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Sample records for estuary area china

  1. Water Quality and Environmental Flow Management in Rapidly Urbanizing Shenzhen Estuary Area, China

    Science.gov (United States)

    Qin, H.; Su, Q.

    2011-12-01

    Shenzhen estuary is located in a rapidly urbanizing coastal region of Southeast China, and forms the administrative border between mainland China and Hong Kong. It receives the waters of the Shenzhen River, where it enters the Deep Bay. The estuary has great ecological importance with the internationally recognized mangrove wetlands, which provides a habitat for some rare and endangered waterfowl and migratory birds.Water quality in the esturay has deteriorated not only due to increasing wastewater discharges from domestic and industrial sources, but also as a consequence of decreasing base environmental flow during rapid urbanization in the Shenzhen River catchment since 1980s. Measures to improve water quality of the estuary include not only reducing pollutant inputs by intercepting wastewater, but also increasing environmental flow by reusing reclaimed wastewater or withdrawing nearshore seawater into the river. However, salinity alternation due to flow increase is deemed to have impacts on the mangrove wetland ecosystem. In this paper, Environmental Fluid Dynamics Code (EFDC) is used to simulate hydrodynamics, salinity, and water quality condition in the Shenzhen estuary. After calibration and validation, the model is used to evaluate effects of various control measures on water quality improvement and salinity alteration in the estuary. The results indicate that implementing different measures independently does not reach the goals of water quality improvement; furthermore, increasing environmental flow by importing nearshore seawater may greatly increase the salinity in the Shenzhen River, destroy the fresh ecosystem of the river and have non-negligible impacts on the mangrove wetland ecosystem. Based on the effectiveness and impacts of the measures, an integrated measure, which combine pollutant loads reduction and environmental flow increase by reusing reclaimed wastewater, is proposed to achieve water environmental sustainability in the study area.

  2. Mercury profiles in sediments of the Pearl River Estuary and the surrounding coastal area of South China

    International Nuclear Information System (INIS)

    Shi Jianbo; Ip, Carman C.M.; Zhang Gan; Jiang Guibin; Li Xiangdong

    2010-01-01

    The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201 ng/g, with an average of 54.4 ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the 210 Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades. - The spatial and historical changes of Hg in sediment reflect the industrial development and urbanization of the region in south China.

  3. Temporal distribution of bacterial community structure in the Changjiang Estuary hypoxia area and the adjacent East China Sea

    International Nuclear Information System (INIS)

    Liu Min; Huang Huiqin; Bao Shixiang; Xiao Tian; Zhang Wuchang; Wu Ying; Zhou Feng

    2012-01-01

    Bacterial community structure and the effects of environmental factors on the microbial community distribution were investigated in the Changjiang Estuary hypoxia area and its adjacent area in the East China Sea (ECS) in June, August and October, 2006. Profiles of bacterial communities were generated by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes followed by DNA sequence analysis. The dominant bacterial groups were affiliated to Gammaproteobacteria, Cytophaga–Flavobacteria–Bacteroides (CFB), Deltaproteobacteria, Cyanobacteria and Firmicutes, which were mostly from the marine seawater ecosystem. Effects of environmental factors on the bacterial community distribution were analyzed by the ordination technique of canonical correspondence analysis (CCA). The environmental factors significantly influencing bacterial community structure were different in the three months; dissolved organic carbon (DOC) and temperature in June and nitrite in August. No environmental variables displayed significant influence on the bacterial community at the 5% level in October. The seasonal environmental heterogeneity in the Changjiang Estuary and the adjacent ECS, such as seasonal hydrodynamic conditions and riverine input of nutrients, might be the reason for the difference in the key environmental factors determining the bacterial community in the three months. (letter)

  4. 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.

  5. Polycyclic aromatic hydrocarbons in suspended particulate matter and sediments from the Pearl River Estuary and adjacent coastal areas, China

    International Nuclear Information System (INIS)

    Luo Xiaojun; Chen Shejun; Mai Bixian; Yang Qingshu; Sheng Guoying; Fu Jiamo

    2006-01-01

    The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin. - PAH were determined in suspended particulate matter and sediments from Pearl River Estuary

  6. Microplastic in three urban estuaries, China

    International Nuclear Information System (INIS)

    Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2015-01-01

    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 (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban 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. - Highlights: • Suspended microplastic were investigated within three densely populated/developed urban estuaries, China. • Economical structures may contribute to the abundances of microplastic particles within the studied estuaries. • Typhoon Soulik didn't influence microplastic densities in the water column of Minjiang Estuary. • Microplastics (<5 mm in diameter) dominated more than 90% of the total plastic by number. - Suspended microplastics (MPs) levels were quantified within three urban estuaries, China. MPs densities were consistent with the urban economical structure, and that in Minjiang were unaffected by Typhoon.

  7. Trace metal distribution in sediments of the Pearl River Estuary and the surrounding coastal area, South China

    International Nuclear Information System (INIS)

    Ip, Carman C.M.; Li Xiangdong; Zhang Gan; Wai, Onyx W.H.; Li, Y.-S.

    2007-01-01

    Surface sediments and sediment cores collected at the Pearl River Estuary (PRE) and its surrounding coastal area were analysed for total metal concentrations, chemical partitioning, and Pb isotopic compositions. The distribution of Cu, Cr, Pb, and Zn demonstrated a typical diffusion pattern from the land to the direction of the sea. Two hotspots of trace metal contamination were located at the mixed zone between freshwater and marine waters. The enrichment of metals in the sediments could be attributed to the deposition of the dissolved and particulate trace metals in the water column at the estuarine area. The similar Pb isotopic signatures of the sediments at the PRE and its surrounding coastal area offered strong evidence that the PRE was a major source of trace metals to the adjacent coastal area. Slightly lower 206 Pb/ 207 Pb ratios in the coastal sediments may indicate other inputs of Pb in addition to the PRE sources, including the inputs from Hong Kong and other parts of the region. - The distribution of trace metals in sediments reflected contaminant sources, physical and chemical deposition processes

  8. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    Science.gov (United States)

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd heavy metals in surface sediments was in the order of Cd heavy metals in water, suspended solids and sediment. In particular, the effects of salinity and suspended solids matter were most significant. The integrated pollution index assessment showed that the water quality was good except individual stations. The geoaccumulation index assessment showed that As was the major pollution element in surface sediments.

  9. Riverbed Micromorphology of the Yangtze River Estuary, China

    Directory of Open Access Journals (Sweden)

    Shuaihu Wu

    2016-05-01

    Full Text Available Dunes are present in nearly all fluvial channels and are vital in understanding sediment transport, deposition, and flow conditions during floods of rivers and estuaries. This information is pertinent for helping developing management practices to reduce risks in river transportation and engineering. Although a few recent studies have investigated the micromorphology of a portion of the Yangtze River estuary in China, our understanding of dune development in this large estuary is incomplete. It is also poorly understood how the development and characteristics of these dunes have been associated with human activities in the upper reach of the Yangtze River and two large-scale engineering projects in the estuarine zone. This study analyzed the feature in micromorphology of the entire Yangtze River estuary bed over the past three years and assessed the morphological response of the dunes to recent human activities. In 2012, 2014, and 2015, multi-beam bathymetric measurements were conducted on the channel surface of the Yangtze River estuary. The images were analyzed to characterize the subaqueous dunes and detect their changes over time. Bottom sediment samples were collected for grain size analysis to assess the physical properties of the dunes. We found that dunes in the Yangtze River estuary can be classified in four major classes: very large dunes, large dunes, medium dunes, and small dunes. Large dunes were predominant, amounting to 51.5%. There was a large area of dunes developed in the middle and upper reaches of the Yangtze River estuary and in the Hengsha Passage. A small area of dunes was observed for the first time in the turbidity maximum zone of the Yangtze River estuary. These dunes varied from 0.12 to 3.12 m in height with a wide range of wavelength from 2.83 to 127.89 m, yielding a range in height to wavelength of 0.003–0.136. Sharp leeside slope angles suggest that the steep slopes of asymmetrical dunes in the middle and upper

  10. Interactions between the range expansion of saltmarsh vegetation and hydrodynamic regimes in the Yangtze Estuary, China

    NARCIS (Netherlands)

    Zhu, Z.; Zhang, L.; Wang, N.; Schwarz, C.; Ysebaert, T.

    2012-01-01

    >Over the last 15 years, rapid invasion of large areas of the saltmarshes of Chongming Island, in the Yangtze Estuary, China by the exotic species Spartina alterniflora has occurred. Two types of advancing fronts are found: the S. alterniflora–mudflat (S–M front) and the S.

  11. 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...

  12. Distribution, sources and ecological risk assessment of PAHs in surface sediments from the Luan River Estuary, China.

    Science.gov (United States)

    Zhang, Daolai; Liu, Jinqing; Jiang, Xuejun; Cao, Ke; Yin, Ping; Zhang, Xunhua

    2016-01-15

    The distribution, sources and risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) of surface sediments in the Luan River Estuary, China, have been investigated in the research. The results indicated that the total concentrations of 16 PAHs in surface sediments of the Luan River Estuary ranged from 5.1 to 545.1 ng g(-1)dw with a mean value of 120.8 ng g(-1)dw, which is relatively low in comparison with other estuaries around the world. The PAHs in the study area were mainly originated from pyrogenic sources. Besides, PAHs may be contaminated by petrogenic PAHs as indicated by the selected ratios of PAHs, the 2-tailed Pearson correlation analysis and principal components analysis at different sites. The result of the ecological risk assessment shows little negative effect for most individual PAHs in surface sediments of the Luan River Estuary, China. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 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 (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.

  14. Current status of emerging hypoxia in a eutrophic estuary: The lower reach of the Pearl River Estuary, China

    Science.gov (United States)

    Qian, Wei; Gan, Jianping; Liu, Jinwen; He, Biyan; Lu, Zhongming; Guo, Xianghui; Wang, Deli; Guo, Liguo; Huang, Tao; Dai, Minhan

    2018-05-01

    We examine the current status of dissolved oxygen (DO) and its trend over the past 25 years in the lower Pearl River Estuary, a large eutrophic estuary located in Southern China and surrounded by large cities including Hong Kong, Shenzhen and Guangzhou. Monthly cruises conducted from April 2010 to March 2011 clearly show that DO depletion began to emerge in the bottom layer of the lower estuary off Hong Kong in June, and became fully developed in July and August when oxygen-deficient water occupied ∼1000 km2 before gradually becoming re-oxygenated in September and October. The development of the low oxygen zone was closely coupled with phytoplankton blooms in the surface water, which was supersaturated with respect to DO suggesting the importance of autochthonous organic matter in fueling bottom DO consumption after settling through the pycnocline. Long-term monitoring data collected in the study area adjacent to Hong Kong by the Hong Kong Environmental Protection Department showed a decreasing trend of ∼2 ± 0.9 μmol kg-1 yr-1 in the annual minimum DO concentration in bottom water over the past 25 years. Associated with the decrease in DO was an increase in the annual maximum surface concentration of dissolved inorganic nitrogen (DIN) at a rate of ∼1.4 ± 0.3 μmol kg-1 yr-1, suggesting again that eutrophication is the most plausible driver of oxygen deficiency in this region. Therefore, our monthly cruises, along with the decadal monitoring data, reveal a large low oxygen zone, likely developing into a large hypoxic zone driven primarily by anthropogenic eutrophication. This new development suggests environmental stressors such as eutrophication may have a cascading effect, with important and expensive consequences for the regional environment.

  15. 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 < 0.01) but negatively by salinity (P < 0.05); the phytoplankton diversity was highly positively affected by salinity (P < 0.05) but negatively by silicate and nitrate (P < 0.01; P < 0.05, respectively). Anthropogenic activities played a critical role in the phytoplankton distribution and biomass of the study area. Further research is necessary to reveal the influence mechanism of environmental factors on the phytoplankton.

  16. 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

    2018-05-01

    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.

  17. Distribution and sources of the polycyclic aromatic hydrocarbons in the sediments of the Pearl River estuary, China.

    Science.gov (United States)

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

    2015-10-01

    The Pearl River delta, one of the most prosperous economically region in China, has experienced significant contaminant inputs. However, the dynamics of pollutants in the Pearl River estuary and the adjacent coastal areas are still unclear at present. In the paper, distribution and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments of the Pearl River estuary. The total PAHs concentrations ranged from 126.08 to 3828.58 ng/g with a mean value of 563.52 ng/g, whereas the highest PAHs were observed in Guangzhou channel. Among the U.S. Environmental Protection Agency's 16 priority PAHs, PAHs with 3-4 rings exhibited relative higher levels. A positive relationship was found between PAHs and total organic carbon. The source analysis further showed that the major sources of PAHs in the Pearl River estuary were originated from the pyrolytic inputs, reflecting a mixed energy structure such as wood, coal and petroleum combustion. In summary, although PAHs in Lingding Bay and the adjacent coastal areas of the Pearl River estuary exhibited a relatively low pollution level, the relatively high pollution level of PAHs in Guangzhou channel will be attended.

  18. Detecting the transport barriers in the Pearl River estuary, Southern China with the aid of Lagrangian coherent structures

    Science.gov (United States)

    Wei, Xing; Zhan, Haigang; Cai, Shuqun; Zhan, Weikang; Ni, Peitong

    2018-05-01

    Knowledge of horizontal transport pathways is important for the protection of the marine ecosystem in coastal areas. In this paper, we develop a 3D model to simulate hydrodynamics and particle transport in the Pearl River Estuary (PRE), Southern China, to study the barriers to transport in the PRE. Specifically, we use the flow velocity produced by the model to locate Lagrangian coherent structures (LCSs) hidden in ocean surface currents. Our findings show that a remarkable LCS begins upstream near the Humen inlet, extends to the Wanshan Islands via Neilingding Island, and can act as a transport barrier in the estuary. This LCS appeared 1-2 h after high tide and was persistent for 6-7 h during every ebb tide. Particles released on the west side of the LCS moved downstream, exited the estuary by Daxi Channel, and seldom spread to the east side, especially the Hong Kong Sea area. An analysis of several scenarios suggested that the formation of this LCS was due to topography restrictions and tidal forces.

  19. Environmental Settings and Harmful Algal Blooms in the Sea Area Adjacent to the Changjiang River Estuary

    OpenAIRE

    Zhou, Mingjiang

    2010-01-01

    The characteristics of the environmental settings of the sea area adjacent to the Changjiang River estuary include complex currents and water masses, the diluted water plume and its redirection, upwelling, front, and nutrients and their sources. The Changjiang River estuary characteristics also include the phytoplankton community, which can affect the growth, migration, assembling, resting and competition of algae to form red tides in this area.. The features of red tide events recorded in th...

  20. Carbonate system and nutrients in the Pearl River estuary, China: Seasonal and inter-annual variations

    Science.gov (United States)

    Guo, X.

    2017-12-01

    Located in southern China and surrounded by several metropolis, the Pearl River estuary is a large subtropical estuary under significant human perturbation. We examined the impact of sewage treatment rate on the water environmental factors. Carbonate system parameters (Dissolved inorganic carbon or DIC, Total alkalinity or TA, and pH), and nutrients were surveyed in the Pearl River estuary from 2000 to 2015. Spatially, concentrations of nutrients were high at low salinity and decreased with salinity in both wet and dry seasons although seasonal variation occurred. However, distribution patterns of DIC and TA differed in wet and dry seasons. In wet season, both DIC and TA were low at low salinity (600-1500 umol kg-1) and increased with salinity, but in dry season they were high at low salinity (3000-3500 umol kg-1) and decreased with salinity. Compared with the years before 2010, both values and distribution patterns of DIC, TA and pH were similar among the years in wet season, but they were conspicuously different in the upper estuary in dry season. Both DIC and TA were more than 1000 umol kg-1 lower than those in the years before 2010. For nutrients at low salinity, the ammonia concentration was much lower in the years after 2010 (200 vs. 400 umol kg-1 in wet season and 400 vs. 800 umol kg-1 in dry season), but nitrate concentration was slightly higher (180 vs 120 mmol kg-1 in wet season and 200 vs 180 mmol kg-1 in dry season). As a reference, carbonate system parameters and nutrients were stable among the 16 years in the adjacent northern South China Sea. The variations in biogeochemical processes induced by nutrients concentration and structure as a result of sewage discharge will be discussed in detail. The decrease in DIC, TA and nutrients in the upper Pearl River estuary after 2010 was due mainly to the improvement of sewage treatment rate and capacity.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Hydrochemical and isotopic characteristics of estuarial seawater and river water of Bailanghe in Laizhou Bay, China

    Science.gov (United States)

    Yang, Qiaofeng; Xu, Suning; Wang, Ruijiu; Li, Wenpeng; Wang, Zhiyi; Mei, Junjun; Ding, Zhilei; Yang, Peijie; Yu, Liangju; Lv, Tieying; Bai, Gang; Kang, Wei

    2016-04-01

    In the study of seawater intrusion, seawater is usually taken as an end-member that mixes with other source(s). However, compared to standard seawater, the coastal seawater particularly that near the estuary, can be strongly influenced by the rivers into the sea and by coastal human activities. Their composition can be thus continuously changed and redistributed with space and time. Therefore, before investigating seawater intrusion in a certain area, it is essentially important to determine the features of the estuarine seawater (e.g. the mixture percentage between standard seawater and river water). In this study, we aimed to gain a clear situation of the seawater intrusion in Laizhou Bay, Southern Bohai, China. The issue aforementioned was investigated by comparing the stable isotopic and hydrochemical composition of the marine and river water collected in this area. Samples investigated include 5 surface water samples collected at the downstream of the Bailanghe and 7 seawater samples near the estuary of Laizhou Bay. Inert tracers (δD, δ18O, Cl, Br) and reaction tracers (Na, Mg, SO4, HCO3, Ca, NO3) are particularly analyzed. The major results are as follows: 1) All the river water samples fall below the Global Meteoric Water Line in the δD - δ18O diagram, reflecting evaporation of the upstream reservoir water. The seawater samples fall on the mixing line of standard seawater and the river water in the stable isotopic diagram. 2) The Cl-δ18O diagram indicates widespread dissolution of evaporate into the river, while high concentration of Ca and HCO3-, as well as the SO42- - Cl relation of the river water samples reflect the dissolution of CO2 , carbonate and sulfate in the atmosphere and on the ground. 3) The Br/Cl ratios of seawater samples are closed to the marine ratios. This together with the plots of major ions vs. Cl suggest that the seawater samples are originated from the mixture of standard seawater and river water. Therefore, when referring to the

  6. Biogeochemistry of Dimethylsulfide, Dimethylsulfoniopropionate, and Acrylic Acid in the Changjiang Estuary and the East China Sea

    Science.gov (United States)

    Wu, Xi; Li, Pei-Feng; Liu, Chun-Ying; Zhang, Hong-Hai; Yang, Gui-Peng; Zhang, Sheng-Hui; Zhu, Mao-Xu

    2017-12-01

    The distributions of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), and acrylic acid (AA) were investigated in the Changjiang Estuary during winter (dry season) and summer (wet season) 2014 and in the East China Sea (ECS) during summer 2015. The rates of dissolved DMSP (DMSPd) degradation with DMS and AA production, DMS degradation, and AA degradation in the ECS were also studied. Significant seasonal variations in DMS(P) and AA concentrations were observed in the Changjiang Estuary with higher values during the wet season than during the dry season. The maximum ratio of AA/chlorophyll a (Chl a) occurred at the mouth of the Changjiang Estuary due to the combined effects of production from DMSP and terrestrial inputs from the Changjiang Estuary. The distributions of DMS(P) and AA in the ECS were dramatically influenced by the Kuroshio Current and the upwelling caused by the Taiwan Warm Current. The ratios of DMS(P)/Chl a and AA/Chl a exhibited similar patterns in the surface seawater of the ECS, which indicated that phytoplankton species and biomass might play important roles in controlling the distributions of DMS(P) and AA. In vertical profiles, high values of AA emerged in the upper water column and bottom seawater of the Changjiang Estuary. Meanwhile, the maxima of DMS(P) and AA generally appeared in the surface or euphotic layer, whereas their minima arose in the bottom seawater of the ECS. The degradation rates of DMSPd, DMS, and AA in the inshore waters were higher than those in the open sea.

  7. Monitoring the Invasion of Spartina alterniflora Using Multi-source High-resolution Imagery in the Zhangjiang Estuary, China

    Directory of Open Access Journals (Sweden)

    Mingyue Liu

    2017-05-01

    Full Text Available Spartina alterniflora (S. alterniflora is one of the most harmful invasive plants in China. Google Earth (GE, as a free software, hosts high-resolution imagery for many areas of the world. To explore the use of GE imagery for monitoring S. alterniflora invasion and developing an understanding of the invasion process of S. alterniflora in the Zhangjiang Estuary, the object-oriented method and visual interpretation were applied to GE, SPOT-5, and Gaofen-1 (GF-1 images. In addition, landscape metrics of S. alterniflora patches adjacent to mangrove forests were calculated and mangrove gaps were recorded by checking whether S. alterniflora exists. The results showed that from 2003–2015, the areal extent of S. alterniflora in the Zhangjiang Estuary increased from 57.94 ha to 116.11 ha, which was mainly converted from mudflats and moved seaward significantly. Analyses of the S. alterniflora expansion patterns in the six subzones indicated that the expansion trends varied with different environmental circumstances and human activities. Land reclamation, mangrove replantation, and mudflat aquaculture caused significant losses of S. alterniflora. The number of invaded gaps increased and S. alterniflora patches adjacent to mangrove forests became much larger and more aggregated during 2003–2015 (the class area increased from 12.13 ha to 49.76 ha and the aggregation index increased from 91.15 to 94.65. We thus concluded that S. alterniflora invasion in the Zhangjiang Estuary had seriously increased and that measures should be taken considering the characteristics shown in different subzones. This study provides an example of applying GE imagery to monitor invasive plants and illustrates that this approach can aid in the development of governmental policies employed to control S. alterniflora invasion.

  8. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

    Science.gov (United States)

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-05-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China

    International Nuclear Information System (INIS)

    Ying Liu; Ling Chen; Zhao Jianfu; Huang Qinghui; Zhu Zhiliang; Gao Hongwen

    2008-01-01

    Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust. - Surface sediments of two rivers and an estuary in Shanghai were contaminated by PAHs

  10. Distribution, historical trends and inventories of polychlorinated biphenyls in sediments from Yangtze River Estuary and adjacent East China Sea

    International Nuclear Information System (INIS)

    Yang Huayun; Zhuo Shanshan; Xue Bin; Zhang Chunlong; Liu Weiping

    2012-01-01

    A large portion of polychlorinated biphenyls (PCBs) from e-waste released into the coastal areas may be the potential source of PCBs to the global oceans. The paper presents data of PCBs concentrations in fifty surface sediment samples and a dated sediment core in Yangtze River Delta (YRE) and adjacent East China Sea (ECS). The total PCBs levels varied from 5.08 to 19.64 ng/g dry weight, with the highest concentrations situate within the river-sea boundary zone which is so-called “marginal filter”. Concurrent with the operation of e-waste recycling over the last two decades, PCB fluxes started to rise again after 1980s and reached a maximum in this century. The full data set was used to estimate the burden of PCBs in YRE and adjacent ECS. A total sediment burdens were 192.8 tons, with the spatial density of 364 ng/cm 2 which accounts for 1.9% of all the PCBs in China. - Highlights: ► PCBs residues remained widespread in Yangtze River Delta and adjacent East China Sea. ► Highest PCBs concentrations situate within the river-sea boundary zone. ► Congener profiles and PCA highlight the influence of e-waste recycling. ► Temporal distributions indicated PCB fluxes reached a maximum in this century. ► Total sediment burdens accounts for 1.9 % of all the PCBs in China. - Spatial and temporal distributions of polychlorinated biphenyls have been delineated in sediments from Yangtze River Estuary and adjacent East China Sea.

  11. Fate of polybrominated diphenyl ethers in the environment of the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Guan Yufeng; Sojinu, O.S. Samuel; Li Shaomeng; Zeng, Eddy Y.

    2009-01-01

    Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Σ 17 PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange, dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Σ 10 PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Σ 10 PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the PRE to coastal ocean. Besides sedimentation and degradation, the majority of Σ 10 PBDE and BDE-209 discharged into the PRE via riverine runoff was transported to the coastal ocean. - Fate of polybrominated diphenyl ethers in the environment the Pearl River Estuary, South China.

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

    Directory of Open Access Journals (Sweden)

    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

  13. 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.

  14. Spatial distribution and sources of heavy metals and petroleum hydrocarbon in the sand flats of Shuangtaizi Estuary, Bohai Sea of China.

    Science.gov (United States)

    Yang, Xiaolong; Yuan, Xiutang; Zhang, Anguo; Mao, Yuze; Li, Qiang; Zong, Humin; Wang, Lijun; Li, Xiaodong

    2015-06-15

    The concentrations of heavy metals and petroleum hydrocarbons (PHCs) in surface sediments were investigated in the sand flats of Shuangtaizi Estuary, Bohai Sea of China in May, 2013. Ecological risk assessment indicated that most heavy metals cause low ecological risk to the estuarine environment, with the exception of Cd and Hg (considerable and moderate risk, respectively). Principal component analysis in combination with correlation analysis among heavy metals, PHCs and geological factors (e.g., granularity) was used to identify possible sources of pollutants in Shuangtaizi Estuary. Results showed that the main pollution sources of the area come from anthropogenic factors, such as sewage discharge and oil exploitation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Emergy and Economic Evaluations of Four Fruit Production Systems on Reclaimed Wetlands Surrounding the Pearl River Estuary, China

    Science.gov (United States)

    Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The evaluations...

  16. 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.

  17. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China

    International Nuclear Information System (INIS)

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-01-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC–MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEs_l_o_w_, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16–5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. - Highlights: • This is the first study concentrating specifically on PBDEs in the study area. • The commercial Penta/Octa/Deca-BDE products were the possible sources. • The debromination of highly brominated PBDEs were also found to be the sources. • Scientific attention should not be reduced on these outdated chemical compounds. - The commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds were found to be the possible sources.

  18. China (country/area statements).

    Science.gov (United States)

    1985-09-01

    According to this statement presented to the Committee on Population of the UN Economic and Social Commission for Asia and the Pacific, China is similar to other countries in the region in that its rate of population growth has declined due to government family planning efforts while the absolute size of the population continues to increase because of the widening population base. However, China's enormous population of over 1 billion sets it apart and places great strain on economic development efforts. In the past decade the Chinese government has provided population education for the masses, explaining the relationship between population and socioeconomic development, and its overall family planning program has helped reduce population growth from 24.82/1000 in 1974 to 10.81/1000 in 1984. The net population increase has been over 100 million in the past 10 years, and if the present rate of increase with a total fertility rate of 2.1 is maintained for another 15 years, the total population would exceed 1.3 billion by 2000, posing a grave threat to China's socioeconomic development. The nucleus of China's population policy is its birth policy, whose main points are to promote family planning so that population growth will be in keeping with socioeconomic development and the utilization of natural resources and environmental protection. The policy is in line with the principles and objectives of the World Population Plan of Action adopted in 1974. The government has advocated the practice of "1 couple, 1 child" since 1979 to carry out the population policy and limit the total population to about 1.2 billion by the century's end. 28.17 million couples, 18.25% of the 150 million married couples of childbearing age, had received 1-child certificates by the end of 1984. Generally speaking, most couples in urban areas would be satisfied with 1 child, while those in rural areas usually prefer 2 children. The family planning program is carried out through publicity

  19. 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.

  20. Ostracoda and foraminifera as short-term tracers of environmental changes in very polluted areas: the Odiel Estuary (SW Spain)

    International Nuclear Information System (INIS)

    Ruiz, F.; Gonzalez-Regalado, M.L.; Borrego, J.; Abad, M.; Pendon, J.G.

    2004-01-01

    The analysis of 17 cores collected in the Odiel Estuary (SW Spain) permits delimiting the recent evolution of this zone during the past decades and the influence of natural and anthropogenic factors on the distribution of Ostracoda and Foraminifera. In the upper estuary, the coincidence of acid waters, prolonged subaerial exposure, and coarse sediments may explain the absence or the disappearance of these microorganisms during the industrial period (1966-1985) in the major part of this area. In the lower estuary, sedimentary evolution and industrial wastes are the main factors influencing both the distribution and trends of the populations of these two groups. Finally, the main changes observed in the marine estuary are due to the sedimentary effects of the construction of two banks and the dredging of the main estuarine channel. - In a polluted estuary, the meiofaunal assemblages experience different changes even in adjacent sedimentary environments, closely related to anthropogenic and natural causes

  1. Occurrences of dissolved trace metals (Cu, Cd, and Mn) in the Pearl River Estuary (China), a large river-groundwater-estuary system

    Science.gov (United States)

    Wang, Deli; Lin, Wenfang; Yang, Xiqian; Zhai, Weidong; Dai, Minhan; Arthur Chen, Chen-Tung

    2012-12-01

    This study for the first time examined dissolved metals (Cu, Cd, and Mn) together with dissolved oxygen and carbonate system in the whole Pearl River Estuary system, from the upper rivers to the groundwater discharges until the estuarine zone, and explored their potential impacts in the adjacent northern South China Sea (SCS) during May-August 2009. This river-groundwater-estuary system was generally characterized by low dissolved metal levels as a whole, whilst subject to severe perturbations locally. In particular, higher dissolved Cu and Cd occurred in the North River (as high as 60 nmol/L of Cu and 0.99 nmol/L of Cd), as a result of an anthropogenic source from mining activities there. Dissolved Cu levels were elevated in the upper estuary near the city of Guangzhou (Cu: ˜40 nmol/L), which could be attributable to sewage and industrial effluent discharges there. Elevated dissolved metal levels (Cu: ˜20-40 nmol/L; Cd: ˜0.2-0.8 nmol/L) also occurred in the groundwaters and parts of the middle and lower estuaries, which could be attributable to a series of geochemical reactions, e.g., chloride-induced desorption from the suspended sediments, oxidation of metal sulfides, and the partial dissolution of minerals. The high river discharge during our sampling period (May-August 2009) significantly diluted anthropogenic signals in the estuarine mixing zone. Of particular note was the high river discharge (which may reach 18.5 times as high as in the dry season) that transported anthropogenic signals (as indicated by dissolved Cu and Cd) into the adjacent shelf waters of the northern SCS, and might have led to the usually high phytoplankton productivity there (chlorophyll-a value >10 μg/L).

  2. PPCPs in Jiulong River estuary (China): Spatiotemporal distributions, fate, and their use as chemical markers of wastewater.

    Science.gov (United States)

    Sun, Qian; Li, Yan; Li, Mingyue; Ashfaq, Muhammad; Lv, Min; Wang, Hongjie; Hu, Anyi; Yu, Chang-Ping

    2016-05-01

    The occurrence and fate of 50 pharmaceuticals and personal care products (PPCPs) were investigated in the surface water of Jiulong River estuary in the southeast of China in spring, wet season, summer, autumn and winter. Results demonstrated a wide distribution of PPCPs in Jiulong River estuary, where 34 PPCPs were detected at least once and 5 PPCPs were detected in all the samples, including caffeine, diclofenac, metoprolol, methyl paraben, and propyl paraben. Spatial and seasonal variations were observed. Special emphasis was placed on the PPCP fate in the estuary. Most PPCPs showed a non-conservative behavior in the estuary, while the non-steroidal anti-inflammatory drugs and bisphenol A showed a pseudo-conservative behavior. The non-conservative and pseudo-conservative behavior was attributed to the combination of the seawater dilution, the introduction of PPCPs via the sewage water, and the physical, chemical, or biological removal processes. Furthermore, PPCP concentrations showed drastic variations in the turbidity maximum zones. To our best knowledge, this is the first work to indicate the pseudo-conservative behavior of PPCPs in the estuary, and to show the drastic variations of PPCPs in the turbidity maximum zone. In addition, the ratio of labile to conservative PPCPs was calculated to track the source of untreated sewage contamination. Results showed a significantly higher ratio compared to the average value in WWTP effluents, indicating the ubiquitous discharge of untreated domestic wastewater in Jiulong River estuary. In addition, the high ratio of bisphenol A to conservative PPCPs implied the potential input of untreated industrial wastewater in Jiulong River estuary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Organic Carbon Storage in China's Urban Areas

    Science.gov (United States)

    Zhao, Shuqing; Zhu, Chao; Zhou, Decheng; Huang, Dian; Werner, Jeremy

    2013-01-01

    China has been experiencing rapid urbanization in parallel with its economic boom over the past three decades. To date, the organic carbon storage in China's urban areas has not been quantified. Here, using data compiled from literature review and statistical yearbooks, we estimated that total carbon storage in China's urban areas was 577±60 Tg C (1 Tg  = 1012 g) in 2006. Soil was the largest contributor to total carbon storage (56%), followed by buildings (36%), and vegetation (7%), while carbon storage in humans was relatively small (1%). The carbon density in China's urban areas was 17.1±1.8 kg C m−2, about two times the national average of all lands. The most sensitive variable in estimating urban carbon storage was urban area. Examining urban carbon storages over a wide range of spatial extents in China and in the United States, we found a strong linear relationship between total urban carbon storage and total urban area, with a specific urban carbon storage of 16 Tg C for every 1,000 km2 urban area. This value might be useful for estimating urban carbon storage at regional to global scales. Our results also showed that the fraction of carbon storage in urban green spaces was still much lower in China relative to western countries, suggesting a great potential to mitigate climate change through urban greening and green spaces management in China. PMID:23991014

  5. Brominated flame retardants in mangrove sediments of the Pearl River Estuary, South China: spatial distribution, temporal trend and mass inventory.

    Science.gov (United States)

    Zhang, Zai-Wang; Sun, Yu-Xin; Sun, Kai-Feng; Xu, Xiang-Rong; Yu, Shen; Zheng, Tian-Ling; Luo, Xiao-Jun; Tian, Yun; Hu, Yong-Xia; Diao, Zeng-Hui; Mai, Bi-Xian

    2015-03-01

    Sediments were collected from three mangrove wetlands in the Pearl River Estuary (PRE) of South China to investigate spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Concentrations of ΣPBDEs, DBDPE and BTBPE in mangrove sediments of the PRE ranged from 1.25-206, 0.364-34.9, and not detected-0.794 ng g(-1) dry weight, respectively. The highest concentrations of ΣPBDEs, DBDPE and BTBPE were found at the mangrove wetland from Shenzhen, followed by Zhuhai and Guangzhou, showing the dependence on the proximity to urban areas. PBDEs were the predominant brominated flame retardants (BFRs) in mangrove sediments. The concentrations of ΣPBDEs, DBDPE and BTBPE in sediment cores showed an increasing trend from the bottom to top layers, reflecting the increasing usage of these BFRs. The inventories of ΣPBDEs, DBDPE and BTBPE in mangrove sediments were 1962, 245, and 4.10 ng cm(-2), respectively. This is the first study to report the occurrence of DBDPE and BTBPE in mangrove ecosystems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Organochlorine pesticides in surface sediments and suspended particulate matters from the Yangtze estuary, China

    International Nuclear Information System (INIS)

    Liu Min; Cheng Shubo; Ou Dongni; Yang Yi; Liu Hualin; Hou Lijun; Gao Lei; Xu Shiyuan

    2008-01-01

    Total HCHs' and total DDTs' levels in surface sediments (SS) ranged from 0.5 to 17.5 ng g -1 and from 0.9 to 33.1 ng g -1 , averaged 6.0 and 8.2 ng g -1 , respectively. Total HCHs' and total DDTs' levels in suspended particulate matters (SPM) varied from 6.2 to 14.8 ng g -1 with a mean value of 12.3 ng g -1 and were from 3.4 to 25.7 ng g -1 with an average of 16.4 ng g -1 , respectively. Lindane is the main HCHs' source and continuing use in the Yangtze Delta areas of 'pure' γ-HCH (lindane) rather than technical HCH (a mix of largely α- and some γ-HCH). DDTs in SS are mainly accumulated in history. However, high DDT fractions in SPM are indicators of new input of typical dicofol type DDT from 2002 to 2004. It can be seen that most samples from the Yangtze estuary were in ranges where adverse biological effects are expected, either occasionally or frequently. - SPM, more polluted than SS, had similar contaminant composition. New input of lindane and typical dicofol type DDT were found and Yangtze estuary had been affected adversely

  7. Organochlorine pesticides in surface sediments and suspended particulate matters from the Yangtze estuary, China

    Energy Technology Data Exchange (ETDEWEB)

    Liu Min [Department of Geography, Key Laboratory of Geographical Information Sciences of the State Ministry of Education, East China Normal University, Shanghai 200062 (China)], E-mail: mliu@geo.ecnu.edu.cn; Cheng Shubo; Ou Dongni [Department of Geography, Key Laboratory of Geographical Information Sciences of the State Ministry of Education, East China Normal University, Shanghai 200062 (China); Yang Yi [Vienna University, Department of Environmental Geoscience (Austria); Liu Hualin [Department of Geography, Key Laboratory of Geographical Information Sciences of the State Ministry of Education, East China Normal University, Shanghai 200062 (China); Hou Lijun [State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062 (China); Gao Lei; Xu Shiyuan [Department of Geography, Key Laboratory of Geographical Information Sciences of the State Ministry of Education, East China Normal University, Shanghai 200062 (China)

    2008-11-15

    Total HCHs' and total DDTs' levels in surface sediments (SS) ranged from 0.5 to 17.5 ng g{sup -1} and from 0.9 to 33.1 ng g{sup -1}, averaged 6.0 and 8.2 ng g{sup -1}, respectively. Total HCHs' and total DDTs' levels in suspended particulate matters (SPM) varied from 6.2 to 14.8 ng g{sup -1} with a mean value of 12.3 ng g{sup -1} and were from 3.4 to 25.7 ng g{sup -1} with an average of 16.4 ng g{sup -1}, respectively. Lindane is the main HCHs' source and continuing use in the Yangtze Delta areas of 'pure' {gamma}-HCH (lindane) rather than technical HCH (a mix of largely {alpha}- and some {gamma}-HCH). DDTs in SS are mainly accumulated in history. However, high DDT fractions in SPM are indicators of new input of typical dicofol type DDT from 2002 to 2004. It can be seen that most samples from the Yangtze estuary were in ranges where adverse biological effects are expected, either occasionally or frequently. - SPM, more polluted than SS, had similar contaminant composition. New input of lindane and typical dicofol type DDT were found and Yangtze estuary had been affected adversely.

  8. Impacts of sea cucumber farming on biogeochemical characteristics in the Yellow River estuary, Northern China

    Science.gov (United States)

    Fu, Jing; Yokoyama, Hisashi; Cui, Baoshan; Zhou, Jin; Yan, Jiaguo; Ma, Xu; Shibata, Shozo

    2017-02-01

    To investigate the potential environmental effects of pond farming for Apostichopus japonicas in Yellow River estuary, we examined discrepancies of distance-based typical pollution indicators (TOC, TN, NO3-, NH4+, NO2- and PO43-) and biochemical tracers (δ13C and δ15N) in water column and sediment, as well as dietary characteristics of dominant macrobenthos between farming and non-farming areas. The results revealed that studied variables in water column showed no uniform spatial differences. Meanwhile, those in sediment displayed similar decrease tendencies from farming pond to the adjacent tidal flat, which was considered to represent the environmental effects of farming. Biochemical tracers (δ13C and δ15N) in both water column and sediment confirmed the origin of organic matters from the aquaculture waste. The detectable dispersion distance of aquaculture waste was restricted to an area within 50 m distance as determined by most variables in sediment (TOC, TN, NO3- and NH4+), particularly by C:N ratio and δ13C with which origins of the wastes were traced. Bayesian mixing models indicated that in the farming area BMA had a larger contribution, while POM(marine) showed a smaller contribution to the diets of Helice tridens and Macrophthalmus abbreviates compared to those in the non-farming area. The overall results showed that pond farming for Apostichopus japonicus in the Yellow River estuary altered the local environment to a certain extent. For methodological consideration, sediment biogeochemical characteristics as a historical recorder much more effectively reflected aquaculture waste accumulation, and stable isotope approaches are efficient in tracing the origin and extent of various allogenous sources.

  9. [Distributions and seasonal variations of total dissolved inorganic arsenic in the estuaries and coastal area of eastern Hainan].

