [School of Resources and Environmental Engineering, East China University of Science and Technology/State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, Shanghai 200237 (China); Wang, Chunyan [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035 (China); Zhang, Wei [School of Resources and Environmental Engineering, East China University of Science and Technology/State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, Shanghai 200237 (China); Cui, Changyuan [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035 (China); Lin, Junda [Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Dong, Qiaoxiang, E-mail: dqxdong@163.com [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035 (China); Huang, Changjiang, E-mail: cjhuang5711@163.com [Zhejiang Provincial Key Lab for Technology and Application of Model Organisms, Institute of Watershed Science and Environmental Ecology, Wenzhou Medical College, Wenzhou 325035 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We examined PBDE concentrations in various matrices from different industrial areas. Black-Right-Pointing-Pointer Elevated PBDE levels were found in areas with low-voltage electrical manufactures. Black-Right-Pointing-Pointer Areas with e-waste recycling activities also had higher PBDE concentrations. Black-Right-Pointing-Pointer PBDE content and composition in water samples varied from one area to another. Black-Right-Pointing-Pointer PBDE composition in sediment/soil and biological samples was predominated by BDE-209. - Abstract: Polybrominated diphenyl ethers (PBDEs) have been used extensively in electrical and electronic products, but little is known about their distribution in the environment surrounding the manufacturing factories. This study reports PBDE contamination in various matrices from the location (Liushi, Zhejiang province) that produces more than 70% of the low-voltage electrical appliances in China. Additionally, PBDE contamination was compared with other industries such as the e-waste recycling business (Fengjiang) in the same region. Specifically, we measured seven PBDE congeners (BDEs - 47, 99, 100, 153, 154, 183, and 209) in water, sediment, soil, plant, and animal tissues from four different areas in this region. The present study revealed elevated PBDE concentrations in all matrices collected from Liushi and Fengjiang in comparison with highly industrialized areas without significant PBDE contamination sources. In water samples, there were large variations of PBDE content and composition across different areas. In sediment/soil and biological samples, BDE-209 was the predominant congener and this could be due to the abundant usage of deca-BDE mixtures in China. Our findings provide the very first data on PBDE contamination in the local environments surrounding the electronics industry, and also reveal widespread PBDE contamination in highly industrialized coastal regions of China.

  1. Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area, China.

    Science.gov (United States)

    Zhang, L X; Ulgiati, S; Yang, Z F; Chen, B

    2011-03-01

    Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer's decisions, the accessibility of land for the required use and investment ability determine the farmer's choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making. Copyright © 2010

  2. [Relationship between pesticide exposure and adverse pregnancy outcomes among reproductive couples in rural areas of China].

    Science.gov (United States)

    Qu, Y M; Chen, S; Li, J J; Jin, R R; Pan, H; Jiang, Y

    2017-06-10

    Objective: To analyze the association between pesticide exposure and adverse pregnancy outcomes in women from the rural areas of China. Methods: Data of "National Free Preconception Health Examination Project (NFPHEP)" from January 2010 to December 2012 was used for analysis. A total of 248 501 families that were planning to deliver a baby in the next 6 months were enrolled. Data on paternal exposure to pesticides before or during pregnancy was collected through questionnaires, with related outcomes on pregnancy recorded by doctors. Results: Among all the 248 501 participants, 1 806 (0.74%) women and 2 653 (1.09%) men reported to have been exposed to pesticide before pregnancy, with 505 (0.21%) reported of having been exposed to pesticide during the period of pregnancy. Maternal exposure to pesticide was found a risk factor related to stillbirth (OR=3.37, 95%CI: 2.05-5.55), peculiar smell pregnancy (OR=3.17, 95%CI:1.18-8.55) and low birth weight (OR=7.56, 95% CI: 5.36-10.66). Paternal exposure to pesticide was also found related to miscarriage (OR=1.37, 95% CI: 1.03-1.80), low birth weight (OR=3.65, 95% CI:1.51-8.84), or giant infant (OR=0.64, 95%CI: 0.44-0.93). Maternal exposure to pesticide during pregnancy appeared a risk factor on miscarriage (OR=4.65, 95% CI: 3.47-6.24). Other adverse outcomes on pregnancy would include premature birth and high birth weight. Conclusion: Parental pesticide exposure appeared a risk factor on stillbirth, peculiar smell pregnancy, low birth weight and miscarriage.

  3. Bacterial diversity in goat milk from the Guanzhong area of China.

    Science.gov (United States)

    Zhang, Fuxin; Wang, Zhaoxia; Lei, Feiyan; Wang, Bini; Jiang, Shuaiming; Peng, Qiannan; Zhang, Jiachao; Shao, Yuyu

    2017-10-01

    In this study, the V3 and V4 regions of the 16S rRNA gene from metagenomic DNA were sequenced to identify differences in microbial diversity in raw milk of Saanen and Guanzhong goats from the Guanzhong area of China. The results showed that Proteobacteria was the predominant phylum, accounting for 71.31% of all phyla identified in milk from the 2 breeds, and Enterobacter was the predominant genus (24.69%) within the microbial community. Microbial alpha diversity from Saanen goat milk was significantly higher than that of Guanzhong goat milk based on bioinformatic analysis of indices of Chao1, Shannon, Simpson, observed species, and the abundance-based coverage estimator. Functional genes and their likely metabolic pathways were predicted, which demonstrated that the functional genes present in the bacteria in goat milk were enriched in pathways for amino acid metabolism and carbohydrate metabolism, which represented 11.93 and 11.23% of functional genes, respectively. Physicochemical properties such as pH, protein, fat, and AA levels were also determined and correlations made with microbial diversity. We detected a significant difference in the content of lactose and 6 AA, which were higher in Saanen milk than in Guanzhong milk, and positively correlated with microbial carbohydrate metabolism and AA metabolism. Lactococcus, Lactobacillus, Bifidobacterium, Enterococcus, and Streptococcus, which are lactose-utilizing genera, were more abundant in Saanen milk than in Guanzhong milk. Higher levels of lactose in Saanen goat milk may explain its greater microbial diversity. We also demonstrated that most of the AA metabolism-related bacterial genera (e.g., Massilia, Bacteroides, Lysobacter) were enriched in Saanen goat milk. In this research, both probiotic and pathogenic bacteria were identified in goat milk, which provided the microbial information necessary to direct the utilization of beneficial microbial resources and prevent the development of harmful organisms in

  4. Ecological Footprint Analysis Based on Changing Food Consumption in a Poorly Developed Area of China

    Directory of Open Access Journals (Sweden)

    Lin Zhen

    2017-08-01

    Full Text Available The per capita ecological footprint (EF is a useful tool to compare consumption with nature's ability to support this consumption. Guyuan is an economically impoverished region in China, where EF provides important insights into whether human consumption can be sustained by the local per capita biological capacity (BC, which represents the environment’s ability to support resource use. We estimated the EF of food consumption using local equivalence and yield factors, and compared EF in 1998 and 2013 with BC, which represented the existing biologically productive area (including cultivated land, grassland, forest, and water bodies that supports this consumption. Data were collected from household surveys, government statistics, and land use maps. We found that food consumption changed, with decreasing consumption of staple foods and increasing consumption of meat, eggs, milk, edible oils, fruit, and vegetables. Decreased staple food consumption decreased the EF for this food group, but the large increase in meat consumption greatly increased EF from meat production (to more than 41 times the 1998 value. Cultivated land contributed greatly to both EF and BC, and staple foods and vegetables were the main EF components for this land. Overall, EF from food consumption decreased from 1998 to 2013, but local BC remained 188,356 ha below EF (i.e., current consumption is not sustainable based on local resources. The Grain for Green program, which focuses on increasing the BC of forest and grassland by replacing degraded cultivated land with these land use types, decreased the BC of cultivated land, leading to wide spatial variation in both EF and BC. These results will inform policy development by revealing the condition of each region’s use of the locally available production resources.

  5. An equity analysis of health examination service utilization by women from underdeveloped areas in western China.

    Science.gov (United States)

    Qian, Yuyan; Gao, Jianmin; Zhou, Zhongliang; Yan, Ju'e; Xu, Yongjian; Yang, Xiaowei; Li, Yanli

    2017-01-01

    This study sought to examine the sources of inequity in health examination service utilization by women from underdeveloped areas in western China. Based on data from the 5th National Health Service Survey in Shaanxi province, women's utilization of health examination services was examined according to gynecological, cervical smear, and breast examination rates. The equity of health examination service utilization by 15- to 64-year-old women and the factors contributing to inequity were determined using the health concentration index, decomposition of the concentration index, and the horizontal inequity index. The examination rates for gynecological, cervical smear, and breast exams for 15- to 64-year-old women in Shaanxi province were 40.61%, 27.08%, and 24.59%, respectively. The horizontal inequity indices of gynecological, cervical smear, and breast examination rates were 0.0480, 0.0423, and 0.0764, respectively, and each examination rate was higher for wealthy individuals. The contribution rates of economic status to the inequalities in gynecological, cervical smear, and breast examination rates were 65.80%, 74.31%, and 56.49%, respectively. The contribution rates of educational status to the inequalities in gynecological, cervical smear, and breast examination rates were 21.01%, 14.83% and 30.00%, respectively. The contribution rates of age to the inequalities in gynecological, cervical smear, and breast examination rates were 25.77%, 26.55%, and 18.40%, respectively. Women's health examination rates differed between populations with different socio-demographic characteristics. There is pro-wealth inequality in each examination rate. This study found that financial status, age, and education level were the main reasons for the unequal utilization of health examination services.

  6. An equity analysis of health examination service utilization by women from underdeveloped areas in western China.

    Directory of Open Access Journals (Sweden)

    Yuyan Qian

    Full Text Available This study sought to examine the sources of inequity in health examination service utilization by women from underdeveloped areas in western China.Based on data from the 5th National Health Service Survey in Shaanxi province, women's utilization of health examination services was examined according to gynecological, cervical smear, and breast examination rates. The equity of health examination service utilization by 15- to 64-year-old women and the factors contributing to inequity were determined using the health concentration index, decomposition of the concentration index, and the horizontal inequity index.The examination rates for gynecological, cervical smear, and breast exams for 15- to 64-year-old women in Shaanxi province were 40.61%, 27.08%, and 24.59%, respectively. The horizontal inequity indices of gynecological, cervical smear, and breast examination rates were 0.0480, 0.0423, and 0.0764, respectively, and each examination rate was higher for wealthy individuals. The contribution rates of economic status to the inequalities in gynecological, cervical smear, and breast examination rates were 65.80%, 74.31%, and 56.49%, respectively. The contribution rates of educational status to the inequalities in gynecological, cervical smear, and breast examination rates were 21.01%, 14.83% and 30.00%, respectively. The contribution rates of age to the inequalities in gynecological, cervical smear, and breast examination rates were 25.77%, 26.55%, and 18.40%, respectively.Women's health examination rates differed between populations with different socio-demographic characteristics. There is pro-wealth inequality in each examination rate. This study found that financial status, age, and education level were the main reasons for the unequal utilization of health examination services.

  7. [Effect of air pollution on respiratory health in school-aged children in the main urban area of Chongqing, China].

    Science.gov (United States)

    Fan, Ming-Yue; Tang, Xu; Huang, Wei; Dai, Hua; Liu, Xing-Can; Xia, Yin-Yin; Meng, Pan; Zhang, Rui-Yuan; Guo, Yu-Ming; Cheng, Shu-Qun

    2017-04-01

    To investigate the effect of air pollution on respiratory health in school-aged children in the main urban area of Chongqing, China. The main urban area of Chongqing was divided into polluted area and clean area according to the air pollution data shown on the Environmental Protection Agency Website of Chongqing between 2010 and 2015. A cluster sampling method was used to select 695 third- or fourth-grade children from 2 primary schools in the clean or polluted area as study subjects, with 313 children from the clean area and 382 children from the polluted area. Pulmonary function was examined for all children and a standard American epidemiological questionnaire (ATS-DLD-78-C) was used to investigate the prevalence of respiratory diseases and symptoms. Compared with the clean area, the polluted area had significantly higher concentrations of inhalable particles (PM10), fine particulate matter (PM2.5), and nitric oxide (NOX) (Ppolluted area had significantly higher risks of cough (OR=1.644), cough during cold (OR=1.596), expectoration during cold (OR=2.196), persistent expectoration (OR=1.802), and wheezing (OR=2.415). The boys and girls in the clean area had significantly higher forced vital capacity and forced expiratory volume in one second than those in the polluted area (Ppollution in the main urban area of Chongqing is associated with the increased prevalence of respiratory symptoms in school-aged children and has certain effect on children's pulmonary function.

  8. Sediment balance of intertidal mudflats in a macrotidal estuary

    Science.gov (United States)

    lafite, R.; Deloffre, J.; Lemoine, M.

