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Spatial distribution, seasonal variation and regionalization of PM_(2.5) concentrations in China

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Science China Chemistry 2015年第9期58卷 1435-1443页

作者： Shuai Wang Guogang Li Zhengyu Gong Li Du Qingtao Zhou Xiaoyan Meng Shuyan Xie Lei Zhou Department of Ambient Air Quality monitoring China National Environmental Monitoring Center Civil and environmental Engineering Syracuse University

In order to provide scientific support to policy makers in the regulation of PM2.5 pollution in China, it is important to accurately assess the current status, spatiotemporal characteristics and regionalization data for this air pollutant. An analysis of the pollution status of PM2.5 was conducted using daily averaged mass concentration data recorded in 74 cities in 2013 and 161 cities in 2014. The rotated empirical orthogonal function(REOF) method was applied to analyze this data. Results showed that the average annual PM2.5 concentration in urban areas of China is 62.2±21.5 ?g/m3, and that the distribution is spatially heterogeneous. The North China Plain, middle and lower Yangtze River Plain, Sichuan Basin and Guanzhong Plain had relatively high annual PM2.5 concentrations compared with the southeast coastal region, the Tibetan Plateau and the Yungui Plateau. PM2.5 mass concentrations tended to be higher in winter than in summer, however, the data for many cities showed a small peak in concentrations from May to July. An analysis of the spatial correlation of PM2.5 indicated a significant influence of topographic conditions. A lower correlation was observed where terrain features varied greatly. Based on the results of the REOF analysis and topographic characteristics, ten regions were identified in mid-eastern China, which could be considered as basic pollution prevention divisions for PM2.5; these include the North China Plain region, Pearl River Delta region, Jianghuai Plain region, middle Yangtze River Plain region, Northeast Plain region, Jiangnan coastal region, Sichuan Basin region, Qiantao Plain region, Guanzhong-Central Plain region and Yungui Plateau region. Seasonal variations in the regionalization data were observed, especially for the North China Plain and Pearl River Delta regions. Among the ten regions identified in this study, the North China Plain, Guanzhong-Central Plain, middle Yangtze River Plain and Jianghuai Plain had relatively high PM2.5

关键词： PM2.5 spatiotemporal variability REOF spatial regionalization

Revisiting the seasonal wave height variability in the South China Sea with merged satellite altimetry observations

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Acta Oceanologica Sinica 2017年第11期36卷 38-50页

作者： SU Hui WEI Chunlei JIANG Shaocai LI Peiliang ZHAI Fangguo Central Marine environmental monitoring Station of Xiamen East China Sea BranchState Oceanic Administration Beihai Marine environmental monitoring Center South China Sea BranchState Oceanic Administration College of Oceanic and Atmospheric Sciences Ocean University of China

The seasonal variability of the significant wave height（SWH） in the South China Sea（SCS） is investigated using the most up-to-date gridded daily altimeter data for the period of September 2009 to August 2015. The results indicate that the SWH shows a uniform seasonal variation in the whole SCS, with its maxima occurring in December/January and minima in May. Throughout the year, the SWH in the SCS is the largest around Luzon Strait（LS） and then gradually decreases southward across the basin. The surface wind speed has a similar seasonal variation, but with different spatial distributions in most months of the year. Further analysis indicates that the observed SWH variations are dominated by swell. The wind sea height, however, is much smaller. It is the the largest in two regions southwest of Taiwan Island and southeast of Vietnam Coast during the northeasterly monsoon, while the largest in the central/southern SCS during the southwesterly monsoon. The extreme wave condition also experiences a significant seasonal variation. In most regions of the northern and central SCS, the maxima of the 99 th percentile SWH that are larger than the SWH theoretically calculated with the wind speed for the fully developed seas mainly appear in August–November, closely related to strong tropical cyclone *** with previous studies, it is also implied that the wave climate in the Pacific Ocean plays an important role in the wave climate variations in the SCS.

关键词： significant wave height seasonal variability South China Sea satellite observations

Object-based image analysis for mapping geomorphic zones of coral reefs in the Xisha Islands, China

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Acta Oceanologica Sinica 2016年第12期35卷 19-27页

作者： XU Jingping ZHAO Jianhua LI Fang WANG Lin SONG Derui WEN Shiyong WANG Fei GAO Ning National Marine environmental monitoring Center

Mapping regional spatial patterns of coral reef geomorphology provides the primary information to understand the constructive processes in the reef ecosystem. However, this work is challenged by the pixel-based image classification method for its comparatively low accuracy. In this paper, an object-based image analysis(OBIA)method was presented to map intra-reef geomorphology of coral reefs in the Xisha Islands, China using Landsat 8satellite imagery. Following the work of the Millennium Coral Reef Mapping Project, a regional reef class hierarchy with ten geomorphic classes was first defined. Then, incorporating the hierarchical concept and integrating the spectral and additional spatial information such as context, shape and contextual relationships, a large-scale geomorphic map was produced by OBIA with accuracies generally more than 80%. Although the robustness of OBIA has been validated in the applications of coral reef mapping from individual reefs to reef system in this paper, further work is still required to improve its transferability.