    Science.gov (United States)

    Cao, Xiu-Hong; Ren, Jing-Ling; Zhang, Gui-Ling; Zhang, Jin-E; Du, Jin-Zhou; Zhu, De-Di

    2012-03-01

    The concentrations of total dissolved inorganic arsenic (TDIAs) were measured by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS). Two cruises were carried out in the river, estuary, coastal area and groundwater of eastern Hainan in December 2006 and August 2007. The concentrations of TDIAs in the Wanquan and Wenchang/Wenjiao rivers and their estuaries, coastal area in December 2006 were 4.0-9.4, 1.3-13.3, 13.3-17.3 nmol x L(-1), respectively. The concentrations of TDIAs in the Wanquan and Wenchang/Wenjiao rivers and their estuaries, coastal area in August 2007 were 1.6-15.5, 2.4-15.9, 10.8-17.6 nmol x L(-1), respectively. There was no significantly seasonal variation of TDIAs in the rivers and estuaries during the dry and wet seasons. Compared with other areas in the world, the concentration of TDIAs in the Eastern Hainan remained at pristine levels. TDIAs showed conservatively mixing in the both estuaries. The concentration of TDIAs of groundwater was below detection limit (BDL)-41.7 nmol x L(-1). The submarine groundwater discharge (SGD) to the coastal area was estimated in the drainage basin of Wenchang/Wenjiao river based on the average concentration of TDIAs in the groundwater and SGD water discharge, with the value of 1 153 mol x a(-1). Budget estimation indicated that the SGD discharge is one of the important sources of arsenic in the coastal area.

  10. 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

  11. An analytical solution for tidal propagation in the Yangtze Estuary, China

    Directory of Open Access Journals (Sweden)

    E. F. Zhang

    2012-09-01

    Full Text Available An analytical model for tidal dynamics has been applied to the Yangtze Estuary for the first time, to describe the tidal propagation in this large and typically branched estuary with three-order branches and four outlets to the sea. This study shows that the analytical model developed for a single-channel estuary can also accurately describe the tidal dynamics in a branched estuary, particularly in the downstream part. Within the same estuary system, the North Branch and the South Branches have a distinct tidal behaviour: the former being amplified demonstrating a marine character and the latter being damped with a riverine character. The satisfactory results for the South Channel and the South Branch using both separate and combined topographies confirm that the branched estuary system functions as an entity. To further test these results, it is suggested to collect more accurate and dense bathymetric and tidal information.

  12. Organophosphorus flame retardants in mangrove sediments from the Pearl River Estuary, South China.

    Science.gov (United States)

    Hu, Yong-Xia; Sun, Yu-Xin; Li, Xiao; Xu, Wei-Hai; Zhang, Ying; Luo, Xiao-Jun; Dai, Shou-Hui; Xu, Xiang-Rong; Mai, Bi-Xian

    2017-08-01

    Forty-eight surface sediments were collected from three mangrove wetlands in the Pearl River Estuary (PRE) of South China to investigate the distribution of organophosphorus flame retardants (OPFRs) and the relationship between OPFRs and microbial community structure determined by phospholipid fatty acid. Concentrations of ΣOPFRs in mangrove sediments of the PRE ranged from 13.2 to 377.1 ng g -1 dry weight. Levels of ΣOPFRs in mangrove sediments from Shenzhen and Guangzhou were significantly higher than those from Zhuhai, indicating that OPFRs were linked to industrialization and urbanization. Tris(chloropropyl)phosphate was the predominant profile of OPFRs in mangrove sediments from Shenzhen (38.9%) and Guangzhou (35.0%), while the composition profile of OPFRs in mangrove sediments from Zhuhai was dominated by tris(2-chloroethyl) phosphate (25.5%). The mass inventories of OPFRs in the mangrove sediments of Guangzhou, Zhuhai and Shenzhen were 439.5, 133.5 and 662.3 ng cm -2 , respectively. Redundancy analysis revealed that OPFRs induced a shift in the structure of mangrove sediment microbial community and the variations were significantly correlated with tris(1,3-dichloro-2-propyl)phosphate and tris(2-butoxyethyl) phosphate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Tidal impact on the dynamic behavior of dissolved pharmaceuticals in the Yangtze Estuary, China.

    Science.gov (United States)

    Zhao, Heng; Zhou, Jun Liang; Zhang, Jing

    2015-12-01

    The dynamic behavior of 24 dissolved pharmaceuticals over tidal cycles in the Yangtze Estuary, China was studied to assess the tidal impact on the fate of pharmaceutical residues. The results show that most pharmaceuticals were frequently detected with concentrations from below detection to 27.2 ng/L, with sulfamethoxazole, sulfamethazine, erythromycin, thiamphenicol and florfenicol dominating. During tidal cycles, pharmaceutical concentrations decreased during tidal rise, then increasing during tidal receding for all locations, except at site S2 which showed an opposite trend due to unique water movement there. It was observed that most compounds showed a non-conservative behavior, while diazepam and sulfamethoxazole displayed a conservative behavior. The pharmaceutical concentrations were found to increase with dissolved organic carbon (DOC) concentration, suggesting DOC as a carrier of pharmaceuticals. In addition, many compounds showed a significant negative relationship with suspended particulate matter (SPM) concentration, indicating SPM-water interactions as a control of pharmaceutical behavior in estuarine environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 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.

  15. Mathematical modelling for distribution of heavy metals in estuary area of Red River (Vietnam)

    Science.gov (United States)

    Nguyen, N. T. T.; Volkova, I. V.

    2018-05-01

    In this paper, the authors studied the features of spatial distribution of some heavy metals (Pb, Hg, As) in the system “suspended substance - bottom sediments” in the mouth area of the Red River (Vietnam). A mathematical modelling for diffusion processes of heavy metals in a suspended form, in bottom sediments and the spatial analysis for the results of these models were proposed and implemented. The studies were carried out during main hydrological seasons of 2014 - 2016 (during the flood and inter-natal periods). The propagation of heavy metals was modeled by solving the equation of turbulent diffusion. A spatial analysis of the content of heavy metals in the suspended form and in the bottom sediments was implemented by using the interpolation model in ArcGIS 10.2.2. The distribution of Pb, Hg, As concentration of the suspended form and bottom sediment phases in the estuary area of the Red River was characterized by maximum in the mouths of the branches and general decreasing gradient towards the sea. Maximum concentrations of Pb, Hg in suspended forms were observed in the surface layer of water at the river-sea barrier. The content of Hg and As in the estuary region of the Red River was observed in the following order: SSsurfBS.

  16. Characterizing the parent and alkyl polycyclic aromatic hydrocarbons in the Pearl River Estuary, Daya Bay and northern South China Sea: Influence of riverine input

    International Nuclear Information System (INIS)

    Yuan, Ke; Wang, Xiaowei; Lin, Li; Zou, Shichun; Li, Yan; Yang, Qingshu; Luan, Tiangang

    2015-01-01

    Distributions of 31 parent polycyclic aromatic hydrocarbons (PAHs) and 29 alkyl PAHs in surface sediments of the Pearl River Estuary (PRE), Daya Bay (DYB) and northern South China Sea (SCS) were examined to study the influence of riverine input. It was found that the contributions of riverine input to sediment PAHs in PRE was much higher than other areas. However, higher proportion of alkyl PAHs and low molecular weight PAHs in DYB and the northern SCS was observed, indicating their different sources. Nevertheless, the sediment PAHs in PRE were heterogeneous and affected by the hydrodynamic conditions. The high molecular weight PAHs were dominant in PRE and enriched in the depositional area of suspended particular matter (SPM). Moreover, the concentration of PAHs in SPM was similar to those in surface sediments and dominated in water columns. Therefore, SPM played a very important role in transportation and distribution of PAHs in PRE. - Highlights: • EPA 16 PAHs contributed a small amount of total PAHs. • Alkyl PAHs showed different behaviors from parent PAHs. • High weight PAHs preferably indicated riverine input. • PAHs distribution in sediment was related with the suspended particle deposition. - Suspended particular matter played a very important role in distribution of PAHs in tide-dominated estuary and alkyl PAHs showed different behavior from parent PAHs

  17. An analytical solution for tidal propagation in the Yangtze Estuary, China

    NARCIS (Netherlands)

    Zhang, E.F.; Savenije, H.H.G.; Chen, S.L.; Mao, X.H.

    2012-01-01

    An analytical model for tidal dynamics has been applied to the Yangtze Estuary for the first time, to describe the tidal propagation in this large and typically branched estuary with three-order branches and four outlets to the sea. This study shows that the analytical model developed for a

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

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonghang, E-mail: yonghang_xu@163.com [Open Laboratory of Ocean and Coast Environmental Geology, Third Institute of Oceanography State Oceanic Administration, 178 Daxue Road, Xiamen 361005 (China); Sun, Qinqin [Fujian Provincial Key Laboratory of Coast and Island Management Technology Study, Fujian Institute of Oceanography, Xiamen 361013 (China); Yi, Liang [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029 (China); Yin, Xijie; Wang, Aijun; Li, Yunhai; Chen, Jian [Open Laboratory of Ocean and Coast Environmental Geology, Third Institute of Oceanography State Oceanic Administration, 178 Daxue Road, Xiamen 361005 (China)

    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 < 1.5, indicating minor 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 {sup 206}Pb/{sup 207}Pb and {sup 206}Pb/{sup 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. - Highlights: • Grain size, clay mineral and Pb isotope were used to identify sediment sources. • The contribution of Yangtze River to northern of Taiwan Strait was quantified. • Enrichment factors indicated Cu and Pb have increased over the last decades. • Coal combustion was the prevailing contamination source. • The anthropogenic Pb concentrations ranged from 6% in 1950 to 23.7% in 2010.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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 < 1.5, indicating minor 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. - Highlights: • Grain size, clay mineral and Pb isotope were used to identify sediment sources. • The contribution of Yangtze River to northern of Taiwan Strait was quantified. • Enrichment factors indicated Cu and Pb have increased over the last decades. • Coal combustion was the prevailing contamination source. • The anthropogenic Pb concentrations ranged from 6% in 1950 to 23.7% in 2010

  20. Organic carbon and nitrogen stable isotopes in the intertidal sediments from the Yangtze Estuary, China

    International Nuclear Information System (INIS)

    Liu, M. . E-mail mliu@geo.ecnu.edu.cn; Hou, L.J.; Xu, S.Y.; Ou, D.N.; Yang, Y.; Yu, J.; Wang, Q.

    2006-01-01

    The natural isotopic compositions and C/N elemental ratios of sedimentary organic matter were determined in the intertidal flat of the Yangtze Estuary. The results showed that the ratios of carbon and nitrogen stable isotopes were respectively -29.8 per mille to - 26.0 per mille and 1.6 per mille -5.5 per mille in the flood season (July), while they were -27.3 per mille to - 25.6 per mille and 1.7 per mille -7.8 per mille in the dry season (February), respectively. The δ 13 C signatures were remarkably higher in July than in February, and gradually increased from the freshwater areas to the brackish areas. In contrast, there were relatively complex seasonal and spatial changes in stable nitrogen isotopes. It was also reflected that δ 15 N and C/N compositions had been obviously modified by organic matter diagenesis and biological processing, and could not be used to trace the sources of organic matter at the study area. In addition, it was considered that the mixing inputs of terrigenous and marine materials generally dominated sedimentary organic matter in the intertidal flat. The contribution of terrigenous inputs to sedimentary organic matter was roughly estimated according to the mixing balance model of stable carbon isotopes

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

    Science.gov (United States)

    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.

  2. The changes in trace metal contamination over the last decade in surface sediments of the Pearl River Estuary, South China.

    Science.gov (United States)

    Chen, Baowei; Liang, Ximei; Xu, Weihai; Huang, Xiaoping; Li, Xiangdong

    2012-11-15

    Surface sediments can provide useful information on the recent pollution status of an estuary. One recent field survey was carried out in the Pearl River Estuary (PRE), South China in 2011. The comparisons with previous surveys demonstrated that the concentrations of Ni and Pb in the PRE declined over the last decade, but the concentration of Cu increased in the same time frame. The significant decreases in the concentrations of Ni and Pb were probably due to a reduction of anthropogenic inputs, such as industrial wastewater, into the PRE environment, and the ban imposed on leaded gasoline. Statistical analyses have consistently demonstrated that the process of the sedimentation of fine particles was the dominant factor in controlling the transport and distribution of trace metals in the PRE. The riverine trace metals generally displayed a pattern of diffusion from the northwest to the southeast in the estuary. However, the riparian industrial activities at the east bank of the inner PRE caused significant metal contamination in sediments. In general, effective pollution control measures in the PRD region have decreased the levels of some trace metals in the entire PRE over the last decade with the exception of Cu. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Over one hundred years of trace metal fluxes in the sediments of the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Ip, C.C.M.; Li, X.D.; Zhang, G.; Farmer, J.G.; Wai, O.W.H.; Li, Y.S.

    2004-01-01

    The rapid economic development in the Pearl River Delta (PRD) region in South China in the last three decades has had a significant impact on the local environment. Estuarine sediment is a major sink for contaminants and nutrients in the surrounding ecosystem. The accumulation of trace metals in sediments may cause serious environmental problems in the aquatic system. Thirty sediment cores were collected in the Pearl River Estuary (PRE) in 2000 for a study on trace metal pollution in this region. Heavy metal concentrations and Pb isotopic compositions in the four 210 Pb-dated sediment cores were determined to assess the fluxes in metal deposits over the last one hundred years. The concentrations of Cu, Pb and Zn in the surface sediment layers were generally elevated when compared with the sub-surface layers. There has been a significant increase in inputs of Cu, Pb and Zn in the PRE since the 1970s. The results also showed that different sampling locations in the estuary received slightly different types of inputs. Pb isotopic composition data indicated that the increased Pb in the recent sediments was of anthropogenic origin. The results of trace metal influxes showed that about 30% of total Pb and 15% of total Zn in the sediments in the 1990s were from anthropogenic sources. The combination of trace metal analysis, Pb isotopic composition and 210 Pb dating in an estuary can provide vital information on the long-term accumulation of metals in sediments

  4. Optimization of sample preparation and chromatography for the determination of perfluoroalkyl acids in sediments from the Yangtze Estuary and East China Sea.

    Science.gov (United States)

    Wang, Qian-Wen; Yang, Gui-Peng; Zhang, Ze-Ming; Zhang, Jing

    2018-08-01

    Perfluoroalkyl acids (PFAAs) are ubiquitous pollutants present in various environmental media, including marine sediments. A method was proposed for the determination of 17 target PFAA analytes in marine sediment samples (n = 49) collected from the Yangtze Estuary and East China Sea. The proposed method involves the use of an optimized pretreatment procedure and ultrahigh-performance liquid chromatography electrospray ionization-tandem mass spectrometry in dynamic multiple reaction monitoring mode. The method relied on extraction cycles using methanol followed by concentration, filtration, and small volume injection to UHPLC-MS/MS. The recovery, time efficiency, and detection limit of the proposed method are improved relative to those of traditional methods. Limits of detection varied from 0.003 to 0.045 ng/g, and spike recoveries to sediment ranged from 90% to 110% with suitable precisions (1.7%-14.6%). PFAAs were widely present in the samples, and ΣPFAAs ranged from 0.67 ng/g dw to 36.75 ng/g dw. Results indicated that terrigenous input strongly influences PFAA distribution in sediments from the study areas. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) were identified as the dominant perfluorocarboxylic acid (PFCA) and perfluoroalkylsulfonate (PFSA) in sediment samples from the Yangtze Estuary and the East China Sea. Preliminary environmental risk assessment indicated that PFOS may pose a higher environmental risk than PFOA. Furthermore, risk quotient values indicated that PFOS poses a significant risk to the aquatic ecosystem of the study areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. INDONESIAN TRADE UNDER CHINA FREE TRADE AREA

    Directory of Open Access Journals (Sweden)

    Tavi Supriana

    2011-09-01

    Full Text Available This paper investigates the implementation of CAFTA (China-Asean Free Trade Area on the international trade flows across Indonesia, China and the rest of ASEAN using a gravitation model. It finds the evidence that the influence of diversion and creation effects on China are significant, while the influence of both effects on Indonesia are not significant. It also finds that the diversion effect, which leads to a decrease in society’s wealth, is greater than that of the creation effect. As a consequence, the gap across countries involved in the trade agreement is wider. Keywords: CAFTA, gravitation model, diversion effect, creation effectJEL classification numbers: F13, F14, F15

  6. Spatial distribution and risk assessment of heavy metals in sediments of Shuangtaizi estuary, China

    International Nuclear Information System (INIS)

    Li, Chen; Song, Chengwen; Yin, Yanyan; Sun, Menghan; Tao, Ping; Shao, Mihua

    2015-01-01

    Highlights: • Five heavy metals are analyzed in the sediments from Shuangtaizi estuary. • Particle size of the sediment effects the concentration of heavy metals. • Pb, Cu, Zn and Hg pose low ecological risks in the Shuangtaizi estuary. • Heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd. - Abstract: In order to evaluate the spatial distribution and potential ecological risk of Pb, Cu, Zn, Cd, and Hg, the surface sediments were collected from 18 sites in the Shuangtaizi estuary. The concentrations of Pb, Cu, Zn, Cd, and Hg were analyzed by atomic absorption spectrophotometry and atomic fluorescence spectrometry after digestion. The particle sizes of the sediments were analyzed using a laser diffraction particle size analyzer. The results show that the heavy metal contents in the sediments are observed in the following order: Zn (18.25–126.75 mg/kg) > Pb (4.38–9.65 mg/kg) > Cu (1.80–17.68 mg/kg) > Cd (0.241–0.764 mg/kg) > Hg (0.007–0.021 mg/kg). In comparison with the concentrations of heavy metals in other regions, the concentrations of Pb, Cu, and Zn in the Shuangtaizi estuary are generally low, and the Cd concentrations are close to those reported in other regions. Both the potential ecological risk index and the geoaccumulation index reveal that the heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  9. Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): Sources and depositional history

    International Nuclear Information System (INIS)

    Martins, Cesar C.; Bicego, Marcia C.; Mahiques, Michel M.; Figueira, Rubens C.L.; Tessler, Moyses G.; Montone, Rosalinda C.

    2011-01-01

    Highlights: → In early 1980s, Santos Estuary became known as one of the worst polluted in the world. → PAHs levels were similar to the values reported for marine sediments worldwide. → PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin). → The decline of oil consumption due to the world oil crisis (late 1970s) was shown. → The input of organic pollutants is a historical problem for the Santos Estuary. - Abstract: Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatao industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  12. Sources and distribution of aromatic hydrocarbons in a tropical marine protected area estuary under influence of sugarcane cultivation.

    Science.gov (United States)

    Arruda-Santos, Roxanny Helen de; Schettini, Carlos Augusto França; Yogui, Gilvan Takeshi; Maciel, Daniele Claudino; Zanardi-Lamardo, Eliete

    2018-05-15

    Goiana estuary is a well preserved marine protected area (MPA) located on the northeastern coast of Brazil. Despite its current state, human activities in the watershed represent a potential threat to long term local preservation. Dissolved/dispersed aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments across the estuarine salt gradient. Concentration of aromatic hydrocarbons was low in all samples. According to results, aromatic hydrocarbons are associated to suspended particulate matter (SPM) carried to the estuary by river waters. An estuarine turbidity maximum (ETM) was identified in the upper estuary, indicating that both sediments and contaminants are trapped prior to an occasional export to the adjacent sea. PAHs distribution in sediments were associated with organic matter and mud content. Diagnostic ratios indicated pyrolytic processes as the main local source of PAHs that are probably associated with sugarcane burning and combustion engines. Low PAH concentrations probably do not cause adverse biological effects to the local biota although their presence indicate anthropogenic contamination and pressure on the Goiana estuary MPA. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Tracking historical lead pollution in the coastal area adjacent to the Yangtze River Estuary using lead isotopic compositions

    International Nuclear Information System (INIS)

    Hao Yunchao; Guo Zhigang; Yang Zuosheng; Fan, Dejiang; Fang Ming; Li Xiangdong

    2008-01-01

    The rapid economic development in the Yangtze River Delta (YRD), China in the last three decades has had a significant impact on the environment of the East China Sea (ECS). Lead isotopic compositions of a 210 Pb dated sediment core collected from the coastal ECS adjacent to the Yangtze River Estuary were analyzed to track the Pb pollution in the region. The baseline Pb concentration in the coastal ECS sediments before the industrialization in China was 32 μg g -1 , and the corresponding 206 Pb/ 207 Pb ratio was 1.195. The high-resolution profiles of Pb flux and 206 Pb/ 207 Pb ratios had close relationships with the economic development and the history of the use of leaded gasoline in China, and they were clearly different from those of most European countries and United States. - The combination of Pb concentration, sedimentary flux, Pb isotopic composition and 210 Pb dating in the coastal ECS sediments revealed the historical Pb pollution in China

  15. 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.

  16. Heavy metal pollution in coastal areas of South China: A review

    International Nuclear Information System (INIS)

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

    2013-01-01

    Highlights: • Heavy metal contamination in coastal areas of South China has been reviewed. • Heavy metal levels were closely related to economic development in past decades. • Heavy metal levels from Hong Kong continually decreased from the early 1990s. • Higher concentrations of heavy metals were found in mollusk. • Levels of heavy metals in part of seafood exceeded the safety limit. -- Abstract: 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 1990s. 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

  17. Using a dual isotopic approach to trace sources and mixing of sulphate in Changjiang Estuary, China

    International Nuclear Information System (INIS)

    Li Siliang; Liu Congqiang; Patra, Sivaji; Wang Fushun; Wang Baoli; Yue Fujun

    2011-01-01

    Highlights: → Changjiang Estuary plays an important role in transportation of the water and solute. → The dual isotopic method could be used to understand sulfate biogeochemistry in estuaries. → Mixing processes should be a major factor involved in the distribution of water and sulphate. → Sulphate in the Changjiang River mainly derived from atmospheric deposition, evaporite dissolution and sulphide oxidation. - Abstract: The dual isotopic compositions of dissolved SO 4 2- in aquatic systems are commonly used to ascertain SO 4 2- sources and possible biogeochemical processes. In this study, the physical parameters, major anions and isotopic compositions of SO 4 2- in water samples from Changjiang River (Nanjin) to the East Sea in Changjiang Estuary were determined. The salinity ranged from 0 per mille to 32.3 per mille in the estuary water samples. The Cl - ,SO 4 2- concentrations and δ 18 O-H 2 O values followed the salinity variations from freshwater to seawater, which indicated that mixing processes might be a major factor involved in the distribution of water and solutes. The contents and isotopic compositions of SO 4 2- suggested that atmospheric deposition, evaporite dissolution and sulphide oxidation were the major sources of dissolved SO 4 2- in the freshwater of Changjiang River. In addition, the mixing model calculated by contents and isotopic compositions of SO 4 2- indicated that the mixing of freshwater and sea water was the major factor involved in SO 4 2- distribution in Changjiang Estuary. However, slightly elevated δ 18 O-SO 4 values were observed in the turbidity maximum zone, which suggested that biological processes might affect the O isotopic compositions of SO 4 2- there.

  18. Status, trends, and changes in freshwater inflows to bay systems in the Corpus Christi Bay National Estuary Program study area

    Science.gov (United States)

    Asquith, W.H.; Mosier, J. G.; Bush, P.W.

    1997-01-01

    This report presents the results of a study to quantify current (1983–93) mean freshwater inflows to the six bay systems (open water and wetlands) in the Corpus Christi Bay National Estuary Program study area, to test for historical temporal trends in inflows, and to quantify historical and projected changes in inflows. The report also addresses the adequacy of existing data to estimate freshwater inflows.

  19. Relationship of photosynthetic carbon fixation with environmental changes in the Jiulong River estuary of the South China Sea, with special reference to the effects of solar UV radiation

    International Nuclear Information System (INIS)

    Li Gang; Gao Kunshan; Yuan Dongxing; Zheng Ying; Yang Guiyuan

    2011-01-01

    Highlights: → C-fixation is the highest in turbidity front, though UV resulted in higher inhibition. → Increased availability of CO 2 appeared to stimulate photosynthetic machinery. → Osmotic stress made phytoplankton more sensitive to UV. - Abstract: Phytoplankton cells in estuary waters usually experience drastic changes in chemical and physical environments due to mixing of fresh and seawaters. In order to see their photosynthetic performance in such dynamic waters, we measured the photosynthetic carbon fixation by natural phytoplankton assemblages in the Jiulong River estuary of the South China Sea during April 24-26 and July 24-26 of 2008, and investigated its relationship with environmental changes in the presence or the absence of UV radiation. Phytoplankton biomass (Chl a) decreased sharply from the river-mouth to seawards (17.3-2.1 μg L -1 ), with the dominant species changed from chlorophytes to diatoms. The photosynthetic rate based on Chl a at noon time under PAR-alone increased from 1.9 μg C (μg Chl a) -1 L -1 in low salinity zone (SSS -1 L -1 in turbidity front (SSS within 10-20), and then decreased to 2.1 μg C (μg Chl a) -1 L -1 in mixohaline zone (SSS > 20); accordingly, the carbon fixation per volume of seawater increased from 12.8 to 149 μg C L -1 h -1 , and decreased to 14.3 μg C L -1 h -1 . Solar UVR caused the inhibition of carbon fixation in surface water of all the investigated zones, by 39% in turbidity area and 7-10% in freshwater or mixohaline zones. In the turbidity zone, higher availability of CO 2 could have enhanced the photosynthetic performance; while osmotic stress might be responsible for the higher sensitivity of phytoplankton assemblages to solar UV radiation.

  20. Effects of Spartina alterniflora Invasion on Soil Respiration in the Yangtze River Estuary, China

    Science.gov (United States)

    Bu, Naishun; Qu, Junfeng; Li, Zhaolei; Li, Gang; Zhao, Hua; Zhao, Bin; Li, Bo; Chen, Jiakuan; Fang, Changming

    2015-01-01

    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. PMID:25799512

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

    Science.gov (United States)

    Bu, Naishun; Qu, Junfeng; Li, Zhaolei; Li, Gang; Zhao, Hua; Zhao, Bin; Li, Bo; Chen, Jiakuan; Fang, Changming

    2015-01-01

    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.

  2. 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.

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

    International Nuclear Information System (INIS)

    Gao Xuelu; Chen Shaoyong; Xie Xueliang; Long Aimin; Ma Fujun

    2007-01-01

    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 μg g -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 μg g -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

  4. The characteristics of heat flow in the Shenhu gas hydrate drilling area, northern South China Sea

    Science.gov (United States)

    Xu, Xing; Wan, Zhifeng; Wang, Xianqing; Sun, Yuefeng; Xia, Bin

    2016-12-01

    Marine heat flow is of great significance for the formation and occurrence of seabed oil, gas and gas hydrate resources. Geothermal gradient is an important parameter in determining the thickness of the hydrate stability zone. The northern slope of the South China Sea is rich in gas hydrate resources. Several borehole drilling attempts were successful in finding hydrates in the Shenhu area, while others were not. The failures demand further study on the distribution regularities of heat flow and its controlling effects on hydrate occurrence. In this study, forty-eight heat flow measurements are analyzed in the Shenhu gas hydrate drilling area, located in the northern South China Sea, together with their relationship to topography, sedimentary environment and tectonic setting. Canyons are well developed in the study area, caused mainly by the development of faults, faster sediment supply and slumping of the Pearl River Estuary since the late Miocene in the northern South China Sea. The heat flow values in grooves, occurring always in fault zones, are higher than those of ridges. Additionally, the heat flow values gradually increase from the inner fan, to the middle fan, to the external fan subfacies. The locations with low heat flow such as ridges, locations away from faults and the middle fan subfacies, are more conducive to gas hydrate occurrence.

  5. Effects of cluster land reclamation projects on storm surge in Jiaojiang Estuary, China

    Directory of Open Access Journals (Sweden)

    Zhi-lin Sun

    2017-01-01

    Full Text Available Variations in coastline geometry caused by coastal engineering affect tides, storm surges, and storm tides. Three cluster land reclamation projects have been planned for construction in the Jiaojiang Estuary during the period from 2011 to 2023. They will cause significant changes in coastline geometry. In this study, a surge-tide coupled model was established based on a three-dimensional finite-volume coastal ocean model (FVCOM. A series of numerical experiments were carried out to investigate the effects of variations in coastline geometry on tides, storm surges, and storm tides. This model was calibrated using data observed at the Haimen and Ruian gauge stations and then used to reproduce the tides, storm surges, and storm tides in the Jiaojiang Estuary caused by Typhoon Winnie in 1997. Results show that the high tide level, peak storm surge, and high storm tide level at the Haimen Gauge Station increased along with the completion of reclamation projects, and the maximum increments caused by the third project were 0.13 m, 0.50 m, and 0.43 m, respectively. The envelopes with maximum storm tide levels of 7.0 m and 8.0 m inside the river mouth appeared to move seaward, with the latter shifting 1.8 km, 3.3 km, and 4.4 km due to the first project, second project, and third project, respectively. The results achieved in this study contribute to reducing the effects of, and preventing storm disasters after the land reclamation in the Jiaojiang Estuary.

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

    International Nuclear Information System (INIS)

    Zhang Yuanzhi; Lin Hui; Chen, Chuqun; Chen Liding; Zhang Bing; Gitelson, Anatoly A

    2011-01-01

    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 -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 -3 and total suspended matter from 9.9 to 21.5 g m -3 . A close relationship was found between chl-a concentration and total suspended matter concentration with the determining coefficient (R 2 ) above 0.89. The MBR calculated in the spectral bands of MODIS proved to be a good proxy for chl-a concentration (R 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 -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.

  7. Depositional history of sedimentary linear alkylbenzenes (LABs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil)

    International Nuclear Information System (INIS)

    Martins, Cesar C.; Bicego, Marcia C.; Mahiques, Michel M.; Figueira, Rubens C.L.; Tessler, Moyses G.; Montone, Rosalinda C.

    2010-01-01

    This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by 137 Cs. Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide. LAB concentrations increased towards the surface, indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis. Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels. Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area. - The contamination history of a large South American industrial coastal area indicated by molecular indicator of sewage input.

  8. Territorial disputes simmer in areas of South China Sea

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that China's award of an exploration cooperation contact in the Nansha area of the South China Sea has revived territorial disputes in the area centering ton the Spratly and Paracel islands. The key dispute is between China and Viet Nam, which earlier engaged in military action over ownership of the islands, believed to have world class potential for hydrocarbon discoveries. Those two nations, as well as Brunei, Malaysia, Philippines, and Taiwan, lay claim to overlapping boundaries of the Spratly Islands. Separately, China and Viet Nam dispute territorial claims in the Paracels. Tensions continue to mount, and regional governments are trying to negotiate compromises to avoid a repeat of warfare

  9. [Spatiotemporal dynamic fuzzy evaluation of wetland environmental pollution risk in Dayang estuary of Liaoning Province, Northeast China based on remote sensing].

    Science.gov (United States)

    Sun, Yong-Guang; Zhao, Dong-Zhi; Zhang, Feng-Shou; Wei, Bao-Quan; Chu, Jia-Lan; Su, Xiu

    2012-11-01

    Based on the aerial image data of Dayang estuary in 2008, and by virtue of Analytic Hierarchy Process (AHP) , remote sensing technology, and GIS spatial analysis, a spatiotemporal evaluation was made on the comprehensive level of wetland environmental pollution risk in Dayang estuary, with the impacts of typical human activities on the dynamic variation of this comprehensive level discussed. From 1958 to 2008, the comprehensive level of the environmental pollution risk in study area presented an increasing trend. Spatially, this comprehensive level declined from land to ocean, and showed a zonal distribution. Tourism development activities unlikely led to the increase of the comprehensive level, while human inhabitation, transportation, and aquaculture would exacerbate the risk of environmental pollution. This study could provide reference for the sea area use planning, ecological function planning, and pollutants control of estuary region.

  10. Natural 222Rn and 220Rn indicate the impact of the Water–Sediment Regulation Scheme (WSRS) on submarine groundwater discharge in the Yellow River estuary, China

    International Nuclear Information System (INIS)

    Xu, Bochao; Xia, Dong; Burnett, William C.; Dimova, Natasha T.; Wang, Houjie; Zhang, Longjun; Gao, Maosheng; Jiang, Xueyan; Yu, Zhigang

    2014-01-01

    Highlights: • 220 Rn and 222 Rn were combined to locate intensive SGD sites. • Influence of WSRS to SGD was found for the first time. • SGD was a dominant nutrient pathway in the Yellow River estuary. - Abstract: Submarine groundwater discharge (SGD) in estuaries brings important influences to coastal ecosystems. In this study, we observed significant SGD in the Yellow River estuary, including a fresh component, during the Water–Sediment Regulation Scheme (WSRS) period. We used the 222 Rn and 220 Rn isotope pair to locate sites of significant SGD within the study area. Three apparent SGD locations were found during a non-WSRS period, one of which became much more pronounced, according to the remarkably elevated radon levels, during the WSRS. Increased river discharge (from 245 m 3 s −1 to 3560 m 3 s −1 ) and the elevated river water level (from 11 m to 13 m) during the WSRS led to a higher hydraulic head, enhancing groundwater discharge in the estuary. Our results suggest that high river discharge (>3000 m 3 s −1 ) might be necessary for elevated fresh submarine groundwater discharging (FSGD). Vertical profiles of salinity, DO and turbidity anomalies along the benthic boundary layer also indicated significant FSGD in the estuary during the WSRS. Nutrient concentrations had positive correlations with 222 Rn during a 24-h observation, which indicates that SGD is a dominant nutrient pathway in this area

  11. Sources, transformation and fate of particulate amino acids and hexosamines under varying hydrological regimes in the tropical Wenchang/Wenjiao Rivers and Estuary, Hainan, China

    Science.gov (United States)

    Unger, Daniela; Herbeck, Lucia S.; Li, Min; Bao, Hongyan; Wu, Ying; Zhang, Jing; Jennerjahn, Tim

    2013-04-01

    The small tropical Wenchang and Wenjiao Rivers on the island of Hainan, tropical China, are affected by effluents from municipal sewage, aquaculture and agriculture, and by contrasting hydrological regimes related to monsoon and tropical storms. In order to obtain information on the sources, transformation and fate of organic matter (OM) we investigated the amount and composition of amino acids and hexosamines as well as the carbon isotope composition in suspended particulate matter (SPM) from the Wenchang/Wenjiao Estuary. SPM was collected along the salinity gradient starting from the river sites, along the lagoon-shaped Bamen Bay to coastal waters during four sampling campaigns between 2006 and 2009. SPM concentrations ranged between 4.7 and 58.2 mg L-1. Apart from highest values after heavy rain events in spring and summer, SPM showed little seasonal variation, but increased with salinity. From SPM POC% (1.2-20.9%), C/N (4.9-16.5) and δ13Corg (-31.5 to -19.5‰), the molar composition and content of amino acids and hexosamines (8.2-156.2 mg g-1 dry weight) and by comparison with sediments, mangroves, soils and plants we are able to show that soil-derived material, freshwater and marine plankton were the major sources of suspended OM. High POC and amino acid contents were related to primary production sustained by dissolved nutrients to a large extent stemming from municipal and aquaculture effluents. Factor analysis showed that the suite of biogeochemical parameters measured clearly depict the terrestrial vs. marine origin and the freshness/reactivity of OM. The four groups of samples resulting from cluster analysis were basically related to varying hydrological regimes. With respect to the sources, degradation and fate of particulate OM the major factors were: (i) the year round input of labile, amino acid rich riverine OM matter at the freshwater dominated sites, (ii) high input of degraded soil OM after heavy rains with dispersal throughout the estuary and

  12. Antibiotics in riverine runoff of the Pearl River Delta and Pearl River Estuary, China: Concentrations, mass loading and ecological risks

    International Nuclear Information System (INIS)

    Xu, Weihai; Yan, Wen; Li, Xiangdong; Zou, Yongde; Chen, Xiaoxiang; Huang, Weixia; Miao, Li; Zhang, Ruijie; Zhang, Gan; Zou, Shichun

    2013-01-01

    Ten antibiotics belonging to three groups (macrolides, fluoroquinolones and sulfonamides) were investigated in riverine runoff of the Pearl River Delta (PRD) and Pearl River Estuary (PRE), South China for assessing the importance of riverine runoff in the transportation of contaminants from terrestrial sources to the open ocean. All antibiotics were detected in the eight outlets with concentrations ranging from 0.7 to 127 ng L −1 . The annual mass loadings of antibiotics from the PRD to the PRE and coast were 193 tons with 102 tons from the fluoroquinolone group. It showed that antibiotics decreased from the riverine outlets to the PRE and open ocean. Risk assessment showed that most of these antibiotics showed various ecological risks to the relevant aquatic organisms, in which ofloxacin (OFL), erythromycin (ETM) and ciprofloxacin (CIP) posed high ecological risks to the studied aquatic environments. -- Highlights: •Antibiotics were ubiquitous in the river water and costal water in the Pearl River Delta. •Antibiotics exhibited distinct temporal and spatial trends in the riverine runoff outlets. •Annual outflows of antibiotics were 193 tons from the Pearl River to coastal ocean. •Some antibiotics posed high risks to some organisms in the PRD environments. -- Antibiotics were ubiquitous in the river and coastal water in the Pearl River Delta and posed various ecological risks to the relevant aquatic organisms

  13. A multi-proxy study of sedimentary humic substances in the salt marsh of the Changjiang Estuary, China

    Science.gov (United States)

    Zhang, Yaoling; Du, Jinzhou; Zhao, Xin; Wu, Wangsuo; Peng, Bo; Zhang, Jing

    2014-12-01

    To better understand the origin, composition, and reactivity of sedimentary humic substances (HSs) in salt marshes in the Changjiang Estuary, HS samples were isolated from a sediment core that was collected from the Eastern Chongming salt marsh. Chemical and spectroscopic methods were used to analyze the features of these HSs. The results indicate that the studied HSs in the salt marsh sediments are mainly terrestrial-derived and that the sedimentary organic matter (SOM) in the top layer may contain more organic matter from marine sources and/or autochthonous materials due to the dramatic decreasing of the sediment supply as a result of damming. The degradation of labile carbohydrates and proteins and the preservation of refractory lignin components dominate the early diagenetic reactions of SOM in the salt marsh area. The average contents of the carboxylic groups in FAs and HAs are 11.64 ± 1.08 and 7.13 ± 0.16 meq/gC, and those of phenolic groups are 1.95 ± 0.13 and 2.40 ± 0.44 meq/gC, respectively. The content of carboxylic groups increased with increasing depth, while there were no obvious changes in the content of phenolic groups. The average concentration of total proton-binding sites is approximately 12.5 μmol/g sediment for the studied HSs. These values may provide insight into the migration and fate of HS-bound contaminants in sediments and the overlying sea water in the salt marsh areas of the Changjiang Estuary.

  14. Numerical study of hydrodynamic and salinity transport processes in the Pink Beach wetlands of the Liao River estuary, China

    Directory of Open Access Journals (Sweden)

    H. Qiao

    2018-06-01

    Full Text Available Interaction studies of vegetation within flow environments are essential for the determination of bank protection, morphological characteristics and ecological conditions for wetlands. This paper uses the MIKE 21 hydrodynamic and salinity model to simulate the hydrodynamic characteristics and salinity transport processes in the Pink Beach wetlands of the Liao River estuary. The effect of wetland plants on tidal flow in wetland areas is represented by a varying Manning coefficient in the bottom friction term. Acquisition of the vegetation distribution is based on Landsat TM satellites by remote sensing techniques. Detailed comparisons between field observation and simulated results of water depth, salinity and tidal currents are presented in the vegetated domain of the Pink Beach wetlands. Satisfactory results were obtained from simulations of both flow characteristics and salinity concentration, with or without vegetation. A numerical experiment was conducted based on variations in vegetation density, and compared with the tidal currents in non-vegetated areas; the computed current speed decreased remarkably with an increase in vegetation density. The impact of vegetation on water depth and salinity was simulated, and the findings revealed that wetland vegetation has an insignificant effect on the water depth and salinity in this wetland domain. Several stations (from upstream to downstream in the Pink Beach wetlands were selected to estimate the longitudinal variation of salinity under different river runoff conditions; the results showed that salinity concentration decreases with an increase in river runoff. This study can consequently help increase the understanding of favourable salinity conditions for particular vegetation growth in the Pink Beach wetlands of the Liao River estuary. The results also provide crucial guidance for related interaction studies of vegetation, flow and salinity in other wetland systems.

  15. Trace/heavy metal pollution monitoring in estuary and coastal area of Bay of Bengal, Bangladesh and implicated impacts.

    Science.gov (United States)

    Kibria, Golam; Hossain, Md Maruf; Mallick, Debbrota; Lau, T C; Wu, Rudolf

    2016-04-15

    Using artificial mussels (AMs), this study reports and compares time-integrated level of eleven trace metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, U, Zn) in Karnafuli River estuary and coastal area of the Bay of Bengal, Bangladesh. Through this study, "hot spots" of metal pollution were identified. The results may demonstrate that the Karnafuli Estuary, and adjacent coastal area of Chittagong, Bangladesh are highly polluted by high risk metals (cadmium, chromium, copper, mercury, nickel, lead, uranium). Agricultural, domestic and industrial wastes directly discharged into the waterways have been identified as the main causes of metal pollution in Chittagong, Bangladesh. The high level of metal pollution identified may impact on local water quality, and seafood catch, livelihoods of people and public health resulting from seafood consumption. There is a need for regular monitoring to ascertain that local water quality with respect to metal levels are within acceptable levels to safeguards both environmental health and public health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Nutrient budgets for large Chinese estuaries

    Directory of Open Access Journals (Sweden)

    S. M. Liu

    2009-10-01

    Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO43− with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

  17. 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.