    2012-12-01

    Intertidal area contributes widely to fine-grained sediment balance in estuarine environments. Their sedimentary dynamics is controlled by several forcing parameters including tidal range, river flow and swell, affected by human activities such as dredging, construction or vessels traffic leading to modify sediment transport pattern. Although the estuarine hydrodynamics is well documented, the link between forcing parameters and these sedimentary processes is weakly understood. One of the main reasons is the difficulty to integrate spatial (from the fluvial to the estuary mouth) and temporal (from swell in seconds to pluriannual river flow variability) patterns. This study achieved on intertidal mudflats distributed along the macrotidal Seine estuary (France) aims (i) to quantify the impact of forcing parameters on each intertidal area respect to its longitudinal position in the estuarine system and (ii) to assess the fine-grained sediment budget at estuarine scale. The Seine estuary is a macrotidal estuary developed over 160 km up the upstream limit of tidal wave penetration. With an average river flow of 450m3.s-1, 80% of the Suspended Particles Matter (SPM) annual flux is discharged during the flood period. In the downstream part, the Seine estuary Turbidity Maximum (TM) is the SPM stock located near the mouth. During their transfer toward the sea, the fine particles can be trapped in (i) the intertidal mudflats; preferential areas characterized by low hydrodynamics and generally sheltered of the tidal dominant flow, the main tidal current the Seine River and (ii) the TM. The Seine estuary is an anthropic estuary in order to secure navigation: one consequence of these developments is the tidal bore disappearance. Along the macrotidal Seine estuary hydrodynamics features and sedimentary fluxes were followed during at least 1 year using respectively Acoustic Doppler Velocimeter, Optical BackScatter and altimeter. Results in the fluvial estuary enhance the role of

  9. GIS-based logistic regression for landslide susceptibility mapping of the Zhongxian segment in the Three Gorges area, China

    Science.gov (United States)

    Bai, Shi-Biao; Wang, Jian; Lü, Guo-Nian; Zhou, Ping-Gen; Hou, Sheng-Shan; Xu, Su-Ning

    2010-02-01

    A detailed landslide susceptibility map was produced using a logistic regression method with datasets developed for a geographic information system (GIS). Known as one of the most landslide-prone areas in China, the Zhongxian-Shizhu segment in the Three Gorges Reservoir region of China was selected as a suitable case to evaluate the frequency and distribution of landslides. The site covered an area of 260.9 km 2 with a landslide area of 5.3 km 2. Four data domains were used in this study: remote sensing products, thematic maps, geological maps, and topographical maps, all with 25 × 25 m 2 pixels or cells. Statistical relationships for landslide susceptibility were developed using landslide and landslide causative factor databases. We extended the application of logistic regression approaches to use all continuous variables as they are, and the landslide density is used to transform these nominal variables to numeric variable. According to the map, 2.8% of the study area was identified as an area with very high-susceptibility, whereas very low-, low-, medium- and high-susceptibility zones covered 18.2%, 36.2%, 26.7%, and 16.1% of the area, respectively. The quality of susceptibility mapping was validated, and the correct classification percentage and root mean square error (RMSE) values for the validation data were 81.4% and 0.392, respectively.

  10. NEW DATA ABOUT MACROZOOBENTHOS OF BEYSUGSKY ESTUARY (SEA OF AZOV

    Directory of Open Access Journals (Sweden)

    N. I. Bulysheva

    2013-01-01

    Full Text Available Abstract. Aim. Beysugsky Estuary is one of the biggest estuaries of the Azov-Kuban’ lowland. Like the other water bodies in the South of Russia, this one is subject to strong anthropogenic load: detachment of the freshwater part for establishing the Beysug spawning area; regulation of the flow of the rivers feeding the estuary; destruction of the Yasenskaya spit and narrowing of the Bugaz mouth; disorganized tourism. The ongoing reformation of the ecosystem makes it necessary to carry out the analyses of the modern state of the biota of this water body and uncover reasons and regularities of its change.Location. Beysug Estuary of the Sea of Azov.Methods. Quantitative zoobenthos samples were taken with the Petersen dredger (sampling area 0,034 m2 from board of the inflatable “Zodiac” boat. Qualitative samples were taken in the coastal zone by hand and with the dredge. All the samples taken were washed through the bag made of mill sieve with mesh size 0,5 mm, and then were fixed in a plastic bucket by 4 % formaldehyde (quantitative samples or 70 % ethyl alcohol (qualitative samples. Taking and processing of samples were carried out in field and laboratory environment using common methods. 22 samples at 7 stations were taken in total.Results. Macrozoobenthos was presented by 14 invertebrate species. Estuarine fauna is the depleted version of the euryhaline one of the Sea of Azov with Holocene relic macrophyte-dwelling elements. Biodiversity and quantitative characters of the estuarine communities decrease from west to east. Pelophylic detritophages predominated in the benthic communities of the estuary. The results of this research are meant to be used for uncovering historical ways of forming of benthic fauna and clearing up the dependence of community structure on the seawater influence, freshwater flow, regulation of freshwater and seawater sources, nature of changing of faunas at salinization of estuaries connected with the sea and the

  11. Spatial distribution of chromium and lead in the benthic environment of coastal areas of the Río de la Plata estuary (Montevideo, Uruguai

    Directory of Open Access Journals (Sweden)

    P Muniz

    Full Text Available Twenty-four sediment samples were collected seasonally during one year from the partially closed Montevideo Bay and the adjacent coastal zone, in Uruguay, in order to determine the impact of chromium and lead in the sediments. Analysis of related environmental variables included bottom water temperature, salinity, pH, dissolved oxygen, and several sedimentological variables such as redox potential and total organic matter. Concentrations and range of variation of these two metals were similar to those found in urbanized and industrialized estuarine environments. Metal enrichment is higher in the bay than in the adjacent coastal zone, however an important increase especially in Pb content was detected in an area previously considered as a pristine one. Considering both metal content and benthic environment characteristics, the study area can be clearly divided in at least two well-defined regions. One is the inner region of the bay near the streams, and the outermost stations of the bay and the adjacent coastal zone form the other. The first one can be considered highly polluted and the other moderately polluted. The values of the metals studied indicated that adverse biological effects are probably occurring, specially in the innermost region of Montevideo Bay.

  12. The Application Study in Solar Energy Technology for Highway Service Area: A Case Study of West Lushan Highway Low-Carbon Service Area in China

    Directory of Open Access Journals (Sweden)

    Xiaochun Qin

    2015-01-01

    Full Text Available A lot of research works have been made concerning highway service area or solar technology and acquired great achievements. However, unfortunately, few works have been made combining the two topics together of highway service areas and solar energy saving to make a systemic research on solar technology application for highway service area. In this paper, taking West Lushan highway low-carbon service area in Jiangxi Province of China as the case study, the advantages, technical principles, and application methods of solar energy technology for highway service area including solar photoelectric technology and solar water heating technology were discussed based on the analysis of characteristics of highway low-carbon service area; the system types, operation mode, and installing tilt angle of the two kinds of solar systems suitable for highway service areas were confirmed. It was proved that the reduction of the cost by electricity savings of solar system was huge. Taking the investment of the solar systems into account, the payback period of solar photoelectric systems and solar water heating systems was calculated. The economic effect of the solar systems in West Lushan highway service area during the effective operation periods was also calculated and proved very considerable.

  13. Ascaridoid parasites infecting in the frequently consumed marine fishes in the coastal area of China: A preliminary investigation.

    Science.gov (United States)

    Zhao, Wen-Ting; Lü, Liang; Chen, Hui-Xia; Yang, Yue; Zhang, Lu-Ping; Li, Liang

    2016-04-01

    Marine fishes represent the important components of the diet in the coastal areas of China and they are also natural hosts of various parasites. However, to date, little is known about the occurrence of ascaridoid parasites in the frequently consumed marine fishes in China. In order to determine the presence of ascaridoid parasites in the frequently consumed marine fishes in the coastal town Huizhou, Guangdong Province, China, 211 fish representing 45 species caught from the South China Sea (off Daya Gulf) were examined. Five species of ascaridoid nematodes at different developmental stages were detected in the marine fishes examined herein, including third-stage larva of Anisakis typica (Diesing, 1860), third and fourth-stage larvae of Hysterothylacium sp. IV-A of Shamsi, Gasser & Beveridge, 2013, adult and third-stage larvae of Hysterothylacium zhoushanense Li, Liu & Zhang, 2014, adults and third-stage larvae of Raphidascaris lophii (Wu, 1949) and adults of Raphidascaris longispicula Li, Liu & Zhang, 2012. The overall prevalence of infection is 18.0%. Of them, Hysterothylacium sp. IV-A with the highest prevalence (17.5%) and intensity (mean=14.6) of infection was the predominant species. The prevalence and intensity of A. typica were very low (1/211 of marine fish infected with an intensity of one parasite per fish). The morphological and molecular characterization of all nematode species was provided. A cladistic analysis based on ITS sequence was constructed in order to determine the phylogenetic relationships of these ascaridoid parasites obtained herein. The present study provided important information on the occurrence and diagnosis of ascaridoid nematodes in the commercially important marine fishes from the South China Sea. The low level of infection and the species composition of ascaridoid nematodes seem to indicate the presence of low risk of human anisakidosis when local population consumed these marine fishes examined herein. Copyright © 2015 Elsevier

  14. Seasonal and Spatial Variability of Virioplanktonic Abundance in Haihe River, China

    Directory of Open Access Journals (Sweden)

    Lili Ma

    2013-01-01

    Full Text Available In order to understand the composition and dynamics of planktonic viruses and their relationship with environmental parameters in natural freshwater, flow cytometry was optimized with filtration/fixation/staining/dilution and then applied to the analysis of samples collected from 9 stations (covering urban, rural, and estuarial areas along the Haihe River, China, over a one-year period of study. The total viral abundance exhibited an apparent peak in the spring. Spatially, the highest viral abundance was recorded in estuarial areas. The correlation analysis indicated that the bacteria in the Haihe River significantly influenced viral abundance. The relationship between abiotic variables and viral abundance remained the same as with bacterial abundance, indicating that environmental parameters could possibly influence viral abundance in virtue of their bacterial host cells. The influence of environmental factors on viral abundance differed in the three sampling areas, suggesting different drivers of viral abundance in different stretches of the river associated with their utilization and surroundings.

  15. [Area changes of emergent herbaceous wetlands in relation to water level in East Dongting Lake, China in 1989-2011].

    Science.gov (United States)

    Tang, Yue; Xie, Yong-Hong; Li, Feng; Chen, Xin-Sheng

    2013-11-01

    Based on multi-temporal Landsat MSS/TM/ETM+ images, and by using decision tree method, this paper extracted the areas of emergent herbaceous wetlands with different water levels in 1989-2011 in the East Dongting Lake, China. The change characteristics and change trends of the emergent herbaceous wetlands areas were investigated based on the DEM data and the daily water level data from the Chenglingji Hydrological Station. The area of the emergent herbaceous wetlands was significantly affected by water level (R2 = 0.875, P wetlands area decreased with increasing water level. The higher the water level, the smaller the effects of the water level on the emergent area were. The emergent area changed regularly with water level. In January-July, water level increased, and the emergent area decreased; in July-December, it was opposite. In 1989-2011, the areas of emergent herbaceous wetlands had a continual increase. The newly emergent herbaceous wetlands area was mainly transformed from mudflat. The emergent herbaceous wetlands expansion was the co-effects of the increase of the emergent herbaceous wetlands areas at different elevations, and the rapid expansion of the emergent herbaceous wetlands in low bottomland (22-25 m of Yellow Sea elevation) played the most important role in the expansion. The change of water level at different elevations was the dominant cause for the changes of emergent herbaceous wetlands areas in the East Dongting Lake in the past 20 years.

  16. Evidence for natural Borna disease virus infection in healthy domestic animals in three areas of western China.

    Science.gov (United States)

    Zhang, Liang; Wang, Xiao; Zhan, Qunling; Wang, Zhenhai; Xu, Mingming; Zhu, Dan; He, Feng; Liu, Xia; Huang, Rongzhong; Li, Dan; Lei, Yang; Xie, Peng

    2014-08-01

    Borna disease virus (BDV) is a non-cytolytic, neurotropic RNA virus that can infect many vertebrate species, including humans. To date, BDV infection has been reported in a range of animal species across a broad global geographic distribution. However, a systematic epidemiological survey of BDV infection in domesticated animals in China has yet to be performed. In current study, BDV RNA and antibodies in 2353 blood samples from apparently healthy animals of eight species (horse, donkey, dog, pig, rabbit, cattle, goat, sheep) from three areas in western China (Xinjiang province, Chongqing municipality, and Ningxia province) were assayed using reverse transcription qPCR (RT-qPCR) and ELISA assay. Brain tissue samples from a portion of the BDV RNA- and/or antibody-positive animals were subjected to RT-qPCR and western blotting. As a result, varying prevalence of BDV antibodies and/or RNA was demonstrated in various animal species from three areas, ranging from 4.4 % to 20.0 %. Detection of BDV RNA and/or antibodies in Chongqing pigs (9.2 %) provided the first known evidence of BDV infection in this species. Not all brain tissue samples from animals whose blood was BDV RNA and/or antibody positive contained BDV RNA and protein. This study provides evidence that BDV infection among healthy domestic animal species is more widespread in western China than previously believed.

  17. Initiation of breastfeeding and prevalence of exclusive breastfeeding at hospital discharge in urban, suburban and rural areas of Zhejiang China

    Directory of Open Access Journals (Sweden)

    Binns Colin W

    2009-01-01

    Full Text Available Abstract Background Rates of exclusive breastfeeding in China are relatively low and below national targets. The aim of this study was to document the factors that influence exclusive breastfeeding initiation in Zhejiang, PR China. Methods A cohort study of infant feeding practices was undertaken in Zhejiang Province, an eastern coastal region of China. A total of 1520 mothers who delivered in four hospitals located in city, suburb and rural areas during late 2004 to 2005 were enrolled in the study. Multivariate logistic regression analysis was used to explore factors related to exclusive breastfeeding initiation. Results On discharge from hospital, 50.3% of the mothers were exclusively breastfeeding their infants out of 96.9% of the mothers who had earlier initiated breastfeeding. Exclusive breastfeeding was positively related to vaginal birth, baby's first feed being breast milk, mother living in the suburbs or rural areas, younger age of mother, lower maternal education level and family income. Conclusion The exclusive breastfeeding rate in Zhejiang is only 50.3% on discharge and does not reach Chinese or international targets. A number of behaviours have been identified in the study that could be potentially incorporated into health promotion activities.

