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1.
通过对湖泊沉积物研究领域的文献信息的网络分析,对了解目前该领域在全球的研究现状、研究热点及其未来的发展趋势具有重要的意义,也为我国长江下游湖泊群的科学研究和生态保护提供了科学参考。以Web of Science中1931~2016年的文献信息为数据源,以“lake sediment*”作为标题的字段进行信息检索,结合文献计量法,采用词频统计、聚类分析和网络分析方法,评估了湖泊沉积物研究领域的研究现状和发展趋势。结果表明:该领域共检索到相关文献9 126篇,且文献的发表数量随时间变化呈指数增长(R2=0.98,P<0.01);美国发表文献数量最多,共有2 086篇,占总出版文献数的20.5%,中国发表文献的数量为2 086篇,仅次于美国,欧美等发达国家对研究文献量的贡献较大,发展中国家中,中国的贡献较大;研究文献涉及最多的三大学科分别为环境科学与生态、地质学和海洋与淡水生物学,属于这三大学科的文献分别有3 368(22.0%)、2 698(17.6%)、2 099(13.7%)篇;Journal of Paleolimnology、Hydrobiologia和Limnology and Oceanography为该研究领域文献发表较多的期刊,发表文献数量分别为412、366、237篇,分别占总文献数量的4.5%、4.0%、2.6%;从该领域的研究热点和发展趋势上来看,重金属和有机污染物的污染与风险、湖泊沉积物与古气候的研究、湖泊富营养化等研究成为湖泊沉积物研究的热点方向,它们作为关键词出现频率位于前10,未来模型和多元统计运用等方向作为新的关键词出现,且出现频次进入前50,说明这两个方向具有一定的研究价值和发展空间。  相似文献   

2.
This paper examines patterns in recently published research addressing Indigenous capacity for collaborative natural resource development in Canada’s forestry, energy, and mining sectors. As Indigenous involvement in natural resource development increases, so too does the body of associated scholarship. We gathered information on several core metrics (year of publication, authorship, and gender, author affiliation, journal titles, citation counts and impacts factors, and keywords) to analyze research output, trends, and gaps. Our bibliometric analysis of 49 articles from peer-reviewed journals confirms that Indigenous natural resource development and capacity research has steadily increased over the past decade in terms of the number and range of papers, authors, institutions, and cases examined. Research output peaked in 2013 and 2015. Authorship is distributed evenly between male and female lead researchers, with teams located across southern Canada, with highest concentrations in urban population centers of British Columbia, Manitoba, and Ontario. In contrast, the research sites are located in more northern, rural, and remote locations. That communities and projects under study are not currently matched with sites of research capacity raises questions about capacity building and the nature of research “on” versus “with” Indigenous peoples. Policies and programs designed to enhance Indigenous involvement and capacity must address these asymmetries in order to be representative, effective, and responsive to current Indigenous priorities.  相似文献   

3.
This study conducted a bibliometric analysis of 1251 articles related to Antarctic krill from 1960 to2015, based on the Core Collection in Thomson Reuters' Web of Science. We analyzed the results from four aspects: annual distribution, Web of Science categories and the major journals, international collaboration and author keywords. The Antarctic krill research has developed rapidly since 1978, with an increasing article output. The studies mostly focused on the fields of marine and freshwater biology, oceanography, and ecology. Polar Biology, Marine Ecology-Progress Series and Deep-Sea Research Part Ⅱ-Topical Studies in Oceanography, were the top three journals to publish the Antarctic krill-related papers. Although Russia is the earliest state to report Antarctic krill, U.S.A. and England were leaders with the largest output quantity and the highest cooperation frequencies. The researches in PR China have taken a blooming since 2009 and will play a more and more important role in the world. The frequencies of author keywords were counted. The high-frequency keywords were further divided into four groups with cohesive subgroup analysis, which suggested the major themes. This paper depicts the existing publications on Antarctic krill. Our goal is to serve a point of reference and provide the direction for the future work.  相似文献   