  18. 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 (I geo ) 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.

  19. Distribution and risk assessment of trace metals in sediments from Yangtze River estuary and Hangzhou Bay, China.

    Science.gov (United States)

    Li, Feipeng; Mao, Lingchen; Jia, Yubao; Gu, Zhujun; Shi, Weiling; Chen, Ling; Ye, Hua

    2018-01-01

    The Yangtze River estuary (YRE) and Hangzhou Bay (HZB) is of environmental significance because of the negative impact from industrial activities and rapid development of aquaculture on the south bank of HZB (SHZB) in recent years. This study investigated the distribution and risk assessments of trace metals (Cr, Cu, Zn, Hg, Pb, and Cd) accumulated in surface sediments by sampling in YRE, outer and south HZB. Copper and Zn concentration (avg. 35.4 and 98.7 mg kg -1 , respectively) in surface sediments were generally higher than the background suggesting a widespread of Cu and Zn in the coastal area of Yangtze River Delta. High concentrations of Cu (~ 42 mg kg -1 ), Zn (~ 111 mg kg -1 ), Cd (~ 0.27 mg kg -1 ), and Hg (~ 0.047 mg kg -1 ) were found in inner estuary of YRE and decreased offshore as a result of terrestrial input and dilution effect of total metal contents by "cleaner" sediments from the adjacent sea. In outer HZB, accumulation of terrestrial derived metal has taken place near the Zhoushan Islands. Increase in sediment metal concentration from the west (inner) to the east (outer) of SHZB gave rise to the input of fine-grained sediments contaminated with metals from outer bay. According the results from geoaccumulation index, nearly 75% of samples from YRE were moderately polluted (1.0 < I geo  < 2.0) by Cd. Cadmium and Hg contributed for 80~90% to the potential ecological risk index in the YRE and HZB, with ~ 72% sites in HZB under moderate risk (150 ≤ RI < 300) especially near Zhoushan Islands.

  20. Heavy metal distribution and partitioning in the vicinity of the discharge areas of Lisbon drainage basins (Tagus Estuary, Portugal)

    Science.gov (United States)

    Duarte, Bernardo; Silva, Gilda; Costa, José Lino; Medeiros, João Paulo; Azeda, Carla; Sá, Erica; Metelo, Inês; Costa, Maria José; Caçador, Isabel

    2014-10-01

    Worldwide estuarine ecosystems are by their privileged geographic location, anthropogenically impacted systems. Heavy metal contamination in estuarine waters and sediments are well known to be one of the most important outcomes driven from human activities. The partitioning of these elements has been widely focused, due to its importance not only on the estuarine biogeochemistry but also on its bioavailability to the trophic webs. As observed in other estuaries, in the Tagus basin, no increase in the partition coefficients with the increasing suspended particulate matter concentrations was observed, mostly due to a permanent dilution process of the suspended matter, rich in heavy metals and less contaminated and resuspended bottom sediments. Another important outcome of this study was the common origin of all the analysed heavy metals, probably due to the large industrialization process that the margins of the Tagus estuary suffered in the past, although no relationship was found with the presence of the different discharge areas. In fact, metal partitioning seems to be mostly influenced by the chemical species in which the pollutant is delivered to the system and on water chemistry, with a higher emphasis on the metal cycling essentially between the particulate and dissolved phase. This partitioning system acquires a relevant importance while evaluating the impacts of marine construction and the associated dredging operations, and consequent changes in the estuarine water chemistry.

  1. Heavy metal and Pb isotopic compositions of aquatic organisms in the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Ip, C.C.M.; Li, X.D.; Zhang, G.; Wong, C.S.C.; Zhang, W.L.

    2005-01-01

    The accumulation of trace metals in aquatic organisms may lead to serious health problems through the food chain. The present research project aims to study the accumulation and potential sources of trace metals in aquatic organisms of the Pearl River Estuary (PRE). Four groups of aquatic organisms, including fish, crab, shrimp, and shellfish, were collected in the PRE for trace metal and Pb isotopic analyses. The trace metal concentrations in the aquatic organism samples ranged from 0.01 to 2.10 mg/kg Cd, 0.02 to 4.33 mg/kg Co, 0.08 to 4.27 mg/kg Cr, 0.15 to 77.8 mg/kg Cu, 0.17 to 31.0 mg/kg Ni, 0.04 to 30.7 mg/kg Pb, and 8.78 to 86.3 mg/kg Zn (wet weight). High concentrations of Cd were found in crab, shrimp and shellfish samples, while high concentration of Pb was found in fish. In comparison with the baseline reference values in other parts of the world, fish in the PRE had the highest elevated trace metals. The results of Pb isotopic compositions indicated that the bioaccumulation of Pb in fish come from a wide variety of food sources and/or exposure pathways, particularly the anthropogenic inputs. - Relative high concentrations of Cd were found in crab, shrimp and shellfish samples while high concentration of Pb was found in fish, particularly from the anthropogenic inputs

  2. Are vegetated areas of mangroves attractive to juvenile and small fish? The case of Dongzhaigang Bay, Hainan Island, China

    Science.gov (United States)

    Wang, Mao; Huang, Zhenyuan; Shi, Fushan; Wang, Wenqing

    2009-11-01

    Well-developed aerial roots of mangroves make it difficult to study how fish utilize the mangrove forest as a habitat. In the present study, we compared the differences in fish assemblages in three major types of habitats of mangrove estuary (vegetated area, treeless mudflat, and creek) of a mangrove bay in Hainan Island, China, at different seasons during two consecutive years. Three types of gears, centipede net, gill net and cast net, were used in the different habitats of mangrove estuary and sampling efficiencies among gears were evaluated. Centipede nets were used in all the three types of habitats and cast nets and gill nets in treeless mudflats and creeks. Fish assemblages were dependent on gears used. Centipede net could efficiently catch fish occurring both inside and outside of vegetated areas efficiently. A total of 115 fish species in 51 families were collected. In terms of numbers of species per family, Gobiidae was the most diverse (17 species), followed by Mugilidae (5 species). Almost all of the fish were juvenile or small fish and few predators were recorded, implying low predation pressure in the bay. ANOVA analysis showed that significant seasonal and spatial variation existed in species richness, abundance, and biomass, which were less in the vegetated areas than those of treeless mudflats and creeks. The attraction of vegetated areas to fish was less than that of creeks and mudflats. Many species were specific to a particular habitat type, 4 species occurring exclusively in the creeks, 45 species occurring exclusively in the treeless mudflats, and 5 species occurring exclusively in the vegetated areas. The results indicated that mangrove estuaries were potentially attractive habitats for juvenile and small fish, but this attraction was accomplished by a connection of vegetated areas, treeless mudflats and creeks, not only by vegetated areas.

  3. Diversity, Novelty, and Antimicrobial Activity of Endophytic Actinobacteria From Mangrove Plants in Beilun Estuary National Nature Reserve of Guangxi, China

    Directory of Open Access Journals (Sweden)

    Zhong-ke Jiang

    2018-05-01

    Full Text Available Endophytic actinobacteria are one of the important pharmaceutical resources and well known for producing different types of bioactive substances. Nevertheless, detection of the novelty, diversity, and bioactivity on endophytic actinobacteria isolated from mangrove plants are scarce. In this study, five different mangrove plants, Avicennia marina, Aegiceras corniculatum, Kandelia obovota, Bruguiera gymnorrhiza, and Thespesia populnea, were collected from Beilun Estuary National Nature Reserve in Guangxi Zhuang Autonomous Region, China. A total of 101 endophytic actinobacteria strains were recovered by culture-based approaches. They distributed in 7 orders, 15 families, and 28 genera including Streptomyces, Curtobacterium, Mycobacterium, Micrococcus, Brevibacterium, Kocuria, Nocardioides, Kineococcus, Kytococcus, Marmoricola, Microbacterium, Micromonospora, Actinoplanes, Agrococcus, Amnibacterium, Brachybacterium, Citricoccus, Dermacoccus, Glutamicibacter, Gordonia, Isoptericola, Janibacter, Leucobacter, Nocardia, Nocardiopsis, Pseudokineococcus, Sanguibacter, and Verrucosispora. Among them, seven strains were potentially new species of genera Nocardioides, Streptomyces, Amnibacterium, Marmoricola, and Mycobacterium. Above all, strain 8BXZ-J1 has already been characterized as a new species of the genus Marmoricola. A total of 63 out of 101 strains were chosen to screen antibacterial activities by paper-disk diffusion method and inhibitors of ribosome and DNA biosynthesis by means of a double fluorescent protein reporter. A total of 31 strains exhibited positive results in at least one antibacterial assay. Notably, strain 8BXZ-J1 and three other potential novel species, 7BMP-1, 5BQP-J3, and 1BXZ-J1, all showed antibacterial bioactivity. In addition, 21 strains showed inhibitory activities against at least one “ESKAPE” resistant pathogens. We also found that Streptomyces strains 2BBP-J2 and 1BBP-1 produce bioactive compound with inhibitory

  4. Diversity, Novelty, and Antimicrobial Activity of Endophytic Actinobacteria From Mangrove Plants in Beilun Estuary National Nature Reserve of Guangxi, China

    Science.gov (United States)

    Jiang, Zhong-ke; Tuo, Li; Huang, Da-lin; Osterman, Ilya A.; Tyurin, Anton P.; Liu, Shao-wei; Lukyanov, Dmitry A.; Sergiev, Petr V.; Dontsova, Olga A.; Korshun, Vladimir A.; Li, Fei-na; Sun, Cheng-hang

    2018-01-01

    Endophytic actinobacteria are one of the important pharmaceutical resources and well known for producing different types of bioactive substances. Nevertheless, detection of the novelty, diversity, and bioactivity on endophytic actinobacteria isolated from mangrove plants are scarce. In this study, five different mangrove plants, Avicennia marina, Aegiceras corniculatum, Kandelia obovota, Bruguiera gymnorrhiza, and Thespesia populnea, were collected from Beilun Estuary National Nature Reserve in Guangxi Zhuang Autonomous Region, China. A total of 101 endophytic actinobacteria strains were recovered by culture-based approaches. They distributed in 7 orders, 15 families, and 28 genera including Streptomyces, Curtobacterium, Mycobacterium, Micrococcus, Brevibacterium, Kocuria, Nocardioides, Kineococcus, Kytococcus, Marmoricola, Microbacterium, Micromonospora, Actinoplanes, Agrococcus, Amnibacterium, Brachybacterium, Citricoccus, Dermacoccus, Glutamicibacter, Gordonia, Isoptericola, Janibacter, Leucobacter, Nocardia, Nocardiopsis, Pseudokineococcus, Sanguibacter, and Verrucosispora. Among them, seven strains were potentially new species of genera Nocardioides, Streptomyces, Amnibacterium, Marmoricola, and Mycobacterium. Above all, strain 8BXZ-J1 has already been characterized as a new species of the genus Marmoricola. A total of 63 out of 101 strains were chosen to screen antibacterial activities by paper-disk diffusion method and inhibitors of ribosome and DNA biosynthesis by means of a double fluorescent protein reporter. A total of 31 strains exhibited positive results in at least one antibacterial assay. Notably, strain 8BXZ-J1 and three other potential novel species, 7BMP-1, 5BQP-J3, and 1BXZ-J1, all showed antibacterial bioactivity. In addition, 21 strains showed inhibitory activities against at least one “ESKAPE” resistant pathogens. We also found that Streptomyces strains 2BBP-J2 and 1BBP-1 produce bioactive compound with inhibitory activity on protein

  5. Application of passive sampling in assessing the occurrence and risk of antibiotics and endocrine disrupting chemicals in the Yangtze Estuary, China.

    Science.gov (United States)

    Shi, X; Zhou, J L; Zhao, H; Hou, L; Yang, Y

    2014-09-01

    Polar organic chemical integrative sampler (POCIS) was used in assessing the occurrence and risk of 12 widely used antibiotics and 5 most potent endocrine disrupting chemicals (EDCs) in the Yangtze Estuary, China. During laboratory validation, the kinetics of pollutant uptake by POCIS were linear, and the sampling rates of most compounds were raised by flow rate and salinity, reaching the highest values at salinity 14‰. The sampling rates varied with the target compounds with the EDCs showing the highest values (overall average=0.123Ld(-1)), followed by chloramphenicols (0.100Ld(-1)), macrolides (0.089Ld(-1)), and finally sulfonamides (0.056Ld(-1)). Validation in the Yangtze Estuary in 2013 showed that the field sampling rates were significantly greater for all compounds except bisphenol A, in comparison to laboratory results, and high-frequency spot sampling is critical for fully validating the passive sampler. The field studies show that antibiotics were widely detected in the Yangtze Estuary, with concentrations varying from below quantification to 1613ngL(-1), suggesting their widespread use and persistence in estuarine waters. The dominating pollutants in July were sulfonamides with a total concentration of 258ngL(-1) and in October were macrolides with a total concentration of 350ngL(-1). The calculation of risk quotient suggested that sulfapyridine, sulfaquinoxaline and erythromycin-H2O may have caused medium damage to sensitive organisms such as fish. Copyright © 2014. Published by Elsevier Ltd.

  6. Riverine input of organic carbon and nitrogen in water-sediment system from the Yellow River estuary reach to the coastal zone of Bohai Sea, China

    Science.gov (United States)

    Wang, Chuanyuan; Lv, Yingchun; Li, Yuanwei

    2018-04-01

    The temporal-spatial distribution of the carbon and nitrogen contents and their isotopic compositions of suspended matter and sediments from the Yellow River estuary reach (YRER), the estuary to the offshore area were measured to identify the source of organic matter. The higher relative abundances of suspended and sedimentary carbon and nitrogen (POC, TOC, PN and TN) in the offshore marine area compared to those of the riverine and estuarine areas may be due to the cumulative and biological activity impact. The organic matter in surface sediments of YRER, the estuary and offshore area of Bohai Sea is basically the mixture of continental derived material and marine material. The values of δ13Csed fluctuate from values indicative of a land source (- 22.50‰ ± 0.31) to those indicative of a sea source (- 22.80‰ ± 0.38), which can be attributed to the fine particle size and decrease in terrigenous inputs to the offshore marine area. Contrary to the slight increase of POC and PN during the dry season, TOC and TN contents of the surface sediments during the flood season (October) were higher than those during the dry season (April). The seasonal differences in water discharge and suspended sediment discharge of the Yellow River Estuary may result in seasonal variability in TOC, POC, TN and PN concentrations in some degree. Overall, the surface sediments in the offshore area of Bohai Sea are dominated by marine derived organic carbon, which on average, accounts for 58-82% of TOC when a two end-member mixing model is applied to the isotopic data.

  7. 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

  8. Seasonal atmospheric deposition and air-sea gaseous exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes

    Science.gov (United States)

    Jiang, Y.; Guo, Z.

    2017-12-01

    As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of air samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of air-sea gaseous exchange and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous exchange of PAHs was referred as the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH exchange flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and air-sea concentration gradient difference among seasons. Based on the simplified mass balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at air

  9. 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...... between tree cover change and general human pressure. We did not find a significant correlation between tree cover change inside and outside PAs with increasing general human pressures. The lack of correlation could be due to the huge reforestation China has carried out the last years, mainly to stop...

  10. Characterization of phosphorus sorption on the sediments of Yangtze River Estuary and its adjacent areas

    International Nuclear Information System (INIS)

    Cao, Xiaoyan; Liu, Xiaoyue; Zhu, Jiamei; Wang, Lisha; Liu, Sumei; Yang, Guipeng

    2017-01-01

    This paper studied the kinetics, isotherm and thermodynamics of phosphorus sorption onto the sediments of the Yangtze River estuary and its adjacent waters, as well as the sediments' compositions and physicochemical properties. The process could be described well by a two-compartment first order equation. The sorbed phosphorus mainly consisted of Ex-P and Fe-P, with Ex-P being the dominant. The equilibrium isotherms could be fitted well with a modified Langmuir equation. The calculations of the thermodynamic parameters indicated that the process was spontaneous and exothermic. The CEC and the fractions of clay, calcite and organic matter were correlated with the sorption parameters, while the surface proton charge of the sediments was significantly negatively correlated with them. Considering the kinetics and phosphorus forms changes during the process, the sorption in our study could be considered that the physical process plays an important role. - Highlights: • The kinetic curves and phosphorus fractions changes during sorption were studied. • The sorbed phosphorus mainly consisted of Ex − P and Fe-P, with Ex − P being dominant. • The equilibrium isotherms and thermodynamic parameters were investigated. • Sediment composition and surface characteristics influenced phosphorus sorption parameters.

  11. 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.

  12. Relationships between pesticides and organic carbon fractions in sediments of the Danshui River estuary and adjacent coastal areas of Taiwan

    International Nuclear Information System (INIS)

    Hung, C.-C.; Gong, G.-C.; Chen, H.-Y.; Hsieh, H.-L.; Santschi, Peter H.; Wade, Terry L.; Sericano, Jose L.

    2007-01-01

    In order to understand the fate of pesticides in marine environments, concentrations of pesticides and different carbonaceous fractions were determined for surface sediments in the Danshui River and nearby coastal areas of Taiwan. The major compounds detected were tetrachlorobenzene, HCHs, chlordane, aldrin, DDDs, DDEs and DDTs. Total concentrations of pesticides in the sediments ranged from not detectable to 23 ng g -1 , with the maximum value detected near the discharge point of the marine outfall from the Pali sewage treatment plant. These results confirm that pesticides persist in estuarine and nearby coastal environments of the Danshui River well after their ban. Concentrations of total pesticides significantly correlate with concentrations of total organic carbon and black carbon in these sediments, suggesting that total organic carbon and black carbon regulate the distribution of trace organic pollutants in fluvial and coastal marine sediments. - Total organic carbon and black carbon regulate the distribution of trace organic pollutants in sediments of the Danshui River estuary and adjacent coastal areas of Taiwan

  13. Area selection for a geological repository of high level radioactive waste in China

    International Nuclear Information System (INIS)

    Jin Yuanxin; Wang Ju; Chen Weiming; Guo Yonghai; Su Rui; Zhao Honggang; Xu Guoqing

    2012-01-01

    China started research on HLW disposal in 1985 and 6 areas, including Northwest, Southwest, East China, South China, Inner Mongolia and Xinjiang area, are selected. The results show that the Northwest area has obvious comprehensive advantages, which can be considered as the first area for site selection, while site characterization and comparison research in the area should be continued. (authors)

  14. Using fecal sterols to assess dynamics of sewage input in sediments along a human-impacted river-estuary system in eastern China.

    Science.gov (United States)

    He, Ding; Zhang, Kai; Tang, Jianhui; Cui, Xingqian; Sun, Yongge

    2018-05-01

    Sedimentary fecal sterols and other sterol biomarkers, combined with bulk total organic carbon (TOC) and its stable carbon isotope were applied to characterize the sewage contamination across a ca. 280 km transect from the Xiaoqing River to the Laizhou Bay, a typical river-estuary system subjected to extensive anthropogenic stress due to rapid regional urbanization and industrialization in eastern China. Two sampling events were performed in both spring and summer seasons in the Laizhou Bay adjacent to the Xiaoqing River in order to assess the potential seasonal variation. Fecal sterols such as coprostanol and epicoprostanol, which are typical indicators of anthropogenic sewage input, displayed high concentrations of up to 63.2 μg g -1 dry weight (dw) and 13.1 μg g -1 dw, respectively. Results suggested that most of the stations along the Xiaoqing River were severely contaminated by fecal inputs with a decreasing trend from the river to the estuary that was mainly explained by the increasing distance from the diffuse sewage sources and the gradual dilution by sea water. Although there was no significant difference in fecal sterol concentrations between spring and summer in the Laizhou Bay, suggestive of no significant difference in sewage abundance, significantly higher average epicoprostanol/coprostanol and lower coprostanol/epicoprostanol ratios were observed in spring than summer, indicative of different sewage sources (e.g., human vs. non-human). Seasonal discharge and land-runoff, air temperature related to microbial activity differences and different extend of animal manure irrigation during agricultural planting could be additional reasons and need further investigation. Nevertheless, fecal sterol concentrations, distributions and diagnostic ratios should all be taken into consideration to better understand sewage inputs and source dynamics in river-estuary ecosystems. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Sources of Nutrients to Nearshore Areas of a Eutrophic Estuary: Implications for Nutrient-Enhanced Acidification in Puget Sound

    Science.gov (United States)

    Pacella, S. R.

    2016-02-01

    Ocean acidification has recently been highlighted as a major stressor for coastal organisms. Further work is needed to assess the role of anthropogenic nutrient additions in eutrophied systems on local biological processes, and how this interacts with CO2 emission-driven acidification. This study sought to distinguish changes in pH caused by natural versus anthropogenically affected processes. We quantified the variability in water column pH attributable to primary production and respiration fueled by anthropogenically derived nitrogen in a shallow nearshore area. Two study sites were located in shallow subtidal areas of the Snohomish River estuary, a eutrophic system located in central Puget Sound, Washington. These sites were chosen due to the presence of heavy agricultural activity, urbanized areas with associated waste water treatment, as well as influence from deep, high CO2 marine waters transported through the Strait of Juan de Fuca and upwelled into the area during spring and summer. Data was collected from July-December 2015 utilizing continuous moorings and discrete water column sampling. Analysis of stable isotopes, δ15N, δ18O-NO3, δ15N-NH4, was used to estimate the relative contributions of anthropogenic versus upwelled marine nitrogen sources. Continuous monitoring of pH, dissolved oxygen, temperature, and salinity was conducted at both study sites to link changes in nutrient source and availability with changes in pH. We predicted that isotope data would indicate greater contributions of nitrogen from agriculture and wastewater rather than upwelling in the shallow, nearshore study sites. This study seeks to distinguish the relative magnitude of pH change stimulated by anthropogenic versus natural sources of nitrogen to inform public policy decisions in critically important nearshore ecosystems.

  16. 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 (CO 2 ), methane (CH 4 ) emission, and environmental factors, with respect to estuarine marshes, has not been clarified thoroughly. This study investigated the crucial factors controlling the emission of CO 2 and CH 4 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 CO 2 and CH 4 emissions from the two marshes showed pronounced seasonal variations. The CO 2 and CH 4 emissions from both marshes demonstrated significant positive correlations with the air/soil temperature (pemissions between the freshwater and brackish marshes in the subtropical estuary, whereas there was a difference in the CH 4 emissions between the two sites (pemissions from the estuarine freshwater marshes, these factors had little effect on the CO 2 emissions with respect to an increase in salinity 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.

  17. 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

  18. 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.

  19. 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

  20. 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, and ...

  1. 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

  2. Absorption features of chromophoric dissolved organic matter (CDOM) and tracing implication for dissolved organic carbon (DOC) in Changjiang Estuary, China

    OpenAIRE

    Zhang, X. Y.; Chen, X.; Deng, H.; Du, Y.; Jin, H. Y.

    2013-01-01

    Chromophoric dissolved organic matter (CDOM) represents the light absorbing fraction of dissolved organic carbon (DOC). Studies have shown that the optical properties of CDOM can be used to infer the distribution and diffusion characteristics of DOC in the estuary and coastal zone. The inversion of DOC concentrations from remote sensing has been implemented in certain regions. In this study we investigate the potential of tracing DOC from CDOM by the measure...

  3. Development of a relative risk model for evaluating ecological risk of water environment in the Haihe River Basin estuary area.

    Science.gov (United States)

    Chen, Qiuying; Liu, Jingling; Ho, Kin Chung; Yang, Zhifeng

    2012-03-15

    Ecological risk assessment for water environment is significant to water resource management of basin. Effective environmental management and systems restoration such as the Haihe River Basin require holistic understanding of the relative importance of various stressor-related impacts throughout the basin. As an effective technical tool for evaluating the ecological risk, relative risk model (RRM) was applied in regional scale successfully. In this study, the risk transfer from upstream of basin was considered and the RRM was developed through introducing the source-stressor-habitat exposure filter (SSH), the endpoint-habitat exposure filter (EH) and the stressor-endpoint effect filter (SE) to reflect the meaning of exposure and effect more explicit. Water environment which includes water quality, water quantity and aquatic ecosystems was selected as the assessment endpoints. We created a conceptual model which depicting potential and effect pathways from source to stressor to habitat to endpoint. The Haihe River Basin estuary (HRBE) was selected as the model case. The results showed that there were two low risk regions, one medium risk region and two high risk regions in the HRBE. The results also indicated that urbanization was the biggest source, the second was shipping and the third was industry, their risk scores are 5.65, 4.71 and 3.68 respectively. Furthermore, habitat destruction was the largest stressor with the risk scores (2.66), the second was oxygen consuming organic pollutants (1.75) and the third was pathogens (1.75). So these three stressors were the main influencing factors of the ecological pressure in the study area. For habitats, open waters (9.59) and intertidal mudflat were enduring the bigger pressure and should be taken considerable attention. Ecological service values damaged (30.54) and biodiversity decreased were facing the biggest risk pressure. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. China National Scenic Area and Its Planning Characteristics

    Institute of Scientific and Technical Information of China (English)

    Jia Jianzhong; Deng Wugong; Li Caige

    2016-01-01

    Thirty years since the foundation of China's scenic area system,a comparatively comprehensive structural system,legal system,and management system have been established in this field,which has protected precious landscape resources and made remarkable achievements.The planning of scenic areas has its own attributes and technical characteristics,which attaches great importance to establishing a functional structure that combines the three systems of sightseeing,tourism services,and social management of local residents.Moreover,with the development of scenic areas,the planning will lay more emphasis on the connection between different levels,give full play to the comprehensive function of scenic areas,pay attention to the research on village and town planning within the area,and learn from the experience of national parks in foreign countries.

  5. Income and managing problems of the protected areas in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    n 2000, the authors collected a great quantity of relevant data by investigating more than 50 nature reserves. Based on the analysis of development and management situation of the protected areas in China, the main problems were put forward, such as, no unified management for income and managing activities, lack of special guideline and effective supervision, lack of income and investment, investing financial difference in different provinces. All these problems caused the lack of funds for construction, as well as the damage of resources and environment. Furthermore the conserving activities have to transmit to the profits in many protected areas. Combined with these problems, the primary solution programmers also were put forward.

  6. Investigation of sediment movement in the North Navigation Channel Area of the estuary of the Yangtze river using natural radiotracers and INAA methods

    International Nuclear Information System (INIS)

    Zhang Yunhui; Li Guiqun; Zhang Qixing, Sun Maoyi

    1996-01-01

    This is a preliminary investigation of sediment in the North Navigation Channel Area of the estuary of the Yangtze river, which has been made by determining the natural radioisotopes and the INAA of 30 natural sand samples. Multivariate statistical method was used to process and analyze the data obtained. It can be seen that there are tow sediment movement routes in the investigation area. The orientation of the main sediment movement is from northwest to southeast in accordance with the results obtained from the field submarine drag-monitorings after the radiotracer injection. Besides, there is also another sand movement route existed. (author). 5 refs., 3 figs., 4 tabs

  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. 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.

  9. Land claim and loss of tidal flats in the Yangtze Estuary.

    Science.gov (United States)

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-04-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world's largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km(2), a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.

  10. 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.

  11. [Distributions and air-sea fluxes of dissolved nitrous oxide in the Yangtze River estuary and its adjacent marine area in spring and summer].

    Science.gov (United States)

    Wang, Lan; Zhang, Gui-ling; Sun, Ming-shuang; Ren, Jing-ling

    2014-12-01

    Distributions and air-sea fluxes of nitrous oxide (N2O) in the seawaters of the Yangtze River estuary and its adjacent marine area were investigated during two cruises in March and July 2012. Dissolved N2O concentrations in surface waters ranged from 9.34 to 49.08 nmol x L(-1) with an average of (13.27 ± 6.40) nmol x L(-1) in spring and ranged from 7.27 to 27.81 nmol x L(-1) with an average of (10.62 ± 5.03) nmol x L(-1) in summer. There was no obvious difference between surface and bottom N2O concentrations. N2O concentrations in both surface and bottom waters decreased along the freshwater plume from the river mouth to the open sea. High values of dissolved N2O were found in turbidity maximum zone, which suggests that maximal turbidity enhances nitrification. Temperature had dual effects on dissolved N2O concentrations. N2O saturations in surface waters ranged from 86.9% to 351.3% with an average of (111.5 ± 41.4)% in spring and ranged from 111.7% to 396.0% with an average of (155.9 ± 68.4)% in summer. N2O were over-saturated at most stations. The sea-to-air fluxes of N2O were estimated to be (3.2 ± 10.9), (5.5 ± 19.3) and (12.2 ±52.3) μmol x (m2 x d)(-1) in spring and (7.3 ± 12.4), (12.7 ± 20.4) and (20.4 ± 35.9) μmol x (m2 x d)(-1) in summer using the LM86, W92 and RC01 relationships, respectively. The annual emissions of N2O from the Yangtze River estuary and its adjacent marine area were estimated to be 0.6 x 10(-2) Tg x a(-1) (LM86), 1.1 x 10(-2) Tg x a(-1) (W92) and 2.0 x 10(-2) Tg x a(-1) (RC01). Although the area of the Yangtze River estuary and its adjacent marine area only accounts for 0.02% of the total area of the world's oceans, their emission of N2O accounts for 0.06% of global oceanic N2O emission, indicating that the Yangtze River estuary and its adjacent marine area is an active area to produce and emit N2O.

  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. 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...

  14. Effect of drainage on CO2, CH4, and N2O fluxes from aquaculture ponds during winter in a subtropical estuary of China.

    Science.gov (United States)

    Yang, Ping; Lai, Derrick Y F; Huang, Jia F; Tong, Chuan

    2018-03-01

    Aquaculture ponds are dominant features of the landscape in the coastal zone of China. Generally, aquaculture ponds are drained during the non-culture period in winter. However, the effects of such drainage on the production and flux of greenhouse gases (GHGs) from aquaculture ponds are largely unknown. In the present study, field-based research was performed to compare the GHG fluxes between one drained pond (DP, with a water depth of 0.05m) and one undrained pond (UDP, with a water depth of 1.16m) during one winter in the Min River estuary of southeast China. Over the entire study period, the mean CO 2 flux in the DP was (0.75±0.12) mmol/(m 2 ·hr), which was significantly higher than that in the UDP of (-0.49±0.09) mmol/(m 2 ·hr) (paquaculture ponds from a net sink to a net source of CO 2 in winter. Mean CH 4 and N 2 O emissions were significantly higher in the DP compared to those in the UDP (CH 4 =(0.66±0.31) vs. (0.07±0.06) mmol/(m 2 ·hr) and N 2 O=(19.54±2.08) vs. (0.01±0.04) µmol/(m 2 ·hr)) (paquaculture ponds can increase the emissions of potent GHGs from the coastal zone of China to the atmosphere during winter, further aggravating the problem of global warming. Copyright © 2017. Published by Elsevier B.V.

  15. Seasonal variation, flux estimation, and source analysis of dissolved emerging organic contaminants in the Yangtze Estuary, China.

    Science.gov (United States)

    Zhao, Heng; Cao, Zhen; Liu, Xue; Zhan, Yi; Zhang, Jing; Xiao, Xi; Yang, Yi; Zhou, Junliang; Xu, Jiang

    2017-12-15

    The occurrence and seasonal variation of 24 dissolved emerging organic contaminants in the Yangtze Estuary were studied, including 12 non-antibiotic pharmaceuticals, seven sulfonamides, two macrolides and three chloramphenicols. Sulfadiazine, erythromycin, thiamphenicol and paracetamol were the primary contaminants in sulfonamides, macrolides, chloramphenicols and non-antibiotic pharmaceutical groups, respectively. Compared to the concentrations at Datong, chloramphenicols at Xuliujing were significantly higher in autumn and winter, while macrolides were lower in spring. Based on the flux estimation, approximately 37.1 tons of sulfonamides, 17.4 tons of macrolides, 79.2 tons of chloramphenicols and 14.1 tons of non-antibiotic pharmaceuticals were discharged into the Yangtze Estuary from June 2013 to May 2014. However, the total flux from the Huangpu River only represented 5% of the total. The pharmaceutical sources were speculated on by analyzing the seasonal variations in pharmaceutical concentrations and fluxes at various sites. Both environmental and social factors might affect the fluxes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Mid-Holocene hydrology change in the south Taihu area of the Yangtze delta plain, China, and its relationship to the development of Neolithic cultures

    Science.gov (United States)

    Chen, T.; Ryves, D.; Wang, Z.; Lewis, J.

    2017-12-01

    During the middle Holocene, the hydrological environments in the Taihu Plain, Yangtze Delta, China, varied tremendously under the influence of sea-level and climate change. Simultaneously, several Neolithic cultures, such as, the Majiabang, Songze, and Liangzhu culture, developed in this region. Basing on AMS14C dating, diatom identification, measurements of C-N elements and their stable isotopes of sediments from core DTX4 and DTX10, obtained in the East Tiaoxi Plain, south Taihu plain, we discussed the influence of hydrology changes on the development of Neolithic cultures. The results revealed that the East Tiaoxi River plain was in an estuary (the Palaeo-Taihu Estuary) condition at 7500 cal. yr BP, undergoing elevated in-fill in response to rapid sea-level rise. After 7500 cal. yr BP, low salinity conditions occurred, likely influenced by the Yangtze freshwater evidenced by constant occurrence of Aulacoseira granulata, which implied Yangtze runoff discharged along the channel of Palaeo-incised Taihu valley into the Hangzhou Bay during the middle Holocene. Sea-water penetration interrupted after 7000 cal. yr BP caused by an abrupt sea-level rise. During 6500-5600 cal. yr BP, sea-water retreated gradually, corresponding to the infilling of Palaeo-Taihu Estuary. Combing records from previously studied cores in the Taihu plain, stable freshwater condition (or dry land) established in most area of the Taihu plain after 5600 cal. yr BP due to the closure of the Palaeo-Taihu Estuary. We speculate that the low-salinity marsh started at about 7500-7000 cal. yr BP probably attracted the early Majiabang people to live around the Palaeo-Taihu Estuary. The sea water penetration between 7000-6500 cal. yr BP matches the left of the late Majiabang and the early-middle Songze people lived in the east of the Palaeo-Taihu Estuary, to the north and east of the Taihu Plain. The context of stable freshwater condition (or dry land) in the East Tiaoxi River plain promoted the

  18. Heavy metals (As, Hg and V) and stable isotope ratios (δ13C and δ15N) in fish from Yellow River Estuary, China.

    Science.gov (United States)

    Liu, Yuan; Liu, Guijian; Yuan, Zijiao; Liu, Houqi; Lam, Paul K S

    2018-02-01

    The Yellow River Estuary is a significant fishery, but at present there are few studies about the concentrations of arsenic (As), mercury (Hg) and vanadium (V) in fish from this area, which might cause potential health risk to fish consumers. The aim of this study was to research on the accumulation and potential sources of heavy metals in the fish of the Yellow River Estuary. Arsenic, Hg, V and stable isotope ratios (δ 15 N and δ 13 C) in 11 species of 129 fish were analyzed. Results showed that the concentrations of As and Hg were all lower than the guideline levels established by international organizations and legal limits by several countries. The mean concentrations of V in samples in this study were significantly higher than the results of previous studies on other regions. Arsenic, Hg and V significantly differed across species (PHg, which could be explained by the positive correlation between Hg concentrations and δ 15 N in fish. Through estimation of daily intake of inorganic As (iAs), Hg and V via fish consumption, the heavy metal contamination level of fish samples fell in an acceptable range, indicating no potentially hazardous for human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The distribution and speciation of trace metals in surface sediments from the Pearl River Estuary and the Daya Bay, Southern China

    International Nuclear Information System (INIS)

    Yu Xiujuan; Yan Yan; Wang Wenxiong

    2010-01-01

    Surface sediments collected from the Pearl River Estuary (PRE) and the Daya Bay (DYB) were analyzed for total metal concentrations and chemical phase partitioning. The total concentrations of Cr, Cu, Ni, Pb, and Zn in the PRE were obviously higher than those in DYB. The maximum concentrations of trace metals in DYB occurred in the four sub-basins, especially in Dapeng Cove, while the concentrations of these metals in the western side of the PRE were higher than those in the east side. Such distribution pattern was primarily due to the different hydraulic conditions and inputs of anthropogenic trace metals. The chemical partitioning of metals analyzed by the BCR sequential extraction method showed that Cr, Ni, and Zn of both areas were present dominantly in the residual fraction, while Pb was found mostly in the non-residual fractions. The partitioning of Cu showed a significant difference between the two areas.

  20. Bacterial community structure in response to environmental impacts in the intertidal sediments along the Yangtze Estuary, China.

    Science.gov (United States)

    Guo, Xing-Pan; Lu, Da-Pei; Niu, Zuo-Shun; Feng, Jing-Nan; Chen, Yu-Ru; Tou, Fei-Yun; Liu, Min; Yang, Yi

    2018-01-01

    This study was designed to investigate the characteristics of bacterial communities in intertidal sediments along the Yangtze Estuary and their responses to environmental factors. The results showed that bacterial abundance was significantly correlated with salinity, SO 4 2- and total organic carbon, while bacterial diversity was significantly correlated with SO 4 2- and total nitrogen. At different taxonomic levels, both the dominant taxa and their abundances varied among the eight samples, with Proteobacteria being the most dominant phylum in general. Cluster analysis revealed that the bacterial community structure was influenced by river runoff and sewerage discharge. Moreover, SO 4 2- , salinity and total phosphorus were the vital environmental factors that influenced the bacterial community structure. Quantitative PCR and sequencing of sulphate-reducing bacteria indicated that the sulphate reduction process occurs frequently in intertidal sediments. These findings are important to understand the microbial ecology and biogeochemical cycles in estuarine environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 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 C 12 -C 33 and C 13 -C 34 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.

  2. [Sagittal otolith morphology and the relationship between its mass and the age of Liza haematocheila in the Yangtze Estuary, China].

    Science.gov (United States)

    Ji, Yan; Zhao, Feng; Yang, Qin; Ma, Rong Rong; Yang, Gang; Zhang, Tao; Zhuang, Ping

    2018-03-01

    To examine the relationship of morphological characters of sagittal otolith and the age of Liza haematocheila in the Yangtze Estuary, we analyzed the morphological parameters of 324 pairs of otoliths extracted from 358 L. haematocheila specimens from the Yangtze Estuary in February to June of 2017. The results showed that sagittal otolith had rostrum, antirostrum and obvious central notch. The size and shape of sagittal otolith significantly changed with their growth, from regular melon seeds shape outline to long narrow leaf shape and increasing irregular wavy outline. The average density of sagittal otolith was 1.52 mg·mm -2 . The average rectangularity was 0.68. The length of sagittal otolith was 0.021%-0.047% of entire body length (BL), the width was 0.009%-0.021% of entire BL, and the mass was 0.045‰-0.731‰ of the entire body mass (BM). Otolith length (OL), otolith width (OW) and otolith mass (OM) were all significantly related to the BL, with the determination coefficient for OW and OM model being the highest (R 2 =0.928). The relationship between OM and BL was described best by exponential regression: OM=0.0009BL 1.8737 (R 2 =0.967). The relationships between OM and age (A), BL and A were well fitted by multinomial regressions, respectively: OM=2.9262A 2 +4.8437A+2.1894 (R 2 =0.847), BL=-3.2248A 2 +102.54A+38.373 (R 2 =0.858). In addition, OM was linearly correlated with A. The estimated otolith's ages from the model did not significantly variate from the real ages counting from annulus counts. Therefore, OM could be an effective parameter for the age estimation of L. haematocheila.

  3. 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).

  4. Wind energy for water pumping in rural areas of China

    International Nuclear Information System (INIS)

    Dechang, S.

    1991-01-01

    After 1980, as the supply of conventional energy has not been able to follow the tremendous increase of the production demand in rural areas of China, a renewed interest for the application of wind energy was shown in many places. Therefore, the Chinese government began to pay more attention to wind energy utilization in rural areas. During the last ten years, several R ampersand D tasks for new modern wind pumps were carried out. Among them, three projects are the developments of wind energy screw pump systems (FDG-5 wind pump, FDG-7 wind pump and TFS-5 wind pump). At present, 50 of these wind pumps are working successfully in the rural areas for farmland drainage, salt ponds water lifting and aquatic product breeding, etc. The field tests show that these wind energy screw pump systems are suitable for low lifting head (< 3 meter) and large water flow (50 m/hr to 120 m/hr) operation in the coastal areas. Because the wind energy resource in many rural areas is sufficient for attractive application of wind pumps, and the supply of electricity as well as fuels is insufficient in these areas, the wind pumps will be spread on a rather large scale in the near future. 7 figs., 2 tabs., 3 refs

  5. 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)...