  18. Quantitative Impacts of Climate Change and Human Activities on Water-Surface Area Variations from the 1990s to 2013 in Honghu Lake, China

    National Research Council Canada - National Science Library

    Bianrong Chang; Rendong Li; Chuandong Zhu; Kequn Liu

    2015-01-01

      The water-surface areas of the lakes in the mid-lower reaches of the Yangtze River, China, have undergone significant changes under the combined impacts of global climate change and local anthropogenic stress...

  19. Patrilineal background of esophageal cancer and gastric cardia cancer patients in a Chaoshan high-risk area in China.

    Directory of Open Access Journals (Sweden)

    Shuhui Liu

    Full Text Available The Taihang Mountain range of north-central China, the Southern region area of Fujian province, and the Chaoshan plain of Guangdong province are 3 major regions in China well known for their high incidence of esophageal cancer (EC. These areas also exhibit high incidences of gastric cardia cancer (GCC. The ancestors of the Chaoshanese, now the major inhabitants in the Chaoshan plain, were from north-central China. We hypothesized that EC and GCC patients in Chaoshan areas share a common ancestry with Taihang Mountain patients. We analyzed 16 East Asian-specific Y-chromosome biallelic markers (single nucleotide polymorphisms; Y-SNPs and 6 Y-chromosome short tandem repeat (Y-STR loci in 72 EC and 48 GCC patients from Chaoshan and 49 EC and 63 GCC patients from the Taihang Mountain range. We also compared data for 32 Chaoshan Hakka people and 24 members of the aboriginal She minority who live near the Chaoshan area. Analysis was by frequency distribution and principal component, correlation and hierarchical cluster analysis of Y-SNP. Chaoshan patients were closely related to Taihang Mountain patients, even though they are geographically distant. Y-STR analysis revealed that the 4 patient groups were more closely related with each other than with other groups. Network analysis of the haplogroup O3a3c1-M117 showed a high degree of patient-specific substructure. We suggest that EC and GCC patients from these 2 areas share a similar patrilineal genetic background, which may play an important role in the genetic factor of EC and GCC in these populations.

  20. Numerical Modeling of Hydrodynamic and Sediment Siltation Due to Typhoon in Estuary Channel Regulation

    Directory of Open Access Journals (Sweden)

    Zhao Hongbo

    2015-09-01

    Full Text Available Oujiang Estuary is a complex tidal estuary with many channels and shoals in the East China Sea, which was affected by typhoon frequently. The navigation channel of Wenzhou Port is located in the north branch of Oujiang Estuary, which happened serious sediment siltation in many times due to typhoon impact. The regulation is considered to decrease siltaion of the channel and protect shoals as well. According to the site survey data, the mathematic model is established and validated, which simulates the hydrodynamic, sediment transport and channel siltation due to typhoon in Oujiang Estuary. The channel regulation scenario is studied by the model simulation after analysis of the silation character. It indicates that the high concentration sediment from shoals north of channel is main sediment source caused siltation in the channel, which can be prevented into the channel by the regulation scenario and decrease siltation efficiently.

  1. Dissolved organic matter (DOM) export to a temperate estuary: Seasonal variations and implications of land use

    DEFF Research Database (Denmark)

    Stedmon, C. A.; Markager, S.; Søndergaard, M.

    2006-01-01

    Inputs of dissolved carbon, nitrogen, and phosphorus were assessed for an estuary and its catchment (Horsens, Denmark). Seasonal patterns in the concentrations of DOM in the freshwater supply to the estuary differed depending on the soil and drainage characteristics of the area. In streams draining......, and the percentage of catchment area used for agriculture. Colored DOM (CDOM) loading measurements were found to be a good predictor of dissolved organic carbon (DOC) loading across the different subcatchments, offering a rapid and inexpensive alternative of operationally monitoring DOC export. For all the dissolved...... nutrient inputs to the estuary, dissolved inorganic nitrogen (DIN) and dissolved organic phosphorus dominated the loadings. Although 81% of the nitrogen annually supplied to the estuary was DIN, 83% of the nitrogen exported from the estuary was dissolved organic nitrogen (DON). Results show that increasing...

  2. Environmental Life Cycle Assessment of long-term organic rice production in a Subtropical area of China

    DEFF Research Database (Denmark)

    Xueqing, He; Qiao, Yuhui; Liang, Long

    2018-01-01

    conversion and compare it to conventional rice (CR) in subtropical China. The life cycle assessment (LCA) method was used to assess environmental impact of rice production systems with regard to nine environmental impact categories: Non-renewable Energy Depletion (NED), Water Depletion (WD), Land Occupation......Organic farming is considered as a promising solution for reducing the environmental burden related to agricultural practices. China is one of the top-five countries with the largest organic area in the world and produces a major part of the world's organic rice. Rice cultivation causes...... a considerable environmental impact and changing from conventional to organic rice cultivation might therefore have a potentially great impact. Meanwhile, it takes time for the organic farming systems to reach a new steady state after conversion to organic. Thus, the environmental profile of the organic products...

  3. Global patterns and predictors of fish species richness in estuaries.

    Science.gov (United States)

    Vasconcelos, Rita P; Henriques, Sofia; França, Susana; Pasquaud, Stéphanie; Cardoso, Inês; Laborde, Marina; Cabral, Henrique N

    2015-09-01

    1. Knowledge of global patterns of biodiversity and regulating variables is indispensable to develop predictive models. 2. The present study used predictive modelling approaches to investigate hypotheses that explain the variation in fish species richness between estuaries over a worldwide spatial extent. Ultimately, such models will allow assessment of future changes in ecosystem structure and function as a result of environmental changes. 3. A comprehensive worldwide data base was compiled of the fish assemblage composition and environmental characteristics of estuaries. Generalized Linear Models were used to quantify how variation in species richness among estuaries is related to historical events, energy dynamics and ecosystem characteristics, while controlling for sampling effects. 4. At the global extent, species richness differed among marine biogeographic realms and continents and increased with mean sea surface temperature, terrestrial net primary productivity and the stability of connectivity with a marine ecosystem (open vs. temporarily open estuaries). At a smaller extent (within a marine biogeographic realm or continent), other characteristics were also important in predicting variation in species richness, with species richness increasing with estuary area and continental shelf width. 5. The results suggest that species richness in an estuary is defined by predictors that are spatially hierarchical. Over the largest spatial extents, species richness is influenced by the broader distributions and habitat use patterns of marine and freshwater species that can colonize estuaries, which are in turn governed by history contingency, energy dynamics and productivity variables. Species richness is also influenced by more regional and local parameters that can further affect the process of community colonization in an estuary including the connectivity of the estuary with the adjacent marine habitat, and, over smaller spatial extents, the size of these

  4. Prevalence of Hypertension among Adults in Remote Rural Areas of Xinjiang, China

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    Yulin Wang

    2016-05-01

    Full Text Available Objective: The present study aimed to estimate prevalence of hypertension among adults in rural remote areas of Xinjiang, China and evaluate the associated factors of hypertension. Methods: The survey was based on questionnaire interviews and clinical measurements of 11,340 individuals (≥18 years old, and was conducted during 2009–2010 via a stratified cluster random sampling method in the remote rural areas of Xinjiang, about 4407 km away from the capital Beijing. Hypertension was defined according to WHO/ISH criteria. Results: Systolic blood pressure (SBP and diastolic blood pressure (DBP of the population were (126.3 ± 21.4 and (80.9 ± 13.4 mmHg. Compared with Han nationality subjects, SBP and DBP of Kazakh nationality subjects were significantly high (p < 0.05, while the SBP and DBP of Uyghur subjects were significantly low (Kazakh: (128.7 ± 23.9 and (83.0 ± 14.6 mmHg, Uyghur: (123.6 ± 19.3 and (77.4 ± 12.7 mmHg, Han: (126.5 ± 20.5 and (82.6 ± 11.9 mmHg, p < 0.05. Prevalence of hypertension of the population was 32.1%, and was greater among Kazakhs and lower among Uyghur than Han (Kazakh: 36.9%, Uyghur: 26.1%, Han: 33.7%, p < 0.05. The age-standardized prevalence of hypertension was 30.2%, and was greater among Kazakhs while lower among Uyghurs than Han subjects (Kazakh: 37.0%, Uyghur: 26.0%, Han: 33.8%, p < 0.05, p < 0.05. Multivariate logistic regression analyses showed Gender (OR = 1.324, age (OR = 2.098, 3.681, 6.794, 9.473, 14.646, nationality (OR = 1.541, occupation (OR = 1.659, 1.576, education (OR = 1.260, BMI (OR = 1.842, WC (OR = 1.585, WHR (OR = 1.188, WHR (OR = 1.188, diabetes (OR = 1.879, hypertriglyceridemia (OR = 1.361, hypercholesterolemia (OR = 1.131 and high blood low density lipoprotein cholesterol (LDL-C (OR = 1.956 were all positively correlated with hypertension, while low blood high density lipoprotein cholesterol (HDL-C (OR = 0.765 was negatively correlated with hypertension. Conclusions: Prevalence of

  5. Adaptive Effectiveness of Irrigated Area Expansion in Mitigating the Impacts of Climate Change on Crop Yields in Northern China

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    Tianyi Zhang

    2017-05-01

    Full Text Available To improve adaptive capacity and further strengthen the role of irrigation in mitigating climate change impacts, the Chinese government has planned to expand irrigated areas by 4.4% by the 2030s. Examining the adaptive potential of irrigated area expansion under climate change is therefore critical. Here, we assess the effects of irrigated area expansion on crop yields based on county-level data during 1980–2011 in northern China and estimate climate impacts under irrigated area scenarios in the 2030s. Based on regression analysis, there is a statistically significant effect of irrigated area expansion on reducing negative climate impacts. More irrigated areas indicate less heat and drought impacts. Irrigated area expansion will alleviate yield reduction by 0.7–0.8% in the future but associated yield benefits will still not compensate for greater adverse climate impacts. Yields are estimated to decrease by 4.0–6.5% under future climate conditions when an additional 4.4% of irrigated area is established, and no fundamental yield increase with an even further 10% or 15% expansion of irrigated area is predicted. This finding suggests that expected adverse climate change risks in the 2030s cannot be mitigated by expanding irrigated areas. A combination of this and other adaptation programs is needed to guarantee grain production under more serious drought stresses in the future.

  6. Analysis on Residents’ Travel Activity Pattern in Historic Urban Areas: A Case Study of Historic Urban Area of Yangzhou, China

    Directory of Open Access Journals (Sweden)

    Mao Ye

    2013-01-01

    Full Text Available Travel behaviors and activity patterns in the historic urban area of a city are expected to be different from the overall situations in the city area. The primary objective of this study is to analyze the residents’ travel activity patterns in historic urban area. Based on survey data conducted in the historic urban area of Yangzhou, the travel activities of local residents in a whole day were classified into five types of patterns. The multinomial logit (MNL model was developed to evaluate the impacts of explanatory variables on the choices of activity patterns. The results showed that the choice of activity pattern was significantly impacted by five contributing factors including the gender, age, occupation, car ownership, and number of electric bikes in household. The other variables, which were the family population, preschoolers, number of conventional bikes in household, motorcycle ownership, and income, were found to be not significantly related to the choice of activities. The results of this study from historic urban area were compared to findings of previous studies from overall urban area. The comparison showed that the impacts of factors on activity pattern in the historic urban area were different from those in the overall area. Findings of this study provide important suggestions for the policy makings to improve the traffic situations in historic urban areas of cities.

  7. Neoarchean ductile deformation in the Northeastern North China Craton: The Shuangshanzi ductile shear zone in Qinglong area, eastern Heibei, China

    Science.gov (United States)

    Liu, Boran; Neubauer, Franz; Liu, Junlai; Jin, Wei; Li, Weimin; Liang, Chenyue

    2017-04-01

    thus developed to accommodate the upward and downward movements. It is possible that such a tectonic model also applies to many Archean granite-greenstone terrains. Keywords: Neoarchean tectonics, North China Craton, Ductile shear zone, Structural and microstructural analysis, EBSD fabric analysis

  8. Distribution pattern and mass budget of sedimentary polycyclic aromatic hydrocarbons in shelf areas of the Eastern China Marginal Seas

    Science.gov (United States)

    Wang, C. L.; Zou, X. Q.; Zhao, Y. F.; Li, Y. L.; Song, Q. C.; Wang, T.; Yu, W. W.

    2017-06-01

    This study conducted the first extensive and comprehensive investigation of the regional-scale sedimentary polycyclic aromatic hydrocarbons (PAHs) concentration, flux, and budget in the continental shelves of the Eastern China Marginal Seas (ECMSs). Surface sediment samples from multiple sites were collected and assessed, and the latest data from current research were assessed. The spatial distribution pattern of PAHs in the ECMSs was significantly influenced by the regional hydrodynamics, sediment properties (grain-size, total organic carbon [TOC] content, and sedimentation rate), and anthropogenic impacts. Relatively higher PAHs concentrations occurred in areas with fine-grained sediment. Results of source apportionment found that the relative proportions of PAHs showed significant regional variation, mainly influenced by socioeconomic differences between north and south China. The PAHs burial flux in the study area ranged from 11.2 to 1308 ng cm-2 yr-1 with an average value of 101 ± 104 ng cm-2 yr-1. The area-integrated sedimentary PAHs burial flux across the ECMSs was 494 t yr-1. A mass budget calculation revealed that riverine input and atmospheric deposition were the most significant sources contributing, 28.4% and 71.6%, respectively. The study demonstrated that net PAHs transportation occurs between the Bohai Sea (BS) and Yellow Sea (YS), with a flux of approximately 10.2 t yr-1. PAHs were also transported from YS to the East China Sea (ECS), due to water exchange between the YS and ECS. Additionally, substantial amounts of PAHs in the inner shelf of the ECS were transported out of the shelf area due to cross-shelf plume.