4.
为了揭示有关长江研究的热点与发展动态,以Web of Science数据库为资料来源,利用文献计量学方法及TDA软件,对1900~2012年长江研究文献的发文量、国家、机构、作者、期刊、学科、关键词进行数据统计与分析。结果表明:(1)长江研究大致分为3个阶段:初步发展时期;探索时期;快速发展时期;(2)中国发表的关于长江研究的论文最多,国外主要国家及机构来自美国、日本、澳大利亚;(3)中国科学院是国内长江研究的主要机构;(4)国内外十分关注地质学、环境科学、水资源和气象学的研究。  相似文献   

5.
Increased nitrogen (N) and phosphorus (P) inputs are major causes of eutrophication in the coastal waters of the Black Sea. The objective of this study is to analyze the past and future trends in river export of nitrogen and phosphorus to the coastal waters of the Black Sea and to assess the associated potential for coastal eutrophication. The Global NEWS-2 (Nutrient Export from WaterSheds) model was used for this purpose. Currently, most eutrophication occurs in the North Black Sea and the Azov Sea. In the future, however, this may change. We analyzed trends up to 2050 on the basis of the Millennium Ecosystem Assessment (MEA) scenarios. The results indicate that nutrient loads in rivers draining into the North Black Sea and the Azov Sea may decrease in the coming decades as a result of agricultural trends and environmental policy. However, in these scenarios, the targets of the Black Sea Convention are not met. In the South Black Sea, there is currently little eutrophication. But this may change because of increases in nutrient inputs from sewage in the future.  相似文献   

6.
Statistical analysis of water quality parameters including trace metal speciation was undertaken with a view to seeing the interrelationship between different variables and also to identify probable source components in order to explain the pollution status of Chennai Ennore coastal environmental system. Factor analysis has been used in the present work. This is essentially a data reduction technique and will suggest how many variates are important to explain the observed variances in the data. The possible variances in the water quality parameters may be due to either sources of anthropogenic origin or natural variances due to the season or due to different biogeochemical processes that are taking place in the system. When this analysis was carried out with our data on water quality parameters in the above coastal environmental system, we found that the prominent factor or the first factor called the eutrophication factor explained 24.51% of the total variance (comprised of variables like DO, pH, SS, ammonia-N, phosphate and silicate). The second factor called the copper contamination factor explained 10.61% (comprised of variables like labile Cu, total Cu and particulate Cu) and the third factor called metal removal factor explained 10.11% (comprised of variables like particulate Zn, particulate Pb and water temperature) of the variances, respectively. Although there are four more factors, they are all having variances less than 10%. From this study, it is seen that eutrophication is the main source component of pollution to the surface waters of this estuary and its adjacent coastal waters compared to dissolved trace metals.  相似文献   

7.
The consequences of anthropogenic impact on the water area of Amur Bay (the Sea of Japan) near Vladivostok include the eutrophication of coastal waters and littering with various objects used as artificial substrates, which protect sedentary animals from predators and contribute to the survival of their larvae. An indicator of eutrophication, the diatom Skeletonema costatum accounting for 81–96% of the total abundance of phytoplankton (Stonik and Selina, 1995), is consumed mainly by barnacles and the Pacific oyster. Thus, these animals gain an advantage in the colonization of artificial substrates. The results of the study suggest that eutrophication will lead to changes in the structure of the marine community.  相似文献   

8.
Due to growing environmental concern and increasing awareness among customers, reverse supply chain (RSC) has received much attention among researchers and practitioners. Therefore it is necessary to provide a comprehensive list of references for other researchers (or readers), who are interested in RSC research to help stimulate further interest. In this paper, we present classification schemes and a simple analysis for the reverse supply chain. This literature review was mainly based on journal articles but also included web based documents, conference materials, working papers, etc. A total of 543 articles were reviewed, of which 506 were published between 1967 and 2008 from 100 reputed international journals. Based on the literature review carried out and the nature of research observed in RSC, we have introduced two classification schemes to systematically organise the published articles. The first classification scheme is based on the content related issues on RSC and the second one is based on the solution methodology followed by the researchers. These classification schemes indicate that there is considerable research potential for RSC. The results also show that there is strong growth in RSC research.  相似文献   