  6. Levels and bioaccumulation of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in fishes from the Pearl River estuary and Daya Bay, South China

    International Nuclear Information System (INIS)

    Guo Lingli; Qiu Yaowen; Zhang Gan; Zheng, Gene J.; Lam, Paul K.S.; Li Xiangdong

    2008-01-01

    Fifty fish samples were collected from the Pearl River estuary (PRE) and Daya Bay, South China and were analyzed for DDTs, HCHs, chlordanes and polybrominated biphenyl ethers (PBDEs). Except the high concentrations of DDT observed in fishes, the concentrations of HCHs, chlordanes and PBDEs were low when compared to other regions. BDE-47 was the predominant PBDE congener and the BDE-209 concentrations were relatively low, despite its high concentration in surface sediments. The absence of significant increase of DDT, HCH, chlordane and PBDE concentrations towards higher δ 15 N values, as well as the lack of a significant correlation (p 15 N, may indicate a weak biomagnification of these chemicals in the food webs. Good agreement was observed between their concentrations and lipid contents of the organisms. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms in the studied subtropical waters. - Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms of subtropical waters

  7. FUSION OF OPTICAL DATA AND SAR DATA FOR THE ESTIMATION OF NITROGEN CONCENTRATION IN PEARL RIVER ESTUARY HONG KONG SEAS, CHINA

    Directory of Open Access Journals (Sweden)

    X. Liu

    2012-08-01

    Full Text Available The knowledge of nitrogen concentration in the ocean is fundamental for the study of oceanic biogeochemical processes. The objective of this research is to estimate total inorganic nitrogen (TIN by integrating optical parameters from HJ-1 CCD image and polarization parameters from RADARSAT-2 quad-polarization image. The situ data and HJ-1 CCD, RADARSAT-2 image were acquired from Pearl River Estuary Hong Kong Seas, China in August, 2010. The four sensitive parameters, reflectance of Band 4, NDSI (Normalized Difference Spectral Index, the backscattering coefficient of HV and VH were derived as input variables to assess the TIN. A multiple regression model was established between four input variables and TIN. The result showed that the fusion of optical data and SAR data was proved to be successful in estimating TIN in sea surface, with the correlation coefficient (R2 between measured TIN and predicated TIN of 0.774, and the root mean square error (RMSE of 0.063. The optical data in combination with SAR data is promising for detecting biochemical component in sea surface.

  8. International cooperation on wind energy for rural areas in China

    International Nuclear Information System (INIS)

    Pengfei, Shi

    1991-01-01

    An overview of the recent wind energy activities in China is given. China has a long history in harnessing the wind; modern development started during the late seventies. The Chinese wind potential is mainly in the coastal regions (North East and South East) and in Inner Mongolia. The actual total installed wind power is estimated to be 15 MW. For low lift (within 2 meters), high volume applications, e.g. salt making in salt pans along the coast, of mechanical windmills coupled to screw pumps have been developed. In Inner Mongolia, small portable wind generators (50-200 MW) charging car batteries are supplying some 100,000 farmer and herdsman families with electricity for television and lighting. The average energy consumption is between 200 and 300 kWh per year and the corresponding kWh price 0.40 to 0.50 US$. Since 1988 the demand for small wind generators declined due to the lower wool prices on the world market, affecting the income of the herdsman, and due to the fact that the machines have to be marketed in remote, less accesible rural areas. Various demonstration projects have been set up, f.e. a decentralized energy system on Dachen Island, including a wind diesel hybrid system. On Kongdon Island a 60 kW wind turbine and a 60 kW diesel generator were installed. With several foreign wind turbine manufacturers cooperations have been set up for licensed production in China. Also wind farms have been installed. The largest Chinese prototype at the moment is a 32 meter diameter, 200 kW machine. Western organizations or manufacturers are involved in most of the cooperatives. For the next five years the focus is on development of a large 150 and 200 kW machine and a windmill coupled to a centrifugal pump for lifting heads between 2 and 5 meter. 1 fig., 3 refs

  9. Nutrient characterisation of river inflow into the estuaries of the ...

    African Journals Online (AJOL)

    Nutrient characterisation of river inflow into the estuaries of the Gouritz Water ... into the estuaries within the Gouritz Water Management Area (WMA) of South Africa. ... Long-term water quality monitoring data (dissolved inorganic nitrogen, i.e. ...

  10. Evaluating Production of Cyclopentyl Tetraethers by Marine Group II Euryarchaeota in the Pearl River Estuary and Coastal South China Sea: Potential Impact on the TEX86 Paleothermometer

    Directory of Open Access Journals (Sweden)

    Jin-Xiang Wang

    2017-10-01

    Full Text Available TEX86 [TetraEther indeX of glycerol dialkyl glycerol tetraethers (GDGTs with 86 carbon atoms] has been widely applied to reconstruct (paleo- sea surface temperature. Marine Group I (MG-I Thaumarchaeota were thought to be the primary source of GDGTs constituting the TEX86 formula; however, recent research has suggested that Marine Group II (MG-II Euryarchaeota may also contribute significantly to the GDGT pool in the ocean. Little is known regarding the potential impact of MG-II Euryarchaeota-derived GDGTs on TEX86 values recorded in marine sediments. In this study, we assessed the relationship between distributions of GDGTs and MG-II Euryarchaeota and evaluated its potential effect on the TEX86 proxy. Lipid and DNA analyses were performed on suspended particulate matter and surface sediments collected along a salinity gradient from the lower Pearl River (river water and its estuary (mixing water to the coastal South China Sea (SCS, seawater. TEX86-derived temperatures from the water column and surface sediments were significantly correlated and both were lower than satellite-based temperatures. The ring index (RI values in these environments were higher than predicted from the calculated TEX86-RI correlation, indicating that the GDGT pool in the water column of the PR estuary and coastal SCS comprises relatively more cyclopentane rings, which thereby altered TEX86 values. Furthermore, the abundance of MG-II Euryarchaeota 16S rRNA gene in the mixing water was two to three orders of magnitude higher than those observed in the river or seawater. Significant linear correlations were observed between the gene abundance ratio of MG-II Euryarchaeota to total archaea and the fractional abundance of GDGTs with cyclopentane rings. Collectively, these results suggest that MG-II Euryarchaeota likely produce a large proportion of GDGTs with 1–4 cyclopentane moieties, which may bias TEX86 values in the water column and sediments. As such, valid

  11. Surficial and vertical distribution of heavy metals in different estuary wetlands in the Pearl river, South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Honggang; Cui, Baoshan [State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing (China); Zhang, Kejiang [Xinjiang Research Center of Water and Wastewater Treatment, Xinjiang Deland Co., LTD., Urumqi (China)

    2012-10-15

    A total of 87 soil profiles sampled from five types of wetlands in the Pearl River estuary were analyzed to investigate the surficial and vertical distributions of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn). The results show that wetlands directly connected with rivers (e.g., riparian wetlands, estuarine wetlands, and mangrove wetlands) has much higher metal concentrations than those indirectly connected with rivers (e.g., pond wetlands and reclaimed wetlands). The river water is the major pollution source for all investigated heavy metals. The vertical distribution of heavy metals can be classified into three patterns: (i) linear distribution pattern. The concentration of heavy metals gradually decreases with an increase in soil depth (for riparian and estuarine wetlands); (ii) irregular and stable pattern (for pond and reclaimed wetlands); and (iii) middle enrichment pattern (for mangrove wetlands). In addition to river-borne inputs, a variety of vegetation composition, hydraulic conditions, and human activities also contribute to the variation in distribution of heavy metals in different wetlands. Soil properties (e.g., particle size, pH, salinity, and SOM) also affect the distribution of trace metals in each soil layer. The major pollution source of heavy metals is industrial wastewater. Other sources include agriculture and domestic premises, and atmospheric deposition. This study provides a sound basis for the risk assessment of heavy metals in the studied wetlands and for wetland conservation in general. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Spatiotemporal Trends of Heavy Metals in Indo-Pacific Humpback Dolphins (Sousa chinensis) from the Western Pearl River Estuary, China.

    Science.gov (United States)

    Gui, Duan; Yu, Ri-Qing; Karczmarski, Leszek; Ding, Yulong; Zhang, Haifei; Sun, Yong; Zhang, Mei; Wu, Yuping

    2017-02-07

    We assessed the spatiotemporal trends of the concentrations of 11 heavy metals (HMs) in the liver and kidney of Indo-Pacific humpback dolphins (Sousa chinensis) from western Pearl River Estuary (PRE) during 2004-2015. The hepatic levels of Cr, As, and Cu in these dolphins were among the highest reported for cetaceans globally, and the levels of Zn, Cu, and Hg were sufficiently high to cause toxicological effects in some of the animals. Between same age-sex groups, dolphins from Lingdingyang were significantly more contaminated with Hg, Se, and V than those from the West-four region, while the opposite was true for Cd. Generalized additive mixed models showed that most metals had significant but dissimilar temporal trends over a 10-year period. The concentrations of Cu and Zn increased significantly in recent years, corresponding to the high input of these metals in the region. Body-length-adjusted Cd levels peaked in 2012, accompanied by the highest annual number of dolphin stranding events. In contrast to the significant decrease in HM levels in the dolphins in Hong Kong waters (the eastern reaches of the PRE), the elevated metal exposure in the western PRE raises serious concerns.

  13. Human exposure to polybrominated diphenyl ethers at production area, China.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian

    2010-05-01

    The concentrations of polybrominated diphenyl ethers (PBDEs) were detected in air and aquatic products in PBDEs production areas which are located at the south coast area of Laizhou Bay, Shandong province, China in this study. Concentrations of SigmaPBDEs in the air ranged from 0.47 ng/m3 to 161 ng/m3. In aquatic products, concentrations of SigmaPBDEs ranged from 2.7 ng/g wet weight to 42 ng/g wet weight. The mean dietary intake of SigmaPBDEs via aquatic products consumption in this study was 218 ng/day. Daily intake of SigmaPBDEs via inhalation in this study was 612 ng for men and 455 ng for women. With a contribution of 80%, BDE-209 was predominant in the total intake. Dietary intake and breathing inhalation contributed 29 and 71%, respectively, to the total PBDEs intake. The results indicate that breathing inhalation also plays a very significant pathway for the population of the PBDEs production area. Compared with similar studies in other countries, human exposure to PBDEs via diet and inhalation in this study was the highest in the world. Copyright (c) 2010 SETAC.

  14. Karst collapse in cities and mining areas, China

    International Nuclear Information System (INIS)

    Jian Chen

    1988-01-01

    Karst collapse is a dynamic geological phenomenon, in which the rock mass or deposits overlying the karstified zone subsides down along the karst cavity, resulting in a collapse pit or sinkhole. After discussing the typical examples of collapse emerging in the karst cities and mines in provinces and regions of South China, such as Guangdong, Guangxi, Hunan, Hubei, Zhejiang, Yunnan, Guizhou, and Jiangxi, it is considered that human activities of economy and production have become a major effect in causing karst collapse. Man-made collapses make 66.4 percent of the total, whereas natural ones 33.6 percent. Most of the collapses occurred to the area with soil overburden (96.7 percent), only a few in areas of bedrock overburden (3.3 percent). The karst collapses have a close relationship with the extent of karst development, the character and the thickness of overburden, and the dynamic condition of underground water. Collapse usually occurs in those parts of an area that are more intensely karstified, with soil thickness less than 5 m and a high amplitude of water table fluctuation. Many kinds of mechanical effects are caused by pumping or draining on the over-burden and destroying its equilibrium, leading to the collapse. These effects included the support loss and load-added effect, penetrating suffusion, gas explosion, water-hammer, suction pressure erosion, and liquefaction effects. The collapses are the result of varied comprehensive effects, particularly the support loss and load-added, and penetrating suffusion

  15. Ecology of estuaries

    International Nuclear Information System (INIS)

    Kennish, M.J.

    1992-01-01

    Ecology of Estuaries: Anthropogenic Effects represents the most definitive and comprehensive source of reference information available on the human impact on estuarine ecosystems. The book discusses both acute and insidious pollution problems plaguing these coastal ecotones. It also provides a detailed examination of the deleterious and pervasive effects of human activities on biotic communities and sensitive habitat areas in estuaries. Specific areas covered include organic loading, oil pollution, polynuclear aromatic hydrocarbons, chlorinated hydrocarbons, heavy metals, dredging and dredge-spoil disposal, radionuclides, as well as other contaminants and processes. The diverse components of these anthropogenic influences are assembled in an organized framework and presented in a clear and concise style that will facilitate their understanding

  16. Distribution and Behaviors of Cd, Cu, and Ni in the East China Sea Surface Water off the Changjiang Estuary

    OpenAIRE

    Kuo-Tung Jiann; Liang-Saw Wen; Gwo-Ching Gong

    2009-01-01

    Trace metal (Cd, Cu, and Ni) dis tri bu tions and be hav iors in sur face waters of the East China Sea continental shelf were investigated during an expeditioncon ducted in June 2004. Dissolved and particulate trace metal con centrations, as well as fractions of dissolved trace metals, fraction ated based on their different chemical affinities to ion exchangers, were determined using ultra-clean techniques and graphite furnace atomic absorption spectrometry (GFAAS). Large variations of dissol...

  17. 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

  18. 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...

  19. Reverse trends of TEX86 temperature in coastal areas of the East China Sea over the last 100 years: implication for global warming and regional circulation

    Science.gov (United States)

    Cao, Y.; Xing, L.; Zhang, T.

    2017-12-01

    To reconstruct and compare the SST changes in different regions of the ECS over the last 100 years, in this study, we analyzed iGDGTs compounds and TEX86 index in two sediment cores (DH5-1 and DH6-2) from the inner shelf of the East China Sea (ECS). GDGT-0 and GDGT-5 in the two cores account for 80% of iGDGTs, significantly more abundant than the other iGDGTs compounds. It is also found that iGDGTs are mainly derived from marine Thaumarchaeota. TEXH86 temperatures varied from 17 °C to 22 °C (average 19.4 °C), showing a gradual increase in Core DH5-1 near the Changjiang River Estuary, corresponding to global warming and temperature rise in the ECS over the last 100 years. However, in Core DH6-2 further away from the Changjiang River Estuary, TEXH86 temperatures gradually decreased over the last 80 years with a range of 15.3 °C-18.3 °C, which is attributed to the strengthened near-shore Kuroshio Branch Current transporting more subsurface cold water to the ECS coastal area. In future, more sites should be investigated to confirm the range of the coastal area where the decrease in SST is caused by upwelling subsurface water.

  20. The research of modern He discharge in volcanic and tectonically active areas of China's continent

    International Nuclear Information System (INIS)

    Shangguan, Z.G.

    1999-01-01

    The realising features of modern helium in volcanic and tectonically active areas of China's continent are here discussed, presenting that the current escaped He in volcanic areas are mainly the mantle-derived He. The 3 He/ 4 He ratios of crustal gases in Eastern China are relatively higher than those gases in Middle-Western China. The author considers difficult to interpret this phenomenon by means of the differences of tectonic activity in those areas: it may be related to the variation of crustal thickness of China's continent from East to West

  1. Molecular and stable isotopic evidence for the occurrence of nitrite-dependent anaerobic methane-oxidizing bacteria in the mangrove sediment of Zhangjiang Estuary, China.

    Science.gov (United States)

    Zhang, Manping; Luo, Yi; Lin, Li'an; Lin, Xiaolan; Hetharua, Buce; Zhao, Weijun; Zhou, Mengkai; Zhan, Qing; Xu, Hong; Zheng, Tianling; Tian, Yun

    2018-03-01

    Nitrite-dependent anaerobic methane oxidation (n-damo), which is mediated by "Candidatus Methylomirabilis oxyfera-like" bacteria, is unique in linking the carbon and nitrogen cycles. However, the niche and activity of n-damo bacteria in the mangrove ecosystem have not been confirmed. Here, we report the occurrence of the n-damo process in the mangrove wetland of the Zhangjiang Estuary, China. The widespread occurrence of n-damo bacteria in mangrove wetland was confirmed using real-time quantitative polymerase chain reaction (qPCR) assay, which showed that the abundance of Methylomirabilis oxyfera-like bacterial 16S rRNA and pmoA genes ranged from 2.43 × 10 6 to 2.09 × 10 7 and 2.07 × 10 6 to 3.38 × 10 7 copies per gram of dry soil in the examined sediment cores. The highest amount of targeting genes was all detected in the upper layer (0-20 cm). Phylogenetic analyses of n-damo bacterial 16S rRNA and pmoA genes illustrated the depth-specific distribution and high diversity of n-damo bacteria in the mangrove wetland. Stable isotope experiments further confirmed the occurrence of n-damo in the examined mangrove sediments, and the potential n-damo rates ranged from 25.93 to 704.08 nmol CO 2 per gram of dry soil per day at different depths of the sediment cores, with the n-damo being more active in the upper layer of the mangrove sediments. These results illustrate the existence of active M. oxyfera-like bacteria and indicate that the n-damo process is a previously overlooked microbial methane sink in the mangrove wetlands.

  2. 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

  3. 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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  4. Distribution and Behaviors of Cd, Cu, and Ni in the East China Sea Surface Water off the Changjiang Estuary

    Directory of Open Access Journals (Sweden)

    Kuo-Tung Jiann

    2009-01-01

    Full Text Available Trace metal (Cd, Cu, and Ni dis tri bu tions and be hav iors in sur face waters of the East China Sea continental shelf were investigated during an expeditioncon ducted in June 2004. Dissolved and particulate trace metal con centrations, as well as fractions of dissolved trace metals, fraction ated based on their different chemical affinities to ion exchangers, were determined using ultra-clean techniques and graphite furnace atomic absorption spectrometry (GFAAS. Large variations of dissolved (< 0.45 mm metal concentrations in the East China Sea shelf waters were found (n = 16 and ranged between 0.036 - 0.287 nM for Cd, 0.87 - 8.66 nM for Cu, and 2.66 - 6.04 nM for Ni. Particulate metal contributions were highest near the river mouth. Dis solved Cd and Ni were pre dominantly present (98% for Cd and 86% for Ni as Chelex-labile fractions in the shelf waters.

  5. Eco-morphological problems in the Yangtze Estuary and the Western Scheldt

    NARCIS (Netherlands)

    De Vriend, H.J.; Wang, Z.B.; Ysebaert, T.; Herman, P.M.J.; Ding, P.X.

    2011-01-01

    This paper compares the Yangtze Estuary in China and the Western Scheldt Estuary in The Netherlands by their morphodynamic and ecological systems, their engineering works and estuarine management issues, and the major challenges in studying them. Physically speaking, the two estuaries are very

  6. Effects of conversion of mangroves into gei wai ponds on sediment heavy metals accumulation in tidal flat estuary, South China

    Science.gov (United States)

    Li, R.; Qiu, G.; Chai, M.; Li, R.

    2017-12-01

    Gei wai ponds act as important component in mangrove ecosystem, but the conversion of mangroves into gei wai ponds and its ecological function on heavy metal accumulation is still not clear. The study quantified the sediment heavy metal concentration and speciation in gei wai pond, Avicennia marina marsh and mudflat in Futian mangrove wetlands, South China. The results showed that gei wai pond acidified the sediment and reduced its fertility due to reduced pH, electronic conductivity (EC) and total organic carbon (TOC) compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all depth in gei wai pond sediment were also lower than other sites, indicating reduced storage function on heavy metals. Multiple analysis implied that heavy metals in all sites could be attributed to anthropogenic sources, with Cr as natural and anthropogenic sources in gei wai pond. Gei wai pond sediment had lower heavy metal pollution based on multiple evaluation methods, including potential ecological risk coefficient (Eir), potential ecological risk index (RI), geo-accumulation index (Igeo), mean PEL quotients (m-PEL-q), pollution load index (PLI), mean ERM quotients (m-ERM-q) and total toxic unit (∑TU). Heavy metal speciation analysis indicated that gei wai pond improved the conversion from the immobilized Cd and Cr to the mobilized fraction. SEM-AVS analysis indicated no adverse toxicity occurred in all sites, and the role of TOC in relieving sediment heavy metal toxicity of gei wai pond is limited.

  7. A theoretical framework for analyzing the effect of external change on tidal dynamics in estuaries

    Science.gov (United States)

    CAI, H.; Savenije, H.; Toffolon, M.

    2013-12-01

    The most densely populated areas of the world are usually located in coastal areas near estuaries. As a result, estuaries are often subject to intense human interventions, such as dredging for navigation, dam construction and fresh water withdrawal etc., which in some areas has led to serious deterioration of invaluable ecosystems. Hence it is important to understand the influence of such interventions on tidal dynamics in these areas. In this study, we present one consistent theoretical framework for tidal hydrodynamics, which can be used as a rapid assessment technique that assist policy maker and managers to make considered decisions for the protection and management of estuarine environment when assessing the effect of human interventions in estuaries. Analytical solutions to the one-dimensional St. Venant equations for the tidal hydrodynamics in convergent unbounded estuaries with negligible river discharge can be cast in the form of a set of four implicit dimensionless equations for phase lag, velocity amplitude, damping, and wave celerity, as a function of two localized parameters describing friction and convergence. This method allows for the comparison of the different analytical approaches by rewriting the different solutions in the same format. In this study, classical and more recent formulations are compared, showing the differences and similarities associated to their specific simplifications. The envelope method, which is based on the consideration of the dynamics at high water and low water, can be used to derive damping equations that use different friction approximations. This results in as many analytical solutions, and thereby allows one to build a consistent theoretical framework. Analysis of the asymptotic behaviour of the equations shows that an equilibrium tidal amplitude exits reflecting the balance between friction and channel convergence. The framework is subsequently extended to take into account the effect of river discharge. Hence, the

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

    NARCIS (Netherlands)

    Li, Zhengtao; Folmer, Henk; Xue, Jianhong

    2016-01-01

    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

  9. On Financial Support System for Compulsory Education in China's Western Minority Areas

    Science.gov (United States)

    Jinyu, Qi

    2008-01-01

    China's Western Development is a policy adopted to boost its less developed Western regions, that is, a systematic project and a longterm and arduous task. The development of compulsory education in China's minority areas is the key to it. This paper attempts to use the beneficial experience of developing compulsory education support system of…

  10. The Effect of ASEAN-China Free Trade Area (ACFTA on Indonesia Export

    Directory of Open Access Journals (Sweden)

    Indriyani Indriyani

    2016-10-01

    Full Text Available ASEAN-China Free Trade Area (ACFTA is an agreement between the members of ASEAN and China to create a free trade area by removing tariff and non-tariff barriers. This agreement begins with the signing of the agreement on November 5, 2002 in Phnom Penh. Implementation is done in phases beginning January 1, 2004. The purpose of this study determines the effect of the implementation of ACFTA on Indonesia's exports to the ASEAN countries and China. This study complements previous research regarding the ACFTA. The data used in this study are the data of Indonesian exports to ASEAN countries and China for 15 years from 2000 until 2014. The tests were conducted with a fixed effect panel data model with cross section SUR. The results of this study indicate that the ACFTA increase Indonesian exports to the ASEAN countries and China.DOI: 10.15408/etk.v15i2.3331

  11. “Population Invasion” versus Urban Exclusion in the Tibetan Areas of Western China

    OpenAIRE

    Fischer, Andrew Martín

    2008-01-01

    textabstractThis article examines the confluence of local population transitions (demographic transition and urbanization) with non-local in-migration in the Tibetan areas of western China. The objective is to assess the validity of Tibetan perceptions of "population invasion" by Han Chinese and Chinese Muslims. The article argues that migration to Tibet from other regions in China has been concentrated in urban areas and has been counterbalanced by more rapid rates of natural increase in the...

  12. 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.

  13. Study on the regional crust stability of Beishan area, Gansu province, NW China-the preselected area for China's high level radioactive waste repository

    International Nuclear Information System (INIS)

    Wang Ju; Xu Guoqing; Jin Yuanxin; Chen Weiming; Guo Yonghai; Yang Tianxiao

    2004-01-01

    This paper summarizes the research results on the crust stability of the Beishan area, Gansu province, NW China-the preselected area for China's high level radioactive waste repository. The studies include regional tectonic structure and its evolution, regional geophysical field, crust structure, regional deep-rooted faults, regional seismological activity, regional neo-tectonics, regional modern stress field and its numerical simulation, geological interpretation of TM satellite and its application in the study of crust stability, and the evaluation on crust stability. The research in the past years indicates that the west part of Gansu province (the area we studied) can be divided into 8 parts with different crust stability: (1) Beishan stable area; (2) East Huahai stable area; (3) Huahai sub-stable area; (4) Yumenzheng sub-unstable area; (5) Yumenshi sub-unstable area; (6) Daxueshan sub-unstable area; (7) Jiayuguan unstable area; and (8) Beiqilian unstable area. Among those parts, the Beishan area possess the best conditions, its crust stability accords with the demands on candidate site for HLW repositories, which are described in the International atomic energy agency's safety series No.111-G-4.1 Guidelines. Therefore, the Beishan area is suitable region for further work. (author)

  14. Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  15. 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.

  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. Distribution study of fatty acids (FAs) in sediments of Al-Kabeer Al-Shemali river estuary area using (HPLC) technique

    International Nuclear Information System (INIS)

    Nasser, M.; Ali, B.; Ali, A.

    2010-01-01

    Samples of sediments from fife sites of Al-kabeer Al-shemali river estuary area were collected during the period (22/2/2007-7/11/2007). The samples were extracted to determine their content of Fatty acids qualitatively and quantitatively by using ( HPLC) technique for determination resources of organic matter in studied sediments . The total concentrations of (FAs) varied from (0.36-1245.5μg/g dry weight).The saturated fatty acids were dominated in all samples (12.1 - 100 %) of total fatty acids. The levels of polyunsaturated fatty acids (PUFAs) were tested percent (0-18 %) of total fatty acids except one sample from surficial sediments in St 3 during 8/8/2007 .while the concentrations of monounsaturated fatty acids (MUFAs) were low (0 -21.6 %) of total fatty acids . We can use the saturated long chain fatty acid (C-22) as terrestrial biomarker. poly unsaturated fatty acid (C 1 8: 2ω6) as plankton biomarker and the Mono unsaturated fatty acid (C 1 8 : 1ω7) as bacterial biomarker.(author)

  18. Environmental management of estuarine areas: a proposal for conservation of water and biodiversity to the mangroves of the Paraiba do Sul River estuary, Gargaú, RJ

    Directory of Open Access Journals (Sweden)

    Edêmea Faria Carlos Rocha

    2016-12-01

    Full Text Available Being impacted by illegal occupation and untreated sewage release, the mangrove estuary of the Paraíba do Sul River has high biodiversity and provides various ecosystem services. In this study, we focused on strategies for sustainability promotion in Gargaú, a locality in this estuarine region, associating mangrove conservation to the uses of common resources practiced by locals. The main investigated issues were: “Would it be feasible to create a Conservation Unit in order to reinforce legal mechanisms to protect the mangrove?”; and “How does the local community see the scenario of environmental degradation and the proposal of creating a Conservation Unit in the region?”. Locals strongly depend on the estuarine area resources and perceive mangrove deforestation as well as untreated sewage release as the main causes of negative impacts. Despite not knowing what a Conservation Unit actually is, local key informants agreed to its creation after clarification of the categories and groups fixed by Brazilian legislation. Although accepting it with reservation, they understood it is a necessary measure to conserve the mangrove that sustains them.

  19. Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

    International Nuclear Information System (INIS)

    Wang Chen; Li Wei; Chen Jiwei; Wang Hongqijie; Li Tongchao; Shen Guofeng; Shen Huizhong; Huang Ye; Wang Rong; Wang Bin; Zhang Yanyan; Tang Jianhui; Liu Wenxin; Wang Xilong; Tao Shu

    2012-01-01

    High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m 3 ) and other 13 PBDEs (16 ± 12 pg/m 3 ) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively. - Graphical abstract: Concentration of PBDEs at each site of the studied area. Highlights: ► High levels of PBDEs with BDE-209 domination were detected in air in northern China. ► PBDE concentrations in rural residential areas were significantly higher than those in rural open fields. ► Proportions of BDE-209 in urban areas were higher than those in rural areas. ► PBDE concentrations were correlated to local population density and Gross Domestic Production. - In northern China, PBDEs in air in rural residential areas were significantly higher than those in open fields.

  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

    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. PMID:26580966

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Quantification and Evaluation of Soil Erosion in the Estuaries of Cameroon, Gulf of Guinea: Case of Nylon Area

    Directory of Open Access Journals (Sweden)

    Eric Flavien Mbiakouo-Djomo

    2018-01-01

    Full Text Available The area of Nylon represents a sensible and vulnerable environment where water erosion is the cause of many soil losses contributing to the production and movement of sediments from the upstream to the lowest depths. The high level of rainfall in this town, soil texture (sand-clay-silt, and the anarchic occupation of the area play a part in the important deterioration of the bare ground on the upstream of the catchment area. This causes with time an instability of structures and living places which can lead to their progressive disappearance. In order to assess the quantities of displaced sediments, the studies on the quantification of soil moved annually by water erosion are carried out. A direct method is used consisting in using a minisimulator of rain (NEME in order to understand the phenomena involved and assess the quantity of sediments which can be moved. It helps in assessing erosion caused by the rain and extrapolating results over the catchment area of the chosen field of study. USLE relation has permit to make an extrapolation of the quantity of soil affected, and the result shows that the average potential of loss of soil is 153.57 t/ha/annum.

  6. Anemia Prevalence among Pregnant Women and Birth Weight in Five Areas in China

    NARCIS (Netherlands)

    Ma, A.G.; Schouten, E.G.; Wang, Y.; Xu, R.X.; Zheng, M.C.; Li, Y.; Sun, Y.Y.; Wang, Q.Z.

    2009-01-01

    Objectives: To investigate the current prevalence of anemia among pregnant women in different areas of China and the association with birth weight and educational level. Methods: A total of 6,413 women aged 24-37 in the third trimester of pregnancy from five areas were randomly selected from all

  7. Pembentukan Perdagangan Bebas Asean-China (Asean-China Free Trade Area) Dan Dampaknya Bagi Petani Di Indonesia

    OpenAIRE

    Indriastuti, Suyani

    2005-01-01

    Recently, free trade is a global phenomenon where the regions effort to make an exclusive free trade area. The Association of South East Asian Nations (ASEAN) and China signed a comprehensive economic partnership agreement on the teenth of ASEAN summit. The parties agreed to strenghthen their coorperation in many sectors which the one of that was agriculture sector. So Indonesian as ASEAN member has enthusiasm to apply this agreement. It has many impacts for Indonesian farmer.

  8. 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

  9. 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.

  10. 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.

  11. Organochlorine concentrations in breast milk and risk assessment in the urban and rural areas of Northern China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J.H.; Sun, S.U. [Jichi Medical School, Tochigi (Japan). Dept. of Environmental Medicine, Center for Community Medicine]|[CREST-JST, Kawaguchi, Saitama (Japan); Koga, M. [Prefectural Univ. of Kumamoto (Japan). Fac. of Environmental and Symbiotic Sciences] (and others)

    2004-09-15

    In China, during the past 40 years, organochlorine pesticides (OPs) with impurity were produced and used in a large quantity. However, little is known on the OPs contamination status of the residents in mainland of China. To elucidate body burden of organochlorine compounds and factors associated with organochlorine levels of the residents in North China, we performed life style questionnaire and collected breast milk specimens at Shijiazhuang urban and Tangshan rural area, Hebei Province, North China.

  12. Natural radioactivity assessment of surface sediments in the Yangtze Estuary

    International Nuclear Information System (INIS)

    Wang, Jinlong; Du, Jinzhou; Bi, Qianqian

    2017-01-01

    The activities of the natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) of the surface sediments in the Yangtze Estuary were determined and used to evaluate radiation hazards in the study area. The of activities of 238 U, 232 Th, 226 Ra and 40 K ranges from 14.1 to 62.3, 26.1 to 71.9, 13.7 to 52.3, and 392 to 898 Bq kg −1 , respectively, which were comparable to values of other regions in China. The activities of 232 Th, 40 K and 226 Ra were clearly different from the global recommended values. The radium equivalent activity was less than the recommended limit of 370 Bq kg −1 ; therefore, the sediment in this area can be safely used for reclamation. The external hazard index values were less than one. The average absorbed gamma dose rate and annual effective dose equivalent values were slightly greater than the world average value. 226 Ra/ 238 U and 232 Th/ 238 U ratios could potentially be applied for tracing sediment source. - Highlights: • The natural radioactivity of surface sediments in the Yangtze Estuary was observed. • The radiological hazards of the sediments are insignificant in this study area. • The ratios of natural radionuclides can potentially be applied for sediment source.

  13. China National Scenic Area and Its Planning Characteristics

    Institute of Scientific and Technical Information of China (English)

    Jia; Jianzhong; Deng; Wugong; Li; Caige

    2016-01-01

    Thirty years since the foundation of China’s scenic area system, a comparatively comprehensive structural system, legal system, and management system have been established in this field, which has protected precious landscape resources and made remarkable achievements. The planning of scenic areas has its own attributes and technical characteristics, which attaches great importance to establishing a functional structure that combines the three systems of sightseeing, tourism services, and social management of local residents. Moreover, with the development of scenic areas, the planning will lay more emphasis on the connection between different levels, give full play to the comprehensive function of scenic areas, pay attention to the research on village and town planning within the area, and learn from the experience of national parks in foreign countries.

  14. 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.

  15. GlobeLand30 shows little cropland area loss but greater fragmentation in China

    Science.gov (United States)

    Yu, Qiangyi; Hu, Qiong; van Vliet, Jasper; Verburg, Peter H.; Wu, Wenbin

    2018-04-01

    Understanding of cropland dynamics in a large geographical extent is mostly based on observations of area change, while the changes in landscape pattern are hardly assessed. The total amount of cropland in China has remained relatively stable in recent years, which might suggest there was little change. In this analysis, we combine the number of cropland patches (NP) with the total cropland area (TA) for a more comprehensive characterization of cropland change in China. We use GlobeLand30-a global land cover dataset with a 30 m resolution for the years 2000 and 2010-and characterize changes in TA and NP for each county as increase, stable, or decrease. This characterization shows that 703 out of 2420 counties experienced both cropland loss and increased fragmentation. The predominant cropland loss in these areas, especially in the North China Plain, is converted to artificial land. Another 212 are characterized by the opposite developments: an increase in cropland and decreased fragmentation. These counties, are mainly characterized by a conversion of forest areas and grassland areas. It suggests that the cropland conservation policy in China effectively protected the total cropland area in overall, but the consequences in terms of fragmentation might be underestimated. Counties with no obvious change in both indicators, measuring 279 counties, are mainly located in the Southeast. Our results are further compared with local level case studies: the fair consistency indicates alternatives of applying GlobeLand30 for analyzing landscape changes across scales and for cross-site comparisons.

  16. Projected land use changes impacts on water yields in the karst mountain areas of China

    Science.gov (United States)

    Lang, Yanqing; Song, Wei; Deng, Xiangzheng

    2018-04-01

    Human-induced land use changes over short time scales have significant impacts on water yield, especially in China because of the rapid social economic development. As the biggest developing country of the world, China's economy is expected to continuously grow with a high speed in the next few decades. Therefore, what kind of land use changes will occur in the future in China? How these changes will influence the water yields? To address this issue, we assessed the water yields in the karst mountain area of China during the periods of 1990-2010 and 2010-2030 by coupling an Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and a Conversion of Land Use and its Effects (CLUE) model. Three different land use scenarios i.e. natural growth, economic development, and ecological protection, were developed in 2030 using the CLUE model. It was concluded that, given land use changes between 1990 and 2010, total water yields in the karst mountain area are characterized by a trend towards fluctuating reduction. However, total water yields of 2030 in the economic development scenario revealed an increase of 1.25% compared to the actual water yields in 2010. The economy development in karst mountain areas of China in the future has a slight positive influence on water yields.

  17. Local Estuary Programs

    Science.gov (United States)

    This page provides information about Local Individual Estuary Programs including links to their NEP homepages, social media, Comprehensive Conservation and Management Plans, and state of the bay reports.

  18. Milwaukee Estuary AOC

    Science.gov (United States)

    The rivers in the Milwaukee estuary in Wisconsin drain into Lake Michigan. Wastewater treatment plants and combined sewer overflows contribute pollution which affects fish and wildlife and recreation.

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

    Directory of Open Access Journals (Sweden)

    Pengze Yan

    Full Text Available Nitrite-dependent anaerobic methane oxidation (n-damo is performed by "Candidatus Methylomirabilis oxyfera" (M. oxyfera, 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. oxyfera-like sequences analysis based on the 16S rRNA gene revealed greater diversity compared with the pmoA gene; the 16S rRNA gene sequences retrieved from the Yellow River Estuary sediments belong to groups A as well as B and were mainly found in freshwater habitats. Quantitative PCR showed that 16S rRNA gene abundance varied from 9.28±0.11×10(3 to 2.10±0.13×10(5 copies g(-1 (dry weight, and the pmoA gene abundance ranged from 8.63±0.50×10(3 to 1.83±0.18×10(5 copies g(-1 (dry weight. A correlation analysis showed that the total organic carbon (TOC and ammonium (NH4(+ as well as the ratio of total phosphorus to total nitrogen (TP/TN influenced the M. oxyfera-like bacteria distribution in the Yellow River Estuary sediments. These findings will aid in understanding the n-damo bacterial distribution pattern as well as their correlation with surrounding environmental factors in temperate estuarine ecosystems.

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

    Science.gov (United States)

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

    2015-01-01

    Nitrite-dependent anaerobic methane oxidation (n-damo) is performed by "Candidatus Methylomirabilis oxyfera" (M. oxyfera), 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. oxyfera-like sequences analysis based on the 16S rRNA gene revealed greater diversity compared with the pmoA gene; the 16S rRNA gene sequences retrieved from the Yellow River Estuary sediments belong to groups A as well as B and were mainly found in freshwater habitats. Quantitative PCR showed that 16S rRNA gene abundance varied from 9.28±0.11×10(3) to 2.10±0.13×10(5) copies g(-1) (dry weight), and the pmoA gene abundance ranged from 8.63±0.50×10(3) to 1.83±0.18×10(5) copies g(-1) (dry weight). A correlation analysis showed that the total organic carbon (TOC) and ammonium (NH4(+)) as well as the ratio of total phosphorus to total nitrogen (TP/TN) influenced the M. oxyfera-like bacteria distribution in the Yellow River Estuary sediments. These findings will aid in understanding the n-damo bacterial distribution pattern as well as their correlation with surrounding environmental factors in temperate estuarine ecosystems.

  1. “Population Invasion” versus Urban Exclusion in the Tibetan Areas of Western China

    NARCIS (Netherlands)

    A.M. Fischer (Andrew Martín)

    2008-01-01

    textabstractThis article examines the confluence of local population transitions (demographic transition and urbanization) with non-local in-migration in the Tibetan areas of western China. The objective is to assess the validity of Tibetan perceptions of "population invasion" by Han Chinese and

  2. 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...

  3. Holocene aeolian activity in the Dinggye area (Southern Tibet, China)

    Science.gov (United States)

    Pan, Meihui; Wu, Yongqiu; Zheng, Yinghua; Tan, Lihua

    2014-03-01

    The Dinggye area (Southern Tibet) contains numerous aeolian sediments, including modern and ancient aeolian sand deposition. In this study, we determined the chronological sequences of several profiles of Holocene paleo-aeolian deposits using Optically Stimulate Luminescence (OSL) and radiocarbon (Accelerator Mass Spectrometry (AMS) 14C and conventional 14C) dating. Using the grain size, magnetic susceptibility, organic content and chrome characteristics of the deposits, we reconstructed the Holocene aeolian processes in the Dinggye area. The results from the paleo-aeolian depositional record indicate multiple changes in the intensity of aeolian activity and soil fixing with alternations between cool-dry and warm-humid climate conditions in the Dinggye area during the Holocene. From 12.8 ka B.P. to the present, the climate has fluctuated frequently. From 12.8 to 11.6 ka B.P. and from 9.3 to 4.9 ka B.P., the climate was warm and humid with weak aeolian activity, and a sandy paleosol developed. The peak Holocene megathermal period and the main period of pedogenesis in the study area was from 6.6 to 4.9 ka B.P. Between 11.6 and 9.3 ka B.P. and since 2.0 ka B.P., the sandlot expanded due to a cool, dry and windy climate; aeolian activity was strong and caused the development of moving dunes. The period between 4.9 and 2.0 ka B.P. was relatively cool and dry with slightly strengthened aeolian activity that developed stationary and semi-stationary dunes. In general, the Holocene events recorded by the paleo-aeolian deposits correspond well with those interpreted by other methods, such as records from ice-cores, lacustrine deposits and tree rings, but there are minor discrepancies between the methods.