  9. Soil quality degradation processes along a deforestation chronosequence in the Ziwuling Area, China

    Science.gov (United States)

    Accelerated erosion caused by deforestation and soil degradation has become the primary factor limiting sustainable utilization of soil resources on the Loess Plateau of Northwestern China. We studied the physical, chemical, and microbiological processes of soil degradation along a chronosequence o...

  10. Molecular survey of hard ticks in endemic areas of tick-borne diseases in China.

    Science.gov (United States)

    Lu, Xin; Lin, Xian-Dan; Wang, Jian-Bo; Qin, Xin-Cheng; Tian, Jun-Hua; Guo, Wen-Ping; Fan, Fei-Neng; Shao, Renfu; Xu, Jianguo; Zhang, Yong-Zhen

    2013-06-01

    Over the past several years, there was a substantial increase in the number of cases of known and novel tick-borne infections in humans in China. To better understand the ticks associated with these infections, we collected hard ticks from animals or around livestock shelters in 29 localities in 5 provinces (Beijing, Henan, Hubei, Inner Mongolia, and Zhejiang) where cases of tick-borne illness were reported. We collected 2950 hard ticks representing 7 species of 4 genera (Dermacentor sinicus, Haemaphysalis flava, Haemaphysalis longicornis, Ixodes granulatus, Ixodes persulcatus, Rhipicephalus microplus, and Rhipicephalus sanguineus). These ticks were identified to species using morphological characters initially. We then sequenced the mitochondrial small subunit rRNA (12S rRNA) gene, cytochrome oxidase subunit 1 (COI) gene, and the second internal transcribed spacer (ITS2) gene of these ticks, and conducted phylogenetic analyses. Our analyses showed that the molecular and morphological data are consistent in the identification of the 7 tick species. Furthermore, all these 7 tick species from China were genetically closely related to the same species or related species found outside China. Rapid and accurate identification and long-term monitoring of these ticks will be of significance to the prevention and control of tick-borne diseases in China. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Quartz in ash, and air in a high lung cancer incidence area in China

    NARCIS (Netherlands)

    Downward, George S|info:eu-repo/dai/nl/412435667; Hu, Wei; Rothman, Nat; Reiss, Boris|info:eu-repo/dai/nl/314119205; Tromp, Peter; Wu, Guoping; Wei, Fusheng; Xu, Jun; Seow, Wei Jie; Chapman, Robert S.; Lan, Qing; Vermeulen, Roel|info:eu-repo/dai/nl/216532620

    Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung

  12. Perchlorate in sewage sludge, rice, bottled water and milk collected from different areas in China.

    Science.gov (United States)

    Shi, Yali; Zhang, Ping; Wang, Yawei; Shi, Jianbo; Cai, Yaqi; Mou, Shifen; Jiang, Guibin

    2007-10-01

    As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography-electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56-379.9 microg/kg, 0.16-4.88 mug/kg, 0.037-2.013 microg/L and 0.30-9.1 microg/L, respectively. The results show that perchlorate has been widespread in China.

  13. The potential impact of invasive woody oil plants on protected areas in China under future climate conditions.

    Science.gov (United States)

    Dai, Guanghui; Yang, Jun; Lu, Siran; Huang, Conghong; Jin, Jing; Jiang, Peng; Yan, Pengbo

    2018-01-18

    Biodiesel produced from woody oil plants is considered a green substitute for fossil fuels. However, a potential negative impact of growing woody oil plants on a large scale is the introduction of highly invasive species into susceptible regions. In this study, we examined the potential invasion risk of woody oil plants in China's protected areas under future climate conditions. We simulated the current and future potential distributions of three invasive woody oil plants, Jatropha curcas, Ricinus communis, and Aleurites moluccana, under two climate change scenarios (RCP2.6 and RCP8.5) up to 2050 using species distribution models. Protected areas in China that will become susceptible to these species were then identified using a spatial overlay analysis. Our results showed that by 2050, 26 and 41 protected areas would be threatened by these invasive woody oil plants under scenarios RCP2.6 and RCP8.5, respectively. A total of 10 unique forest ecosystems and 17 rare plant species could be potentially affected. We recommend that the invasive potential of woody oil plants be fully accounted for when developing forest-based biodiesel, especially around protected areas.

  14. Variations of Near Surface Energy Balance Caused by Land Cover Changes in the Semiarid Grassland Area of China

    Directory of Open Access Journals (Sweden)

    Qun’ou Jiang

    2014-01-01

    Full Text Available This study applies the Dynamics of Land System (DLS model to simulating the land cover under the designed scenarios and then analyzes the effects of land cover conversion on energy flux in the semiarid grassland area of China with the Weather Research and Forecasting (WRF model. The results indicate that the grassland will show a steadily upgrowing trend under the coordinated environmental sustainability (CES scenario. Compared to the CES scenario, the rate of increase in grassland cover is lower, while the rate of increase in urban land cover will be higher under the rapid economic growth (REG scenario. Although the conversion from cropland to grassland will reduce the energy flux, the expansion of urban area and decreasing of forestry area will bring about more energy flux. As a whole, the energy flux of near surface will obviously not change under the CES scenario, and the climate therefore will not be possible to be influenced greatly by land cover change. The energy flux under the REG scenario is higher than that under the CES scenario. Those research conclusions can offer valuable information for the land use planning and climate change adaptation in the semiarid grassland area of China.

  15. Influence of black shales on soils and edible plants in the Ankang Area, Shanxi Province, P.R. of China

    Energy Technology Data Exchange (ETDEWEB)

    Fang, W.; Hu, R.; Wu, P. [Institute of Geochemistry, Chinese Academy of Sciences, Guiyang (China). Lab. of Ore Deposit Geochemistry (LODG)

    2002-03-01

    The Ankang black shales in China provides an important example of natural geological materials containing toxic elements. This paper presents the results of environmental geochemical research on black shales, soils, waters and edible plants in the Ankang areas, Shanxi Province of China. The study area lies in the northern margin of the Yangtze Platform; there are black shales which contains black shale, carbonaceous rocks and coal in the Cambrian Donghe Formation throughout the area. Mean trace element concentrations of the coal were high. Soils derived from these rocks tends to reflect their extreme geochemical composition. Chemical analysis of common plant species in the Ankang area showed a heterogeneous distribution of Se, Mo and V within the single and among plant species. Selenium was more concentrated in radish than in legumes, and in potato more than in green vegetable. High V concentrations were found in two kinds of Chinese tea. Legume had more Mo in the seed than potato, although Mo concentrations in radish vary. Higher concentrations of Se and Mo are present in the leaf of radish. 26 refs., 3 figs., 5 tabs.

  16. The status of fish conservation in South African estuaries.

    Science.gov (United States)

    Whitfield, A K; Cowley, P D

    2010-06-01

    Estuary-dependent fish species are defined as those taxa whose populations would be adversely affected by the loss of estuarine habitats. Of the 155 species regularly recorded in South African estuaries, only 32 (21%) are completely dependent on these systems, but this figure increases to 103 species (66%) if partially dependent taxa are included in the analysis. The conservation of fishes in estuaries on the subcontinent is threatened by a number of factors, including habitat degradation, disruption of essential ecological processes, hydrological manipulations, environmental pollution, overexploitation due to fishing activities and, more recently, climate change and the effects of introduced aquatic animals. Although major threats to fishes are usually linked to environmental degradation, there is increasing evidence that the stocks of certain fish species are overexploited or collapsed. Fish conservation and fisheries management does not depend on the implementation of a single action, but rather the co-ordination of a detailed plan, often in a multidisciplinary context. Some examples of innovative means of contributing to estuarine fish conservation in a South African context include the determination and implementation of the ecological freshwater requirements for estuaries, the zoning of estuaries for different uses and the recognition that the maintenance of ecological processes are vital to aquatic ecosystem health. Apart from the designation of protected areas, the main direct means of conserving fish species and stocks include habitat conservation, controls over fishing methods, effort, efficiency and seasonality, pollution control and the prevention of artificial manipulation of estuary mouths. Since becoming a democracy in 1994, environmental legislation, policy and institutional arrangements in South Africa have undergone some major changes, which, if fully implemented, will be very positive for fish conservation in estuaries on the subcontinent.

  17. [Research progress on remote sensing of ecological and environmental changes in the Three Gorges Reservoir area, China].

    Science.gov (United States)

    Teng, Ming-jun; Zeng, Li-xiong; Xiao, Wen-fa; Zhou, Zhi-xiang; Huang, Zhi-lin; Wang, Peng-cheng; Dian, Yuan-yong

    2014-12-01

    The Three Gorges Reservoir area (TGR area) , one of the most sensitive ecological zones in China, has dramatically changes in ecosystem configurations and services driven by the Three Gorges Engineering Project and its related human activities. Thus, understanding the dynamics of ecosystem configurations, ecological processes and ecosystem services is an attractive and critical issue to promote regional ecological security of the TGR area. The remote sensing of environment is a promising approach to the target and is thus increasingly applied to and ecosystem dynamics of the TGR area on mid- and macro-scales. However, current researches often showed controversial results in ecological and environmental changes in the TGR area due to the differences in remote sensing data, scale, and land-use/cover classification. Due to the complexity of ecological configurations and human activities, challenges still exist in the remote-sensing based research of ecological and environmental changes in the TGR area. The purpose of this review was to summarize the research advances in remote sensing of ecological and environmental changes in the TGR area. The status, challenges and trends of ecological and environmental remote-sensing in the TGR area were further discussed and concluded in the aspect of land-use/land-cover, vegetation dynamics, soil and water security, ecosystem services, ecosystem health and its management. The further researches on the remote sensing of ecological and environmental changes were proposed to improve the ecosystem management of the TGR area.

  18. Hydrothermal alteration of the Ediacaran Doushantuo Formation in the Yangtze Gorges area (South China)

    Science.gov (United States)

    Derkowski, Arkadiusz; Bristow, Thomas F.; Wampler, J. M.; Środoń, Jan; Marynowski, Leszek; Elliott, W. Crawford; Chamberlain, C. Page

    2013-04-01

    The geochemical and fossil record preserved in the Ediacaran age (635-551 Ma) Doushantuo Formation of South China has been extensively examined to explore the impact of changing climate and the oxidation state of the oceans on the development and distribution of early multicellular life. In the Yangtze Gorges area, this formation shows many of the geochemical trends and features thought to typify global ocean chemistry in the Ediacaran Period, but there are indications that post-sedimentary processes modified these signals. This study of clay minerals and organic matter builds a more detailed picture of the type and degree of post-sedimentary alteration at different stratigraphic levels of the formation and focuses on how this alteration influenced stable carbon and oxygen isotope records. In the cratonward Jiulongwan and Huajipo sections of the Doushantuo Formation, its lower part (Members 1 and 2) consists largely of dolomitic shale, rich in authigenic saponite that crystallized in an alkaline sedimentary basin. Saponite has been altered to chlorite via corrensite across tens of meters of strata in lower Member 2, with increased alteration downward toward the cap dolostone. The greater chloritization is accompanied by lower δ18O and higher δD values of trioctahedral clays. This pattern of alteration of trioctahedral clays is likely due to hydrothermal fluid activity in the underlying, relatively permeable Nantuo Formation and cap dolostone. A concomitant increase of solid bitumen reflectance toward the base of the formation supports this idea. In the uppermost part of the formation in the Yangtze Gorges area (Member 4), a typical open water marine dolomitic shale rich in illite and organic matter, increases in the methylphenanthrenes ratio index and solid bitumen reflectance correlate with decrease of the bulk rock K/Al ratio upward, providing evidence for hot fluid migration above the nearly impermeable shale. Clay from the upper part of the formation is

  19. Structural heterogeneities in the source area of the Mw 7.9 2008 Wenchuan Earthquake, China

    Science.gov (United States)

    Wang, Z.; Fukao, Y.; Pei, S.

    2008-12-01

    The Mw 7.9 Wenchuan Earthquake occurred on May 12, 2008 (06:28:01 UTC) in the Longmen-Shan fault zone at the eastern margin of Tibet and adjacent to the Sichuan foreland basin, where as much as 9 m of coseismic slip was observed. This is the most significant earthquake to have struck China since the 1976 Tangshan Earthquake (Mw 7.6). Chinese authorities estimated more than 69,000 people were killed and 374,176 injured. About 1,485,000 people were forced into temporary shelters (http://www.gov.cn). The coseismic faulting zone coincides roughly with this aftershock distribution. The extent of the great damage may have resulted from the variation of crustal structures along the tectonic thrust faulting and strike slipping zone, causing significant coseismic displacement and acceleration on a regional scale. For a better understanding of what may have triggered this earthquake and how the rupture proceeded after the initiation, we conducted an investigation of the seismic structure in the Wenchuan earthquake source area. A large number of arrival time data of P and Pn, S and Sn phases from local earthquakes were collected and inverted jointly for the three-dimensional P- and S-wave velocity (Vp and Vs) models. The Poisson's ratio model was then calculated from these velocity models. The overall patterns of Vp and Vs anomalies are similar to each other at any of these three depths. The Sichuan Basin is a distinct entity in tomographic images, anomalously slow at 13 km depth and anomalously fast at 20 km depth, in sharp contrast to the anomalies on the mountain side across the Longmen-Shan fault zone. The area of the fault zone is characterized in general by high Vp and Vs anomalies at a depth of 13 km, although a low Vp and Vs anomaly patch is present in the middle of a total fault length of 300 km. At depths around 20 km, low Vp and Vs anomalies dominate on the mountain side including its eastern margin, where the shallower (˜13 km) and deeper (˜30 km) depths are

  20. FLORA OF MOLOCHNYI ESTUARY COASTS

    Directory of Open Access Journals (Sweden)

    Kolomiychuk V.P.