关键词： object-based Landsat 8 geomorphic mapping Xisha Islands

Evaluating the performances of accelerated-solvent extraction, microwave-assisted extraction, and ultrasonic-assisted extraction for determining PCBs, HCHs and DDTs in sediments

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Chinese Journal of Oceanology and Limnology 2011年第5期29卷 1103-1112页

作者：张蓬葛林科周传光姚子伟 National Marine environmental monitoring Center

Three extraction techniques have been recently used for the quantitative extraction of semi-volatile organic pollutants in sediments, i.e. accelerated solvent extraction （ASE）, microwave assisted extraction （MAE） and ultrasonic assisted extraction （UAE）. However, their extraction efficiencies have rarely been quantitatively compared using rigorous mathematical methods. In this paper, one-way analysis of variance （ANOVA） was employed to evaluate the performance of ASE, MAE and UAE in the overall extraction of PCBs, DDTs and HCHs by analysis of their recoveries from the Standard Reference Material IAEA-417, a sediment sample certified by many international laboratories. Conclusions were drawn at a significance level of P〈 0.05. No significant differences were found among the mean values for method recoveries using ASE, MAE and UAE. The mean values for real recoveries using ASE and MAE were nearly identical, but the real recovery using UAE was much lower. The concentrations of all PCBs, DDTs and HCHs except for CB52 and o,p＇-DDT using UAE were the lowest. Comparing the results obtained using ASE with MAE, the concentrations of CB28, CB52, CB138, ct-HCH, [3-HCH, p,p＇-DDE and p,p＇-DDD were nearly identical, while the concentrations of other compounds were significantly different. Based on the low recoveries, it was concluded that UAE is a relatively inefficient extraction method, while ASE and MAE are equivalent methods. Taking into consideration the relative standard deviation （RSD） values, solvent volume, extraction time, and purchasing costs of the apparatus, MAE was considered superior to ASE for extraction of PCBs, DDTs and HCHs.

关键词： extraction technique sediment PCB HCH DDT

Spatio-temporal Change and Carrying Capacity Evaluation of Human Coastal Utilization in Liaodong Bay,China from 1993 to 2015

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Chinese Geographical Science 2019年第3期29卷 463-473页

作者： XU Jingping LI Fang SUO Anning ZHAO Jianhua SU Xiu National Marine environmental monitoring Center

In China, promoting the development of coastal areas has been included in a series of national strategic development *** the same time, many marine environmental problems have been associated with the rapid development of coastal sea use. In order to quantify the impact of human activities on the coast, the characteristics of coastlines and near-shore sea use of Liaodong Bay, Northeast China, were first classified using multi-source, remotely sensed imagery using automatic or semi-automatic extraction methods for five periods between 1993 and 2015. Sea use dynamics and coastline dynamics resulting from human activates were analyzed. Results showed a significant trend of continuous growth in sea use and a progressive increase in the total length of artificial coastline, but a noticeable loss of natural coastline during the five periods. Reclaimed land and enclosed areas were the main types of sea use. Most coastal human activities were distributed in the northern part of the bay. In recent years, rapid industrialization and urbanization in China's coastal areas have promoted large-scale land reclamation. Accordingly, the observed coastline changes during each period had a close relationship with coastal development and sea area utilization. Based on marine functional zoning(MFZ), the sea use carrying capacity was evaluated by means of indexes to describe human exploitation of the marine and coastal environments in the bay. This showed that the intensity of coastal utilization in Liaodong Bay has increased year-on-year. Sea use carrying capacity reached a ‘critically loaded'state by 2008 and was ‘overloaded' by 2015.

关键词： carrying capacity sea use coastline Liaodong Bay remote sensing

Atmospheric concentration characteristics and gas/particle partitioning of PCBs from the North Pacific to the Arctic Ocean

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Acta Oceanologica Sinica 2014年第9期33卷 32-39页

作者： WANG Zhen NA Guangshui GAO Hui WANG Yanjie YAO Ziwei National Marine environmental monitoring Center