  4. Synthetic hydrogeological study on Beishan preselected area for high-level radioactive waste repository in China

    International Nuclear Information System (INIS)

    Guo Yonghai; Su Rui; Ji Ruili; Wang Hailong; Liu Shufen; Zong Zihua; Dong Jiannan; Zhang Ming

    2014-01-01

    On the basis of large scale field hydrogeological investigation, synthetic hydrogeological studies related to groundwater system characteristics, permeability of rock bodies, groundwater dynamic, hydrogeochemistry, isotopic hydrology, CFC's of groundwater and groundwater flow field simulation were carried out for Beishan area, Gansu province. According to analysis on a large amount of hydrogeological data, the characteristics of groundwater circulation, groundwater hydrodynamics and hydrgeochemistry were described and the suitability of Beishan area as the potential area of high-level radioactive waste disposal was evaluated in the paper. Through this study, the hydrogeological study and evaluation methods in the siting of China's high level radioactive waste repository were set up. Furthermore, the important hydrogeological scientific evidence was provided for optimal site filtration of China's high-level radioactive waste repository in Beishan area. (authors)

  5. Hyperspectral Estimation of the Chlorophyll Content in Short-Term and Long-Term Restorations of Mangrove in Quanzhou Bay Estuary, China

    Directory of Open Access Journals (Sweden)

    Zhiguo Dou

    2018-04-01

    Full Text Available The chlorophyll content can indicate the general health of vegetation, and can be estimated from hyperspectral data. The aim of this study is to estimate the chlorophyll content of mangroves at different stages of restoration in a coastal wetland in Quanzhou, China, using proximal hyperspectral remote sensing techniques. We determine the hyperspectral reflectance of leaves from two mangrove species, Kandelia candel and Aegiceras corniculatum, from short-term and long-term restoration areas with a portable spectroradiometer. We also measure the leaf chlorophyll content (SPAD value. We use partial-least-squares stepwise regression to determine the relationships between the spectral reflectance and the chlorophyll content of the leaves, and establish two models, a full-wave-band spectrum model and a red-edge position regression model, to estimate the chlorophyll content of the mangroves. The coefficients of determination for the red-edge position model and the full-wave-band model exceed 0.72 and 0.82, respectively. The inverted chlorophyll contents are estimated more accurately for the long-term restoration mangroves than for the short-term restoration mangroves. Our results indicate that hyperspectral data can be used to estimate the chlorophyll content of mangroves at different stages of restoration, and could possibly be adapted to estimate biochemical constituents in leaves.

  6. 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

  7. 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…

  8. Are master plans effective in limiting development in China's disaster-prone areas?

    OpenAIRE

    Kim, Saehoon; Rowe, Peter G.

    2013-01-01

    The effectiveness of urban master plans in limiting development in a disaster-prone area of China was empirically investigated by measuring cities’ land-cover changes against their master plans. If a master plan serves as guidance for urban polices that reduce property loss from earthquakes, floods, landslides,land subsidence, and rises in sea level, it will substantially limit urban development in areas at risk from environmental hazards. An environmental risk map weighted toward valuable...

  9. Research on Building Urban Sustainability along the Coastal Area in China

    OpenAIRE

    Sun Jiaojiao; Fu Jiayan

    2015-01-01

    At present, in China, the research about the urban sustainability construction is still in the exploratory stage. The ecological problems of the coastal area are more sensitive and complicated. In the background of global warming with serious ecological damage, this paper deeply researches on the main characteristics of urban sustainability and measures how to build urban sustainability. Through combining regional environmental with economic ability along the coastal area...

  10. 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.

  11. 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

    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......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...... 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...

  12. Distribution and assessment of sediment toxicity in Tamaki Estuary, Auckland, New Zealand

    Science.gov (United States)

    Abrahim, G. M. S.; Parker, R. J.; Nichol, S. L.

    2007-07-01

    Heavy metal levels in surface sediments from Tamaki Estuary demonstrate significant up estuary increases in Cu, Pb, Zn, Cd and mud concentrations. Increased metal levels towards the head of the estuary are linked to local catchment sources reflecting the historical development, industrialisation and urbanisation of catchment areas surrounding the upper estuary. The relatively narrow constriction in the middle estuary (Panmure area), makes it susceptible to accumulation of upper estuary pollutants, since the constriction reduces circulation and extends the time required for fine waterborne sediments in the upper estuary to exchange with fresh coastal water. As a result fine fraction sediments trapped in the upper estuary facilitate capture and retention of pollutants at the head of the estuary. The increase in sandy mud poor sediments towards the mouth of the estuary is associated with generally low metal concentrations. The estuary’s geomorphic shape with a mid estuary constriction, sediment texture and mineralogy and catchment history are significant factors in understanding the overall spatial distribution of contaminants in the estuary. Bulk concentration values for Cu, Pb, Zn, and Cd in all the studied surface samples occur below ANZECC ISQG-H toxicity values. Cd and Cu concentrations are also below the ISQG-L toxicity levels for these elements. However, Pb and Zn concentrations do exceed the ISQG-L values in some of the surface bulk samples in the upper estuary proximal to long established sources of catchment pollution.

  13. 33 CFR 165.1190 - Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA.

    Science.gov (United States)

    2010-07-01

    ..., Oakland Estuary, Alameda, CA. 165.1190 Section 165.1190 Navigation and Navigable Waters COAST GUARD... § 165.1190 Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA. (a) Location. The following area is a security zone: All navigable waters of the Oakland Estuary, California, from the surface to...

  14. Dynamic Modeling and Simulation of an Isolated Hybrid Power System in a Rural Area of China

    Directory of Open Access Journals (Sweden)

    Bojian Jiang

    2018-01-01

    Full Text Available In some rural areas in the northwest of China, people are suffering from not only the voltage drop due to long distance transmission but also the power outages due to remoteness and poorly maintained grid. In recent few years, the price of solar energy has been reduced drastically every year in China due to the government policy on renewable energy. In the near future, isolated hybrid power systems for home use could be affordable and used by residences in these rural areas. Thus, it is necessary to design a hybrid power system based on local load and weather condition to check system feasibility and expected performance. It includes load simulation, system sizing, and dynamic system modeling and simulation. This paper firstly introduces current development of renewable energy in China and then goes through the sizing, modeling, and simulation of the system design for a typical remote home in China and finally discusses the system’s availability based on the simulation results. In this paper, the NASA website is the source for weather data, and BEopt is used to generate load data. During system modeling, the MPPT algorithm is much simpler designed than the complex incremental method. A soft starter is adopted with the diesel generator for stability. The charge controller of the battery storage provides external command to the MPPT and diesel PID controller to prevent the battery storage from overcharging. The rms value of the fundamental load voltage is used in the voltage control loop of the inverter.

  15. 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.

  16. 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.

  17. 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.

  18. [Mutation analysis of the PAH gene in children with phenylketonuria from the Qinghai area of China].

    Science.gov (United States)

    He, Jiang; Wang, Hui-Zhen; Xu, Fa-Liang; Yang, Xi; Wang, Rui; Zou, Hong-Yun; Yu, Wu-Zhong

    2015-11-01

    To study the mutation characteristics of the phenylalanine hydroxylase (PAH) gene in children with phenylketonuria (PKU) from the Qinghai area of China, in order to provide basic information for genetic counseling and prenatal diagnosis. Mutations of the PAH gene were detected in the promoter and exons 1-13 and their flanking intronic sequences of PAH gene by PCR and DNA sequencing in 49 children with PKU and their parents from the Qinghai area of China. A total of 30 different mutations were detected in 80 out of 98 mutant alleles (82%), including 19 missense (63%), 5 nonsense (17%), 3 splice-site (10%) and 3 deletions (10%). Most mutations were detected in exons 3, 6, 7, 11 and intron 4 of PAH gene. The most frequent mutations were p.R243Q (19%), IVS4-1G>A (9%), p.Y356X (7%) and p.EX6-96A>G(5%). Two novel mutations p.N93fsX5 (c.279-282delCATC) and p.G171E (c.512G>A) were found. p.H64fsX9(c.190delC) was documented for the second time in Chinese PAH gene. The mutation spectrum of the gene PAH in the Qinghai population was similar to that in other populations in North China while significantly different from that in the populations from some provinces in southern China, Japan and Europe. The mutations of PAH gene in the Qinghai area of China demonstrate a unique diversity, complexity and specificity.

  19. Determination and distribution of elements in suspended matter and bottom sediments from the estuaries of the Sea of Japan, the East China Sea, the South China Sea and the Bering Sea

    International Nuclear Information System (INIS)

    Kolesov, G.M.; Anikiev, V.V.

    1997-01-01

    Some aspects of sample analysis (for example, sampling, sample preparing, experimental conductions) from estuaries zones of the west part of Pacific shore have been discussed. The content of elements with different physico-chemical and geological properties in the water samples, suspended matter, bottom sediments, plankton and aerosols have been studied by the methods of neutron activation analysis, X-ray fluorescence and also atomic emission (with ICP) and atomic absorption. Some peculiarities of their distribution and accumulation have been revealed. (author)

  20. Harvested area gaps in China between 1981 and 2010: effects of climatic and land management factors

    Science.gov (United States)

    Yu, Qiangyi; van Vliet, Jasper; Verburg, Peter H.; You, Liangzhi; Yang, Peng; Wu, Wenbin

    2018-04-01

    Previous analyses have shown that cropland in China is intensifying, leading to an increase in crop production. However, these output measures leave the potential for further intensification largely unassessed. This study uses the harvested area gap (HAG), which expresses the amount of harvested area that can be gained if all existing cropland is harvested as frequently as possible, according to their potential limit for multi-cropping. Specifically, we calculate the HAG and changes in the HAG in China between 1981 and 2010. We further assess how climatic and land management factors affect these changes. We find that in China the HAG decreases between the 1980s and the 1990s, and subsequently increases between the 1990s and the 2000s, resulting in a small net increase for the entire study period. The initial decrease in the HAG is the result of an increase in the average multi-cropping index throughout the country, which is larger than the increase in the potential multi-cropping index as a result of the changed climatic factors. The subsequent increase in the HAG is the result of a decrease in average multi-cropping index throughout the country, in combination with a stagnant potential. Despite the overall increase in harvested area in China, many regions, e.g. Northeast and Lower Yangtze, are characterized by an increased HAG, indicating their potential for further increasing the multi-cropping index. The study demonstrates the application of the HAG as a method to identify areas where the harvested area can increase to increase crop production, which is currently underexplored in scientific literature.

  1. Prevalence of hypertension in rural areas of china: a meta-analysis of published studies.

    Directory of Open Access Journals (Sweden)

    Xiaofang Chen

    Full Text Available Hypertension is one of the leading causes of disease burden across the world. In China, the latest nationwide survey of prevalence of hypertension was ten year ago, and data in rural areas is little known. More information about hypertension prevalence could help to improve overall antihypertensive health care. We aimed to estimate the pooled prevalence of hypertension in rural areas of China.Comprehensive electronic searches of PubMed, Web of Knowledge, Chinese Web of Knowledge, Wangfang, Weipu and SinoMed databases were conducted to identify any study in each database published from January 1, 2004 to December 31, 2013, reporting the prevalence of hypertension in Chinese rural areas. Prevalence estimates were stratified by age, area, sex, publication year, and sample size. All statistical calculations were made using the Stata Version 11.0 (College Station, Texas and Statsdirect Version 2.7.9.We identified 124 studies with a total population of 3,735,534 in the present meta-analysis. Among people aged 18 years old in Chinese rural areas, the summarized prevalence is 22.81% (19.41%-26.41%. Subgroup analysis shows the following results: for male 24.46% (21.19%-27.89%, for female 22.17% (18.25%-26.35%. For 2004-2006: 18.94% (14.41%-23.94%, for 2007-2009, 21.24% (15.98%-27.01% for 2010-2013: 26.68%, (20.79%-33.02%. For Northern region 25.76% (22.36%-29.32%, for Southern region 19.30%, (15.48%-24.08%.The last decade witnessed the growth in prevalence of hypertension in rural areas of China compared with the fourth national investigation, which has climbed the same level as the urban area. Guidelines for screening and treatment of hypertension in rural areas need to be given enough attention.

  2. 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.

  3. Priority conservation plans of ecological function areas for terrestrial endangered mammals in China

    OpenAIRE

    Gongqi Sun; Yi Qu; Meiqing Tang; Xiao Liu; Xiaofeng Luan

    2013-01-01

    To reduce costs and maximize species protection in China, we identified conservation priorities of endangered terrestrial mammals. Using geographic information system (GIS), we identified the irreplaceable values (IR) of 1,434 units of the terrestrial ecological function areas. Based on the IR values of the units, we divided the units into three classes with decreasing priorities, including the mandatory reserve (MR) units (20), the negotiable reserve (NR) units (29), and the partially reserv...

  4. 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.

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

    OpenAIRE

    Zongtang Xie; Jiuping Xu; Yanfei Deng

    2016-01-01

    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 asse...

  6. 长江口外海域沉积物中有机物的来源及分布%Spatial distributions of organic carbon and nitrogen and their isotopic compositions in sediments of the Changjiang Estuary and its adjacent sea area

    Institute of Scientific and Technical Information of China (English)

    高建华; 汪亚平; 潘少明; 张瑞; 李军; 白风龙

    2008-01-01

    The spatial distribution patterns of total organic carbon and total nitrogen show significant correlations with currents of the East China Sea Shelf. Corresponding to distributions of these currents, the study area could be divided into four different parts. Total organic carbon, total nitrogen, and organic carbon and nitrogen stable isotopes in sediments show linear correlations with mean grain size, respectively, thus "grain size effect" is an important factor that influences their distributions. C/N ratios can reflect source information of organic matter to a certain degree. In contrast, nitrogen stable isotope shows different spatial distribution patterns with C/N and organic carbon stable isotope, according to their relationships and regional distributions. The highest contribution (up to 50%) of terrestrial organic carbon appears near the Changjiang Estuary with isolines projecting towards northeast, indicating the influence of the Changjiang dilution water. Terrestrial particulate organic matter suffers from effects of diagenesis, benthos and incessant inputting of dead organic matter of plankton,after depositing in seabed. Therefore, the contribution of terrestrial organic carbon to particulate organic matter is obviously greater than that to organic matter in sediments in the same place.

  7. 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.

  8. Research on the quality of the wine grapes in corridor area of China

    Directory of Open Access Journals (Sweden)

    Guo Cheng

    2015-03-01

    Full Text Available The corridor area of Gansu Province is one of the most important wine grape growing regions in China, and this strip of land results in a significant difference in terms of terroir between its regions. Chemical composition and antioxidant capacity of the main wine grape varieties (Vitis vinifera L. cultivated in the corridor area of Gansu Province in northwest China were compared. Three regions (Zhangye, Wuwei, and Jiayuguan were selected to explain the influence of soil and climate conditions on the quality of wine grapes. This study aims to investigate the effect of different regions on berry composition and antioxidant capacity, providing a general evaluation of red and white wine grapes quality in the corridor area of China. The results showed that ‘Merlot’ grapes grown in Zhangye had the best quality among the different varieties in the three regions of Gansu evaluated. The moderate temperature and nitrogen deficiency were associated with improved fruit quality. It was identified that the most suitable grape variety from Zhangye is ‘Merlot’, and that ‘Cabernet Sauvignon’ and ‘Italian Resling’ are the most suitable varieties from Wuwei and Jiayuguan, respectively.

  9. Effects of sediment burial disturbance on macro and microelement dynamics in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary, China.

    Science.gov (United States)

    Sun, Zhigao; Mou, Xiaojie

    2016-03-01

    From April 2008 to November 2009, a field decomposition experiment was conducted to investigate the effects of sediment burial on macro (C, N) and microelement (Pb, Cr, Cu, Zn, Ni, and Mn) variations in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary. Three one-off sediment burial treatments [no sediment burial (0 mm year(-1), S0), current sediment burial (100 mm year(-1), S10), and strong sediment burial (200 mm year(-1), S20)] were laid in different decomposition sites. Results showed that sediment burials showed significant influence on the decomposition rate of P. australis, in the order of S10 (0.001990 day(-1)) ≈ S20 (0.001710 day(-1)) > S0 (0.000768 day(-1)) (p macro and microelement in decomposing litters of the three burial depths exhibited different temporal variations except for Cu, Zn, and Ni. No significant differences in C, N, Pb, Cr, Zn, and Mn concentrations were observed among the three burial treatments except for Cu and Ni (p > 0.05). With increasing burial depth, N, Cr, Cu, Ni, and Mn concentrations generally increased, while C, Pb, and Zn concentrations varied insignificantly. Sediment burial was favorable for C and N release from P. australis, and, with increasing burial depth, the C release from litter significantly increased, and the N in litter shifted from accumulation to release. With a few exceptions, Pb, Cr, Zn, and Mn stocks in P. australis in the three treatments evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. Stocks of Cu and Ni in P. australis in the S10 and S20 treatments were generally positive, evidencing incorporation of the two metals in most sampling times. Except for Ni, the variations of C, N, Pb, Cr, Cu, Zn, and Mn stocks in P. australis in the S10 and S20 treatments were approximated, indicating that the strong burial episodes (S20) occurred in P. australis marsh in the future

  10. 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

  11. 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...

  12. [Soil seed bank research of China mining areas: necessity and challenges].

    Science.gov (United States)

    Chang, Qing; Zhang, Da-Wei; Li, Xue; Peng, Jian; Guan, Ai-Nong; Liu, Xiao-Si

    2011-05-01

    Soil seed bank consists of all living seeds existed in soil and its surface litter, especially in topsoil, and can reflect the characteristics of regional biodiversity. As the base of vegetation restoration and potential greening material, topsoil and its seed bank are the limited and non-renewable resources in mining areas. The study of soil seed bank has become one of the hotspots in the research field of vegetation restoration and land reclamation in China mining areas. Owing to the special characteristics of mining industry, the soil seed bank study of mining areas should not only concern with the seed species, quantities, and their relations with ground surface vegetation, but also make use of the research results on the soil seed bank of other fragile habitats. Besides, a breakthrough should be sought in the thinking ways and research approach. This paper analyzed the particularity of mining area's soil seek bank research, summarized the research progress in the soil seed bank of mining areas and other fragile habitats, and put forward the challenges we are facing with. It was expected that this paper could help to reinforce the soil seed bank research of China mining areas, and provide scientific guidelines for taking great advantage of the significant roles of soil seed bank in land reclamation and vegetation restoration in the future.

  13. [Assessment of dietary iodine intake of population in non-high-iodine areas in China].

    Science.gov (United States)

    Song, Xiaoyu; Li, Fengqin; Liu, Zhaoping; He, Yuna; Sui, Haixia; Mao, Weifeng; Liu, Sana; Yan, Weixing; Li, Ning; Chen, Junshi

    2011-03-01

    To assess the potential risk of dietary iodine insufficiency of population in non-high-iodine areas (water iodine China. The dietary iodine intake of 13 age-sex population groups were estimated by combining the data of iodine intake from food, table salt and drinking water. Two conditions were considered: consuming iodized salt or non-iodized salt. The data of food and table salt consumption were derived from the Chinese National Nutrition and Health Survey in 2002. Water consumption was calculated as the recommended water intake. Iodine contents of food, table salt and water were calculated from China Food Composition Table and iodine surveillance data. Under the condition of consuming iodized salt, the average iodine intake of all population groups was higher than the Recommended Nutrient Intake (RNI), while the iodine intakes of individuals above Upper Limits (UL) and below RNI were 5.8% and 13.4% respectively, and the iodine intake of individuals lower than the Estimated Average Requirement (EAR) was 9.4% in adults above 18 years of age (including pregnant and lactating women). If non-iodized salt was consumed, the average iodine intake of most sex-age population groups was higher than RNI, but the iodine intake of 97.6% of individuals would be lower than RNI, while the iodine intake of 97.4% of adults would be lower than EAR. The contribution of iodine from table salt was much higher than that from drinking water and food in the condition of consuming iodized salt, while food was the predominant contributor of dietary iodine in the condition of consuming non-iodized salt. The health risk of iodine deficiency was higher than that of iodine excess in areas where water iodine was China, and the risk of iodine insufficiency was much higher if non-iodized salt was consumed. Iodized salt should be the main sources of dietary iodine intake for population in areas where water iodine was China.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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. - Research highlights: → Fe, Cr and Cu have higher contributions to the sum of toxic units. → More than 75.4% soil samples have moderate toxicity in PRE. → Heavy metals in typical soil profiles exceed the LEL thresholds. → Heavy metals (except Fe and Mn) mainly originate from anthropogenic source. → Long reclamation history can lead to greater heavy metal loss in wetland soils. - The findings of this study reveal higher effects of long-term reclamation on heavy metal pollution of wetland soils and contribute to coastal wetland management in subtropical regions.

  15. 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.

  16. 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

  17. Spatial distribution of Cd and Cu in soils in Shenyang Zhangshi Irrigation Area (SZIA), China*

    Science.gov (United States)

    Sun, Li-na; Yang, Xiao-bo; Wang, Wen-qing; Ma, Li; Chen, Su

    2008-01-01

    Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area (SZIA) in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium (Cd) and copper (Cu) contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil (LSGSS) in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd contamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils. PMID:18357631

  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. Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

    Science.gov (United States)

    Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

    2017-07-01

    The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

  20. Tissue partition and risk assessments of trace elements in Indo-Pacific Finless Porpoises (Neophocaena phocaenoides) from the Pearl River Estuary coast, China.

    Science.gov (United States)

    Zhang, Xiyang; Lin, Wenzhi; Yu, Ri-Qing; Sun, Xian; Ding, Yulong; Chen, Hailiang; Chen, Xi; Wu, Yuping

    2017-10-01

    Throughout the last few decades, an increased number of stranded marine mammals, particularly the Indo-Pacific Finless Porpoises (Neophocaena phocaenoides), were observed in the Pearl River Estuary (PRE). As long-lived, apex predators vulnerable to bioaccumulation of contaminants, the tissue residue levels and health risk of trace elements (TEs) in N. phocaenoides from the PRE have been little studied. Eleven typical TEs distributed in skin, liver and kidney tissues were investigated from 25 specimens stranded along the PRE from 2007 to 2015 in the present study. It revealed that most TEs were highly accumulated in internal organs (liver and kidney), except for Zn with high residue levels in external skin. Compared with the TEs in prey items, the residue levels of Hg, Se, Zn, Cu, Cd and Cr in N. phocaenoides increased 4-618 times, indicating a potentially significant biomagnification. Sex-related differences of TE accumulation were not obvious, except for renal Mn, in which the females showed lower mean concentrations than males. Significantly positive correlations between body length and TE levels were found for Hg, Se and Cd. Results of the calculated risk quotients (RQ) suggested that the risks to N. phocaenoides from consumption of prey items were generally low, but further attentions should be paid to Cd, Cr, Cu, Hg and As due to the elevated RQ values. The concentrations of Hg, Cd and Se in the epidermis were positively correlated with the levels found in internal organs. Our investigation provides evidence to support the use of skin as one biomonitoring approach on Hg, Cd and Se contamination of internal tissues in this species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effect of reclamation on soil organic carbon pools in coastal areas of eastern China

    Science.gov (United States)

    Li, Jianguo; Yang, Wenhui; Li, Qiang; Pu, Lijie; Xu, Yan; Zhang, Zhongqi; Liu, Lili

    2018-06-01

    The coastal wetlands of eastern China form one of the most important carbon sinks in the world. However, reclamation can significantly alter the soil carbon pool dynamics in these areas. In this study, a chronosequence was constructed for four reclamation zones in Rudong County, Jiangsu Province, eastern China (reclaimed in 1951, 1974, 1982, and 2007) and a reference salt marsh to identify both the process of soil organic carbon (SOC) evolution, as well as the effect of cropping and soil properties on SOC with time after reclamation. The results show that whereas soil nutrient elements and SOC increased after reclamation, the electrical conductivity of the saturated soil extract (ECe), pH, and bulk density decreased within 62 years following reclamation and agricultural amendment. In general, the soil's chemical properties remarkably improved and SOC increased significantly for approximately 30 years after reclamation. Reclamation for agriculture (rice and cotton) significantly increased the soil organic carbon density (SOCD) in the top 60 cm, especially in the top 0-30 cm. However, whereas the highest concentration of SOCD in rice-growing areas was in the top 0-20 cm of the soil profile, it was greater at a 20-60 cm depth in cottongrowing areas. Reclamation also significantly increased heavy fraction organic carbon (HFOC) levels in the 0-30 cm layer, thereby enhancing the stability of the soil carbon pool. SOC can thus increase significantly over a long time period after coastal reclamation, especially in areas of cultivation, where coastal SOC pools in eastern China tend to be more stable.

  2. Effect of reclamation on soil organic carbon pools in coastal areas of eastern China

    Science.gov (United States)

    Li, Jianguo; Yang, Wenhui; Li, Qiang; Pu, Lijie; Xu, Yan; Zhang, Zhongqi; Liu, Lili

    2018-04-01

    The coastal wetlands of eastern China form one of the most important carbon sinks in the world. However, reclamation can significantly alter the soil carbon pool dynamics in these areas. In this study, a chronosequence was constructed for four reclamation zones in Rudong County, Jiangsu Province, eastern China (reclaimed in 1951, 1974, 1982, and 2007) and a reference salt marsh to identify both the process of soil organic carbon (SOC) evolution, as well as the effect of cropping and soil properties on SOC with time after reclamation. The results show that whereas soil nutrient elements and SOC increased after reclamation, the electrical conductivity of the saturated soil extract (ECe), pH, and bulk density decreased within 62 years following reclamation and agricultural amendment. In general, the soil's chemical properties remarkably improved and SOC increased significantly for approximately 30 years after reclamation. Reclamation for agriculture (rice and cotton) significantly increased the soil organic carbon density (SOCD) in the top 60 cm, especially in the top 0-30 cm. However, whereas the highest concentration of SOCD in rice-growing areas was in the top 0-20 cm of the soil profile, it was greater at a 20-60 cm depth in cottongrowing areas. Reclamation also significantly increased heavy fraction organic carbon (HFOC) levels in the 0-30 cm layer, thereby enhancing the stability of the soil carbon pool. SOC can thus increase significantly over a long time period after coastal reclamation, especially in areas of cultivation, where coastal SOC pools in eastern China tend to be more stable.

  3. Evaluation of Soil Contamination Indices in a Mining Area of Jiangxi, China

    Science.gov (United States)

    Wu, Jin; Teng, Yanguo; Lu, Sijin; Wang, Yeyao; Jiao, Xudong

    2014-01-01

    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. PMID:25397401

  4. 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.

  5. Chromosome translocation in residents of the high background radiation areas in southern China

    International Nuclear Information System (INIS)

    Hayata, Isamu; Minamihisamatsu, Masako; Wang Chunyan; Wei Zhang; Chen Deqing; Morishima, Hiroshige; Yuan Yongling; Wei Luxin; Sugahara, Tsutomu

    2000-01-01

    We performed a cytogenetical study using chromosome painting analysis on 9 residents of the naturally high background radiation areas (HBRA) and 8 residents of the control areas in southern China. The estimated dose (air kerma) of each resident measured by an electric pocket dosimeter showed 2.20-4.23 mGy/year in HBRA and 0.56-0.70 mGy/year in the control areas. A total of 14,096 cells (1,566 cells/case) in the former and 17,522 cells (2,190 cells/case) in the latter were analyzed. Children, both in HBRA and in the control areas, had translocations at low frequencies. The frequency of translocations among elder individuals varied widely and it was not possible to detect dose effect although it was detected in dicentrics. The effect of radiation on the induction of chromosome aberrations, which have a statistically potential risk of causing malignant or congenital diseases, seems to be less significant than those of metabolic factors and/or mutagenic agents (excluding radiation) even in HBRA in China. (author)

  6. About Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions.

  7. 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...

  8. The Application Study in Solar Energy Technology for Highway Service Area: A Case Study of West Lushan Highway Low-Carbon Service Area in China

    OpenAIRE

    Qin, Xiaochun; Shen, Yi; Shao, Shegang

    2015-01-01

    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...

  9. 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.

  10. 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.

  11. Why Gas Hydrate Occurrenced Over Topographic Highs in Shenhu Area Northern South China Sea?

    Science.gov (United States)

    Liao, J.

    2015-12-01

    Methane gas hydrate has been drilled by China Geological Survey in shenhu area northern south china sea in 2007 .Shenhu area is located in the middle-lower continental slope and 17 submarine canyons are incised into the shelf,gas hydrtae was observed in boreholes over topographic highs,but origin of the hydrate is controversial.Accumulation of gas hydrate is depending on temperature-pressure field and supply quantities of methane and some other factors,in the same depth of the shallow sediments there is the same press,so temperature field and supply quantities of methane become the most important factors.Lachenbruch(1968) calculated the topographic disturbance to geothermal gradients,in shenhu area consistent local variations were observed, notably low heat flow values over prominent topographic highs and high heat flow values over the flanks of the topographic highs. At some localities over a horizontal distance of 2.5 km, heat flow increased by as much as 50%, from typical values of 65 to 100 mW/m2 .Some vertical fractures were observed beneath topographic highs in previous studies.Based on the profile across borehole SH7,we designed four experiments:A,uniform distribution of heat flux with no vertical fractures;B,Uniform distribution of heat flux with vertical fractures beneath geographic highs;C,uneven distribution of heat flux with no vertical fractures;D,uneven distribution of heat flux with vertical fractures beneath geographic highs.According to previous studies,we restored Palaeobathymetry,abundance of organic matters, sandstone-madstone ratio ,porosity and permeability of each,and parameters of vertical fractures.The result of experiment D shows the similar distribution characteristic with the drilling result,so We believe that low heat flux and Vertical fractures are the most important factors . This work was supported by the National Science Foundation of China(grant no. 41406080).

  12. Environmental contamination of mercury from Hg-mining areas in Wuchuan, northeastern Guizhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Guangle [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 73 Guanshui Road, Guiyang, Guizhou 550002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 73 Guanshui Road, Guiyang, Guizhou 550002 (China)]. E-mail: fengxinbin@vip.skleg.cn; Wang Shaofeng [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 73 Guanshui Road, Guiyang, Guizhou 550002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Shang Lihai [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 73 Guanshui Road, Guiyang, Guizhou 550002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China)

    2006-08-15

    Total Hg and methyl-Hg were evaluated in mine wastes, soils, water, and vegetations from the Wuchuan Hg-mining areas, Guizhou, China. Mine wastes contain high total Hg concentrations, ranging from 79 to 710 {mu}g g{sup -1}, and methyl-Hg from 0.32 to 3.9 ng g{sup -1}. Total Hg in soil samples range from 0.33 to 320 {mu}g g{sup -1} and methyl-Hg from 0.69 to 20 ng g{sup -1}. Vegetations present a high average total Hg concentration of 260 ng g{sup -1}, which greatly exceeds the maximum Hg concentration of 20 ng g{sup -1} recommended by the Chinese National Standard Agency for food sources. The rice samples contain elevated methyl-Hg concentrations, ranging from 4.2 to 18 ng g{sup -1}. Stream water collected from Hg-mining areas is also contaminated, containing Hg as high as 360 ng l{sup -1}, and methyl-Hg reaches up to 5.7 ng l{sup -1}. Data indicate heavy Hg-contaminations and significant conversion of methyl-Hg in the study areas. - Mercury mining activities in Wuchun, Guizhou, China have resulted in seriously mercury contamination to the local environment.

  13. Environmental response to long-term mariculture activities in the Weihai coastal area, China.

    Science.gov (United States)

    Li, Hongmei; Li, Xiaomin; Li, Qiang; Liu, Ying; Song, Jide; Zhang, Yongyu

    2017-12-01

    The environmental impacts of rapid expansion of mariculture have garnered worldwide attention. China is currently one of the largest countries to engage in this practice. In this study, a representative mariculture zone, the Weihai coastal area in China, was explored to determine the temporal variations in regional nutrients, N/P ratio, dissolved oxygen (DO), pH, chlorophyll a (Chl-a), and cellular abundance of diatoms and dinoflagellates in response to the rapid growth in mariculture activities between 2006 and 2014. The temporal variations in inorganic and organic nitrogen concentrations in the surface water presented significantly increasing trends during August, between 2009 and 2014. A marked increase in the ratios of dinoflagellate to diatom abundance, concurrently with ascending N/P ratios, was also observed during August between 2011 and 2014. In addition, dissolved inorganic nitrogen and phosphate variations revealed the highest concentrations during October and lower levels during May and August, which was attributed in part to the seasonal growth characteristics of kelp cultivated in the study area. Moreover, the nutrient concentrations in Sanggou, Rongcheng, Wulei, and Rushan bays were affected significantly by the various cultured organisms in these bays. The intensive mariculture activity in the Weihai coastal area is likely one of the causes of the negative effects on water quality, such as eutrophication and future ocean acidification. The exploration of effective strategies is quite necessary in the future for keeping good quality of coastal environment and sustainable mariculture development. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Environmental contamination of mercury from Hg-mining areas in Wuchuan, northeastern Guizhou, China

    International Nuclear Information System (INIS)

    Qiu Guangle; Feng Xinbin; Wang Shaofeng; Shang Lihai

    2006-01-01

    Total Hg and methyl-Hg were evaluated in mine wastes, soils, water, and vegetations from the Wuchuan Hg-mining areas, Guizhou, China. Mine wastes contain high total Hg concentrations, ranging from 79 to 710 μg g -1 , and methyl-Hg from 0.32 to 3.9 ng g -1 . Total Hg in soil samples range from 0.33 to 320 μg g -1 and methyl-Hg from 0.69 to 20 ng g -1 . Vegetations present a high average total Hg concentration of 260 ng g -1 , which greatly exceeds the maximum Hg concentration of 20 ng g -1 recommended by the Chinese National Standard Agency for food sources. The rice samples contain elevated methyl-Hg concentrations, ranging from 4.2 to 18 ng g -1 . Stream water collected from Hg-mining areas is also contaminated, containing Hg as high as 360 ng l -1 , and methyl-Hg reaches up to 5.7 ng l -1 . Data indicate heavy Hg-contaminations and significant conversion of methyl-Hg in the study areas. - Mercury mining activities in Wuchun, Guizhou, China have resulted in seriously mercury contamination to the local environment

  15. 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.

  16. Dynamics of organic and inorganic carbon in surface sediments of the Yellow River Estuary

    Science.gov (United States)

    Yu, Z.; Wang, X.; Liu, X.; Zhang, E.; Hang, F.

    2017-12-01

    Estuarine sediment is an important carbon reservoir thus may play an important role in the global carbon cycle. However, little is known on the dynamics of organic carbon (OC) and inorganic carbon (IC) in the surface sediment of the Yellow River Estuary, a large estuary in northern China. In this study, we applied element analyses and isotopic approach to study spatial distribution and sources of OC and IC in the Yellow River Estuary. We found that TIC concentration (6.3-20.1 g kg-1) was much higher than TOC (0.2-4.4 g kg-1) in the surface sediment. There showed a large spatial variability in TOC and TIC and their stable isotopes. Both TOC and TIC were higher to the north (2.6 and 14.5 g kg-1) than to the south (1.6 and 12.2 g kg-1), except in the southern bay where TOC and TIC reached 2.7 and 15.4 g kg-1, respectively. Generally, TOC and TIC in our study area was mainly autochthonous. The lower TOC values in the south section were due to relatively higher kinetic energy level whereas the higher values in the bay was attributable to terrigenous matters accumulation and lower kinetic energy level. However, the southern bay revealed the most negative δ13Corg and δ13Ccarb, suggesting that there might exist some transfer of OC to IC in the section. Our study points out that the dynamics of sedimentary carbon in the Yellow River Estuary is influenced by multiple and complex processes, and highlights the importance of carbonate in carbon sequstration.

  17. Quantitative Evaluation of Ecosystem Health in a Karst Area of South China

    Directory of Open Access Journals (Sweden)

    Shengzi Chen

    2016-10-01

    Full Text Available The purpose of this study is to propose a GIS-based mechanism for diagnosing karst rocky desertification (KRD ecosystem health. Using the Huajiang Demonstration Area in Guizhou Province as a case study, this research offers a multi-factor indicator system for diagnosing KRD ecosystem health. A set of geologic, environmental, and socio-economic health indicators were developed based on remote sensing images from field-investigation, hydrological, and meteorological monitoring data. With the use of grid GIS technology, this study gives an indicator for diagnosing the spatial expression of desertification at a 5 m × 5 m grid scale. Using spatial overlaying technology based on grid data, the temporal and spatial dynamics of ecosystem health in the Huajiang Demonstration Area were tracked over a 10 year time span. The results of the analysis indicate that ecosystem health in the Huajiang Demonstration Area varies regionally, and has overall improved over time. The proportion of healthy area increased from 3.7% in 2000 to 8.2% in 2010. However, unhealthy and middle-health areas still accounted for 78.7% of the total area by 2010. The most obvious improvement of ecosystem health was in an area where comprehensive control measures for curbing KRD were implemented. These results suggest that comprehensive control of KRD can effectively mitigate ecosystem deterioration and improve ecosystem health in karst regions of South China.

  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. Characterization and spatial modeling of urban sprawl in the Wuhan Metropolitan Area, China

    Science.gov (United States)

    Zeng, Chen; Liu, Yaolin; Stein, Alfred; Jiao, Limin

    2015-02-01

    Urban sprawl has led to environmental problems and large losses of arable land in China. In this study, we monitor and model urban sprawl by means of a combination of remote sensing, geographical information system and spatial statistics. We use time-series data to explore the potential socio-economic driving forces behind urban sprawl, and spatial models in different scenarios to explore the spatio-temporal interactions. The methodology is applied to the city of Wuhan, China, for the period from 1990 to 2013. The results reveal that the built-up land has expanded and has dispersed in urban clusters. Population growth, and economic and transportation development are still the main causes of urban sprawl; however, when they have developed to certain levels, the area affected by construction in urban areas (Jian Cheng Qu (JCQ)) and the area of cultivated land (ACL) tend to be stable. Spatial regression models are shown to be superior to the traditional models. The interaction among districts with the same administrative status is stronger than if one of those neighbors is in the city center and the other in the suburban area. The expansion of urban built-up land is driven by the socio-economic development at the same period, and greatly influenced by its spatio-temporal neighbors. We conclude that the integration of remote sensing, a geographical information system, and spatial statistics offers an excellent opportunity to explore the spatio-temporal variation and interactions among the districts in the sprawling metropolitan areas. Relevant regulations to control the urban sprawl process are suggested accordingly.

  20. Characteristics of surface O{sub 3} over Qinghai Lake area in Northeast Tibetan Plateau, China

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhenxing, E-mail: zxshen@mail.xjtu.edu.cn [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Cao, Junji [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Leiming [Air Quality Research Division, Environment Canada, Toronto (Canada); Zhao, Zhuzi [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Dong, Jungang [School of Architecture, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Wang, Linqing [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Wang, Qiyuan; Li, Guohui; Liu, Suixin [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Qian [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China)

    2014-12-01

    Surface O{sub 3} was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O{sub 3} ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O{sub 3} followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O{sub 3} showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O{sub 3}. It was found that O{sub 3} was poorly correlated with solar radiation due to the insufficient NO{sub x} in the ambient air, thus limiting O{sub 3} formation under strong solar radiation. In contrast, high O{sub 3} levels always coincided with strong winds, suggesting that stratospheric O{sub 3} and long range transport might be the main sources of O{sub 3} in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O{sub 3} was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O{sub 3} chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O{sub 3} and transport might be the main sources of O{sub 3} in this area.

  1. Characteristics of surface O3 over Qinghai Lake area in Northeast Tibetan Plateau, China

    International Nuclear Information System (INIS)

    Shen, Zhenxing; Cao, Junji; Zhang, Leiming; Zhao, Zhuzi; Dong, Jungang; Wang, Linqing; Wang, Qiyuan; Li, Guohui; Liu, Suixin; Zhang, Qian

    2014-01-01

    Surface O 3 was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O 3 ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O 3 followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O 3 showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O 3 . It was found that O 3 was poorly correlated with solar radiation due to the insufficient NO x in the ambient air, thus limiting O 3 formation under strong solar radiation. In contrast, high O 3 levels always coincided with strong winds, suggesting that stratospheric O 3 and long range transport might be the main sources of O 3 in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O 3 was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O 3 chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O 3 and transport might be the main sources of O 3 in this area

  2. An Integrated Control Strategy Takes Clonorchis sinensis Under Control in an Endemic Area in South China.

    Science.gov (United States)

    Huang, Yalan; Huang, Dana; Geng, Yijie; Fang, Shisong; Yang, Fan; Wu, Chunli; Zhang, Hailong; Wang, Miao; Zhang, Ran; Wang, Xin; Wu, Shuang; Cao, Jianping; Zhang, Renli

    2017-12-01

    Clonorchis sinensis is an important foodborne zoonosis worldwide and prevalent in China for more than 2000 years. According to the experience of controlling Schistosoma japonica, China started to establish the integrated control strategy for C. sinensis in endemic areas. Lou village, the largest village in Shenzhen city in South China was taken as a pilot site. This longitudinal study assessed the infection status of C. sinensis among people and intermediate hosts from 2006 to 2014 in Lou village. After a continuous intervention with the integrated control strategy, the prevalence of C. sinensis decreased significantly to 2.01% in 2014. The infection intensity also reduced significantly with eggs per gram varying from 45.6 ± 3.4 in 2010 to 21.7 ± 1.6 in 2012. There is also a statistically significant decrease of the prevalence of C. sinensis metacercariae in fish hosts from 16.51% in 2008 before the intervention to 5.33% in 2014. All the old-styled toilets were replaced by sanitary ones with a harmless processing design in 2014. No viable parasite eggs were detected in stool samples from the reconstructed toilets. Health education played an important role in changing the eating habits among the local residents, with a significant decrease in the prevalence of eating raw fish from 91.99% in 2008 to 59.87% in 2014. The evaluation suggested that the integrated strategy we have performed in Lou village is effective in controlling the C. sinensis infection and maintaining the infection rate at a lower level, which can be promoted in other endemic areas.