    2013-09-01

    Full Text Available Present-day characteristic of the coastal flora of Molochnyi eastury is given, that is one of the largest estuaries in Ukraine, the shores and waters of which in 2009 became a part of the Pryazov’ya National Nature Park. The analysis of the main parameters of the flora is made. Rare component of the estuary coastal flora is characterized, further steps to conserve the nature of Pryazov’ya are proposed.

  1. Dynamic Assessment of Soil Erosion Risk Using Landsat TM and HJ Satellite Data in Danjiangkou Reservoir Area, China

    Directory of Open Access Journals (Sweden)

    Pengpeng Han

    2013-08-01

    Full Text Available Danjiangkou reservoir area is the main water source and the submerged area of the Middle Route South-to-North Water Transfer Project of China. Soil erosion is a factor that significantly influences the quality and transfer of water from the Danjiangkou reservoir. The objective of this study is to assess the water erosion (rill and sheet erosion risk and dynamic change trend of spatial distribution in erosion status and intensity between 2004 and 2010 in the Danjiangkou reservoir area using a multicriteria evaluation method.The multicriteria evaluation method synthesizes the vegetation fraction cover, slope gradient, and land use. Based on the rules and erosion risk assessment results of the study area in 2004 and 2010, the research obtained the conservation priority map. This study result shows an improvement in erosion status of the study area, the eroded area decreased from 32.1% in 2004 to 25.43% in 2010. The unchanged regions dominated the study area and that the total area of improvement grade erosion was larger than that of deterioration grade erosion. The severe, more severe, and extremely severe areas decreased by 4.71%, 2.28%, and 0.61% of the total study area, respectively. The percentages of regions where erosion grade transformed from extremely severe to slight, light and moderate were 0.18%, 0.02%, and 0.30%, respectively. However, a deteriorated region with a 2,897.60 km2 area was still observed. This area cannot be ignored in the determination of a general governance scheme. The top two conservation priority levels cover almost all regions with severe erosion and prominent increase in erosion risk, accounting for 7.31% of the study area. The study results can assist government agencies in decision making for determining erosion control areas, starting regulation projects, and making soil conservation measures.

  2. Goitre and urinary iodine in coastal and inland areas with low and high iodized salt coverage in Zhejiang province, China.

    Science.gov (United States)

    Mo, Zhe; Wang, Xiao F; Mao, Guang M; Zhu, Wen M; Xu, Pei W; Zou, Yan; Wang, Yuan Y; Lou, Xiao M

    WHO recommended that iodized salt are more than 90% of households in USI programs, which may not be suitable for all regions, especially in coastal areas. This study intended to find out levels of iodine nutrition and give advice from the USI programs for areas with different iodized salt coverage. Coastal and inland areas were selected according to geographical regions in Zhejiang Province, China. The water iodine concentration (spectrophotometer analysis), salt iodine concentration (the colorimetric titration method), salt intake, urinary iodine concentration (spectrophotometer analysis), and thyroid volume examination (ultrasonography), as well as questionnaire, were measured in the two areas. Mean Urinary Iodine concentration (MUIs) of children in coastal areas was 149 μg/L, which was significantly lower than that in inland areas (191 μg/L). MUIs of pregnant women in coastal and inland areas were111 and 138 μg/L, respectively. Pregnant women who consumed iodine-containing supplements had higher MUIs (207 μg/L) than those did not (134 μg/L) in inland areas. Prevalence of goitre in children reached 7.0% and 6.6% in coastal and inland areas, respectively. The lowest prevalence of goitre was reached when the urinary iodine concentration was approximately 120-160 μg/L in coastal areas. Iodine levels of coastal and inland areas were in the adequate range. Advice from the USI program should be specialized for different areas to appropriately reduce the salt iodine concentrations in inland areas and to determine an appropriate proportion of households using iodized salt in coastal areas. Moreover, iodine supplement intake during pregnancy should officially be recommended.

  3. Evaluation of multiple forcing data sets for precipitation and shortwave radiation over major land areas of China

    Science.gov (United States)

    Yang, Fan; Lu, Hui; Yang, Kun; He, Jie; Wang, Wei; Wright, Jonathon S.; Li, Chengwei; Han, Menglei; Li, Yishan

    2017-11-01

    Precipitation and shortwave radiation play important roles in climatic, hydrological and biogeochemical cycles. Several global and regional forcing data sets currently provide historical estimates of these two variables over China, including the Global Land Data Assimilation System (GLDAS), the China Meteorological Administration (CMA) Land Data Assimilation System (CLDAS) and the China Meteorological Forcing Dataset (CMFD). The CN05.1 precipitation data set, a gridded analysis based on CMA gauge observations, also provides high-resolution historical precipitation data for China. In this study, we present an intercomparison of precipitation and shortwave radiation data from CN05.1, CMFD, CLDAS and GLDAS during 2008-2014. We also validate all four data sets against independent ground station observations. All four forcing data sets capture the spatial distribution of precipitation over major land areas of China, although CLDAS indicates smaller annual-mean precipitation amounts than CN05.1, CMFD or GLDAS. Time series of precipitation anomalies are largely consistent among the data sets, except for a sudden decrease in CMFD after August 2014. All forcing data indicate greater temporal variations relative to the mean in dry regions than in wet regions. Validation against independent precipitation observations provided by the Ministry of Water Resources (MWR) in the middle and lower reaches of the Yangtze River indicates that CLDAS provides the most realistic estimates of spatiotemporal variability in precipitation in this region. CMFD also performs well with respect to annual mean precipitation, while GLDAS fails to accurately capture much of the spatiotemporal variability and CN05.1 contains significant high biases relative to the MWR observations. Estimates of shortwave radiation from CMFD are largely consistent with station observations, while CLDAS and GLDAS greatly overestimate shortwave radiation. All three forcing data sets capture the key features of the

  4. Comparison of the Spatial Characteristics of Four Remotely Sensed Leaf Area Index Products over China: Direct Validation and Relative Uncertainties

    Directory of Open Access Journals (Sweden)

    Xinlu Li

    2018-01-01

    Full Text Available Leaf area index (LAI is a key input for many land surface models, ecological models, and yield prediction models. In order to make the model simulation and/or prediction more reliable and applicable, it is crucial to know the characteristics and uncertainties of remotely sensed LAI products before they are input into models. In this study, we conducted a comparison of four global remotely sensed LAI products—Global Land Surface Satellite (GLASS, Global LAI Product of Beijing Normal University (GLOBALBNU, Global LAI Map of Chinese Academy of Sciences (GLOBMAP, and Moderate-resolution Imaging Spectrometer (MODIS LAI, while the former three products are newly developed by three Chinese research groups on the basis of the MODIS land reflectance product over China between 2001 and 2011. Direct validation by comparing the four products to ground LAI observations both globally and over China demonstrates that GLASS LAI shows the best performance, with R2 = 0.70 and RMSE = 0.96 globally and R2 = 0.94 and RMSE = 0.61 over China; MODIS performs worst (R2 = 0.55, RMSE = 1.23 globally and R2 = 0.03, RMSE = 2.12 over China, and GLOBALBNU and GLOBMAP performs moderately. Comparison of the four products shows that they are generally consistent with each other, giving the smallest spatial correlation coefficient of 0.7 and the relative standard deviation around the order of 0.3. Compared with MODIS LAI, GLOBALBNU LAI is the most similar, followed by GLASS LAI and GLOBMAP. Large differences mainly occur in southern regions of China. LAI difference analysis indicates that evergreen needleleaf forest (ENF, woody savannas (SAV biome types and temperate dry hot summer, temperate warm summer dry winter and temperate hot summer no dry season climate types correspond to high standard deviation, while ENF and grassland (GRA biome types and temperate warm summer dry winter and cold dry winter warm summer climate types are responsible for the large relative standard

  5. The disagreement between BSRS and the base of methane hydrate stability zones, in Shenhu area, north of South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; He, L.; Wang, J. [Chinese Academy of Sciences, Beijing (China). Inst. of Geology and Geophysics

    2008-07-01

    Gas hydrate is an ice-like solid material that forms when natural gas is in contact with liquid water or ice under high pressure and low temperature. Gas hydrates occur in oceanic sediments and permafrost regions around the world. Release of methane hydrate into the atmosphere can cause environmental problems and pose a geological hazard. Methane hydrates can also be a potential energy resource. In the South China Sea, successful drilling and recovery of methane hydrate samples have proved that methane hydrate deposits are in existence in the northern South China Sea. The methane hydrate stability zone (HSZ), where the methane hydrate can form or exist stably in the sediments is mainly controlled by the temperature and the pressure conditions. When the temperature and pressure conditions are known, the depth of the base of the methane hydrate stability zone can be obtained. This paper presented a study that compared the bottom simulating reflector (BSR) depth and base of methane hydrate stability zone (BHSZ) in the Shenhu area, north of South China Sea. The paper defined BSRs and BHSZs and provided a comparison between the two. The paper also presented the results and discussion of results including origin of errors. It was concluded that there were greater differences between them than in other places world wide. These differences demonstrated regular spatial distribution and relationship with sedimentation rates and basement topography. The possible reason for the differences in regular spatial distribution was related to the geological setting. 9 refs., 4 figs.

  6. Household, Personal and Environmental Correlates of Rural Elderly’s Cycling Activity: Evidence from Zhongshan Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2014-06-01

    Full Text Available Cycling is an important form of active transport and physical activity to provide substantial health benefits to the elderly. Among voluminous physical activity-related literature, few studies have investigated the correlates of active transport of the rural elderly in China. This study was the first attempt to investigate the impact of the household, personal, and environmental attributes on rural elderly’s cycling activity with data collected in 102 rural neighborhoods of Zhongshan Metropolitan Area, China. The negative binomial regression models suggest that, all else being equal, living in a neighborhood with low proportion of elderly population (over 60, abundant bike lanes, and a compact urban form related to high density and mixed development, are associated with the increase of frequency and duration of the rural elderly’s cycling trips. The models also detect that attitude towards cycling and household bicycle and motorized vehicle ownership are strongly related to cycling trips of the rural elderly in Zhongshan. The findings provide insights for transportation and public health agencies, practitioners, and researchers into the effective design of interventions from the prospective of attitudes, social and built environment on health promotion of the rural elderly in China.

  7. Who Will Use Pre-Trip Traveler Information and How Will They Respond? Insights from Zhongshan Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2015-05-01

    Full Text Available The Intelligent Transportation System (ITS is able to make the transportation system safer, smoother, and more sustainable. The research and practice of pre-trip traveler information (PTI, an indispensable component of ITS, is very limited in China. With data collected from Zhongshan Metropolitan Area, China, this empirical study revealed the socio-demographics of potential PTI users and feasible travel responses in daily trips under PTI. Young-and-middle-aged, influential, and motorized males were the most potential PTI users, while unemployed young females the least. Among the motorized potential users who habitually traveled by car, the high-income sub-group was least likely to shift travel modes under PTI. The younger white-collar or blue-collar had a lower propensity to shift to bicycle, but the younger blue-collar workers were more likely to shift to walking. The low income preferred to shift to bus rather than elevated light rail due to the difference of travel cost. The findings will facilitate our understanding of the market segments and effects of PTI, improve the system design and implementation strategy, and help address urban traffic and environmental issues throughout China.