9.
This paper examines quantitatively the patterns of collaboration over geographical boundaries in the emerging field of sustainability science by empirically analyzing the bibliometric data of scientific articles. The results indicate that an increasing number of countries are engaged in research on sustainability, with the proportion of articles published through international collaboration rising as well. The number of countries engaged in international collaboration on sustainability research has been increasing, and the diversity of countries engaged in research collaboration beyond national borders is also increasing. The geographical patterns of collaboration on sustainability show that research collaboration tends to be conducted between countries which are geographically located closely, suggesting that communication and information exchange might be limited within the regional clusters. The focused fields of research activities on sustainability are significantly different between countries, as each country has its focused fields of research related to sustainability. The specialization of research activities is also observed in international collaboration. While these patterns of international collaboration within regional clusters focusing on specific fields could be effective in promoting the creation, transmission, and sharing of knowledge on sustainability utilizing the already existing regional networks, they could pose a serious obstacle to collecting, exchanging, and integrating diverse types of knowledge, especially when it is necessary to deal with problems involving large-scale complex interactions with long-term implications, such as climate change. It would be of critical importance to establish inter-regional linkages by devising appropriate institutional arrangements for global research collaboration on sustainability science.  相似文献   

10.
土地利用变化下沿海地区吸附态磷负荷动态变化研究   总被引:2,自引:0,他引:2  
吸附态磷是主要的面源污染物之一,它会导致水域环境质量恶化,是水体富营养化的重要污染源。科学估算吸附态磷污染负荷能够为治理沿海地区非点源污染,保护海洋生态安全提供理论依据。以遥感影像、降雨监测资料等多源数据为基础,综合考虑土壤侵蚀、泥沙输移率、磷富集系数等影响因子,构建吸附态磷负荷估算模型,估算了江苏沿海地区2000~2010年吸附态磷负荷量,分析了不同土地利用背景下吸附态磷负荷的动态变化特征,结果显示:(1)2000~2010年,江苏沿海地区吸附态磷负荷明显增加,平均吸附态磷负荷模数由105.89 kg/km2·a增长至201.67 kg/km2·a,吸附态磷负荷总量由3 284t增长至6 255t。(2)10 a间,研究区的吸附态磷负荷热点面积减小,呈现出收敛聚集的态势,但热点区的吸附态磷负荷总量却明显增加,说明研究区内吸附态磷负荷的空间极化现象更为显著。(3)10 a间,各土地利用类型的平均吸附态磷负荷模数都显著增长,不同土地利用背景下吸附态磷负荷总量排序为水田旱地林地草地未利用地园地。研究结果表明,不同土地利用背景下吸附态磷负荷存在显著差异,且不同土地利用类型相互转化时,吸附态磷负荷也随之发生变化,可通过调整土地利用结构,优化景观格局,减少和控制磷污染的发生。  相似文献   

11.
Sustainability is an important concept for society, economics, and the environment, with thousands of research papers published on the subject annually. As sustainability science becomes a distinctive research field, it is important to define sustainability clearly and grasp the entire structure, current status, and future directions of sustainability science. This paper provides an academic landscape of sustainability science by analyzing the citation network of papers published in academic journals. A topological clustering method is used to detect the sub-domains of sustainability science. Results show the existence of 15 main research clusters: Agriculture, Fisheries, Ecological Economics, Forestry (agroforestry), Forestry (tropical rain forest), Business, Tourism, Water, Forestry (biodiversity), Urban Planning, Rural Sociology, Energy, Health, Soil, and Wildlife. Agriculture, Fisheries, Ecological Economics, and Forestry (agroforestry) clusters are predominant among these. The Energy cluster is currently developing, as indicated by the age of papers in the cluster, although it has a relatively small number of papers. These results are compared with those obtained by natural language processing. Education, Biotechnology, Medical, Livestock, Climate Change, Welfare, and Livelihood clusters are uniquely extracted by natural language processing, because they are common topics across clusters in the citation network.  相似文献   