  3. Detection of DDT and its metabolites in two estuaries of South China using a SPME-based device: First report of p,p'-DDMU in water column

    International Nuclear Information System (INIS)

    Xing Yuanna; Guo Ying; Xie Mei; Shen Rulang; Zeng, Eddy Y.

    2009-01-01

    A solid-phase microextration-based sampling method was employed to determine the concentrations of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (DDE) and 1-chloro-2,2-bis(p-chlorophenyl)ethene (DDMU), in two estuarine bays, Daya Bay and Hailing Bay, of South China. Six DDT components including p,p'-DDT, o,p'-DDD, p,p'-DDD, o,p'-DDE, p,p'-DDE, and p,p'-DDMU were detected in Hailing Bay, while only p,p'-DDD was found in Daya Bay. p,p'-DDD was the most abundant DDT component in both bays, sharply different from the previous finding in the water column of the Palos Verdes Shelf, California, USA that p,p'-DDE was prevalent. In addition, the occurrence of p,p'-DDMU (with a range of 0.047-0.21 ng/L in Hailing Bay) has not been reported around the globe, and its presence in our study region appeared to stem from dehydrochlorination of p,p'-DDD, favored under aerobic conditions, but further investigations are clearly needed to confirm the mechanism for generation of DDMU in estuarine environments. - DDT and its metabolites, particularly p,p'-DDMU, are detected in the water column of two estuarine bays in South China using a SPME-based sampler

  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. Accumulation of total mercury and methylmercury in rice plants collected from different mining areas in China

    International Nuclear Information System (INIS)

    Meng, Mei; Li, Bing; Shao, Jun-juan; Wang, Thanh; He, Bin; Shi, Jian-bo; Ye, Zhi-hong; Jiang, Gui-bin

    2014-01-01

    A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk and leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- Highlights: • Distribution patterns indicated different pathways of IHg and MeHg accumulation. • Soil is an important source for both THg and MeHg to rice plants. • Water soluble Hg may play more important role in MeHg accumulation in rice plants. -- The distribution patterns indicate different pathways of IHg and MeHg accumulation in rice plants

  6. Lidar mapping of atmospheric atomic mercury in the Wanshan area, China.

    Science.gov (United States)

    Lian, Ming; Shang, Lihai; Duan, Zheng; Li, Yiyun; Zhao, Guangyu; Zhu, Shiming; Qiu, Guangle; Meng, Bo; Sommar, Jonas; Feng, Xinbin; Svanberg, Sune

    2018-05-08

    A novel mobile laser radar system was used for mapping gaseous atomic mercury (Hg 0 ) atmospheric pollution in the Wanshan district, south of Tongren City, Guizhou Province, China. This area is heavily impacted by legacy mercury from now abandoned mining activities. Differential absorption lidar measurements were supplemented by localized point monitoring using a Lumex RA-915M Zeeman modulation mercury analyzer. Range-resolved concentration measurements in different directions were performed. Concentrations in the lower atmospheric layers often exceeded levels of 100 ng/m 3 for March conditions with temperature ranging from 5 °C to 20 °C. A flux measurement of Hg 0 over a vertical cross section of 0.12 km 2 resulted in about 29 g/h. Vertical lidar sounding at night revealed quickly falling Hg 0 concentrations with height. This is the first lidar mapping demonstration in a heavily mercury-polluted area in China, illustrating the lidar potential in complementing point monitors. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Waterfowl migration and distribution in North West estuaries. V. 1

    International Nuclear Information System (INIS)

    Clark, N.A.; Kirby, J.S.; Langston, R.H.W.; Donald, P.; Mawdesley, T.; Evans, J.

    1990-12-01

    Waterfowl populations may be affected by proposed tidal barrage across the Mersey. This study had three objectives:-(1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey Estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables and results only are presented in Volume 1. (author)

  8. 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.

  9. Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China

    Science.gov (United States)

    Wei, Xiaocong; Deng, Xiangwen; Xiang, Wenhua; Lei, Pifeng; Ouyang, Shuai; Wen, Hongfang; Chen, Liang

    2018-05-01

    Rocky desertification is a major ecological problem of land degradation in karst areas. In these areas, the high soil calcium (Ca) content has become an important environmental factor that can affect the restoration of vegetation. Consequently, the screening of plant species that can adapt to high Ca soil environments is a critical step in vegetation restoration. In this study, three grades of rocky desertification sample areas were selected in karst areas of southwestern Hunan, China (LRD: light rocky desertification; MRD: moderate rocky desertification; and IRD: intense rocky desertification). Each grade of these sample areas had three sample plots in different slope positions, each of which had four small quadrats (one in rocky-side areas, three in non-rocky-side areas). We measured the Ca content of leaves, branches, and roots from 41 plant species, as well as soil total Ca (TCa) and exchangeable Ca (ECa) at depths of 0-15, 15-30, and 30-45 cm in each small quadrat. The results showed that the soil Ca2+ content in rocky-side areas was significantly higher than that in non-rocky-side areas (p desertification, in the order IRD > MRD > LRD. For all plant functional groups, the plant Ca content of aboveground parts was significantly higher than that of the belowground parts (p 1). The differences in Ca2+ content between the aboveground and belowground parts of the 17 dominant species were calculated, and their correlations with soil ECa content were analyzed. The results showed that these 17 species can be divided into three categories: Ca-indifferent plants, high-Ca plants, and low-Ca plants. These findings provide a vital theoretical basis and practical guide for vegetation restoration and ecosystem reconstruction in rocky desertification areas.

  10. The Institutional Sustainability in Protected Area Tourism-Case Studies of Jiuzhaigou National Scenic Area, China and New Forest National Park, United Kingdom

    OpenAIRE

    Xu, Feifei; Fox, Dorothy; Zhang, J.; Cheng, S.

    2014-01-01

    This article considers sustainable tourism development in two protected areas, Jiuzhaigou National Scenic Area in China and the New Forest National Park in the United Kingdom. An inductive approach is used to explore the "fourth component" of sustainable tourism development that is institutional sustainability. Primary data from in-depth interviews, together with a range of secondary data sources, are analyzed to understand the governance and management of each area. These reveal that whilst ...

  11. A review of research on ecosystem of arid area using RS-GIS in China

    Science.gov (United States)

    Han, Hongling

    2007-06-01

    Arid area is classical mountain-oasis-desert ecosystem in North-west China. As the ecosystem has its nature geography character obviously, it has superior to research with remote-sensing and geography information system. The study on arid ecosystem in RS-GIS' way is focused on that the landscape spatial pattern of complex MODS ecosystem, the dynamic development of Land use/land cover, the security of ecological environment of eco-tone and so on. At the same time, the research on the single system is more and more, which has provided more ways and deeper fields of arid area using RS-GIS. Through the use of RS-GIS, desertification, oasis' development, urbanization etc. can be known, which would provide precaution for human-being and suitable ways to adjust the problems.

  12. 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 formulation and adoption of

  13. Natural recovery of different areas of a deserted quarry in South China

    Institute of Scientific and Technical Information of China (English)

    DUAN Wenjun; REN Hai; FU Shenglei; WANG Jun; YANG Long; ZHANG Jinping

    2008-01-01

    A quarry is a surface mining operated place, which produces enormous quantities of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China: terrace for crushed materials (terrace), spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, fems, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.

  14. 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

  15. Is tuberculosis treatment really free in China? A study comparing two areas with different management models.

    Directory of Open Access Journals (Sweden)

    Sangsang Qiu

    Full Text Available China has implemented a free-service policy for tuberculosis. However, patients still have to pay a substantial proportion of their annual income for treatment of this disease. This study describes the economic burden on patients with tuberculosis; identifies related factors by comparing two areas with different management models; and provides policy recommendation for tuberculosis control reform in China.There are three tuberculosis management models in China: the tuberculosis dispensary model, specialist model and integrated model. We selected Zhangjiagang (ZJG and Taixing (TX as the study sites, which correspond to areas implementing the integrated model and dispensary model, respectively. Patients diagnosed and treated for tuberculosis since January 2010 were recruited as study subjects. A total of 590 patients (316 patients from ZJG and 274 patients from TX were interviewed with a response rate of 81%. The economic burden attributed to tuberculosis, including direct costs and indirect costs, was estimated and compared between the two study sites. The Mann-Whitney U Test was used to compare the cost differences between the two groups. Potential factors related to the total out-of-pocket costs were analyzed based on a step-by-step multivariate linear regression model after the logarithmic transformation of the costs.The average (median, interquartile range total cost was 18793.33 (9965, 3200-24400 CNY for patients in ZJG, which was significantly higher than for patients in TX (mean: 6598.33, median: 2263, interquartile range: 983-6688 (Z = 10.42, P < 0.001. After excluding expenses covered by health insurance, the average out-of-pocket costs were 14304.4 CNY in ZJG and 5639.2 CNY in TX. Based on the multivariable linear regression analysis, factors related to the total out-of-pocket costs were study site, age, number of clinical visits, residence, diagnosis delay, hospitalization, intake of liver protective drugs and use of the second

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

    Science.gov (United States)

    2014-04-01

    ensuing global depression . An electro-magnetic pulse (EMP) attack, from an ICBM, long range cruise missile, or satellite, detonated 400km over the U.S...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

  17. Construction area expansion in relation to economic-demographic development and land resource in the Pearl River Delta of China

    NARCIS (Netherlands)

    Liu, Zhijia; Huang, Heqing; Werners, Saskia E.; Yan, Dan

    2016-01-01

    Since 1979, the Pearl River Delta (PRD) of China has experienced rapid socioeconomic development along with a fast expansion of construction area. Affected by both natural and human factors, a complex interdependency is found among the regional changes in construction area, GDP and population. A

  18. Cyanobacteria and macroalgae in ecosystem of the Neva estuary

    Directory of Open Access Journals (Sweden)

    Nikulina V. N.

    2011-07-01

    Full Text Available The Baltic Sea and Neva estuary are plagued by coastal eutrophication. In order to estimate the scale of the problem, quantitative estimates of phytoplankton and macroalgal mats were determined in the Neva estuary. Long-term monitoring (1982–2009 of phytoplankton showed changes in its species composition and abundance. Summer phytoplankton biomass increased significantly in the 1990s, with concomitant changes in species composition, despite a decline of nutrients in the Neva estuary. The cyanobacteria Planktothrix agardhii became a dominant species. The summer biomass of phytoplankton reached a maximum of 5.2 ± 0.4 mg·L-1 in 2002–2004. Monitoring of macroalgal community in the coastal area of the Neva estuary from 2002 to 2009 showed the dominance of the filamentous green alga Cladophora glomerata in the phytobenthos. Average biomass of macroalgae in inner and outer estuary differed significantly at 132 ± 29 and 310 ± 67 g DW·m-2, respectively. This study showed, that fluctuations in macroalgal biomass reflected human influence on estuary, although it was less sensitive to human impact than the phytoplankton community. Thus qualitative and quantitative characteristics of phytoplankton and macroalgal blooms can indicate anthropogenic influence on the ecosystem, and help to better manage the Neva estuary.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. Restoration of the Golden Horn Estuary (Halic).

    Science.gov (United States)

    Coleman, Heather M; Kanat, Gurdal; Aydinol Turkdogan, F Ilter

    2009-12-01

    Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes.

  2. China

    International Nuclear Information System (INIS)

    Segal, G.

    1991-01-01

    This paper reports on the reason for China's future nuclear policy. First, assuming a continued decline in superpower influence, China's focus will be on regional issues. The policies of Japan, the NICs and other Chinese neighbors will be more relevant than those of the superpowers. Second, Chinese domestic politics will have to resume the road to reform. A more unstable and suspicious Chinese leadership will perceive a more hostile and unstable world. Even when China was on the path to reform, its foreign relations were not always peaceful. However, it would be wrong to suggest that even a more xenophobic and unstable Chinese leadership would necessarily expand China's nuclear capability or lead China into a major war. Even at the height of the Cultural Revolution, Chinese foreign policy was careful, nuclear proliferation was avoided and crises were well-managed. Still China's basic domestic and foreign policy needs will likely remain unfulfilled for the foreseeable future. Furthermore, although the East Asian balance of power may not appear to be particularly dangerous at present, there is enough uncertainty to ensure that China remains a nuclear power and a maverick one at that at least in the near term

  3. 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.

  4. The challenge and future of rocky desertification control in karst areas in southwest China

    Science.gov (United States)

    Zhang, J. Y.; Dai, M. H.; Wang, L. C.; Zeng, C. F.; Su, W. C.

    2016-01-01

    Karst rocky desertification occurs after vegetation deteriorates as a result of intensive land use, which leads to severe water loss and soil erosion and exposes basement rocks, creating a rocky landscape. Karst rocky desertification is found in humid areas in southwest China, the region most seriously affected by rocky desertification in the world. In order to promote ecological restoration and help peasants out of poverty, the Chinese government carried out the first phase of a rocky desertification control project from 2006 to 2015, which initially contained the expansion of rocky desertification. Currently, the Chinese government is prepared to implement the second phase of the rocky desertification control project, and therefore it is essential to summarise the lessons learned over the last 10 years of the first phase. In this paper, we analyse the driving social and economic factors behind rocky desertification, summarise the scientific research on rocky desertification in the region, and finally identify the main problems facing rocky desertification control. In addition, we put forward several policy suggestions that take into account the perspective of local peasants, scientific research, and China's economic development and urbanisation process. These suggestions include promoting the non-agriculturalization of household livelihoods, improving ecological compensation, strengthening the evaluation of rocky desertification control and dynamic monitoring, and strengthening research on key ecological function recovery technologies and supporting technologies.

  5. 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.

  6. Measurements and simulation of forest leaf area index and net primary productivity in Northern China.

    Science.gov (United States)

    Wang, P; Sun, R; Hu, J; Zhu, Q; Zhou, Y; Li, L; Chen, J M

    2007-11-01

    Large scale process-based modeling is a useful approach to estimate distributions of global net primary productivity (NPP). In this paper, in order to validate an existing NPP model with observed data at site level, field experiments were conducted at three sites in northern China. One site is located in Qilian Mountain in Gansu Province, and the other two sites are in Changbaishan Natural Reserve and Dunhua County in Jilin Province. Detailed field experiments are discussed and field data are used to validate the simulated NPP. Remotely sensed images including Landsat Enhanced Thematic Mapper plus (ETM+, 30 m spatial resolution in visible and near infrared bands) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER, 15m spatial resolution in visible and near infrared bands) are used to derive maps of land cover, leaf area index, and biomass. Based on these maps, field measured data, soil texture and daily meteorological data, NPP of these sites are simulated for year 2001 with the boreal ecosystem productivity simulator (BEPS). The NPP in these sites ranges from 80 to 800 gCm(-2)a(-1). The observed NPP agrees well with the modeled NPP. This study suggests that BEPS can be used to estimate NPP in northern China if remotely sensed images of high spatial resolution are available.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Twelve-Year Trends of PM10 and Visibility in the Hefei Metropolitan Area of China

    Directory of Open Access Journals (Sweden)

    Lin Huang

    2016-01-01

    Full Text Available China has been experiencing severe air pollution and previous studies have mostly focused on megacities and a few hot spot regions. Hefei, the provincial capital city of Anhui province, has a population of near 5 million in its metropolitan area, but its air quality has not been reported in literature. In this study, daily PM10 and visibility data in 2001–2012 were analyzed to investigate the air quality status as well as the twelve-year pollution trends in Hefei. The results reveal that Hefei has been suffering high PM10 pollution and low visibility during the study period. The annual average PM10 concentrations are 2~3 times of the Chinese Ambient Air Quality Standard. PM10 shows fluctuating variation in 2001–2007 and has a slightly decreasing trend after 2008. The annual average visibility range is generally lower than 7 km and shows a worsening trend from 2001 to 2006 followed by an improving trend from 2007 to 2012. Wind speed, precipitation, and relative humidity have negative effects on PM10 concentrations in Hefei, while temperature could positively or negatively affect PM10. The results provide a general understanding of the status and long-term trends of PM10 pollution and visibility in a typical second-tier city in China.

  9. Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

    Science.gov (United States)

    Yang, Feiling; Hu, Jinming; Wu, Ruidong

    2016-08-01

    Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

  10. Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Huaiyu; Huang, Shanqian [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Zhou, Sen [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Department of Pediatrics, Harvard Medical School, Boston, MA (United States); Bi, Peng [Discipline of Public Health, University of Adelaide, Adelaide (Australia); Yang, Zhicong, E-mail: yangzc@gzcdc.org.cn [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Li, Xiujun [School of Public Health, Shandong University, Jinan (China); Chen, Lifan [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Cazelles, Bernard [UMMISCO, UMI 209 IRD – UPMC, 93142 Bondy (France); Eco-Evolutionary Mathematic, IBENS UMR 8197, ENS, 75230 Paris Cedex 05 (France); Yang, Jing [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Luo, Lei; Jing, Qinlong [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Yuan, Wenping [State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Pei, Yao; Sun, Zhe [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Yue, Tianxiang [State Key Laboratory of Resources and Environment Information System, Chinese Academy of Sciences, Beijing (China); Kwan, Mei-Po [Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, Champaign, IL 61820 (United States); and others

    2016-10-15

    Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment–mosquito–urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface area covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. - Highlights: • Urban dengue outbreak is associated with water area in Guangzhou, 1978–2014. • Surface water area can alter population size of dengue virus in urban area. • Urban dengue outbreak is not associated with annual rainfall in Guangzhou. • Spatiotemporal satellite image fusion can investigate urban environmental change. • Urban environmental change could induce virus, vector, and dengue epidemic change.

  11. Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China

    International Nuclear Information System (INIS)

    Tian, Huaiyu; Huang, Shanqian; Zhou, Sen; Bi, Peng; Yang, Zhicong; Li, Xiujun; Chen, Lifan; Cazelles, Bernard; Yang, Jing; Luo, Lei; Jing, Qinlong; Yuan, Wenping; Pei, Yao; Sun, Zhe; Yue, Tianxiang; Kwan, Mei-Po

    2016-01-01

    Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment–mosquito–urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface area covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. - Highlights: • Urban dengue outbreak is associated with water area in Guangzhou, 1978–2014. • Surface water area can alter population size of dengue virus in urban area. • Urban dengue outbreak is not associated with annual rainfall in Guangzhou. • Spatiotemporal satellite image fusion can investigate urban environmental change. • Urban environmental change could induce virus, vector, and dengue epidemic change.

  12. 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.

  13. Analysis of characteristics and radiation safety situation of uranium mining and metallurgy facilities in north area of China

    International Nuclear Information System (INIS)

    Liu Ruilan; Li Jianhui; Wang Xiaoqing; Huang Mingquan

    2014-01-01

    According to the radiation safety management of uranium mining and metallurgy facilities in north area of China, features and radiation safety conditions of uranium mining and metallurgy facilities in north area of China were analyzed based on summarizing the inspection data for 2011-2013. So the main problems of radiation environment security on uranium mine were studied. The relevant management measures and recommendations were put forward, and the basis for environmental radiation safety management decision making of uranium mining and metallurgy facilities in future was provided. (authors)

  14. Study of climate change related to deforestation in the Xishuangbanna area, Yunnan, China

    International Nuclear Information System (INIS)

    Chungcheng Li; Cong Lai

    1991-01-01

    The analysis of the results of deforestation and the meteorological data of the Xinshuangbanna region of China shows that there are possible relations between the deforestation and climate change. With the forest area decreased by 33% during the past 30 years, the climate of this region has also been changed. The annual mean temperature has been increased by 0.7C, of which the increase is 0.97C in the dry season and 0.53C in the wet season. Together with the annual temperature increase the temperature variations have also been increased, which has resulted in more frequent low temperature damage to the local plantation agriculture. The relative humidity decreased by 3% annually; and the annual precipitation also decreased, with a decrease in the wet season of 6.8% and an increase in the dry season of 20.8%

  15. Juvenile salmon usage of the Skeena River estuary.

    Science.gov (United States)

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    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 salmon populations that

  16. 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

  17. 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

  18. Roots of pioneer trees in the lower sub-tropical area of Dinghushan, Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    HAO Yan-ru; PENG Shao-lin; MO Jiang-ming; LIU Xin-wei; CHEN Zhuo-quan; ZHOU Kai; WU Jin-rong

    2006-01-01

    Representative pioneer tree root systems in the subtropical area of South China were examined with regard to their structure, underground stratification and biomass distribution. Excavation of skeleton roots and observation of fine roots of seven species including the Euphorbiaceae, Theaceae, Melastomataceae, Lauraceae and Fagaceae families was carried out. The results showed that: (1) Pioneer tree roots in the first stage of natural succession were of two types, one characterized by taproot system with bulky plagiotropic branches; the other characterized by flat root system with several tabular roots. The late mesophilous tree roots were characterized by one obvious taproot and tactic braches roots up and down. Shrub species roots were characterized by heart fibrous root type featured both by horizontally and transversally growing branches. Root shapes varied in different dominant species at different stages of succession. (2) Roots of the different species varied in the external features-color, periderm and structure of freshly cut slash. (3) In a set of successional stages the biomass of tree roots increased linearly with the age of growth. During monsoon, the total root biomass amounted to 115.70 t/ha in the evergreen broad-leaved forest; 50.61t/ha in needle and broad-leaved mixed forest dominated by coniferous forest; and 64.20 t/ha in broad-and needle-leaved mixed forest dominated by broad-leaved heliophytes, and are comparable to the underground biomass observed in similar tropical forests. Thisis the first report about roots characteristics of forest in the lower sub-tropical area of Dinghushan, Guangdong, China.

  19. Improved USLE-K factor prediction: A case study on water erosion areas in China

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2016-09-01

    Full Text Available Soil erodibility (K-factor is an essential factor in soil erosion prediction and conservation practises. The major obstacles to any accurate, large-scale soil erodibility estimation are the lack of necessary data on soil characteristics and the misuse of variable K-factor calculators. In this study, we assessed the performance of available erodibility estimators Universal Soil Loss Equation (USLE, Revised Universal Soil Loss Equation (RUSLE, Erosion Productivity Impact Calculator (EPIC and the Geometric Mean Diameter based (Dg model for different geographic regions based on the Chinese soil erodibility database (CSED. Results showed that previous estimators overestimated almost all K-values. Furthermore, only the USLE and Dg approaches could be directly and reliably applicable to black and loess soil regions. Based on the nonlinear best fitting techniques, we improved soil erodibility prediction by combining Dg and soil organic matter (SOM. The NSE, R2 and RE values were 0.94, 0.67 and 9.5% after calibrating the results independently; similar model performance was showed for the validation process. The results obtained via the proposed approach were more accurate that the former K-value predictions. Moreover, those improvements allowed us to effectively establish a regional soil erodibility map (1:250,000 scale of water erosion areas in China. The mean K-value of Chinese water erosion regions was 0.0321 (t ha h·(ha MJ mm−1 with a standard deviation of 0.0107 (t ha h·(ha MJ mm−1; K-values present a decreasing trend from North to South in water erosion areas in China. The yield soil erodibility dataset also satisfactorily corresponded to former K-values from different scales (local, regional, and national.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  2. The Caloosahatchee River Estuary: a monitoring partnership between Federal, State, and local governments, 2007-13

    Science.gov (United States)

    Patino, Eduardo

    2014-01-01

    The tidal Caloosahatchee River and downstream estuaries have substantial environmental, recreational, and economic value for southwest Florida residents and visitors. Modifications to the Caloosahatchee River watershed have altered the predevelopment hydrology, thereby threatening the environmental health of estuaries in the area. Hydrologic monitoring of the freshwater contributions from tributaries to the tidal Caloosahatchee River and its estuaries is necessary to adequately describe the total freshwater inflow and constituent loads to the delicate estuarine system.

  3. The Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; DileepKumar, M.; Shankar, D.

    of their extensive use for fisheries, agriculture, transportation, dumping of waste, etc. The two estuaries have since continued to attract scientific curiosity over the years, thanks in large measure to support from national and local funding agencies. As a... made so far to simulate them in numerical models, and characteristics of stratification and mixing. These are followed by chapters that examine the fun- damentals of biology and chemistry of the estuaries. A distinct characteristic of the estuaries...

  4. Plutonium in Atlantic coastal estuaries in the southeastern United States

    International Nuclear Information System (INIS)

    Hayes, D.W.; LeRoy, J.H.; Cross, F.A.

    1975-01-01

    A survey was made to begin to provide baseline information on the Pu distribution of representative estuarine and coastal areas of the southeastern United States. Sediments and marsh grass (Spartina) were collected and analyzed from three locations within a tidal marsh. In three estuaries (Savannah, Neuse, and Newport), the suspended particulate matter (1 μm and greater) was filtered from waters with different salinities, and the plutonium content of the particulates determined. The Savannah River estuary, in addition to fallout Pu, has received up to 0.3 Ci of Pu from the Savannah River Plant (SRP) of the U. S. Energy Research and Development Administration. The SRP plutonium has a variable isotopic composition that can influence Pu isotopic ratios in the estuarine system. The other estuaries do not have nuclear installations upstream. Data are included on the content of 238 Pu, 239 Pu, and 240 Pu in sediments and marsh grass of the Savannah River estuary

  5. 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.

  6. Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China

    Directory of Open Access Journals (Sweden)

    X. Wei

    2018-05-01

    Full Text Available Rocky desertification is a major ecological problem of land degradation in karst areas. In these areas, the high soil calcium (Ca content has become an important environmental factor that can affect the restoration of vegetation. Consequently, the screening of plant species that can adapt to high Ca soil environments is a critical step in vegetation restoration. In this study, three grades of rocky desertification sample areas were selected in karst areas of southwestern Hunan, China (LRD: light rocky desertification; MRD: moderate rocky desertification; and IRD: intense rocky desertification. Each grade of these sample areas had three sample plots in different slope positions, each of which had four small quadrats (one in rocky-side areas, three in non-rocky-side areas. We measured the Ca content of leaves, branches, and roots from 41 plant species, as well as soil total Ca (TCa and exchangeable Ca (ECa at depths of 0–15, 15–30, and 30–45 cm in each small quadrat. The results showed that the soil Ca2+ content in rocky-side areas was significantly higher than that in non-rocky-side areas (p < 0.05. The mean soil TCa and ECa content increased gradually along with the grade of rocky desertification, in the order IRD > MRD > LRD. For all plant functional groups, the plant Ca content of aboveground parts was significantly higher than that of the belowground parts (p < 0.05. The soil ECa content had significant effects on plant Ca content of the belowground parts but had no significant effects on plant Ca content of the aboveground parts. Of the 41 plant species that were sampled, 17 were found to be dominant (important value > 1. The differences in Ca2+ content between the aboveground and belowground parts of the 17 dominant species were calculated, and their correlations with soil ECa content were analyzed. The results showed that these 17 species can be divided into three categories: Ca-indifferent plants, high

  7. Seasonal and Interannual Variation in Energy Balance in the Semiarid Grassland Area of China

    Directory of Open Access Journals (Sweden)

    Qun’ou Jiang

    2015-01-01

    Full Text Available Near surface energy budget changes have been proved to be induced by the land cover conversion through changing the surface physical properties, which can further impact the regional climate change. This study applies the DLS model to simulate the land cover under the business as usual (BAU scenario and then analyses the seasonal and interannual variation of energy balance in the semiarid grassland area of China based on the simulated land cover with the Weather Research and Forecasting (WRF model. The results indicate that the grassland will show a growing trend under the BAU scenario. Downward long wave radiation and downward short wave radiation will all have small-scale increase with time going by, while the surface net radiation will decrease from 2030 to 2050. However, there is obvious seasonal variation. Summer has the highest downward long wave radiation and downward short wave radiation, followed by spring and autumn. The lowest are in winter. As for the net surface radiation, there is obvious decrease in southeast of study area due to returning cropland to grassland. Those research conclusions can offer valuable information for the land use planning and relieving the effects of land cover change on climate change at the semiarid grassland area.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Xie, Furen; Wang, Zhenming; Liu, Jingwei

    2011-03-01

    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.

  10. A survey of senile dementia in the high background radiation areas in Yangjiang, China

    International Nuclear Information System (INIS)

    Li Jia; Su Gasaki, H.; Yang Yuhua

    1997-01-01

    Objective: To evaluate the effects of long-term low dose and low dose-rate ionizing radiation exposure on the prevalence rate of senile dementia, further assess the effects of low-dose radiation exposure on central nervous system and study the pathogen of senile dementia, and provide direct observational data of human beings. Methods: A cross-sectional study of the prevalence of senile dementia was carried out in high background radiation areas in Yangjiang, Guangdong Province, China. The survey was conducted in two stages. For the initial screening, Hasegawa Dementia Scale (HDS) was used for all subjects. In the second stage, the stage of diagnosis, special questionnaires of healthy state of old people were sued. The final diagnoses were made according to the third revised edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM III-R) of American Psychiatric Association. Results: 1018 inhabitants aged 65 years and over, including 513 persons in HBRA and 505 in CA were observed. According to DSM III-R, 61 cases (31 cases in HBRA and 30 cases in CA) of senile dementia were diagnosed. The prevalence rates of senile dementia are 6.04% in HBRA and 5.94% in CA, the total prevalence rate being 5.99%. Conclusion: No significant statistical difference in the prevalence rate of senile dementia between the two areas was found, suggesting that the prevalence rate of senile dementia in these areas is not associated with the high background radiation exposure

  11. Cytogenetic study of stable chromosome aberrations in residents of a high background radiation area in China

    International Nuclear Information System (INIS)

    Zhang Wei; Wang Chunyan; Chen Deqing; Wei Lvxin

    2004-01-01

    Objective: To investigate the effect of high background radiation on the induction of stable chromosome aberrations. Methods: By fluorescence in situ hybridization (FISH) technique chromosome Nos. 1, 2 and 4 were painted using specific biotin-labeled whole chromosome painting probes. Peripheral blood specimens were taken from 31 individuals living in the high background radiation area (HRBA) and 29 individuals in the control area. Results: No significant difference was found in the frequencies of translocations between HBRA and the control (P>0.05, Mann-Whitney U test) for both children and elderly individuals. On the other hand, correlation between age and translocation frequencies was significant at the 1% level (r s =0.388 with 56DF). Conclusion: There are no differences in the frequencies of translocations between HBRA and the control area. The present result indicates that the contribution of an elevated level of natural radiation in HBRA in China to the induction rate of stable type aberrations (translocations) dose not have a significant effect compared with the contributions from all other sources such as chemical mutagens and(or) metabolic factors. (authors)

  12. Carbon Storages in Plantation Ecosystems in Sand Source Areas of North Beijing, China

    Science.gov (United States)

    Liu, Xiuping; Zhang, Wanjun; Cao, Jiansheng; Shen, Huitao; Zeng, Xinhua; Yu, Zhiqiang; Zhao, Xin

    2013-01-01

    Afforestation is a mitigation option to reduce the increased atmospheric carbon dioxide levels as well as the predicted high possibility of climate change. In this paper, vegetation survey data, statistical database, National Forest Resource Inventory database, and allometric equations were used to estimate carbon density (carbon mass per hectare) and carbon storage, and identify the size and spatial distribution of forest carbon sinks in plantation ecosystems in sand source areas of north Beijing, China. From 2001 to the end of 2010, the forest areas increased more than 2.3 million ha, and total carbon storage in forest ecosystems was 173.02 Tg C, of which 82.80 percent was contained in soil in the top 0–100 cm layer. Younger forests have a large potential for enhancing carbon sequestration in terrestrial ecosystems than older ones. Regarding future afforestation efforts, it will be more effective to increase forest area and vegetation carbon density through selection of appropriate tree species and stand structure according to local climate and soil conditions, and application of proper forest management including land-shaping, artificial tending and fencing plantations. It would be also important to protect the organic carbon in surface soils during forest management. PMID:24349223

  13. Characteristics of total gaseous mercury concentrations at a coastal area of the Yangtze Delta, China.

    Science.gov (United States)

    Diao, Chunyan; Li, Jianfeng; Zhang, Bin; Tang, Shichuang

    2017-03-01

    In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m -3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5-1.7 ng m -3 ); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources. Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An-Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.

  14. Sediment Trapping in Estuaries

    Science.gov (United States)

    Burchard, Hans; Schuttelaars, Henk M.; Ralston, David K.

    2018-01-01

    Estuarine turbidity maxima (ETMs) are generated by a large suite of hydrodynamic and sediment dynamic processes, leading to longitudinal convergence of cross-sectionally integrated and tidally averaged transport of cohesive and noncohesive suspended particulate matter (SPM). The relative importance of these processes for SPM trapping varies substantially among estuaries depending on topography, fluvial and tidal forcing, and SPM composition. The high-frequency dynamics of ETMs are constrained by interactions with the low-frequency dynamics of the bottom pool of easily erodible sediments. Here, we use a transport decomposition to present processes that lead to convergent SPM transport, and review trapping mechanisms that lead to ETMs at the landward limit of the salt intrusion, in the freshwater zone, at topographic transitions, and by lateral processes within the cross section. We use model simulations of example estuaries to demonstrate the complex concurrence of ETM formation mechanisms. We also discuss how changes in SPM trapping mechanisms, often caused by direct human interference, can lead to the generation of hyperturbid estuaries.

  15. 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

  16. Contamination and restoration of an estuary affected by phosphogypsum releases

    International Nuclear Information System (INIS)

    Villa, M.; Mosqueda, F.; Hurtado, S.; Mantero, J.; Manjon, G.; Perianez, R.; Vaca, F.; Garcia-Tenorio, R.

    2009-01-01

    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 226 Ra and 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 210 Pb and 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 226 Ra and 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 can be performed via natural

  17. 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

  18. Levels and isomer profiles of Dechlorane Plus in the surface soils from e-waste recycling areas and industrial areas in South China

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zhiqiang [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Lu Shaoyou; Gao Shutao; Wang Jingzhi [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li Huiru, E-mail: huiruli@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Zeng Xiangying; Sheng Guoying; Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2010-09-15

    Dechlorane Plus (DP) is a highly chlorinated flame retardant. Levels of DP were measured in surface soils from e-waste recycling areas and industrial areas in South China. Higher DP levels were found in e-waste recycling areas (undetectable-47.4 ng/g) than those in industrial areas (0.0336-4.65 ng/g) in South China. The highest DP concentration (3327 ng/g) was found at the e-waste recycling site in Qingyuan, while DP levels fell dramatically with increasing distance away from the recycling site, suggesting that the e-waste recycling activities are an important source of DP emissions. The mean ratios of anti-DP to total DP (f{sub anti}) for different sampling areas ranged from 0.58 to 0.76 and showed no significant difference from the ratio for the technical DP products (t-test, p > 0.05). Further intensive studies are needed to investigate the process of DP degradation and its degradation products. - High DP concentrations were found in the soils from e-waste recycling regions, and e-waste recycling was the major source of DP emissions in South China.

  19. [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

  20. Ship Emission Inventories in Estuary of the Yangtze River Using Terrestrial AIS Data

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

  2. Assessing the impacts of climate change on rice yields in the main rice areas of China

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Fengmei [College of Earth Sciences, The Graduate University of the Chinese Academy of Sciences, 19A, Yuquan Road, Beijing, 100049 (China); Xu, Yinglong; Lin, Erda [Agricultural Environment and Sustainable Development Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 (China); Yokozawa, Masayuki [National Institute for Agro-environmental Sciences, Tsukuba 305-8604 (Japan); Zhang, Jiahua [Chinese Academy of Meteorological Sciences, Beijing, 100081 (China)

    2007-02-15

    This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within {+-} 10% of observed flowering duration and {+-} 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations.

  3. Assessment of dietary intake among pregnant women in a rural area of western China

    Directory of Open Access Journals (Sweden)

    Zhang Xueli

    2009-07-01

    Full Text Available Abstract Background Adequate maternal nutrient intake during pregnancy is important to ensure satisfactory birth outcomes. There are no data available on the usual dietary intake among pregnant women in rural China. The present study describes and evaluates the dietary intake in a cohort of pregnant women living in two counties of rural Shaanxi, western China. Methods 1420 pregnant women were recruited from a trial that examined the effects of micronutrient supplementation on birth outcomes. Dietary information was collected at the end of their trimester or after delivery with an interviewed-administrated semi-quantitative food frequency questionnaire (FFQ. Nutrients intake was calculated from the FFQ and compared to the Estimated Average Requirements (EAR. The EAR cut-offs based on the Chinese Nutrition Society Dietary Reference Intakes (DRIs were used to assess the prevalence of inadequate dietary intakes of energy, protein, calcium, zinc, riboflavin, vitamin C and folate. Mann-Whitney U and Kruskal Wallis tests were used to compare nutrient intakes across subgroups. Results The mean nutrient intakes assessed by the FFQ was similar to those reported in the 2002 Chinese National Nutrition and Health Survey from women living in rural areas except for low intakes of protein, fat, iron and zinc. Of the participants, 54% were at risk of inadequate intake of energy. There were high proportions of pregnant women who did not have adequate intakes of folate (97% and zinc (91%. Using the "probability approach", 64% of subjects had an inadequate consumption of iron. Conclusion These results reveal that the majority of pregnant women in these two counties had low intakes of nutrients that are essential for pregnancy such as iron and folate. Trial registration ISRCTN08850194.

  4. Assessing the impacts of climate change on rice yields in the main rice areas of China

    International Nuclear Information System (INIS)

    Yao, Fengmei; Xu, Yinglong; Lin, Erda; Yokozawa, Masayuki; Zhang, Jiahua

    2007-01-01

    This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within ± 10% of observed flowering duration and ± 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations

  5. Stunting and zinc deficiency among primary school children in rural areas with low soil zinc concentrations in Jiangsu Province, China

    NARCIS (Netherlands)

    Qin, Yu; Boonstra, A.; Zhao, J.; Wu, M.; Hu, X.; Kok, F.J.

    2009-01-01

    OBJECTIVE: To assess stunting and zinc deficiency among primary school children in north rural area of Jiangsu Province with low soil zinc concentrations, eastern part of China. METHODS: Two data collection rounds were conducted. In the first data collection round, 2268 primary school children aged

  6. 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

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

    NARCIS (Netherlands)

    W.-C. Cao (Wu-Chun); 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

  8. 3D Tomographic SAR Imaging in Densely Vegetated Mountainous Rural Areas in China and Sweden

    Science.gov (United States)

    Feng, L.; Muller, J. P., , Prof

    2017-12-01

    3D SAR Tomography (TomoSAR) and 4D SAR Differential Tomography (Diff-TomoSAR) exploit multi-baseline SAR data stacks to create an important new innovation of SAR Interferometry, to unscramble complex scenes with multiple scatterers mapped into the same SAR cell. In addition to this 3-D shape reconstruction and deformation solution in complex urban/infrastructure areas, and recent cryospheric ice investigations, emerging tomographic remote sensing applications include forest applications, e.g. tree height and biomass estimation, sub-canopy topographic mapping, and even search, rescue and surveillance. However, these scenes are characterized by temporal decorrelation of scatterers, orbital, tropospheric and ionospheric phase distortion and an open issue regarding possible height blurring and accuracy losses for TomoSAR applications particularly in densely vegetated mountainous rural areas. Thus, it is important to develop solutions for temporal decorrelation, orbital, tropospheric and ionospheric phase distortion.We report here on 3D imaging (especially in vertical layers) over densely vegetated mountainous rural areas using 3-D SAR imaging (SAR tomography) derived from data stacks of X-band COSMO-SkyMed Spotlight and L band ALOS-1 PALSAR data stacks over Dujiangyan Dam, Sichuan, China and L and P band airborne SAR data (BioSAR 2008 - ESA) in the Krycklan river catchment, Northern Sweden. The new TanDEM-X 12m DEM is used to assist co - registration of all the data stacks over China first. Then, atmospheric correction is being assessed using weather model data such as ERA-I, MERRA, MERRA-2, WRF; linear phase-topography correction and MODIS spectrometer correction will be compared and ionospheric correction methods are discussed to remove tropospheric and ionospheric delay. Then the new TomoSAR method with the TanDEM-X 12m DEM is described to obtain the number of scatterers inside each pixel, the scattering amplitude and phase of each scatterer and finally extract

  9. 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

  10. Hair mercury concentrations and associated factors in an electronic waste recycling area, Guiyu, China

    International Nuclear Information System (INIS)

    Ni, Wenqing; Chen, Yaowen; Huang, Yue; Wang, Xiaoling; Zhang, Gairong; Luo, Jiayi; Wu, Kusheng

    2014-01-01

    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

  11. Thyroid nodularity and chromosome aberrations among women in areas of high background radiation in China

    International Nuclear Information System (INIS)

    Wang, Z.Y.; Boice, J.D. Jr.; Wei, L.X.; Beebe, G.W.; Zha, Y.R.; Kaplan, M.M.; Tao, Z.F.; Maxon, H.R. III; Zhang, S.Z.; Schneider, A.B.