  8. Early diagenesis and authigenic mineral formation in mobile muds of the Changjiang Estuary and adjacent shelf

    Science.gov (United States)

    Zhao, Bin; Yao, Peng; Bianchi, Thomas S.; Xu, Yahong; Liu, Hui; Mi, Tiezhu; Zhang, Xiao-Hua; Liu, Jiwen; Yu, Zhigang

    2017-08-01

    Large-river delta-front estuaries (LDEs) and their adjacent shelf margins are sites of dynamic diagenetic processes that play a significant role in coastal biogeochemical cycling. In this study, we used dissolved inorganic carbon (DIC), redox sensitive elements (Fe2 + and Mn2 +), dissolved inorganic nitrogen (DIN) nutrients (NH4+, NO3-, and NO2-), major cations and anions (K+, Ca2 +, Mg2 +, SO42 -, and Cl-) in bottom-water and sediment pore-waters, to investigate the early chemical diagenesis and authigenic mineral formation in mobile-mud deposits of the Changjiang Estuary and adjacent inner shelf of the East China Sea (ECS). Vertical profiles of DIC and NH4+ in pore-waters had similar trends at most sites, showing a significant increase with depth near the Changjiang Estuary and being relatively constant at offshore sites. Higher pore-water DIC and NH4+ concentrations were observed in nearshore sites in winter, which were likely attributed to exposure of deeper deposits by winter coastal erosion. Nitrification was observed at most sites, and AOB (ammonia-oxidizing bacteria) played a leading role in ammonia oxidation in the study areas. The nitrification-denitrification was likely important in contributing to the loss of DIN in offshore sites during summer. Large inputs of organic carbon (OC) and terrestrial materials from Changjiang River resulted in intense sulfate reduction and Fe and Mn reduction in nearshore sites. Lower C/N and C/S ratios coupled with an apparent decrease in pore-water Ca2 + and Mg2+ concentrations with depth near the Changjiang Estuary, which indicated that authigenic carbonate formation occurs in these sediments. Decreases in K+ and Mg2 + with depth reflected that reverse weathering was an important process of authigenic mineral formation in these sediments. We conclude that adsorption process, seasonal erosion-redeposition, and summer hypoxic conditions of bottom-waters may play an important role in early diagenesis processes and

  9. Empowering village doctors and enhancing rural healthcare using cloud computing in a rural area of mainland China.

    Science.gov (United States)

    Lin, Che-Wei; Abdul, Shabbir Syed; Clinciu, Daniel L; Scholl, Jeremiah; Jin, Xiangdong; Lu, Haifei; Chen, Steve S; Iqbal, Usman; Heineck, Maxwell J; Li, Yu-Chuan

    2014-02-01

    China's healthcare system often struggles to meet the needs of its 900 million people living in rural areas due to major challenges in preventive medicine and management of chronic diseases. Here we address some of these challenges by equipping village doctors (ViDs) with Health Information Technology and developing an electronic health record (EHR) system which collects individual patient information electronically to aid with implementation of chronic disease management programs. An EHR system based on a cloud-computing architecture was developed and deployed in Xilingol county of Inner Mongolia using various computing resources (hardware and software) to deliver services over the health network using Internet when available. The system supports the work at all levels of the healthcare system, including the work of ViDs in rural areas. An analysis done on 291,087 EHRs created from November 2008 to June 2011 evaluated the impact the EHR system has on preventive medicine and chronic disease management programs in rural China. From 2008 to 2011 health records were created for 291,087 (26.25%) from 1,108,951 total Xilingol residents with 10,240 cases of hypertension and 1152 cases of diabetes diagnosed and registered. Furthermore, 2945 hypertensive and 305 diabetic patients enrolled in follow-up. Implementing the EHR system revealed a high rate of cholecystectomies leading to investigations and findings of drinking water contaminated with metals. Measures were taken to inform the population and clean drinking water was supplied. The cloud-based EHR approach improved the care provision for ViDs in rural China and increased the efficiency of the healthcare system to monitor the health status of the population and to manage preventive care efforts. It also helped discover contaminated water in one of the project areas revealing further benefits if the system is expanded and improved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Evaluation and simulation of nitrogen mineralization of paddy soils in Mollisols area of Northeast China under waterlogged incubation.

    Science.gov (United States)

    Zhang, Yuling; Xu, Wenjing; Duan, Pengpeng; Cong, Yaohui; An, Tingting; Yu, Na; Zou, Hongtao; Dang, Xiuli; An, Jing; Fan, Qingfeng; Zhang, Yulong

    2017-01-01

    Understanding the nitrogen (N) mineralization process and applying appropriate model simulation are key factors in evaluating N mineralization. However, there are few studies of the N mineralization characteristics of paddy soils in Mollisols area of Northeast China. The soils were sampled from the counties of Qingan and Huachuan, which were located in Mollisols area of Northeast China. The sample soil was incubated under waterlogged at 30°C in a controlled temperature cabinet for 161 days (a 2: 1 water: soil ratio was maintained during incubation). Three models, i.e. the single first-order kinetics model, the double first-order kinetics model and the mixed first-order and zero-order kinetics model were used to simulate the cumulative mineralised N (NH4+-N and TSN) in the laboratory and waterlogged incubation. During 161 days of waterlogged incubation, the average cumulative total soluble N (TSN), ammonium N (NH4+-N), and soluble organic N (SON) was 122.2 mg kg-1, 85.9 mg kg-1, and 36.3 mg kg-1, respectively. Cumulative NH4+-N was significantly (P 0.05) correlated with C/N ratio, cation exchange capacity (CEC), extractable iron (Fe), clay, and sand. When the cumulative NH4+-N and TSN were simulated, the single first-order kinetics model provided the least accurate simulation. The parameter of the double first-order kinetics model also did not represent the actual data well, but the mixed first-order and zero-order kinetics model provided the most accurate simulation, as demonstrated by the estimated standard error, F statistic values, parameter accuracy, and fitting effect. Overall, the results showed that SON was involved with N mineralization process, and the mixed first-order and zero-order kinetics model accurately simulates the N mineralization process of paddy soil in Mollisols area of Northeast China under waterlogged incubation.

  11. Assessment of iodine status in children, adults, pregnant women and lactating women in iodine-replete areas of China.

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    Fangang Meng

    Full Text Available BACKGROUND: Iodine deficiency disorders (IDD are widespread in China. Presently, IDD have been put under control by Universal Salt Iodisation (USI in China; however, there is a lack of evidence on whether the iodine status in adults, pregnant women and lactating women is optimal. This study was therefore conducted to assess the iodine nutrition and thyroid function of children, adults, pregnant women and lactating women residing in areas where the USI program is fully established. DESIGN: Six areas were selected according to the geographical regions in China. In each of these areas, we selected 4 distinct groups of subjects (children, adults, pregnant women and lactating women in regions where the coverage rate of iodised salt was more than 95% and the levels of iodine and fluoride in drinking water were less than or equal to 10 µg/L and 1 mg/L, respectively. We tested the iodine content of salt, urinary iodine (UI, free thyroxin (FT4, thyrotropin (TSH, thyroglobulin (Tg, thyroglobulin antibody (Tg-Ab and antimicrosomal antibody (TM-Ab in the 4 groups, and examined the thyroid volume in children. RESULTS: The median urinary iodine (MUI concentrations were 271.4 μg/L, 260.2 μg/L, 205.9 μg/L and 193.9 μg/L in children, adults, pregnant women and lactating women, respectively; MUI in children and adults were more than adequate. The goitre prevalence (GP in children was 6.70%. The odds ratios (OR of subclinical hypothyroidism in the Tg-Ab- or TM-Ab-positive groups were 3.80, 7.65, 2.01 and 7.47 for children, adults, pregnant women and lactating women, respectively, compared with the negative groups. CONCLUSIONS: The iodine status in children and adults is above the requirement, we should reduce their iodine intake. Subclinical hypothyroidism easily occurs in the Tg-Ab or TM-Ab positive groups.

  12. Evaluation and simulation of nitrogen mineralization of paddy soils in Mollisols area of Northeast China under waterlogged incubation.

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    Yuling Zhang

    Full Text Available Understanding the nitrogen (N mineralization process and applying appropriate model simulation are key factors in evaluating N mineralization. However, there are few studies of the N mineralization characteristics of paddy soils in Mollisols area of Northeast China.The soils were sampled from the counties of Qingan and Huachuan, which were located in Mollisols area of Northeast China. The sample soil was incubated under waterlogged at 30°C in a controlled temperature cabinet for 161 days (a 2: 1 water: soil ratio was maintained during incubation. Three models, i.e. the single first-order kinetics model, the double first-order kinetics model and the mixed first-order and zero-order kinetics model were used to simulate the cumulative mineralised N (NH4+-N and TSN in the laboratory and waterlogged incubation.During 161 days of waterlogged incubation, the average cumulative total soluble N (TSN, ammonium N (NH4+-N, and soluble organic N (SON was 122.2 mg kg-1, 85.9 mg kg-1, and 36.3 mg kg-1, respectively. Cumulative NH4+-N was significantly (P 0.05 correlated with C/N ratio, cation exchange capacity (CEC, extractable iron (Fe, clay, and sand. When the cumulative NH4+-N and TSN were simulated, the single first-order kinetics model provided the least accurate simulation. The parameter of the double first-order kinetics model also did not represent the actual data well, but the mixed first-order and zero-order kinetics model provided the most accurate simulation, as demonstrated by the estimated standard error, F statistic values, parameter accuracy, and fitting effect.Overall, the results showed that SON was involved with N mineralization process, and the mixed first-order and zero-order kinetics model accurately simulates the N mineralization process of paddy soil in Mollisols area of Northeast China under waterlogged incubation.

  13. Evaluation and simulation of nitrogen mineralization of paddy soils in Mollisols area of Northeast China under waterlogged incubation

    Science.gov (United States)

    Zhang, Yuling; Xu, Wenjing; Duan, Pengpeng; Cong, Yaohui; An, Tingting; Yu, Na; Zou, Hongtao; Dang, Xiuli; An, Jing; Fan, Qingfeng; Zhang, Yulong

    2017-01-01

    Background Understanding the nitrogen (N) mineralization process and applying appropriate model simulation are key factors in evaluating N mineralization. However, there are few studies of the N mineralization characteristics of paddy soils in Mollisols area of Northeast China. Materials and methods The soils were sampled from the counties of Qingan and Huachuan, which were located in Mollisols area of Northeast China. The sample soil was incubated under waterlogged at 30°C in a controlled temperature cabinet for 161 days (a 2: 1 water: soil ratio was maintained during incubation). Three models, i.e. the single first-order kinetics model, the double first-order kinetics model and the mixed first-order and zero-order kinetics model were used to simulate the cumulative mineralised N (NH4+-N and TSN) in the laboratory and waterlogged incubation. Principal results During 161 days of waterlogged incubation, the average cumulative total soluble N (TSN), ammonium N (NH4+-N), and soluble organic N (SON) was 122.2 mg kg-1, 85.9 mg kg-1, and 36.3 mg kg-1, respectively. Cumulative NH4+-N was significantly (P 0.05) correlated with C/N ratio, cation exchange capacity (CEC), extractable iron (Fe), clay, and sand. When the cumulative NH4+-N and TSN were simulated, the single first-order kinetics model provided the least accurate simulation. The parameter of the double first-order kinetics model also did not represent the actual data well, but the mixed first-order and zero-order kinetics model provided the most accurate simulation, as demonstrated by the estimated standard error, F statistic values, parameter accuracy, and fitting effect. Conclusions Overall, the results showed that SON was involved with N mineralization process, and the mixed first-order and zero-order kinetics model accurately simulates the N mineralization process of paddy soil in Mollisols area of Northeast China under waterlogged incubation. PMID:28170409

  14. Long-term monitoring of atmospheric total gaseous mercury (TGM) at a remote site in Mt. Changbai area, northeastern China

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    Fu, X. W.; Feng, X.; Shang, L. H.; Wang, S. F.; Zhang, H.

    2012-02-01

    Total gaseous mercury (TGM) was continuously monitored at a remote site (CBS) in the Mt. Changbai area, northeastern China biennially from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60 ± 0.51 ng m-3, which is lower than those reported from remote sites in eastern, southwestern and western China, indicating a relatively low regional anthropogenic mercury (Hg) emission intensity in northeastern China. Measurements at a site in the vicinity (~1.2 km) of the CBS station during August 2005 and July 2006 showed a significantly higher mean TGM concentration of 3.58 ± 1.78 ng m-3. The divergent result was partially attributed to fluctuations in the regional surface wind system and moreover an effect of local emission sources. The temporal variation of TGM at CBS was obviously influenced by regional sources as well as long-range transported Hg. Regional sources, frequently contributing to episodical high TGM concentrations, were pinpointed as a large iron mining district in northern North Korea and two large power plants and urban areas to the southwest of the sampling site. Source areas in Beijing, Tianjin, southern Liaoning, Hebei, northwestern Shanxi and northwestern Shandong were found to contribute to elevated TGM observations at CBS via long-range transport. The diurnal pattern of TGM at CBS was mainly regulated by regional sources, likely as well as intrusion of air masses from the free troposphere during summer season. There are no discernible seasonal pattern of TGM at CBS, which mainly showed links with the patterns of regional air movements and long-range transport.

  15. Two years of measurements of atmospheric total gaseous mercury (TGM at a remote site in Mt. Changbai area, Northeastern China

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    X. W. Fu

    2012-05-01

    Full Text Available Total gaseous mercury (TGM was continuously monitored at a remote site (CBS in Mt. Changbai area, Northeastern China from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60±0.51 ng m−3, which is lower than those reported from remote sites in Eastern, Southwestern, and Western China, indicating a relatively lower regional anthropogenic mercury (Hg emission intensity in Northeastern China. Measurements at a site in the vicinity (~1.2 km of CBS station from August 2005 to July 2006 showed a significantly higher mean TGM concentration of 3.58±1.78 ng m−3. The divergent result was partially attributed to fluctuations in the relatively frequencies of surface winds during the two study periods and moreover an effect of local emission sources. The temporal variation of TGM at CBS was influenced by regional sources as well as long-range transported Hg. Regional sources frequently contributing to episodical high TGM concentrations were pin-pointed as a large iron mining district in Northern North Korea and two large power plants and urban areas to the southwest of the sampling site. Source areas in Beijing, Tianjin, southern Liaoning, Hebei, northwestern Shanxi, and northwestern Shandong were found to contribute to elevated TGM observations at CBS via long-range transport. Diurnal pattern of TGM at CBS was mainly controlled by regional sources, likely as well as intrusion of air masses from the free troposphere during summer season. There are no consistent seasonal pattern of TGM at CBS, and the monthly TGM variations showed links with the patterns of regional air movements and long-range transport.

  16. Two years of measurements of atmospheric total gaseous mercury (TGM) at a remote site in Mt. Changbai area, Northeastern China

    Science.gov (United States)

    Fu, X. W.; Feng, X.; Shang, L. H.; Wang, S. F.; Zhang, H.