Polychlorinated biphenyls （PCBs） were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteris-tics of PCBs and their gas/particle partitioning. The mean concentration of 26 PCBs （vapor plus particulate phase）（∑PCBs） was 19.116 pg/m^3with a standard deviation of 13.833 pg/m^3. Three most abundant conge-ners were CB-28, -52 and -77, accounting for 43.0% to∑PCBs. The predominance of vapor PCBs （79.0% to∑PCBs） in the atmosphere was observed.∑PCBs were negative correlated with the latitudes and inverse of the absolute temperature （1/T）. The significant correlation for most congeners was also observed between the logarithm of gas/particle partition coefficient （logKp） and 1/T. Shallower slopes （from ∑0.15 to ∑0.46, average ∑0.27） were measured from the regression of the logarithm of sub-cooled liquid vapor pressures （logpoL） and logKP for all samples. The difference of the slopes and intercepts among samples was insignifi-cant （p〉0.1）, implying adsorption and/or absorption processes and the aerosol composition did not differ significantly among different samples. By comparing three models, the J-P adsorption model, the octanol/air partition coefficient （KOA） based model and the soot-air model, the gas/particle partitioning of PCBs in the Arctic atmosphere was simulated more precisely by the soot-air model, and the adsorption onto el-emental carbon is more sensitive than the absorption into organic matters of aerosols, especially for low-chlorinated PCB congeners.

关键词： PCBs gas/particle partitioning Arctic Ocean soot-air model semi-volatile organic compounds

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Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006–2011

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Journal of environmental Sciences 2014年第1期26卷 23-36页

作者： Jinfeng Li Keding Lu Wei Lv Jun Li Liuju Zhong Yubo Ou Duohong Chen Xin Huang Yuanhang Zhang College of environmental Sciences Engineering Peking University Guangdong Provincial environmental monitoring Center

Based on the observation by a Regional Air Quality monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations （non-urban） and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime （13%/yr referred to 2006 level） was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds （VOC）-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.

关键词： O3 cluster analysis temporal variation smog production algorithm Pearl River Delta

Depth profiles of lithogenic and anthropogenic mercury in the sediments from Thane Creek,Mumbai,India

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International Journal of Sediment Research 2014年第3期29卷 431-439页

作者： S.K.SAHU R.C.BHANGARE M.TIWARI P.Y.AJMAL G.G.PANDIT environmental monitoring and Assessment Section Bhabha Atomic Research Centre environmental.monitoring and Assessment Section Bhabha Atomic Research Centre

Mercury(Hg) is well known as one of the most toxic elements to *** coastal environments adjacent to industrial areas are reported to often be contaminated with *** becomes more toxic in the form of methylmercury(Me-Hg) which is converted from inorganic mercury in aqueous systems by microbial activity and can bio-magnify through the food chain.A simple method for the determination of total mercury and methylmercury in sediments was optimized by slightly modifying an old method using the direct mercury analyzer *** sediment samples from Thane Creek,Mumbai,India were collected and analysed for total mercury and *** Hg concentration in the creek varied between 0.54 to 16.03 μg gwhile Me-Hg concentrations ranged between0.04 to 1.07 μg *** surface sediment,mercury concentrations ranged from 4.33 μg gto 12.16μg *** organic carbon content was found to be around 2 percent in different layers of the *** enrichment factors,which indicate the extent of pollution in sediments,were estimated to range from 26 to 50 at different locations in the *** and anthropogenic concentrations of mercury in the creek were also determined to compare the impact of anthropogenic and natural *** inventories were about 5-70 times more in concentration than the lithogenic in the different core sediments.

关键词： Total mercury Methylmercury Enrichment factor Anthropogenic concentration TOC

Terrestrial input and nutrient change reflected by sediment records of the Changjiang River Estuary in recent 80 years

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Acta Oceanologica Sinica 2015年第2期34卷 27-35页

作者： LI Junlong ZHENG Binghui HU Xupeng WANG Yiming DING Ye LIU Fang College of Water Sciences Beijing Normal University State Key Laboratory of environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences State environmental Protection Key Laboratory of Quality Control in environmental monitoring China National Environmental Monitoring Center Zhoushan Marine Ecological environmental monitoring Station

A variety of environmental problems have been observed in the Changjiang River Estuary and adjacent coastal area, including eutrophication, harmful algal blooms（HABs）, and hypoxia in recent decades. Application of sedimentary biogenic element indicators on the study of paleoenvironment can reconstruct environmental evolution history of waters. Two 210Pb-dated cores were collected from the Changjiang River Estuary（S3） and adjacent coastal area（Z13）, and total organic carbon（TOC）, total nitrogen（TN）, biogenic silicon（BSi）, total phosphorus（TP） and phosphorus（P） species were analyzed. Three stages of environmental changes are deduced by the nutrient sedimentary records. First, nutrient concentration increased rapidly since the 1950 s, which attributed to agriculture development and overused chemical fertilizers. Second, nutrient concentration kept high and primary production began to promote during the 1960 s to 1980 s, while diatom abundance and proportion began to decline since the 1970 s, accompanied by reduced 23 Si O- concentration and flux from the river. Third, due to several dams and bridges constructed, river runoff and coastal hydrodynamic conditions reduced to a certain extent since the 1990 s, which aggravated the unbalance in nutrient structure. Multi-nutrient proxies in sediment can reflect the natural environm-ental changes as well as influence of human activities.

关键词： biogenic elements phosphorus species sediment cores Changjiang River Estuary