    1990-01-01

    Thyroid nodularity following continuous low-dose radiation exposure in China was determined in 1,001 women aged 50-65 years who resided in areas of high background radiation (330 mR/yr) their entire lives, and in 1,005 comparison subjects exposed to normal levels of radiation (114 mR/yr). Cumulative doses to the thyroid were estimated to be of the order of 14 cGy and 5 cGy, respectively. Personal interviews and physical examinations were conducted, and measurements were made of serum thyroid hormone levels, urinary iodine concentrations, and chromosome aberrations in circulating lymphocytes. For all nodular disease, the prevalences in the high background and control areas were 9.5% and 9.3%, respectively. For single nodules, the prevalences were 7.4% in the high background area and 6.6% in the control area (prevalence ratio = 1.13; 95% confidence interval = 0.82-1.55). There were no differences found in serum levels of thyroid hormones. Women in the high background region, however, had significantly lower concentrations of urinary iodine and significantly higher frequencies of stable and unstable chromosome aberrations. Increased intake of allium vegetables such as garlic and onions was associated with a decreased risk of nodular disease, which seems consistent with experimental studies suggesting that allium compounds can inhibit tumor growth and proliferation. The prevalence of mild diffuse goiter was higher in the high background radiation region, perhaps related to a low dietary intake of iodine. These data suggest that continuous exposure to low-level radiation throughout life is unlikely to appreciably increase the risk of thyroid cancer. However, such exposure may cause chromosomal damage

  12. 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.

  13. Low risk of pulmonary tuberculosis of residents in high background radiation area, Yangjiang, China

    International Nuclear Information System (INIS)

    Li Xiaojuan; Sun Quanfu

    2006-01-01

    Objective: To examine the pulmonary tuberculosis mortality risk of the residents in high background radiation area (HBRA), Yangjiang, China. Methods: A cohort including 89 694 persons in HBRA and 35 385 persons in control area (CA) has been established since 1979. Person-year tables based on classified variables including sex, attained age, follow-up calendar year, and dose-rate group (high, intermediate, and low in HBRA, and control group) were tabulated using DATAB in EPICURE. Poisson regression analysis was used to estimate the relative risks (RR) of infectious and parasitic disease especially for pulmonary tuberculosis. Cumulative dose for each cohort member was obtained. Results: Two million person-years were accumulated by follow-up and 612 cases of pulmonary tuberculosis ascertained. Compared with risk in the control area, statistically significant lower risk of pulmonary tuberculosis was observed in HBRA among those who aged 60 years and over; markedly decreased risk occurred among males; no significant difference was found among the 6 follow-up stages, two subregions in the HBRA, or different diagnostic facilities. A statistically significantly negative dose-response was observed (P<0.001), the higher accumulative dose, the lower dose the pulmonary tuberculosis mortality risk. Its excess relative risk (ERR/Sv) was estimated to be -1.09 (95% CI: -1.34, -0.85). No established risk factors could explain this lower risk. Conclusions: The mortality of puhnonary tuberculosis among residents in HBRA who were chronically exposed to low-dose radiation was statistically significantly lower than that in the control area, and a significant dose-response relationship was observed, which probably resulted from the immunoenhancement of low dose radiation. (authors)

  14. 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.

  15. Tidal triggering of earthquakes in the Ning'er area of Yunnan Province, China

    Science.gov (United States)

    Xie, Chaodi; Lei, Xinglin; Zhao, Xiaoyan; Ma, Qingbo; Yang, Simeng; Wang, Yingnan

    2017-05-01

    To investigate the potential effect of tidal modulation on the seismicity in the Ning'er area, a seismically and geothermally active zone in Yunnan Province, China, we studied the correlation between Earth tides and the occurrence of M ≥ 6.0 earthquakes dating back to 1970, as well as their aftershock sequences, using theoretically calculated tidal stresses and a statistical test. The results show a significant correlation between Earth tides and the occurrence of earthquakes. Six of seven main events occurred when the Earth tide increased the Coulomb failure stress on the source fault. Four main events occurred in a narrow range of phase angle corresponding to the maximum loading rate of tidal stress. Furthermore, the histories of the aftershock sequence as a function of the tidal phases demonstrate clear tidal modulation with a high significance. Thus, we conclude that Earth tides have a clear role in triggering (or modulating) the rupture of the fault systems in the Ning'er area.

  16. Multivariate statistical evaluation of trace elements in groundwater in a coastal area in Shenzhen, China

    International Nuclear Information System (INIS)

    Chen Kouping; Jiao, Jiu J.; Huang Jianmin; Huang Runqiu

    2007-01-01

    Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the data of trace elements in groundwater using multivariate statistical techniques such as principal component analysis (PCA), Q-mode factor analysis and cluster analysis. The original matrix consisted of 17 trace elements estimated from 55 groundwater samples colleted in 27 wells located in a coastal area in Shenzhen, China. PCA results show that trace elements of V, Cr, As, Mo, W, and U with greatest positive loadings typically occur as soluble oxyanions in oxidizing waters, while Mn and Co with greatest negative loadings are generally more soluble within oxygen depleted groundwater. Cluster analyses demonstrate that most groundwater samples collected from the same well in the study area during summer and winter still fall into the same group. This study also demonstrates the usefulness of multivariate statistical analysis in hydrochemical studies. - Multivariate statistical analysis was used to investigate relationships among trace elements and factors controlling trace element distribution in groundwater

  17. Distribution characteristics of aromatic hydrocarbons pollution in dustfall samples from a coal-mining area, China

    Energy Technology Data Exchange (ETDEWEB)

    Yang Ce; Zhong Ning-ning; Chen Dang-yi; Li yan; Liu Shuang [China University of Petroleum, Beijing (China). Key Laboratory for Hydrocarbon Accumulation

    2007-07-01

    Dustfall samples from the Shilong coal-mining area, Pingdingshan, Henan, China, were tested containing polycyclic aromatic hydrocarbons (PAHs) by means of GC-MS technology, which damage the health of human. One hundred and sixty-nine PAHs have been identified in the samples, including 13 US EPA PAHs. The concentrations of PAHs are different in different dustfall samples from various site, which change from 0.017 to 0.188 mg/g, and the mean value is 0.079 mg/g. Of all the PAHs with 2-7 rings, PAHs with 3 rings are the most abundant. Considering organic geochemical parameters such as MP/P, MPI1, FL/PY and biomarkers, we conclude that lots of coalmines and coal industry plants, which locate in the small area, could have direct effect on the ambient atmosphere. Coal dust and coal combustion products influence the component of PAHs in the atmosphere. In addition, straw and wood combustion are small sources for PAHs. 30 refs., 7 figs., 1 tab.

  18. Topography and Data Mining Based Methods for Improving Satellite Precipitation in Mountainous Areas of China

    Directory of Open Access Journals (Sweden)

    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.

  19. Midlatitude Plasma Bubbles Over China and Adjacent Areas During a Magnetic Storm on 8 September 2017

    Science.gov (United States)

    Aa, Ercha; Huang, Wengeng; Liu, Siqing; Ridley, Aaron; Zou, Shasha; Shi, Liqin; Chen, Yanhong; Shen, Hua; Yuan, Tianjiao; Li, Jianyong; Wang, Tan

    2018-03-01

    This paper presents observations of postsunset super plasma bubbles over China and adjacent areas during the second main phase of a storm on 8 September 2017. The signatures of the plasma bubbles can be seen or deduced from (1) deep field-aligned total electron content depletions embedded in regional ionospheric maps derived from dense Global Navigation Satellite System networks, (2) significant equatorial and midlatitudinal plasma bite-outs in electron density measurements on board Swarm satellites, and (3) enhancements of ionosonde virtual height and scintillation in local evening associated with strong southward interplanetary magnetic field. The bubbles/depletions covered a broad area mainly within 20°-45°N and 80°-110°E with bifurcated structures and persisted for nearly 5 hr (˜13-18 UT). One prominent feature is that the bubbles extended remarkably along the magnetic field lines in the form of depleted flux tubes, reaching up to midlatitude of around 50°N (magnetic latitude: 45.5°N) that maps to an altitude of 6,600 km over the magnetic equator. The maximum upward drift speed of the bubbles over the magnetic equator was about 700 m/s and gradually decreased with altitude and time. The possible triggering mechanism of the plasma bubbles was estimated to be storm time eastward prompt penetration electric field, while the traveling ionospheric disturbance could play a role in facilitating the latitudinal extension of the depletions.

  20. 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.

  1. Crustal structure in Tengchong Volcano-Geothermal Area, western Yunnan, China

    Science.gov (United States)

    Wang, Chun-Yong; Huangfu, Gang

    2004-02-01

    Based upon the deep seismic sounding profiles carried out in the Tengchong Volcano-Geothermal Area (TVGA), western Yunnan Province of China, a 2-D crustal P velocity structure is obtained by use of finite-difference inversion and forward travel-time fitting method. The crustal model shows that a low-velocity anomaly zone exists in the upper crust, which is related to geothermal activity. Two faults, the Longling-Ruili Fault and Tengchong Fault, on the profile extend from surface to the lower crust and the Tengchong Fault likely penetrates the Moho. Moreover, based on teleseismic receiver functions on a temporary seismic network, S-wave velocity structures beneath the geothermal field show low S-wave velocity in the upper crust. From results of geophysical survey, the crust of TVGA is characterized by low P-wave and S-wave velocities, low resistivity, high heat-flow value and low Q. The upper mantle P-wave velocity is also low. This suggests presence of magma in the crust derived from the upper mantle. The low-velocity anomaly in upper crust may be related to the magma differentiation. The Tengchong volcanic area is located on the northeast edge of the Indian-Eurasian plate collision zone, away from the eastern boundary of the Indian plate by about 450 km. Based on the results of this paper and related studies, the Tengchong volcanoes can be classified as plate boundary volcanoes.

  2. Environmental lead pollution and elevated blood lead levels among children in a rural area of China.

    Science.gov (United States)

    Lin, Sihao; Wang, Xiaorong; Yu, Ignatius Tak Sun; Tang, Wenjuan; Miao, Jianying; Li, Jin; Wu, Siying; Lin, Xing

    2011-05-01

    We investigated environmental lead pollution and its impact on children's blood lead levels (BLLs) in a rural area of China. In 2007, we studied 379 children younger than 15 years living in 7 villages near lead mines and processing plants, along with a control group of 61 children from another village. We determined their BLLs and collected environmental samples, personal data, and information on other potential exposures. We followed approximately 86% of the children who had high BLLs (> 15 μg/dL) for 1 year. We determined factors influencing BLLs by multivariate linear regression. Lead concentrations in soil and household dust were much higher in polluted villages than in the control village, and more children in the polluted area than in the control village had elevated BLLs (87%, 16.4 μg/dL vs 20%, 7.1 μg/dL). Increased BLL was independently associated with environmental lead levels. We found a significant reduction of 5 micrograms per deciliter when we retested children after 1 year. Our data show that the lead industry caused serious environmental pollution that led to high BLLs in children living nearby.

  3. Polychlorinated naphthalenes (PCNs) in riverine and marine sediments of the Laizhou Bay area, North China

    International Nuclear Information System (INIS)

    Pan Xiaohui; Tang Jianhui; Chen Yingjun; Li Jun; Zhang Gan

    2011-01-01

    PCN congeners were analyzed in marine and riverine sediments of the Laizhou Bay area, North China. Concentrations of PCNs ranged from 0.12 to 5.1 ng g -1 dry weight (dw) with a mean value of 1.1 ng g -1 dw. The levels of PCNs varied largely, with industrial group approximately ten folds higher than those of the rural in riverine sediment. A strong impact by direct discharge from local factories was suggested. Similar compositional profiles were found within groups. High resemblance of compositional profiles between industrial samples and Halowax 1014 was observed. It was indicated that PCNs in riverine sediments were mainly from release of industrial usage, with additional contributions from industrial thermal process at certain sites. In marine sediments, it was suggested that PCNs along the coast of Laizhou Bay were mainly controlled by riverine input. While in the central bay, PCN distributions were possibly impacted by combined multiple factors. - Highlights: → We investigated the PCN levels both in the riverine and marine surface sediments of Laizhou Bay. → PCN concentrations in the river sediments of industrial group were ten times higher than in the rural group. → Leakage from industrial materials and thermal processes were the major sources. → PCNs in the coastal sites were more influenced by the river discharge. → In the centre bay, PCN distributions were possibly impacted by combined multiple factors. - A systematic sampling of riverine and marine sediments was conducted in Laizhou Bay area to investigate the distribution and possible sources of PCNs.

  4. 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.

  5. Drinking and drinking patterns and health status in the general population of five areas of China.

    Science.gov (United States)

    Hao, Wei; Su, Zhonghua; Liu, Binglun; Zhang, Kui; Yang, Hanqing; Chen, Shaozhong; Biao, Meizi; Cui, Chun

    2004-01-01

    To understand drinking patterns, health status related to drinking and the level of unrecorded alcoholic beverage consumption for the general population living in five areas of China in 2001. By cluster sampling, 24992 community residents aged 15 years or older were interviewed by trained psychiatrists using structured questionnaires provided by WHO. The 1-year drinking rate was 59.0%, and the point prevalence rate of dependence was 3.8%. The average annual consumption of pure alcohol was 4.47 l. The 1-year morbidity from gastritis/ulcer in the whole sample was 7.9%, which associated nonlinearly to alcohol intake, and heart disease and cerebral infarction/cerebral haemorrhage showed V-shaped curve relationships. The rate of alcohol use was higher in men than in women, and the annual alcohol consumption per capita was higher than that in the 1990s in the selected areas. Alcohol consumption plays a role in the development of alcohol-related physical diseases.

  6. Heavy metals in soil at a waste electrical and electronic equipment processing area in China.

    Science.gov (United States)

    Gu, Weihua; Bai, Jianfeng; Yao, Haiyan; Zhao, Jing; Zhuang, Xuning; Huang, Qing; Zhang, Chenglong; Wang, JingWei

    2017-11-01

    For the objective of evaluating the contamination degree of heavy metals and analysing its variation trend in soil at a waste electrical and electronic equipment processing area in Shanghai, China, evaluation methods, which include single factor index method, geo-accumulation index method, comprehensive pollution index method, and potential ecological risk index method, were adopted in this study. The results revealed that the soil at a waste electrical and electronic equipment processing area was polluted by arsenic, cadmium, copper, lead, zinc, and chromium. It also demonstrated that the concentrations of heavy metals were increased over time. Exceptionally, the average value of the metalloid (arsenic) was 73.31 mg kg -1 in 2014, while it was 58.31 mg kg -1 in the first half of 2015, and it was 2.93 times and 2.33 times higher than that of the Chinese Environmental Quality Standard for Soil in 2014 and the first half of 2015, respectively. The sequences of the contamination degree of heavy metals in 2014 and the first half of 2015 were cadmium > lead > copper > chromium > zinc and cadmium > lead > chromium > zinc > copper. From the analysis of the potential ecological risk index method, arsenic and cadmium had higher ecological risk than other heavy metals. The integrated ecological risk index of heavy metals (cadmium, copper, lead, zinc, and chromium) and metalloid (arsenic) was 394.10 in 2014, while it was 656.16 in the first half of 2015, thus documenting a strong ecological risk.

  7. Analysis on Imbalance of Family Intergenerational Exchange in China Rural Area

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

  9. Seasonal atmospheric deposition and air-sea gas exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implications for source-sink processes

    Science.gov (United States)

    Jiang, Yuqing; Lin, Tian; Wu, Zilan; Li, Yuanyuan; Li, Zhongxia; Guo, Zhigang; Yao, Xiaohong

    2018-04-01

    In this work, air samples and surface seawater samples covering four seasons from March 2014 to January 2015 were collected from a background receptor site in the YRE to explore the seasonal fluxes of air-sea gas exchange and dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. Gaseous PAH release from seawater to the atmosphere averaged 3114 ± 1999 ng m-2 d-1 in a year round. The air-sea gas exchange of PAHs was the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of total dry and wet deposition. The gas PAH exchange flux was dominated by three-ring PAHs, with the highest value in summer and lowest in winter, indicating a marked seasonal variation owing to differences in Henry's law constants associated with temperature, as well as wind speed and gaseous-dissolved gradient among seasons. Based on the simplified mass balance estimation, a net 11 tons y-1 of PAHs (mainly three-ring PAHs) were volatilized from seawater to the atmosphere in a ∼20,000 km2 area in the YRE. Other than the year-round Yangtze River input and ocean ship emissions, the selective release of low-molecular-weight PAHs from bottom sediments in winter due to resuspension triggered by the East Asian winter monsoon is another potential source of PAHs. This work suggests that the source-sink processes of PAHs at the air-sea interface in the YRE play a crucial role in regional cycling of PAHs.

  10. Does Taking One Step Back Get You Two Steps Forward? Grade Retention and School Performance in Poor Areas in Rural China

    Science.gov (United States)

    Chen, Xinxin; Liu, Chengfang; Zhang, Linxiu; Shi, Yaojiang; Rozelle, Scott

    2010-01-01

    Despite the rise in grade retention in poor areas in rural China recently, little work has been done to understand the impact of grade retention on the educational performance of students in these areas in rural China. This paper seeks to redress this shortcoming and examines the effect of grade retention on educational performance on 1649…

  11. Vector capacity of Anopheles sinensis in malaria outbreak areas of central China

    Directory of Open Access Journals (Sweden)

    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

  12. 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.

  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. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

    International Nuclear Information System (INIS)

    Han, Dongmei; Cao, Guoliang; McCallum, James; Song, Xianfang

    2015-01-01

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO_3"− 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"1"8O, δ"2H) analysis, "3H 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 (92–467 years) and the NO_3"− 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 (8–411 years) and the NO_3"− 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

  15. Residence times of groundwater and nitrate transport in coastal aquifer systems: Daweijia area, northeastern China

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dongmei [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Cao, Guoliang [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Center for Water Research, College of Engineering, Peking University, Beijing 100871 (China); McCallum, James [National Centre for Groundwater Research and Training, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); School of the Environment, Flinders University, GPO Box 2100, Adelaide, SA 5001 (Australia); Song, Xianfang [Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China)

    2015-12-15

    Groundwater within the coastal aquifer systems of the Daweijia area in northeastern China is characterized by a large of variations (33–521 mg/L) in NO{sub 3}{sup −} 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{sup 18}O, δ{sup 2}H) analysis, {sup 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 (92–467 years) and the NO{sub 3}{sup −} 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 (8–411 years) and the NO{sub 3}{sup −} 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

  16. A socio-ecological survey in Jalantai Area, Alxa League, Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    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.

  17. The Built Environment and Walking Activity of the Elderly: An Empirical Analysis in the Zhongshan Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    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.

  18. [Investigation of urinary cadmium characteristics of the general population in three non-cadmium-polluted rural areas in China].

    Science.gov (United States)

    Han, Jingxiu; Hu, Ji; Sun, Hong; Jing, Qiqing; Wang, Xiaofeng; Lou, Xiaoming; Ding, Zhen; Chen, Xiaodong; Zhang, Wenli; Shang, Qi

    2014-11-01

    To investigate the characteristics of urinary cadmium of the non-occupational-cadmium-exposed population in non-cadmium contaminated rural area in China. Randomly selected non-occupational cadmium exposed population 2548 people (male 1290, female 1258) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr 3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P95) of urinary cadmium after correction by urinary Cr. Urinary cadmium increased with age and showed an upward trend. The urinary cadmium of the population of ≥ 30 years old was significantly higher than that of populations (China (GB Z17-2002). The urinary cadmium reference value of non-occupational-cadmium-exposed populations is China, but for smoking women over 30 year-old it needs more research to explore.

  19. 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

  20. Historical changes in the Columbia River Estuary

    Science.gov (United States)

    Sherwood, Christopher R.; Jay, David A.; Bradford Harvey, R.; Hamilton, Peter; Simenstad, Charles A.

    Historical changes in the hydrology, sedimentology, and physical oceanography of the Columbia River Estuary have been evaluated with a combination of statistical, cartographic, and numerical-modelling techniques. Comparison of data digitized from US Coast and Geodetic Survey bathymetric surveys conducted in the periods 1867-1875, 1926-1937, and 1949-1958 reveals that large changes in the morphology of the estuary have been caused by navigational improvements (jetties, dredged channels, and pile dikes) and by the diking and filling of much of the wetland area. Lesser changes are attributable to natural shoaling and erosion. There has been roughly a 15% decrease in tidal prism and a net accumulation of about 68 × 10 6m 3 of sediment in the estuary. Large volumes of sediment have been eroded from the entrance region and deposited on the continental shelf and in the balance of the estuary, contributing to formation of new land. The bathymetric data indicate that, ignoring erosion at the entrance, 370 to 485 × 10 6m 3 of sediment has been deposited in the estuary since 1868 at an average rate of about 0.5 cm y -1, roughly 5 times the rate at which sea level has fallen locally since the turn of the century. Riverflow data indicate that the seasonal flow cycle of the Columbia River has been significantly altered by regulation and diversion of water for irrigation. The greatest changes have occurred in the last thirty years. Flow variability over periods greater than a month has been significantly damped and the net discharge has been slightly reduced. These changes in riverflow are too recent to be reflected in the available in the available bathymetric data. Results from a laterally averaged, multiple-channel, two-dimensional numerical flow model (described in HAMILTON, 1990) suggest that the changes in morphology and riverflow have reduced mixing, increased stratification, altered the response to fortnightly (neap-spring) changes in tidal forcing, and decreased the

  1. Impact of climate change on Gironde estuary

    International Nuclear Information System (INIS)

    Laborie, Vanessya; Hissel, Francois; Sergent, Philippe

    2014-01-01

    Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. A numerical model of the Gironde Estuary was used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the 21. century using ONERC's pessimistic scenario for sea level rise (60 cm). The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon,, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the flood plain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the flood plain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results. (authors)

  2. Impact of climate change on Gironde Estuary

    Science.gov (United States)

    Laborie, Vanessya; Hissel, François; Sergent, Philippe

    2014-05-01

    Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

  3. 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 draini...

  4. Application of remote sensing techniques to study the distribution of mangroves along the estuaries of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Wafar, S.; Jagtap, T.G.

    Aerial photographs were used to study the distribution of mangroves in the estuaries of Goa during 1978-79. The total area covered by 7 estuaries in Goa including the major Mandovi - Zuari estuarine complex, is approximately 12,000 ha of which...

  5. Design of anti-slide piles for slope stabilization in Wanzhou city, Three Gorges Area, China

    Science.gov (United States)

    Zhou, Chunmei; van Westen, Cees

    2013-04-01

    This study is related to the design of anti-slide piles for several landslides in Wanzhou city located in the Three Gorges area. Due to the construction of the Three Gorges Reservoir the hydro-geological conditions in this area have deteriorated significantly, leading to larger instability problems. China has invested a lot of money in slope stabilization measures for the treatment of landslides in the Three Gorges area. One of the methods for the stabilization of large landslides is the design of anti-sliding piles. This paper focuses on extensive slope stability analysis and modeling of the mechanical behavior of the landslide masses, and the parameters required for designing the number, size and dimensions of reinforced concrete stabilization piles. The study focuses on determining the rock parameters, anchor depth, and the pile and soil interaction coefficient. The study aims to provide guidelines for anti-slide pile stabilization works for landslides in the Wanzhou area. The research work contains a number of aspects. First a study is carried out on the distribution of pressures expected on the piles, using two different methods that take into account the expected pore water pressure and seismic acceleration. For the Ercengyan landslide , the Limit Equilibrium Method and Strength Reduction Method of FEM are compared through the results of the landslide pressure distributions on the piles and stress fields in the piles. The second component is the study of the required anchor depth of antislide piles, which is carried out using a statistical analysis with data from 20 landslides that have been controlled with anti-sliding piles. The rock characteristics of the anchor locations were obtained using laboratory tests, and a classification of rock mass quality is made for the anchors of antislide piles. The relationship between the critical anchor height and the angle of the landslide slip surface is determined. Two different methods are presented for the length

  6. On area-specific underground research laboratory for geological disposal of high-level radioactive waste in China

    Directory of Open Access Journals (Sweden)

    Ju Wang

    2014-04-01

    Full Text Available Underground research laboratories (URLs, including “generic URLs” and “site-specific URLs”, are underground facilities in which characterisation, testing, technology development, and/or demonstration activities are carried out in support of the development of geological repositories for high-level radioactive waste (HLW disposal. In addition to the generic URL and site-specific URL, a concept of “area-specific URL”, or the third type of URL, is proposed in this paper. It is referred to as the facility that is built at a site within an area that is considered as a potential area for HLW repository or built at a place near the future repository site, and may be regarded as a precursor to the development of a repository at the site. It acts as a “generic URL”, but also acts as a “site-specific URL” to some extent. Considering the current situation in China, the most suitable option is to build an “area-specific URL” in Beishan area, the first priority region for China's high-level waste repository. With this strategy, the goal to build China's URL by 2020 may be achieved, but the time left is limited.

  7. Total mercury, methylmercury and selenium in mercury polluted areas in the province Guizhou, China.

    Science.gov (United States)

    Horvat, Milena; Nolde, Natasa; Fajon, Vesna; Jereb, Vesna; Logar, Martina; Lojen, Sonja; Jacimovic, Radojko; Falnoga, Ingrid; Liya, Qu; Faganeli, Jadran; Drobne, Damjana

    2003-03-20

    The province of Guizhou in Southwestern China is currently one of the world's most important mercury production areas. Emissions of mercury from the province to the global atmosphere have been estimated to be approximately 12% of the world total anthropogenic emissions. The main objective of this study was to assess the level of contamination with Hg in two geographical areas of Guizhou province. Mercury pollution in the areas concerned originates from mercury mining and ore processing in the area of Wanshan, while in the area of Quingzhen mercury pollution originates from the chemical industry discharging Hg through wastewaters and emissions to the atmosphere due to coal burning for electricity production. The results of this study confirmed high contamination with Hg in soil, sediments and rice in the Hg mining area in Wanshan. High levels of Hg in soil and rice were also found in the vicinity of the chemical plant in Quingzhen. The concentrations of Hg decreased with distance from the main sources of pollution considerably. The general conclusion is that Hg contamination in Wanshan is geographically more widespread, due to deposition and scavenging of Hg from contaminated air and deposition on land. In Quingzhen Hg contamination of soil is very high close to the chemical plant but the levels reach background concentrations at a distance of several km. Even though the major source of Hg in both areas is inorganic Hg, it was observed that active transformation of inorganic Hg to organic Hg species (MeHg) takes place in water, sediments and soils. The concentration of Hg in rice grains can reach up to 569 microg/kg of total Hg of which 145 microg/kg was in MeHg form. The percentage of Hg as MeHg varied from 5 to 83%. The concentrations of selenium can reach up to 16 mg/kg in soil and up to 1 mg/g in rice. A correlation exists between the concentration of Se in soil and rice, indicating that a portion of Se is bioavailable to plants. No correlation between Hg and Se

  8. Polybrominated diphenyl ethers in atmosphere and soil of a production area in China: levels and partitioning.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Liu, Weizhi; Yang, Congqiao; Hu, Jicheng; Cui, Jian

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of Sigma11PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric particle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer (88.3%), whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners (i.e., BDE-206, BDE-207, BDE-208, and BDE-209) were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.

  9. Polybrominated diphenyl ethers in atmosphere and soil of a production area in China: Levels and partitioning

    Institute of Scientific and Technical Information of China (English)

    Jun Jin; Ying Wang; Weizhi Liu; Congqiao Yang; Jicheng Hu; Jian Cui

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of ∑11 PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric panicle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer (88.3%),whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners (i.e., BDE-206, BDE207, BDE-208, and BDE-209) were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.

  10. Karst water control and management in the Hanxing mining area of North China

    Energy Technology Data Exchange (ETDEWEB)

    Wanfang, Z. [P.E. LaMoreaux and Associates, Inc., Oak Ridge, TN (United States)

    1997-04-01

    The Hanxing mining area of North China includes three coalfields: Fengfeng, Handan and Xingtai. Six or seven coal seams can be commercially mined in Permo-Carboniferous strata, among which the lower three, accounting for 37% of the total reserves, are threatened with karst water from the underlain Ordovician limestone. Hundreds of water inrush accidents have occurred and over 30 mines have been flooded, resulting in heavy economic losses and casualties. In order to avoid water inrushes and keep the mines safely operational, dewatering in the karst aquifer was considered an essential measure. Unfortunately, this practice has caused serious environmental problems such as surface subsidence (sinkhole), dry spring, and water supply shortage. On the basis of a series of investigations and tests in the last 20 years, an alternative method, mining with water pressure, has been proposed and is the main focus of this paper. By using this method, the karst water in the limestone can be preserved to some extent and the coals can be mined in a relatively safe way. (orig.)

  11. Grey relation projection model for evaluating permafrost environment in the Muli coal mining area, China

    Energy Technology Data Exchange (ETDEWEB)

    Wei Cao; Yu Sheng; Yinghong Qin; Jing Li; Jichun Wu [Chinese Academy of Sciences, Lanzhou (China). State Key Laboratory of Frozen Soil Engineering

    2010-12-15

    This study attempts to estimate the current stage of the permafrost environment in the Muli coal mining area, an opencast mining site in the Qinghai-Tibet plateau, China. The estimation is done by regarding this site's permafrost environment as a system which was divided into three subsystems consisting of permafrost freeze-thaw erosion sensibility, permafrost thermal stability, and permafrost ecological fragility. The subsystems were characterized with their influencing indicators, each of which was assigned with a weight according to analytic hierarchy process. The relationship between these indictors is established using an environmental evaluation model based on grey system theory. The evaluated results show that currently the normalised grey relation projection values (GRPV) of permafrost freezing-thawing erosion sensibility, permafrost thermal stability, permafrost ecological fragility and permafrost environment are 0.58 (general situation), 0.47 (bad situation), 0.63 (general situation) and 0.56 (general situation), respectively. These values imply that the permafrost environment has been deteriorated to a certain degree by human activities and potentially could be further degraded. However, at this degree, a new equilibrium could be achieved if the current environmental degradation ratio is held and if effective treatments are constructed against further damages.

  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. 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.

  14. 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.

  15. 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 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 (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. PMID:23342066

  16. Hydrological and pollution processes in mining area of Fenhe River Basin in China.

    Science.gov (United States)

    Yang, Yonggang; Meng, Zhilong; Jiao, Wentao

    2018-03-01

    The hydrological and pollution processes are an important science problem for aquatic ecosystem. In this study, the samples of river water, reservoir water, shallow groundwater, deep groundwater, and precipitation in mining area are collected and analyzed. δD and δ 18 O are used to identify hydrological process. δ 15 N-NO 3 - and δ 18 O-NO 3 - are used to identify the sources and pollution process of NO 3 - . The results show that the various water bodies in Fenhe River Basin are slightly alkaline water. The ions in the water mainly come from rock weathering. The concentration of SO 4 2- is high due to the impact of coal mining activity. Deep groundwater is significantly less affected by evaporation and human activity, which is recharged by archaic groundwater. There are recharge and discharge between reservoir water, river water, soil water, and shallow groundwater. NO 3 - is the main N species in the study area, and forty-six percent of NO 3 - -N concentrations exceed the drinking water standard of China (NO 3 - -N ≤ 10 mg/L content). Nitrification is the main forming process of NO 3 - . Denitrification is also found in river water of some river branches. The sources of NO 3 - are mainly controlled by land use type along the riverbank. NO 3 - of river water in the upper reaches are come from nitrogen in precipitation and soil organic N. River water in the lower reaches is polluted by a mixture of soil organic N and fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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

  18. 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

  19. 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

  20. 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

  1. Precipitation alters plastic film mulching impacts on soil respiration in an arid area of northwest China

    Science.gov (United States)

    Ming, Guanghui; Hu, Hongchang; Tian, Fuqiang; Peng, Zhenyang; Yang, Pengju; Luo, Yiqi

    2018-05-01

    Plastic film mulching (PFM) has widely been used around the world to save water and improve crop yield. However, the effect of PFM on soil respiration (Rs) remains unclear and could be further confounded by irrigation and precipitation. To address these topics, controlled experiments were conducted in mulched and non-mulched fields under drip irrigation from 2014 to 2016 in an arid area of the Xinjiang Uygur Autonomous Region, northwest China. The spatio-temporal pattern of soil surface CO2 flux as an index of soil respiration under drip irrigation with PFM was investigated, and the confounded effects of PFM and irrigation/precipitation on soil respiration were explored. The main findings were as follows. (1) Furrows, planting holes, and plastic mulch are three important pathways of soil CO2 emissions in mulched fields, of which the planting hole efflux outweighs that from the furrow, with the largest values of 8.0 and 6.6 µmol m-2 s-1, respectively, and the plastic mulch itself can emit up to 3.6 µmol m-2 s-1 of CO2. (2) The frequent application of water (i.e. through irrigation and precipitation) elevates soil moisture and soil respiration and enhances their variation. The resultant higher variation of soil moisture further alleviates the sensitivity of soil respiration to soil temperature, leading to a weak correlation and lower Q10 values. (3) Soil CO2 effluxes from furrows and ridges in mulched fields outweigh the corresponding values in non-mulched fields in arid areas. However, this outweighing relation attenuates with increasing precipitation. Furthermore, by combining our results with those from the literature, we show that the difference in soil CO2 effluxes between non-mulched and mulched fields presents a linear relation with the amount of precipitation, which results in negative values in arid areas and positive values in humid areas. Therefore, whether PFM increases soil respiration or not depends on the amount of precipitation during the crop

  2. Spatial-Temporal Variations of Chlorophyll-a in the Adjacent Sea Area of the Yangtze River Estuary Influenced by Yangtze River Discharge

    Science.gov (United States)

    Wang, Ying; Jiang, Hong; Jin, Jiaxin; Zhang, Xiuying; Lu, Xuehe; Wang, Yueqi

    2015-01-01

    Carrying abundant nutrition, terrigenous freshwater has a great impact on the spatial and temporal heterogeneity of phytoplankton in coastal waters. The present study analyzed the spatial-temporal variations of Chlorophyll-a (Chl-a) concentration under the influence of discharge from the Yangtze River, based on remotely sensed Chl-a concentrations. The study area was initially zoned to quantitatively investigate the spatial variation patterns of Chl-a. Then, the temporal variation of Chl-a in each zone was simulated by a sinusoidal curve model. The results showed that in the inshore waters, the terrigenous discharge was the predominant driving force determining the pattern of Chl-a, which brings the risk of red tide disasters; while in the open sea areas, Chl-a was mainly affected by meteorological factors. Furthermore, a diversity of spatial and temporal variations of Chl-a existed based on the degree of influences from discharge. The diluted water extended from inshore to the east of Jeju Island. This process affected the Chl-a concentration flowing through the area, and had a potential impact on the marine environment. The Chl-a from September to November showed an obvious response to the discharge from July to September with a lag of 1 to 2 months. PMID:26006121

  3. How to deal with burden of critical illness: A comparison of strategies in different areas of China.

    Science.gov (United States)

    Liu, Pengcheng; Jiang, Liwen; Li, Chengyue; Sun, Mei; Rieger, Alexander; Hao, Mo

    2014-05-01

    This article aims to introduce, compare and analyze the design and development of Critical Illness Insurance systems in different parts of China under different social and economic conditions, to explain their characteristics and similarities. It may provide references to other countries, especially developing countries, to solve the problem of high medical costs. According to the methods in Comparative Economics, 3 areas (Taicang in Jiangsu, Zhanjiang in Guangdong, Xunyi in Shanxi) which are in high, medium and low socio-economic condition respectively were chosen in China. Their critical illness insurance systems were analyzed in the study. Each system shares several common points, including coordinating urban and rural medical insurance fund, financing from the basic medical insurance surplus, and exploring payment reform and so on. But in the way of management, Taicang and Zhanjiang cooperate with commercial insurance agencies, but Xunyi chooses autonomous management by government. In Xunyi, multi-channel financing is relatively more dispersed, while funds of Taicang and Zhanjiang are mainly from the basic medical insurance surplus. The specific method of payment is different among these three areas. Because of the differences in economic development, population structure, and sources of funds, each area took their own mode on health policy orientation, financing, payment, coverage, and fund management to design their Critical Illness Insurance systems. This might provide references to other areas in China and other developing countries in the world.

  4. 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.

    Science.gov (United States)

    Chen, Min; Liao, Yong; Liu, Jia; Fang, Wenjie; Hong, Nan; Ye, Xiaofei; Li, Jianjun; Tang, Qinglong; Pan, Weihua; Liao, Wanqing

    2016-01-01

    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 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.

  5. 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

  6. 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)

  7. Stable Isotopic Analysis on Water Utilization of Two Xerophytic Shrubs in a Revegetated Desert Area: Tengger Desert, China

    OpenAIRE

    Lei Huang; Zhishan Zhang

    2015-01-01

    Stable isotope studies on stable isotope ratios of hydrogen and oxygen in water within plants provide new information on water sources and water use patterns under natural conditions. In this study, the sources of water uptake for two typical xerophytic shrubs, Caragana korshinskii and Artemisia ordosica, were determined at four different-aged revegetated sites (1956, 1964, 1981, and 1987) in the Tengger Desert, a revegetated desert area in China. Samples from precipitation, soil water at dif...

  8. The estimation of the dose from cosmic radiation received by the population living at mainland areas of China

    International Nuclear Information System (INIS)

    Jin Hua; Yue Qingyu

    1989-01-01

    According to the distribution of cosmic ray ionization with altitude and latitude as well as the census information in all of our country (the end of the year 1986), the population-weighted mean annual effective dose equivalent received by the population living at mainland areas of China is estimated to be about 278 μSv, in which the ionizing component and the neutron component are 252 μSv and 26 μSv, respectively

  9. PERLINDUNGAN HUKUM USAHA MIKRO KECIL MENENGAH (UMKM DARI DAMPAK ADANYA PERJANJIAN ASEAN-CHINA FREE TRADE AREA (ACFTA

    Directory of Open Access Journals (Sweden)

    Ari Ratna Kurniastuti

    2014-08-01

    Full Text Available Abstract Journal writing is about the legal protection of micro small and medium enterprises (SMEs from the impact of the Agreement of the ASEAN-China Free Trade Area (ACFTA. It is motivated by the ACFTA agreement that went into effect on January 1, 2010 many local industries including the SMEs gain a tremendous impact, ranging from reduced turnover, to anyone out of business. Seeing as it is a phenomenon that needs to be assessed on the first position of the ACFTA agreement in the Indonesian legal system relating to the case of a legal conflict with national legislation that protects SMEs. The second study is about the ideal form of legal protection for SMEs from the impact of the ACFTA agreement. Key words: legal protection, the micro, small and medium enterprises (smes, treaty of asean china free trade area (ACFTA   Abstrak Penulisan jurnal ini membahas tentang perlindungan hukum usaha mikro kecil menengah (UMKM dari dampak adanya Perjanjian ASEAN-China Free Trade Area (ACFTA. Hal ini dilatarbelakangi dengan adanya perjanjian ACFTA yang mulai berlaku pada 1 Januari 2010 banyak industri lokal yang termasuk di dalamnya adalah UMKM mendapatkan dampak yang luar biasa, mulai dari penurunan omset, sampai ada yang gulung tikar. Melihat fenomena yang demikian maka perlu dikaji mengenai yang pertama kedudukan Perjanjian ACFTA dalam sistem hukum Indonesia berkaitan dengan apabila terjadi konflik hukum dengan peraturan perundang-undangan nasional yang melindungi UMKM. Kajian kedua adalah tentang bentuk perlindungan hukum yang ideal terhadap UMKM dari dampak adanya  perjanjian ACFTA. Kata kunci: perlindungan hukum, usaha mikro kecil menengah (umkm, perjanjian asean-china free trade area (ACFTA

  10. Heavy Metal Contamination in Soil and Brown Rice and Human Health Risk Assessment near Three Mining Areas in Central China

    OpenAIRE

    Fan, Yu; Zhu, Tingping; Li, Mengtong; He, Jieyi; Huang, Ruixue

    2017-01-01

    Background. Metal mining and waste discharge lead to regional heavy metal contamination and attract major concern because of the potential risk to local residents. Methods. This research was conducted to determine lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), and antimony (Sb) concentrations in soil and brown rice samples from three heavy metal mining areas in Hunan Province, central China, and to assess the potential health risks to local inhabitants. Results. Local soil contaminati...