    2012-05-01

    Total gaseous mercury (TGM) was continuously monitored at a remote site (CBS) in Mt. Changbai area, Northeastern China from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60±0.51 ng m-3, which is lower than those reported from remote sites in Eastern, Southwestern, and Western China, indicating a relatively lower regional anthropogenic mercury (Hg) emission intensity in Northeastern China. Measurements at a site in the vicinity (~1.2 km) of CBS station from August 2005 to July 2006 showed a significantly higher mean TGM concentration of 3.58±1.78 ng m-3. The divergent result was partially attributed to fluctuations in the relatively frequencies of surface winds during the two study periods and moreover an effect of local emission sources. The temporal variation of TGM at CBS was influenced by regional sources as well as long-range transported Hg. Regional sources frequently contributing to episodical high TGM concentrations were pin-pointed as a large iron mining district in Northern North Korea and two large power plants and urban areas to the southwest of the sampling site. Source areas in Beijing, Tianjin, southern Liaoning, Hebei, northwestern Shanxi, and northwestern Shandong were found to contribute to elevated TGM observations at CBS via long-range transport. Diurnal pattern of TGM at CBS was mainly controlled by regional sources, likely as well as intrusion of air masses from the free troposphere during summer season. There are no consistent seasonal pattern of TGM at CBS, and the monthly TGM variations showed links with the patterns of regional air movements and long-range transport.

  17. Relict Mountain Permafrost Area (Loess Plateau, China) Exhibits High Ecosystem Respiration Rates and Accelerating Rates in Response to Warming

    Science.gov (United States)

    Mu, Cuicui; Wu, Xiaodong; Zhao, Qian; Smoak, Joseph M.; Yang, Yulong; Hu, Lian; Zhong, Wen; Liu, Guimin; Xu, Haiyan; Zhang, Tingjun

    2017-10-01

    Relict permafrost regions are characterized by thin permafrost and relatively high temperatures. Understanding the ecosystem respiration rate (ERR) and its relationship with soil hydrothermal conditions in these areas can provide knowledge regarding the permafrost carbon cycle in a warming world. In this study, we examined a permafrost area, a boundary area, and a seasonally frozen ground area within a relict permafrost region on the east edge of the Qinghai-Tibetan Plateau, China. Measurements from July 2015 to September 2016 showed that the mean annual ecosystem CO2 emissions for the boundary area were greater than the permafrost area. The Q10 value of the ERRs in the seasonally frozen ground area was greater than the permafrost area, indicating that the carbon emissions in the nonpermafrost areas were more sensitive to warming. The 1 year open-top chamber (OTC) warming increased soil temperatures in both the permafrost and seasonally frozen ground areas throughout the year, and the warming increased the ERRs by 1.18 (0.99-1.38, with interquartile range) and 1.13 (0.75-1.54, with interquartile range) μmol CO2 m-2 s-1 in permafrost and seasonally frozen ground areas, respectively. The OTC warming increased annual ERRs by approximately 50% for both permafrost and seasonally frozen ground areas with half the increase occurring during the nongrowing seasons. These results suggest that the ERRs in relict permafrost are high in comparison with arctic regions, and the carbon balance in relict permafrost areas could be greatly changed by climate warming.

  18. Feasibility Study on the Promotion and Application of Straw Bale House in Northern Rural Areas in China

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    Li Xiaoming

    2016-01-01

    Full Text Available With the accelerated pace of new rural areas construction in northern China, people have a higher requirements in terms of houses’ quality and function. At the same time, the backward construction methods and developing with the wind blindly has also led to a rapid growth in resource consumption. In order to better meet the requirements of hot comfort, energy saving and environmental protection properties of rural houses in northern areas. Based on the research methods including investigation, mathematical statistics, documentation, and logical analysis, combining with the residential problems in northern rural areas, and the superiority of straw bale house, and the favorable conditions for straw bale buildings. This article identified the feasibility of straw bale housing construction in the northern countryside, and draw the conclusion that the excellent economy, simple construction methods and good energy efficiency of straw bale house will be accepted by the majority of farmers friend.

  19. Case-control study of anaemia among middle-aged and elderly women in three rural areas of China.

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    Song, Pengkun; Li, Lixiang; Man, Qingqing; Wang, Chunrong; Meng, Liping; Zhang, Jian

    2014-08-18

    To propose a feasible suggestion to reduce the high prevalence of anaemia in middle-aged and elderly women by investigating risk factors, particularly nutritional factors, and analysing the effect on anaemia in three different rural areas of China. A case-control study. Three counties of China. Women aged 50-75 years in the three counties. Adjusted OR (95% CI) of anaemia associated with diet, lifestyle and blood biochemical indices. Compared with controls, women with anaemia had lower body mass index (22.1 (3.2) kg/m(2) vs 23.2 (3.5) kg/m(2); pAnaemia was significantly associated with BMI(OR=0.90, 95% CI (0.87 to 0.92)), food shortage experience (OR=1.39, 95% CI (1.15 to 1.69)), total protein (OR=0.66, 95%CI (0.54 to 0.80)), Albumin (OR=0.72, 95%CI (0.59 to 0.87)) in univariate analysis. Multivariate analysis showed that body mass index, experience of food shortage, total protein and albumin were independently related to anaemia. Among middle-aged and elderly women in rural China, the nutrition status of anaemic cases is far below that of controls. Lower body mass index and a greater experience of food shortage are closely related to anaemia. Improving the blood protein status by consuming protein-sufficient foods such as soy food is a feasible approach for elderly anaemic women. Further research is needed on the effect of chronic inflammation and infectious disease on anaemia in elderly women in rural China. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. The gender gap among school children in poor rural areas of western China: evidence from a multi-province dataset.

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    Zhou, Hua; Mo, Di; Zhou, Chengchao; Medina, Alexis; Shi, Yaojiang; Zhang, Linxiu; Rozelle, Scott

    2016-09-29

    The gender gap remains a major impediment in the path towards equality and it is especially wide in low-income countries. Up to the early 2000s, many studies documented extensive inequalities in China: girls had poorer health, less nutrition and less education than their male counterparts. The goal of this study is to examine whether the gender gap persists, given that China is now making the transition into the ranks of upper-middle income countries. We consider educational outcomes, mental and physical health status, as well as non-cognitive outcomes. We draw on a dataset containing 69,565 observations constructed by combining data from 7 different school-level surveys spanning 5 provinces. The surveys were all conducted by the authors between 2008 and 2013 using uniform survey instruments and data collection protocols in randomly selected schools across western provinces in rural China. The sample children range in age from 9 to 14 years (with 79 % of the sample being aged 10 to 12). Our analysis compares rural girls with rural boys in terms of 13 different indicators. With the exception of anemia rates, the health outcomes of girls are equal to those of boys. Girls and boys are statistically identical in terms of weight-for-age, height-for-age, and prevalence of intestinal worm infections. Girls performed better than boys on five of six cognitive and educational performance indicators. Girls performed worse than boys on all mental health indicators. All estimates are robust to the inclusion of different age ranges, controlling for the level of household assets, ethnic minority status, as well as the addition of provincial dummies. Our findings suggest that with the exception of non-cognitive outcomes, anemia and standardized math test scores, the gender gap in our study areas in China appears to be diminishing.

  1. Characterizing Urban Household Waste Generation and Metabolism Considering Community Stratification in a Rapid Urbanizing Area of China.

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    Lishan Xiao

    Full Text Available The relationship between social stratification and municipal solid waste generation remains uncertain under current rapid urbanization. Based on a multi-object spatial sampling technique, we selected 191 households in a rapidly urbanizing area of Xiamen, China. The selected communities were classified into three types: work-unit, transitional, and commercial communities in the context of housing policy reform in China. Field survey data were used to characterize household waste generation patterns considering community stratification. Our results revealed a disparity in waste generation profiles among different households. The three community types differed with respect to family income, living area, religious affiliation, and homeowner occupation. Income, family structure, and lifestyle caused significant differences in waste generation among work-unit, transitional, and commercial communities, respectively. Urban waste generation patterns are expected to evolve due to accelerating urbanization and associated community transition. A multi-scale integrated analysis of societal and ecosystem metabolism approach was applied to waste metabolism linking it to particular socioeconomic conditions that influence material flows and their evolution. Waste metabolism, both pace and density, was highest for family structure driven patterns, followed by lifestyle and income driven. The results will guide community-specific management policies in rapidly urbanizing areas.

  2. Characterizing Urban Household Waste Generation and Metabolism Considering Community Stratification in a Rapid Urbanizing Area of China.

    Science.gov (United States)

    Xiao, Lishan; Lin, Tao; Chen, Shaohua; Zhang, Guoqin; Ye, Zhilong; Yu, Zhaowu

    2015-01-01

    The relationship between social stratification and municipal solid waste generation remains uncertain under current rapid urbanization. Based on a multi-object spatial sampling technique, we selected 191 households in a rapidly urbanizing area of Xiamen, China. The selected communities were classified into three types: work-unit, transitional, and commercial communities in the context of housing policy reform in China. Field survey data were used to characterize household waste generation patterns considering community stratification. Our results revealed a disparity in waste generation profiles among different households. The three community types differed with respect to family income, living area, religious affiliation, and homeowner occupation. Income, family structure, and lifestyle caused significant differences in waste generation among work-unit, transitional, and commercial communities, respectively. Urban waste generation patterns are expected to evolve due to accelerating urbanization and associated community transition. A multi-scale integrated analysis of societal and ecosystem metabolism approach was applied to waste metabolism linking it to particular socioeconomic conditions that influence material flows and their evolution. Waste metabolism, both pace and density, was highest for family structure driven patterns, followed by lifestyle and income driven. The results will guide community-specific management policies in rapidly urbanizing areas.

  3. Blood Lead Levels and Risk Factors among Preschool Children in a Lead Polluted Area in Taizhou, China

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    Zhenyan Gao

    2017-01-01

    Full Text Available Objective. To determine the blood lead levels and identify related risk factors among preschool children in a lead polluted area (Taizhou, China and provide theoretical support for prevention of lead pollution. Methods. A stratified-clustered-random sampling method was used to determine the survey sample. Blood lead levels were determined by the tungsten atomizer absorption spectrophotometer. Results. A total of 2,018 subjects (average age of 59 months; 1,087 boys and 931 girls were included. The arithmetic mean, geometric mean, and median blood lead levels of the preschool children were 56.4 μg/L, 48.9 μg/L, and 46 μg/L. A total of 8.8% children had blood lead levels >100 μg/L and 43.9% had blood lead levels >50 μg/L. Mother’s education level, father’s occupation, decorative tableware, exposure to makeup, and the residential floor were all risk factors for elevated blood lead levels (odds ratios of 1.42, 1.21, 1.11, 1.19, and 1.27, resp., while hand washing before eating food was a protective factor (odds ratio of 0.88. Conclusions. The blood lead levels of preschool children in Taizhou were higher than in other areas in China and in developed countries. Therefore, policies ensuring lead-based industries are not placed in close proximity to residential areas are required.

  4. Spatio-temporal variations in the areas suitable for the cultivation of rice and maize in China under future climate scenarios.

    Science.gov (United States)

    Zhang, Yajie; Wang, Yanfen; Niu, Haishan

    2017-12-01

    Predictions of changes in the distribution of areas suitable for the cultivation of rice and maize in China under future climate change scenarios may provide scientific support for the optimization of crop production and measures to mitigate climate change. We conducted a spatial grid-based analysis using projections of future climate generated by the National Center for Atmospheric Research Community Climate System Model version 4 for two representative concentration pathway scenarios (RCP2.6 and RCP8.5), adopted by the fifth phase of the Coupled Model Intercomparison Project to study the areas suitable for the cultivation of rice and maize in China. We investigated the migration of the centers of gravity of the cultivation areas based on climatic and hydrological factors from 2021 to 2100. The results indicated that, under RCP2.6, the areas suitable for the cultivation of rice were located throughout China, except for on the Qinghai-Tibetan Plateau, while the areas suitable for the cultivation of maize were located in northern, southwestern, central, eastern, parts of northeastern and some northern parts of western China. The distributions of both crops under RCP2.6 showed little change over time. In contrast, the areas suitable for the cultivation of rice and maize under RCP8.5 shifted northward and expanded from northwestern to northern China, as a result of greater warming in northern China and the faster warming trend under RCP8.5. This scenario would require much stronger climate mitigation policies to maintain the stable development of agriculture and to slow down the future migration of crop cultivation areas in China. The distribution of areas suitable for the cultivation of rice and maize should be studied further to design appropriate adaptation strategies for dealing with future climate change. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Caregiving Experience for Children with Intellectual Disabilities among Parents in a Developing Area in China.

    Science.gov (United States)

    Yang, Xue; Byrne, Victoria; Chiu, Marcus Y L

    2016-01-01

    By utilizing grounded theory methodology, this study attempted to fill a gap whereby little research explored family caregiving perspectives in China where public support is insufficient and familial responsibility is highly valued. Data were collected through the qualitative methods of interviews and observations among a purposive sample of 15 parents of children with intellectual disabilities in central China. The central idea emerging from the data encompassed five broad categories of caregiving experiences: (i) unavoidable caregiving responsibility and (ii) uncertain future as the greatest worries which are the perception towards the recipient; (iii) compromising quality of life and (iv) positive roles of caregiving tasks which focus on the self; and (v) community support which is the perceived support from the external system. A recursive relationship existed among these categories. Chinese culture and traditional beliefs dominated throughout these issues. The implications and limitations of this study were discussed. © 2015 John Wiley & Sons Ltd.

  6. International trends in health science librarianship Part 10: The Greater China area.

    Science.gov (United States)

    Xie, Zhiyun; Chan, Julia L Y; Lam, Louisa Mei Chun; Chiu, Tzu-Heng

    2014-06-01

    This is the 10th in a series of articles exploring international trends in health science librarianship. This issue describes developments in health science librarianship in the first decade of the 21st century in China, Hong Kong and Taiwan. The next issue will report on Japan and South Korea. JM. © 2014 The authors. Health Information and Libraries Journal © 2014 Health Libraries Group.