  11. 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

  12. [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.

  13. Daily Dietary Selenium Intake in a High Selenium Area of Enshi, China

    Directory of Open Access Journals (Sweden)

    Xuebin Yin

    2013-03-01

    Full Text Available Enshi is a high selenium (Se region in Hubei, China, where human selenosis was observed between 1958 and 1963. This study investigated the daily dietary Se intake of residents in Shadi, a town located 72 km northeast of Enshi City, to assess the risk of human selenosis in the high Se area. Foods consumed typically by the local residents and their hair samples were analyzed for total Se concentration. Concentrations of Se in different diet categories were as follows: cereals: 0.96 ± 0.90 mg kg−1 DW in rice and 0.43 ± 0.55 mg kg−1 DW in corn; tuber: 0.28 ± 0.56 mg kg−1 in potato and 0.36 ± 0.12 mg kg−1 in sweet potato; vegetables: ranging from 0.23 ± 1.00 mg kg−1 in carrot to 1.57 ± 1.06 mg kg−1 in kidney bean; animal proteins: 1.99 ± 1.11 mg kg−1 in chicken and egg. Based on the food Se concentrations and the daily per-capita consumption, the estimated daily Se intake in Shadi was 550 ± 307 µg per capita. Moreover, the Se concentrations in the hairs of local adult residents were 3.13 ± 1.91 mg kg−1 (n = 122 and 2.21 ± 1.14 mg kg−1 (n = 122 for females and males, respectively, suggesting that females might be exposed to higher levels of Se from daily cooking. Although there was no human selenosis occurrence in recent years, the high level of the daily Se intake suggested that the potential risk of selenosis for local residents, especially females, might be a matter of concern.

  14. 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.

  15. Assessment of polycyclic aromatic hydrocarbons (PAHs) pollution in soil of suburban areas in Tianjin, China.

    Science.gov (United States)

    Lv, Jungang; Shi, Rongguang; Cai, Yanming; Liu, Yong

    2010-07-01

    Soil contamination with polycyclic aromatic hydrocarbons is an increasing problem and has aroused more and more concern in many countries, including China. In this study, representative soil samples (n = 87) of suburban areas in Tianjin (Xiqing, Dongli, Jinnan, Beichen) were evaluated for 16 polycyclic aromatic hydrocarbons. Surface soil samples were air-dried and sieved. Microwave assisted extraction was used for polycyclic aromatic hydrocarbons preparation prior to analysis with gas chromatography-mass spectrometry. The total concentrations of tested polycyclic aromatic hydrocarbons in Xiqing, Dongli, Jinnan, Beichen ranged in 58.5-2,748.3, 36.1-6,734.7, 58.5-4,502.5, 29.7-852.5 ng/g and the averages of total concentration of polycyclic aromatic hydrocarbons were 600.5, 933.6, 640.8, 257.3 ng/g, respectively. Spatial variation of polycyclic aromatic hydrocarbons in soil was illustrated; Pollution status and comparison to other cities were also investigated. Serious polycyclic aromatic hydrocarbons soil pollution was found in Dongli district, on the contrary, Bap in most sites in Beichen did not exceed relative standards and most sites in Beichen should be classified as non-contaminated soil. Principal component analysis was used to identify the possible sources of different districts. It turned out that coal combustion still was the most important sources in three districts except Beichen. Coking, traffic, cooking, biomass combustion also accounted for polycyclic aromatic hydrocarbons pollution to certain extent in different districts. These data can be further used to assess the health risk associated with soils polluted with polycyclic aromatic hydrocarbons and help local government find proper way to reduce polycyclic aromatic hydrocarbons pollution in soils.

  16. Polybrominated diphenyl ethers in water, sediment, soil, and biological samples from different industrial areas in Zhejiang, China

    International Nuclear Information System (INIS)

    Wang, Junxia; Lin, Zhenkun; Lin, Kuangfei; Wang, Chunyan; Zhang, Wei; Cui, Changyuan; Lin, Junda; Dong, Qiaoxiang; Huang, Changjiang

    2011-01-01

    Highlights: ► We examined PBDE concentrations in various matrices from different industrial areas. ► Elevated PBDE levels were found in areas with low-voltage electrical manufactures. ► Areas with e-waste recycling activities also had higher PBDE concentrations. ► PBDE content and composition in water samples varied from one area to another. ► 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.

  17. 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.

  18. Physical biological coupling in the Pearl River Estuary

    Science.gov (United States)

    Harrison, Paul J.; Yin, Kedong; Lee, J. H. W.; Gan, Jianping; Liu, Hongbin

    2008-07-01

    The Pearl River Estuary is a subtropical estuary and the second largest in China based on discharge volume from the Pearl River. Processes in the estuary vary spatially and temporally (wet vs dry season). In the dry season at the head of the estuary, hypoxic and nearly anoxic conditions occur and NH 4 reaches >600 μM, NO 3 is ˜300 μM and nitrite is ˜60 μM indicating that nitrification and denitrification may be important dry season processes in the region extending 40 km upstream of the Humen outlet. There are very few biological studies conducted in this upper section of the estuary in either the dry or wet seasons and hence there is a need for further research in this region of the river. In the wet season, the salinity wedge extends to the Hongqimen outlet and oxygen is low (35-80% saturation). Nitrate is ˜100 μM, silicate ˜140 μM; and phosphate is relatively low at ˜0.5 μM, yielding an N:P ratio up to ˜200:1 in summer. Nutrients decrease in the lower estuary and primary productivity may become potentially P-limited. Eutrophication is not as severe as one would expect from the nutrient inputs from the Pearl River and from Hong Kong's sewage discharge. This estuary shows a remarkable capacity to cope with excessive nutrients. Physical processes such as river discharge, tidal flushing, turbulent dispersion, wind-induced mixing, and estuarine circulation play an important role in controlling the production and accumulation of algal blooms and the potential occurrence of hypoxia. Superimposed on the physical processes of the estuary are the chemical and biological processes involved in the production of the bloom. For example, the 100N:1P ratio indicates that P potentially limits the amount of algal biomass (and potential biological oxygen demand) in summer. While extended periods of hypoxia are rare in Hong Kong waters, episodic events have been reported to occur during late summer due to factors such as low wind, high rainfall and river discharge which

  19. [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 (PM 10 ), fine particulate matter (PM 2.5 ), and nitric oxide (NO X ) (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 (PAir pollution 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.

  20. Accumulated phenocrysts and origin of feldspar porphyry in the Chanho area, western Yunnan, China

    Science.gov (United States)

    Xu, Xing-Wang; Jiang, Neng; Yang, Kai; Zhang, Bao-Lin; Liang, Guang-He; Mao, Qian; Li, Jin-Xiang; Du, Shi-Jun; Ma, Yu-Guang; Zhang, Yong; Qin, Ke-Zhang

    2009-12-01

    The No. 1 feldspar porphyry in the Chanho area, western Yunnan, China is characterized by the development of deformed glomeroporphyritic aggregates (GA) that contain diagnostic gravity settling textures. These textures include interlocking curved grain boundaries caused by compaction, bent twins, and arch-like structures. The GAs are accumulated phenocrysts (AP) and antecrysts. The unstable textural configurations such as extensive penetrative microfractures that are restricted within the AP and fractured cores of zircon grains, all suggest that the GAs are transported fragments of fractured cumulates that formed in a pre-emplacement magma chamber rather than form in situ at the current intrusion site. Compositions of minerals and melt as represented by different mineral aggregates formed at various stages of the magmatic process and their relations to the composition of porphyry bodies in the Chanho area indicate that the porphyritic melt for the No. 1 feldspar porphyry experienced two stages of melt mixing. Pulses of potassic melt flowed into a pre-emplacement magma chamber and mixed with crystallizing dioritic magma containing phenocrysts resulted in the first hybrid alkaline granitic melt. The mixing caused denser phenocrysts to settle and aggregate to form cumulates. Secondly, new dioritic melt was injected into the magma chamber and was mixed with the previously formed hybrid alkaline granitic melt to produce syenitic melt. Geochron data, including U-Pb age of zircon and 39Ar/ 40Ar age of hornblende and oligoclase phenocrysts, indicate that hornblende and oligoclase phenocrysts, as well as the core of zircon grains, were antecrysts that formed in a number of crystallization events between 36.3 and 32.78 Ma. Gravity settling of phenocrysts took place at about 33.1 to 32.78 Ma and melts with deformed GAs were transported upwards and emplaced into the current site at 32 Ma. Results of this research indicate that the No. 1 feldspar porphyry was a shallow

  1. 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.

  2. 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.

  3. Trophic flow structure of a neotropical estuary in northeastern Brazil and the comparison of ecosystem model indicators of estuaries

    Science.gov (United States)

    Lira, Alex; Angelini, Ronaldo; Le Loc'h, François; Ménard, Frédéric; Lacerda, Carlos; Frédou, Thierry; Lucena Frédou, Flávia

    2018-06-01

    We developed an Ecopath model for the Estuary of Sirinhaém River (SIR), a small-sized system surrounded by mangroves, subject to high impact, mainly by the sugar cane and other farming industries in order to describe the food web structure and trophic interactions. In addition, we compared our findings with those of 20 available Ecopath estuarine models for tropical, subtropical and temperate regions, aiming to synthesize the knowledge on trophic dynamics and provide a comprehensive analysis of the structures and functioning of estuaries. Our model consisted of 25 compartments and its indicators were within the expected range for estuarine areas around the world. The average trophic transfer efficiency for the entire system was 11.8%, similar to the theoretical value of 10%. The Keystone Index and MTI (Mixed Trophic Impact) analysis indicated that the snook (Centropomus undecimalis and Centropomus parallelus) and jack (Caranx latus and Caranx hippos) are considered as key resources in the system, revealing their high impact in the food web. Both groups have a high ecological and commercial relevance, despite the unregulated fisheries. As result of the comparison of ecosystem model indicators in estuaries, differences in the ecosystem structure from the low latitude zones (tropical estuaries) to the high latitude zones (temperate system) were noticed. The structure of temperate and sub-tropical estuaries is based on high flows of detritus and export, while tropical systems have high biomass, respiration and consumption rates. Higher values of System Omnivory Index (SOI) and Overhead (SO) were observed in the tropical and subtropical estuaries, denoting a more complex food chain. Globally, none of the estuarine models were classified as fully mature ecosystems, although the tropical ecosystems were considered more mature than the subtropical and temperate ecosystems. This study is an important contribution to the trophic modeling of estuaries, which may also help

  4. 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.

  5. Risk Assessment of Canine Distemper in the Distribution Area of Giant Panda in Sichuan, Shaanxi and Gansu Provinces, China

    Directory of Open Access Journals (Sweden)

    Weigeng Shao

    2017-11-01

    Full Text Available Giant panda is the world-class precious endangered species, facing the canine distemper and other important infectious diseases on its wild and captive population of a serious threat. In this study, we used MaxEnt model and combined with ArcGIS analysis to predict the potential risk of canine distemper to giant panda habitat in Sichuan, Gansu and Shaanxi Provinces, China. The results showed that 35.05% and 19.47% of the distribution areas of the giant pandas were in the high risk and medium risk of canine distemper, respectively. The canine distemper pose a great risk to the healthy survival of giant pandas in China. In future, epidemic prevention, vaccine development and application of wild animals should be enhanced so as to effectively protect the giant panda.

  6. Prospecting direction and favourable target areas for exploration of large and super-large uranium deposits in China

    International Nuclear Information System (INIS)

    Liu Xingzhong

    1993-01-01

    A host of large uranium deposits have been successively discovered abroad by means of geological exploration, metallogenetic model studies and the application of new geophysical and geochemical methods since 1970's. Thorough undertaking geological research relevant to prospecting for super large uranium deposits have attracted great attention of the worldwide geological circle. The important task for the vast numbers of uranium geological workers is to make an afford to discover more numerous large and super large uranium deposits in China. The author comprehensively analyses the regional geological setting and geological metallogenetic conditions for the super large uranium deposits in the world. Comparative studies have been undertaken and the prospecting direction and favourable target areas for the exploration of super large uranium deposits in China have been proposed

  7. Turning the Tide: Estuaries Shaped by Channel-Shoal Interactions, Eco-engineers and Inherited Landscapes

    Science.gov (United States)

    Kleinhans, M. G.; Braat, L.; Leuven, J.; Baar, A. W.; van der Vegt, M.; Van Maarseveen, M. C. G.; Markies, H.; Roosendaal, C.; van Eijk, A.

    2015-12-01

    Estuaries exhibit correlations between inlet dimensions, tidal prism and intertidal area, but to what extent estuary planform shape and shoal patterns resulted from biomorphological processes or from inherited conditions such as coastal plain and drowned valley dimensions remains unclear. We explore the hypothesis that mud flats and vegetation as a self-formed lateral confinement have effects analogous to that of river floodplain on braided versus meandering river patterns. Here we use the Delft3D numerical model and a novel tidal flume setup, the Metronome, to create estuaries from idealized initial conditions, with and without mud supply at the fluvial boundary. Experimental mud was simulated by crushed nutshell. Both the numerical and experimental estuaries were narrower with increasing mud, and had a lower degree of channel braiding. The experimental estuaries developed meanders at the river boundary with floodplain developing on the pointbar whereas cohesionless cases were more dynamic.

  8. Prevalence of Hypertension among Adults in Remote Rural Areas of Xinjiang, China

    Directory of Open Access Journals (Sweden)

    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

  9. 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...

  10. [Association between oxygen saturation and cognitive function in older adults from longevity areas in China].

    Science.gov (United States)

    Su, L Q; Yin, Z X; Xu, N; Lyu, Y B; Luo, J S; Shi, X M

    2016-07-06

    To explore the relationship between oxygen saturation (SpO2) and cognitive function in older adults from longevity areas in China. A total of 2 285 participants aged ≥65 years according to the 2012 Chinese Longitudinal Healthy Longevity Survey were included in this study. Among them, 1 739 participants aged 65-99 years were randomly selected, and 546 participants aged ≥100 years were totally involved. A standardized questionaire was used to collect the information of demographic characteristics, life styles, disease history, etc. Cognitive function was evaluated using the Mini Mental State Examination Scale. Arterial oxygen saturation and heart rate were measured by pulse oximetry. Differences in cognitive function between the low SpO2 group (cognitive function. The total score of cognitive function was 22.6±9.7 for the 1 922 participants in the normal SpO2 group, and 18.8 ± 11.0 for the 363 participants in the low SpO2 group (t=6.11, Pcognitive impairment in the low SpO2 group was 36.6% (n=133), and 22.9% (n=441) in the normal SpO2 group (χ(2)=30.44, Pcognitive impairment increased with each year of increased age (OR 1.07; (95% CI: 1.05-1.09), Pcognitive impairment (OR 1.64; (95% CI: 1.11-2.43), OR 1.73; (95% CI: 1.27-2.35), OR 3.54; (95% CI: 2.62-4.79), OR 1.38; (95% CI: 1.02-1.86), OR 2.05; (95% CI: 1.34-3.13), OR 1.83; (95% CI: 1.13-2.97), respectively, Page group showed that the association between SpO2 and cognitive impairment was most significant in participants aged ≥90 years (OR 1.58; (95% CI: 1.09-2.28), P=0.016). Low oxygen saturation was associated with higher risk of cognitive impairment in our population of elderly adults.

  11. 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.

  12. Dune Mining and the Nhlabane Estuary, South Africa: the Effect of a Dredger Crossing on the Zoobenthic Community

    International Nuclear Information System (INIS)

    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

  13. Waterfowl migration and distribution in North West estuaries. V. 2

    International Nuclear Information System (INIS)

    Clark, N.A.; Kirby, J.S.; Langston, R.H.W.; Donald, P.; Mawdesley, T.; Evans, J.

    1990-12-01

    Waterfowl populations may be affected by the proposed tidal barrage across the Mersey. A study was performed with three objectives: (1) to evaluate the patterns of usage of the intertidal flats of the Mersey estuary by waders and wildfowl and to establish which are the preferred areas; (2) to identify the places of origin and movement patterns of the populations of waders and wildfowl that visit the Mersey estuary; and (3) to evaluate evidence regarding the capacity of British estuaries to absorb waders and wildfowl populations which might be displaced by a Mersey Barrage. The text and tables of results of this study have already been presented in Volume 1. Volume 2 contains the figures describing the results (U.K)

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

    Science.gov (United States)

    2010-06-21

    ... Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request... interagency Estuary Habitat Restoration Council, is providing notice of the Council's intent to revise the ''Estuary Habitat Restoration Strategy'' and requesting public comments to guide its revision. DATES...

  17. Aspects of the ecology of meiofauna in Mngazana estuary, Transkei

    African Journals Online (AJOL)

    of Mngazana estuary were monitored over a period of 15 months from April 1977 .... Salinity was measured at 5 and 15 cm in the sandy area by withd rawing a few ... marina roots and a large number of fiddler crabs (Uca pugilator). The beach ...

  18. Changes in spatiotemporal land use patterns in selected hydrogeomorphic areas of China and the USA

    Science.gov (United States)

    Differences exist in land use/cover pattern and its change between the P. R. China and the USA. In order to describe those differences, land use changes in representative regions were quantitatively analyzed and compared. Xiamen City, Changzhutan region and Liupan Mountains regions were selected to ...

  19. Quartz in ash, and air in a high lung cancer incidence area in China

    NARCIS (Netherlands)

    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

    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

  20. Dynamics of intertidal flats in the Loire estuary

    Science.gov (United States)

    Kervella, Stephane; Sottolichio, Aldo; Bertier, Christine

    2014-05-01

    Tidal flats form at the edges of many tidal estuaries, and are found in broad climatic regions. Their evolution plays a fundamental role in maintaining the morphodynamic equilibrium of an estuary. The Loire estuary is one of the largest macrotidal systems of the french atlantic coast. Since 200 years, its geometry has been drastically modified through channeling, deepening, embanking, infilling of secondary channels, etc. These works altered many intertidal areas. In the recent years, efforts for the rectification of the morphology have been made in order to restore the ecology of the estuary. In this context, it is crucial to better understand the dynamics of intertidal flats, still poorly understood in this estuary. The aim of this work is to analyse a series of original observations conducted for the first time in two intertidal flats of the central Lore estuary between 2008 and 2010. The tidal flats are situated in the northern bank, at 12 and 17 km upstream from the mouth respectively. Six Altus altimeters were deployed at two cross shore transects, measuring continuously and at a high-frequency bed altimetry and water level, providing information on tide and waves. At the semi-diurnal tidal scale, the surficial sediment of intertidal flats is permanently mobilized. Altimetry variations are low, and their amplitude varies as a function of tides and river flow. At the scale of several months, the sedimentation is controlled by the position of the turbidity maximum (and therefore by the river flow) and also by the tidal amplitude. During low river flow periods, altimetry variations are only due to tidal cycles. During decaying tides, suspended sediment settle mainly on the lower part of the tidal flats, forming fluid mud layers of several cm thick, which can consolidate rapidly; under rising tides, the increasing of tidal currents promotes erosion. During periods of high river flow, the turbidity maximum shifts to the lower estuary. The higher suspended sediment

  1. 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.

  2. 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.

  3. Nationwide Distribution of Per- and Polyfluoroalkyl Substances in Outdoor Dust in Mainland China From Eastern to Western Areas.

    Science.gov (United States)

    Yao, Yiming; Sun, Hongwen; Gan, Zhiwei; Hu, Hongwei; Zhao, Yangyang; Chang, Shuai; Zhou, Qixing

    2016-04-05

    From eastern to western areas, per- and polyfluoroalkyl substances (PFASs) were detected at substantial levels in the outdoor dust across mainland China. Urban samples generally showed higher levels compared with those of rural samples. Compared with neutral PFASs, ionizable PFASs (C4-C12 perfluoroalkyl carboxylic acids and C4/C8 perfluoroalkyl sulfonic acids) were more abundant, with the highest total concentration up to 1.6 × 10(2) ng/g and perfluorooctanoic acid (PFOA) being a predominant analogue. Fluorotelomer alcohols (FTOHs) and polyfluoroalkyl phosphoric acid diesters (DiPAPs) were both detected in most samples with total concentrations of 0.12-32 and 0.030-20 ng/g, respectively. Perfluorooctane sulfonamidoethanols/sulfonamides (FOSE/As) were detected at low frequencies (eastern plain areas were characterized by a higher contribution of long-chain ionizable PFASs; whereas the western high plateau areas were characterized by the dominating contribution of short-chain analogues. The difference suggests that the long-range atmospheric transport potential of PFASs from source regions to the inland is probably limited by the increase in altitude, and different sources from adjacent regions may influence the western border area of China.

  4. Modelling extreme climatic events in Guadalquivir Estuary ( Spain)

    Science.gov (United States)

    Delgado, Juan; Moreno-Navas, Juan; Pulido, Antoine; García-Lafuente, Juan; Calero Quesada, Maria C.; García, Rodrigo

    2017-04-01

    Extreme climatic events, such as heat waves and severe storms are predicted to increase in frequency and magnitude as a consequence of global warming but their socio-ecological effects are poorly understood, particularly in estuarine ecosystems. The Guadalquivir Estuary has been anthropologically modified several times, the original salt marshes have been transformed to grow rice and cotton and approximately one-fourth of the total surface of the estuary is now part of two protected areas, one of them is a UNESCO, MAB Biosphere Reserve. The climatic events are most likely to affect Europe in forthcoming decades and a further understanding how these climatic disturbances drive abrupt changes in the Guadalquivir estuary is needed. A barotropic model has been developed to study how severe storm events affects the estuary by conducting paired control and climate-events simulations. The changes in the local wind and atmospheric pressure conditions in the estuary have been studied in detail and several scenarios are obtained by running the model under control and real storm conditions. The model output has been validated with in situ water elevation and good agreement between modelled and real measurements have been obtained. Our preliminary results show that the model demonstrated the capability describe of the tide-surge levels in the estuary, opening the possibility to study the interaction between climatic events and the port operations and food production activities. The barotropic hydrodynamic model provide spatially explicit information on the key variables governing the tide dynamics of estuarine areas under severe climatic scenarios . The numerical model will be a powerful tool in future climate change mitigation and adaptation programs in a complex socio-ecological system.

  5. Frequent Questions about Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  6. Downloading and Installing Estuary Data Mapper (EDM)

    Science.gov (United States)

    Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

  7. Influence of estuaries on shelf foraminiferal species

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    Dabhol-bhatkal stretch of the west coast of India is marked by a number of estuaries. Cavarotalia annectens is selected to monitor the influence of these estuaries on the inner shelf foraminiferal fauna. The percentage distribution of this species...

  8. SANCOR estuaries programme 1982-1986

    CSIR Research Space (South Africa)

    SANCOR

    1983-02-01

    Full Text Available , such research will also aid in the rational management of estuaries. Estuaries on which research should be concentrated are identified and guidelines are given for project proposals and reporting....

  9. Nutrients in some estuaries of Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Venugopal, P.; Remani, K.N.; Zacharias, D.; Unnithan, R.V.

    phosphate and ammonia were high at Kallai compared to other three estuaries. All the estuaries showed an increase in nitrate content during monsoon. Nitrite values were high in postmonsoon. Ammonia levels were generally high except at Korapuzha. Nutrient...

  10. 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

  11. PARASITIC AND SYMBIONIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) COLLECTED FROM THE CALOOSAHATCHEE RIVER AND ESTUARY, FLORIDA

    Science.gov (United States)

    Studies of oysters, Crassostrea virginica, collected from ten sites in the Caloosahatchee River and Estuary, Florida, revealed a varied parasite and symbiotic fauna that have never been reported from this area. Organisms observed included ovacystis virus infecting gametes...

  12. [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.

  13. Geothermal area detection using Landsat ETM+ thermal infrared data and its mechanistic analysis—A case study in Tengchong, China

    Science.gov (United States)

    Qin, Qiming; Zhang, Ning; Nan, Peng; Chai, Leilei

    2011-08-01

    Thermal infrared (TIR) remote sensing is an important technique in the exploration of geothermal resources. In this study, a geothermal survey is conducted in Tengchong area of Yunnan province in China using TIR data from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) sensor. Based on radiometric calibration, atmospheric correction and emissivity calculation, a simple but efficient single channel algorithm with acceptable precision is applied to retrieve the land surface temperature (LST) of study area. The LST anomalous areas with temperature about 4-10 K higher than background area are discovered. Four geothermal areas are identified with the discussion of geothermal mechanism and the further analysis of regional geologic structure. The research reveals that the distribution of geothermal areas is consistent with the fault development in study area. Magmatism contributes abundant thermal source to study area and the faults provide thermal channels for heat transfer from interior earth to land surface and facilitate the present of geothermal anomalies. Finally, we conclude that TIR remote sensing is a cost-effective technique to detect LST anomalies. Combining TIR remote sensing with geological analysis and the understanding of geothermal mechanism is an accurate and efficient approach to geothermal area detection.

  14. Assessing the conditions favorable for the occurrence of gas hydrate in the Tuonamu area Qiangtang basin, Qinghai–Tibetan, China

    International Nuclear Information System (INIS)

    He Jianglin; Wang Jian; Fu Xiugen; Zheng Chenggang; Chen Yanting

    2012-01-01

    Highlights: ► This is a pioneer research on the exploration of gas hydrate in Qiangtang basin. ► The factors influencing the stable of gas hydrate in Tuonamu area were studied. ► Simulation shows that gas hydrate stable zone is about 300 m thick in target area. ► Source condition is the key factor for the formation of gas hydrate in this area. ► The areas around the deeper faults are favorable targets for gas hydrate. - Abstract: Qiangtang basin, which is located in the largest continuous permafrost area in Qinghai–Tibetan Plateau, is expected to be a strategic area of gas hydrate exploitation in China. However, relatively little work has been done on the exploration of gas hydrate in this area. In this work, we evaluated the factors controlling the formation of gas hydrate in the Tuonamu area and provided a preliminary insight into gas hydrate distribution in it on the basis of the core samples, seismic data and laboratory analysis. It can be concluded that the source rock in the deeper formation would be dominant thermogenic source for the formation of gas hydrate in Tuonamu area. The thickness of gas hydrate stable zone in this area is about 300 m. The gas hydrate in the area most probably is in the form of gas-hydrate-water. The source condition is the key factor for the formation of gas hydrate and the gas hydrate layer would be mainly present in the form of interlayer in this area. The areas around the deeper faults are the favorable targets for the exploration of gas hydrate in the Tuonamu area.

  15. 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.

  16. Leven estuary project. Fisheries Department final report

    OpenAIRE

    Bayliss, B.D.

    1997-01-01

    This is the report on the Leven estuary project: Fisheries Department final report produced by the Environment Agency North West in 1997. This report contains information about Leven estuary, river Leven catchment, river Crake catchment and the Ulverston Discharges. The Leven estuary is characterised by being very shallow, and shares the extremely variable tides and currents that characterize the whole of Morecambe Bay. There was little detailed knowledge of the impact on the Leven estuary, a...

  17. Cloud residues and interstitial aerosols from non-precipitating clouds over an industrial and urban area in northern China

    Science.gov (United States)

    Li, Weijun; Li, Peiren; Sun, Guode; Zhou, Shengzhen; Yuan, Qi; Wang, Wenxing

    2011-05-01

    Most studies of aerosol-cloud interactions have been conducted in remote locations; few have investigated the characterization of cloud condensation nuclei (CCN) over highly polluted urban and industrial areas. The present work, based on samples collected at Mt. Tai, a site in northern China affected by nearby urban and industrial air pollutant emissions, illuminates CCN properties in a polluted atmosphere. High-resolution transmission electron microscopy (TEM) was used to obtain the size, composition, and mixing state of individual cloud residues and interstitial aerosols. Most of the cloud residues displayed distinct rims which were found to consist of soluble organic matter (OM). Nearly all (91.7%) cloud residues were attributed to sulfate-related salts (the remainder was mostly coarse crustal dust particles with nitrate coatings). Half the salt particles were internally mixed with two or more refractory particles (e.g., soot, fly ash, crustal dust, CaSO 4, and OM). A comparison between cloud residues and interstitial particles shows that the former contained more salts and were of larger particle size than the latter. In addition, a somewhat high number scavenging ratio of 0.54 was observed during cloud formation. Therefore, the mixtures of salts with OMs account for most of the cloud-nucleating ability of the entire aerosol population in the polluted air of northern China. We advocate that both size and composition - the two influential, controlling factors for aerosol activation - should be built into all regional climate models of China.

  18. Land Use Changes of an Aeolian-Loessial Soil Area in Northwest China: Implications for Ecological Restoration

    Institute of Scientific and Technical Information of China (English)

    CHEN Yu-Fu; LIU Yan-Sui; WANG Jing; YAN Jian-Ping; GUO Xu-Dong

    2009-01-01

    China has experienced dramatic land use changes over recent decades,with marked environmental and socio-economic consequences.Hcngshan County,located in the aeolian-loessial area of Northwest China,was investigated to illustrate land use changes and their implications for environmental and long-term rural economic development.The farmland in Hengshan County significantly decreased during 1990-2003,whereas forest land and grassland increased.The conversion rates of farmland,orchard land,forest land and construction land varied markedly among different periods:1990-1995,1995-2000 and 2000-2003.Conversion of orchard land,grassland and construction land was dominant in 1990-1995,whereas the conversion of farmland to forest land mainly occurred in 2000-2003.The results suggested a profound transition in institutional policy and political economy of land management,including implementation of integrated soil erosion control projects,adoption of a market-oriented economy and the 'Grain-for-Green' policy,during this period in China.To achieve long-term sustainable land use in Hengshan County,efforts should aim at increasing off-farm income of rural families as well as establishing land-economizing mechanisms to promote land productivity,in addition to conservation measures.

  19. 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.

  20. 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.

  1. Indian estuaries: Dynamics, ecosystems, and threats

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.

    the tide pulls the mixed water out of the estuary through its mouth. Different processes within an estuary contribute to mixing of the two waters, the important among these in the Mandovi estuary are: influence of the tide on the advective field within...

  2. 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.

  3. Nutrient input through submarine groundwater discharge in two major Chinese estuaries: the Pearl River Estuary and the Changjiang River Estuary

    Science.gov (United States)

    Liu, Jianan; Du, Jinzhou; Wu, Ying; Liu, Sumei

    2018-04-01

    In this study, we used a 224Ra mass balance model to evaluate the importance of submarine groundwater discharge (SGD) for the budgets of biogenic elements in two major Chinese estuaries: the Pearl River Estuary (PRE) and the Changjiang River Estuary (CRE). The apparent water age in the PRE was estimated to be 4.8 ± 1.1 days in the dry season and 1.8 ± 0.6 days in the wet season using a physical model based on the tidal prism. In the dry season, the water age in the CRE was estimated to be 11.7 ± 3.0 days using the 224Ra/223Ra activities ratios apparent age model. By applying the 224Ra mass balance model, we obtained calculations of the SGD flow in the PRE of (4.5-10) × 108 m3 d-1 (0.23-0.50 m3 m-2 d-1) and (1.2-2.7) × 108 m3 d-1 (0.06-0.14 m3 m-2 d-1) in the dry season and wet season, respectively, and the estimated SGD flux was (4.6-11) × 109 m3 d-1 (0.18-0.45 m3 m-2 d-1) in the dry season of the CRE. In comparison with the nutrient fluxes from the rivers, the SGD-derived nutrient fluxes may play a vital role in controlling the nutrient budgets and stoichiometry in the study areas. The large amount of dissolved inorganic nitrogen and phosphorus fluxes together with high N: P ratios into the PRE and CRE would potentially contribute to eutrophication and the occurrence of red tides along the adjacent waters.

  4. Distribution of atmospheric particulate matter (PM) in rural field, rural village and urban areas of northern China

    International Nuclear Information System (INIS)

    Li, Wei; Wang, Chen; Wang, Hongqijie; Chen, Jiwei; Yuan, Chenyi; Li, Tongchao; Wang, Wentao; Shen, Huizhong; Huang, Ye; Wang, Rong; Wang, Bin; Zhang, Yanyan; Chen, Han; Chen, Yuanchen; Tang, Jianhui; Wang, Xilong; Liu, Junfeng; Coveney, Raymond M.; Tao, Shu

    2014-01-01

    Atmospheric PM 10 were measured for 12 months at 18 sites along a 2500 km profile across northern China. Annual mean PM 10 concentrations in urban, rural village, and rural field sites were 180 ± 171, 182 ± 154, and 128 ± 89 μg/m 3 , respectively. The similarities in PM 10 concentrations between urban and rural village sites suggest that strong localized emissions and severe contamination in rural residential areas are derived from solid fuels combustion in households. High PM 10 concentrations in Wuwei and Taiyuan were caused by either sandstorms or industrial activities. Relatively low PM 10 concentrations were observed in coastal areas of Dalian and Yantai. Particulate air pollution was much higher in winter and spring than in summer and fall. Multiple regression analysis indicates that 35% of the total variance can be attributed to sandstorms, precipitation and residential energy consumption. Over 40% of the measurements in both urban and rural village areas exceeded the national ambient air quality standard. Highlights: • Spatial distribution of PM 10 concentrations in northern China was investigated. • High levels of PM 10 in rural villages were caused by solid fuel emission. • A strong seasonality with high levels of PM 10 in spring and winter was observed. • Influence of sandstorm, energy consumption, and precipitation were evaluated. • Over 40% of the measurements exceeded the national ambient air quality standard. -- PM 10 concentrations in rural villages of China were comparable with those in the cities, indicating severe air pollution in the rural villages caused by coal and biofuel combustion

  5. Assessment of iodine status in children, adults, pregnant women and lactating women in iodine-replete areas of China.

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. Geological Factors and Reservoir Properties Affecting the Gas Content of Coal Seams in the Gujiao Area, Northwest Qinshui Basin, China

    Directory of Open Access Journals (Sweden)

    Zhuo Zou

    2018-04-01

    Full Text Available Coalbed methane (CBM well drilling and logging data together with geological data were adopted to provide insights into controlling mechanism of gas content in major coal seams and establish gas accumulation models in the Gujiao area, Northwest Qinshui Basin, China. Gas content of targeted coals is various in the Gujiao area with their burial depth ranging from 295 to 859 m. Highly variable gas content of coals should be derived from the differences among tectonism, magmatism, hydrodynamism, and sedimentation. Gas content preserved in the Gujiao area is divided into two parts by the geological structure. Gas tends to accumulate in the groundwater stagnant zone with a total dissolved solids (TDS value of 1300–1700 ppm due to water pressure in the Gujiao area. Reservoir properties including moisture content, minerals, and pore structure also significantly result in gas content variability. Subsequently, the gray correlation statistic method was adopted to determine the most important factors controlling gas content. Coal metamorphism and geological structure had marked control on gas content for the targeted coals. Finally, the favorable CBM exploitation areas were comprehensively evaluated in the Gujiao area. The results showed that the most favorable CBM exploitation areas were in the mid-south part of the Gujiao area (Block I.

  8. LONG-TERM REMOTE MONITORING OF THREE TYPICAL LAKE AREA VARIATIONS IN THE NORTHWEST CHINA OVER THE PAST 40 YEARS

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2018-04-01

    Full Text Available water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI and Modified Normalized Difference Water Index (MNDWI were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

  9. Long-Term Remote Monitoring of Three Typical Lake Area Variations in the Northwest China Over the Past 40 Years

    Science.gov (United States)

    Liu, Y.; Lu, Y.; Li, Y.; Yue, H.

    2018-04-01

    water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

  10. Delineating Urban Fringe Area by Land Cover Information Entropy—An Empirical Study of Guangzhou-Foshan Metropolitan Area, China

    Directory of Open Access Journals (Sweden)

    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.

  11. Multi-timescale sediment responses across a human impacted river-estuary system

    Science.gov (United States)

    Chen, Yining; Chen, Nengwang; Li, Yan; Hong, Huasheng

    2018-05-01

    Hydrological processes regulating sediment transport from land to sea have been widely studied. However, anthropogenic factors controlling the river flow-sediment regime and subsequent response of the estuary are still poorly understood. Here we conducted a multi-timescale analysis on flow and sediment discharges during the period 1967-2014 for the two tributaries of the Jiulong River in Southeast China. The long-term flow-sediment relationship remained linear in the North River throughout the period, while the linearity showed a remarkable change after 1995 in the West River, largely due to construction of dams and reservoirs in the upland watershed. Over short timescales, rainstorm events caused the changes of suspended sediment concentration (SSC) in the rivers. Regression analysis using synchronous SSC data in a wet season (2009) revealed a delayed response (average 5 days) of the estuary to river input, and a box-model analysis established a quantitative relationship to further describe the response of the estuary to the river sediment input over multiple timescales. The short-term response is determined by both the vertical SSC-salinity changes and the sediment trapping rate in the estuary. However, over the long term, the reduction of riverine sediment yield increased marine sediments trapped into the estuary. The results of this study indicate that human activities (e.g., dams) have substantially altered sediment delivery patterns and river-estuary interactions at multiple timescales.

  12. The gender gap among school children in poor rural areas of western China: evidence from a multi-province dataset.

    Science.gov (United States)

    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.

  13. 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.

  14. 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.

  15. 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.

  16. Occurrence of perfluorinated alkyl substances in sediment from estuarine and coastal areas of the East China Sea.

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    Yan, Hong; Zhang, Chaojie; Zhou, Qi; Yang, Shouye

    2015-02-01

    Perfluorinated alkyl substances (PFAS) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The occurrence and spatial variation of PFAS were investigated through collection of riverine and marine sediments from estuarine and coastal areas of the East China Sea. Among them, perfluorooctanesulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), and perfluorooctanoic acid (PFOA) were the three predominant PFAS with the highest detection frequencies in the sediment. PFOS up to 32.4 ng g(-1) dw and ∑PFAS up to 34.8 ng g(-1) dw were detected. Compared to other studies, high levels of PFOS were found in sediments from the East China Sea. PFHpA was also detected at higher frequency and concentration than those of other studies, which suggests point sources in this area. Concentrations of PFAS in riverine sediments were much higher than in marine sediments. Analysis of spatial variations presented overall decreasing trends of PFAS from inshore to offshore areas.

  17. [Species-area and species-abundance relationships of arthropod community in various vegetation restoration areas in Zhifanggou watershed, Shaanxi province of Northwest China].

    Science.gov (United States)

    Zhang, Feng; Hong, Bo; Li, Ying-Mei; Chen, Zhi-Jie; Zhang, Shu-Lian; Zhao, Hui-Yan

    2013-02-01

    Taking the Zhifanggou watershed in Ansai, Shaanxi Province of Northwest China as a study unit, an investigation on the arthropods in 8 forest stands was conducted from 2006 to 2008, with the species-area and species-abundance relationships of the arthropods in these stands analyzed by various mathematical models. In these forest stands, the species-area relationship of the arthropods accorded with the formula S= CAm With the increase of investigation area, the species number approached to a constant, and the corresponding smallest investigation area was in the order of natural bush > natural forest > Populus davidiana+Robinia pseudoacacia forest > Hippaphae rhamnoides +Caragana mocrophylla forest> Periploca sepium forest > Hippaphae rhamnoides forest > Robinia pseudoacacia forest > Caragana mocrophylla forest, indicating that the more complex the stands, the larger the minimum area needed to be investigated. Based on sampling investigation, the species-abundance models of the arthropods in various stands were established. Lognormal distribution model (LN) was most suitable to fit the arthropod community in natural recovery stands, suggesting that in the arthropod community, there were more species with medial individual amount and fewer abundant species and rare species, and no obvious dominant species. LogCauchy distribution model (LC) was most suitable to fit the arthropod community in mixed and pure stands. As compared with natural recovery stand, mixed and pure stands had more abundant and rare species, and more dominant species.

  18. [Impacts of land use change on ecosystem services in the agricultural area of North China Plain: A case study of Shangqiu City, Henan Province, China.

    Science.gov (United States)

    Liu, Ya Ru; Wang, Cong; Yan, Li Jiao

    2018-05-01

    Under the rapid urbanization, quantitatively assessing the impacts of land use and cover change (LUCC) on ecosystem service is of great significance for regional ecological environment construction. Based on the land use maps of Shangqiu City (as the typical agricultural area of North China Plain) in the year of 1990, 2005 and 2015, the spatio-temporal dynamics of land use and ecosystem service were analyzed, and the impacts of LUCC on ecosystem services was quantified with the impact assessment model. The results showed that, from 1990 to 2015, farmland and construction land area, which covered more than 95% of the total area of the research area, changed the most in quantity as -104.38 and 201.59 km 2 respectively, while forestland, grassland and water area changed the most by 79.3%, -73.7% and -24.2%, respectively. The total value of ecosystem service continuously decreased by 1.005 billion yuan, among which the value of hydrolo-gical regulation service suffered the most. The value of ecosystem service (ESV) presented an increasing trend in the west and a decreasing trend in the east. Extending from the center of the city to the outside, the value of ecosystem services was "high-low-high" in the east to west direction. The rate of farmland and water