  7. Delineating Urban Fringe Area by Land Cover Information Entropy—An Empirical Study of Guangzhou-Foshan Metropolitan Area, China

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    Junyi Huang

    2016-05-01

    Full Text Available Rapid urbanization has caused many environmental problems, such as the heat island effect, intensifying air pollution, pollution from runoff, loss of wildlife habitat, etc. Accurate evaluations of these problems demand an accurate delineation of the spatial extent of the urban fringe. Conceptual and analytical ambiguity of the urban fringe and a general lack of consensus among researchers have made its measurement very difficult. This study reports a compound and reliable method to delineate the urban fringe area using a case study. Based on the 'fringe effect' theory in landscape ecology, the existing land cover information entropy model for defining the urban fringe is renewed by incorporating scale theory, cartography and urban geography theory. Results show that the urban fringe area of Guangzhou and Foshan metropolitan area covers an area of 2031 km2, and it occupies over 31% of the total study area. Result evaluation by industry structure data shows satisfactory correspondence with different land cover types. This paper reports the method and outcome of an attempt to provide an objective, repeatable and generally applicable method for mapping its spatial extent from remote sensing imageries, and could be beneficial to relevant urban studies and urban fringe management projects.

  8. How Hydrodynamics Control Algal Blooms in the Ythan Estuary, Scotland

    Science.gov (United States)

    Champangern, K.; Hoey, T.; Thomas, R.; Mitchard, E. T.

    2016-12-01

    The Ythan estuary, northeast Scotland, was designated in 2000 as a Nitrate Vulnerable Zone (NVZ) under the European Commission (EC) Nitrates Directive. Much of the catchment is intensively farmed and water quality has been adversely affected by nutrients from agricultural fertilisers. As a result, algal mats develop annually on tidal flats where sediment from upstream and from the adjacent dune systems is deposited. Understanding the patterns of water (river and ocean) circulation in the estuary as well as nutrient transport in the estuary is crucial for comprehending the role of several factors (elevation; sediment characteristics; nutrient flux) control the locations and scale of annual algal blooms. To understand the controls, the Delft3d flow model is used to simulate hydrodynamic patterns and nutrient pathways in the estuary during high flow and low flow events. The results from the simulations reveal that during high river flow in the central part of the estuary, where algal growth is most extensive, flow velocity are higher during flood tide than in the ebb. However, the velocity in this area remain very low throughout the tidal cycle. During low river flow, the velocity during one tidal cycle has the same pattern as in high flow event, although the velocity is generally slightly higher than during high river flow except during slack tide where velocity and shear stress are lower. The modelled nutrient pathways and their concentration also show the movement of nutrients with regard to interaction of both fresh and sea water. The concentration is greatest during low tide in the upper estuary followed by middle and lower estuary, while appearing lowest during high tide. The nutrients mobilise along the main channel where velocity is greater. However, they are also dispersed to shallower areas where algal growth is extensive and remain high concentrated in the areas until a new flood tide. These model results are validated against measured data, of which the

  9. Metamorphic evolution and geochronology of the Dunhuang orogenic belt in the Hongliuxia area, northwestern China

    Science.gov (United States)

    Wang, Hao Y. C.; Wang, Juan; Wang, Guo-Dong; Lu, Jun-Sheng; Chen, Hong-Xu; Peng, Tao; Zhang, Hui C. G.; Zhang, Qian W. L.; Xiao, Wen-Jiao; Hou, Quan-Lin; Yan, Quan-Ren; Zhang, Qing; Wu, Chun-Ming

    2017-03-01

    Garnet-bearing mafic granulites and amphibolites from the Hongliuxia area of the southern Dunhuang orogenic belt, northwestern China, commonly occur as lenses or boudinages enclosed within metapelite or marble, which represent the block-in-matrix feature typical of orogenic mélange. Three to four generations of metamorphic mineral assemblages are preserved in these rocks. In the high-pressure amphibolites, prograde mineral assemblages (M1) occur as inclusions (hornblende + plagioclase + quartz ± chlorite ± epidote ± ilmenite) preserved within garnet porphyroblasts, and formed at 550-590 °C and 7.7-9.2 kbar based on geothermobarometry. The metamorphic peak mineral assemblages (M2) are composed of garnet + hornblende + plagioclase + quartz + clinopyroxene, as well as titanite + zircon + rutile + apatite as accessory minerals in the matrix, and are estimated to have formed at 640-720 °C and 14.1-16.0 kbar. The first retrograde assemblages (M3) are characterized by "white-eye socket" symplectites (hornblende + plagioclase + quartz ± biotite ± epidote ± magnetite) rimming garnet porphyroblasts, which formed at the expense of the garnet rims and adjacent matrix minerals during the decompression stage under P-T conditions of 610-630 °C and 5.6-11.8 kbar. The second retrograde assemblages (M4) are intergrowths of actinolite and worm-like quartz produced by the breakdown of the matrix hornblendes, and formed under P-T conditions of ∼490 °C and ∼2.8 kbar. For the high-pressure mafic granulites, the prograde assemblages (M1) are represented by plagioclase + quartz preserved within the garnet porphyroblasts. The metamorphic peak assemblages (M2) are garnet + matrix minerals (clinopyroxene + plagioclase + quartz + hornblende + rutile + zircon) and were estimated to have formed at ∼680 °C and ∼15.4 kbar. The retrograde assemblages (M3) are characterized by fine-grained patches of hornblende + plagioclase + quartz rimming the garnet porphyroblasts, as well as

  10. [Study on multi-area universal newborn hearing screening in countryside of China].

    Science.gov (United States)

    Huang, Lihui; Cai, Zhenghua; Zhang, Hua; Peng, Shichun; Wu, Dongsheng; Wang, Lei; Fan, Weiping; Yang, Rulan; Huang, Yan; Luo, Xia; Tu, Lin; En, Hui; Qi, Beier; Zhen, Yong; Han, Demin

    2009-08-01

    To investigate the feasibility of universal newborn hearing screening in countryside in order to provide reliable evidence in launching this program all over the countryside of China. Subjects were 12,638 infants who were born in 9 counties from Jan 2004 to Dec 2005. TEOAE was used for the fast hearing screening. Infants were screened on the 2-7 days after the birth. The re-screening was conducted in 4-6 weeks if failed in the initial screening, and follow-up were provided continually if they also failed in the re-screening. Ten thousand eight hundred and forty-five of 12,638 (85.8%) were screened including 9,963 (91.9%) normal newborns and 882 (8.1%) newborns with high-risk. Seven thousand four hundred and fifty (68.7%) newborns passed the initial screening, and 3,395 (31.3%) people failed. One thousand seven hundred and ninety-three (14.2%) infants were refused to be screened. Only 2,536 (74.7%) were re-screened on time, and 859 (25.3%) did not receive re-screening. One hundred and twenty were failed in the re-screening or first screening, and 79 (65.8%) of them received diagnostic assessment. Among the infants received diagnostic assessment, 6 (7.6%) cases were found to have profound hearing loss in both ears, 9 (11.4%) cases were found to be severe hearing loss (7 in both ears and 2 in single ear), 11 (13.9%) cases were found to be moderate hearing loss (5 in both ear and 6 in single ear), 26 (32.9%) were found to have slight hearing loss (11 in both ear and 15 in single ears), and 27 (34.2%) were normal. Fifty-two infants were diagnosed as hearing loss with a prevalence of congenital hearing loss (in binaural and monaural) of 0.5% (52/10845) and a prevalence of bilateral hearing loss of 0.3% (29/10845). A prevalence of congenital hearing loss was 0.2% (22/9,963) in well infants and 3.4% (30/882) in high risk infants. Among the 13 cases of children with severe and profound hearing loss in both ears children, 8 (61.5%) cases were fitted with hearing aids and 1

  11. Influence of gender equity awareness on women's reproductive healthcare in rural areas of midwest China.

    Science.gov (United States)

    Wang, Lei; Cui, Ying; Zhang, Li; Wang, Chao; Jiang, Yan; Shi, Wei

    2013-11-01

    To investigate the impact of married women's gender equity awareness on use of reproductive healthcare services in rural China. The questionnaire-based study recruited 1500 married women who were aged 15-49years, had at least 1 pregnancy, and were living in rural Gansu, Qinghai, Shanxi, or Xinjiang, China, between October and December 2010. "Gender equity awareness" was quantified by responses to 7 statements, graded in accordance with a system scoring the strength of overall belief (≥19, strong; 15-18, moderate; and ≤14, weak). Only 383 women (26.3%) demonstrated high gender equity awareness. The percentage of women who received consistent prenatal care was highest in the group scoring 15 points or more (Pgender equity awareness is not strong in rural midwest China. There was a positive correlation between gender equity awareness and use of reproductive healthcare services. There should be an emphasis on various activities to educate women so that they can fully access reproductive healthcare. © 2013.

  12. Estuary-wide genetic stock distribution and salmon habitat use, tidal-fluvial estuary - Columbia River Estuary Tidal Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the tidal-fluvial estuary study is to determine the estuary's contribution to the spatial structure and life history diversity of Columbia River salmon...

  13. Dune Mining and the Nhlabane Estuary, South Africa: the Effect of a Dredger Crossing on the Zoobenthic Community

    Energy Technology Data Exchange (ETDEWEB)

    Vivier, L.; Cyrus, D.P

    1999-01-01

    The Nhlabane Estuary, located on the north-east coast of South Africa, is situated in a titanium dune mining lease area. During 1993, a mining dredger and concentrator crossed the middle reaches of the estuary. For this purpose, two berm walls were constructed across the estuary. Two impacts stemmed from the crossing. A series of fine sediment intrusions into the estuary from the berm wall area occurred during late 1993 and early 1994 and caused a rapid decline in benthic densities and number of taxa. Recovery of the affected area was slow and characterized by initial proliferation of opportunistic colonizers. The berm walls, which divided the estuary in half, were kept in place for nearly three years and caused changes in water quality and the benthic community of the upper and lower halves of the estuary. Artificial breaching of the estuary in August 1995 and removal of the berm walls in May 1996 initiated recovery of the estuary. The success of a second dredger crossing, scheduled for January 1999, depends on addressing the mistakes made during the first crossing and on the speed with which the carefully planned crossing operation, berm wall removal and estuary rehabilitation proceed.

  14. Sedimentary organic and inorganic records of eutrophication and hypoxia in and off the Changjiang Estuary over the last century.

    Science.gov (United States)

    Zhao, Jun; Feng, Xuwen; Shi, Xiaolai; Bai, Youcheng; Yu, Xiaoguo; Shi, Xuefa; Zhang, Weiyan; Zhang, Rongping

    2015-10-15

    Organic and inorganic sedimentary parameters in and off the Changjiang Estuary have been analyzed to reconstruct historical trends in eutrophication and hypoxia over the last century. The lipid biomarker concentrations in the Changjiang Estuary mud area (CEMA) indicated eutrophication accelerated after the 1970s. Meanwhile, Mo/Al indicated hypoxia has increased since 1960s. Eutrophication and hypoxia in the CEMA are primarily a result of the dramatically increased load of terrestrial nutrients from the Changjiang to the East China Sea. The lipid biomarker concentrations in the southwest Cheju Island mud area (SCIMA) showed primary production is controlled mainly by changes in regional climate and marine current. No significant hypoxia occurred in the SCIMA over the past century as indicated by Mo/Al. Therefore, geochemical indicators of eutrophication and hypoxia revealed different patterns between the CEMA and SCIMA, suggesting the role of river-derived nutrients in sustaining eutrophication and hypoxia in the CEMA since the 1960s. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Does boat traffic cause displacement of fish in estuaries?

    Science.gov (United States)

    Becker, Alistair; Whitfield, Alan K; Cowley, Paul D; Järnegren, Johanna; Næsje, Tor F

    2013-10-15

    Estuaries are increasingly under threat from a variety of human impacts. Recreational and commercial boat traffic in urban areas may represent a significant disturbance to fish populations and have particularly adverse effects in spatially restricted systems such as estuaries. We examined the effects of passing boats on the abundance of different sized fish within the main navigation channel of an estuary using high resolution sonar (DIDSON). Both the smallest (100-300 mm) and largest (>501 mm) size classes had no change in their abundance following the passage of boats. However, a decrease in abundance of mid-sized fish (301-500 mm) occurred following the passage of boats. This displacement may be attributed to a number of factors including noise, bubbles and the rapidly approaching object of the boat itself. In highly urbanised estuarine systems, regular displacement by boat traffic has the potential to have major negative population level effects on fish assemblages. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Ecological studies in the Iture estuary mangrove forest in Ghana ...

    African Journals Online (AJOL)

    The study assessed the floristic composition as well as aspects of the structure of the mangrove vegetation of Iture estuary with the view to determining any possible changes in these attributes over the past few years. The density and basal area of the trees/shrubs were estimated using the Point-Centred Quarter Method.

  17. The importance of the river-estuary interface (REI) zone in estuaries ...

    African Journals Online (AJOL)

    The effect of the REI zone on fish was examined in the freshwater-rich Great Fish Estuary and in the freshwater-deprived Kariega Estuary. Estuarine associated fishes responded strongly to river flow in the Great Fish Estuary but a number of these taxa were limited or absent from the Kariega Estuary. These findings are ...

  18. The influence of surface water - groundwater interactions on the shallow groundwater in agricultural areas near Fu River, China

    Science.gov (United States)

    Brauns, Bentje; Løgstrup Bjerg, Poul; Jakobsen, Rasmus; Song, Xianfang

    2014-05-01

    The Northern China Plain (NPC) is known as a very productive area in China for the production of maize and winter wheat, which is grown by local farmers rotationally without lag phases throughout the year. The needed application of fertilizers and pesticides can hereby have strong impacts