12.
This paper presents a holistic strategy on the interaction of activities in the Elbe river basin and their effects on eutrophication in the coastal waters of the German Bight. This catchment–coastal zone interaction is the main target of the EUROCAT (EUROpean CATchments, catchment changes and their impact on the coast) research project, with the Elbe being one of eight case studies. The definition of socio-economic scenarios is linked with the application of models to evaluate measures in the catchment by estimation of nutrient emissions with MONERIS (MOdelling Nutrient Emissions in RIver Systems), and their effects on coastal waters with the ecosystem model ERSEM (European Regional Seas Ecosystem Model). The cost effectiveness of reduction measures will then be evaluated by application of the CENER model (Cost-Effective Nutrient Emission Reduction) and a multi-criteria analysis. Finally, the interpretation of ecological integrity is used as a measure to describe ecological impacts in an aggregated form.  相似文献   

13.
基于贝叶斯公式的湖泊富营养化随机评价方法及其验证   总被引:29,自引:0,他引:29  
为了准确评价湖泊所处的营养状态,进而为湖泊富营养化的防治提供科学依据,提出了基于贝叶斯公式的湖泊富营养化随机评价方法。该法通过计算单个水质指标属于某个评价级别的概率,由最大似然分类原则确定单个水质指标的评价级别,并采用加权平均法推求湖泊富营养化多个水质指标的综合评价级别,具有方法简单、计算工作量小的特点。经全国30个湖泊实测水质资料的验证,随机评价方法与模糊评价方法和灰色评价方法相比较,有29个湖泊评价结果的差异小于等于一个级别,其比例为96.6%,说明这三种富营养化评价方法的计算精度相当。根据各项评价指标与叶绿素的相关系数,计算各项水质指标在富营养化评价中所占权重的方法,适用于浮游植物型湖泊,如果采取等权重方法,则适用于任何类型的湖泊。确定湖泊富营养化评价的水质指标个数和种类的选择具有不确定性,确定湖泊富营养化的评价级别和各个级别对应的水质标准浓度也具有不确定性,因此湖泊富营养化的评价方法具有不确定性。应采用多种途径对湖泊富营养化的评价方法进行研究,并取长补短,使评价结果更趋合理。  相似文献   

14.
中国环境教育研究的历史与未来趋势分析   总被引:1,自引:0,他引:1  
通过对1979年以来中国环境教育学术文章在数量、内容和研究方法等方面的分析。发现中国环境教育研究自1994年开始持续升温。2000年开始从文章内容和研究方法上明显显示出转向可持续发展教育方向的趋势,2004年开始从文章数量上也显示出转向可持续发展教育的方向o20多年来的环境教育研究中。对环境教育意义的阐述和国外环境教育动态的研究分量最重,研究方法的探讨和研究则表现出对主流教育领域的影响敏感且响应及时。但这些文章显示出的环境教育研究方法绝大多数以思辨为主。实证研究、质的研究缺乏。对文章作者分析结果显示。中国环境教育研究队伍很不稳定。缺乏基本的研究经费支持是研究队伍不能保持稳定并缺乏在本土开展的实证和质的研究的根本制约因素。怎样协调因资源禀赋和发展程度不同而导致各国在开展环境教育时出现环境价值观和环境立场产生差异甚至对立的现象。是未来环境教育研究不可回避的任务。  相似文献   

15.
Coastal marine eutrophication assessment: a review on data analysis   总被引:2,自引:0,他引:2  
A wide variety of data analysis techniques have been applied for quantitative assessment of coastal marine eutrophication. Indicators for assessing eutrophication and frequency distributions have been used to develop scales for characterizing oligotrophy and eutrophication. Numerical classification has also contributed to the assessment of eutrophic trends by grouping sampling sites of similar trophic conditions. Applications of eutrophication assessment based on Principal Component Analysis and Multidimensional Scaling have also been carried out. In addition, the rapid development of Geographical Information Systems has provided the framework for applications of spatial methods and mapping techniques on eutrophication studies. Satellite data have also contributed to eutrophication assessment especially at large scale. Multiple criteria analysis methods can integrate eutrophication variables together with socio-economic parameters providing a holistic approach particularly useful to policy makers. As the current concept of eutrophication problems is to be examined as part of a coastal management approach, more complex quantitative procedures are needed to provide a platform useful for implementation of environmental policy. The present work reviews methods of data analysis used for the assessment of coastal marine eutrophication. The difficulties in applying these methods on data collected from the marine environment are discussed as well as the future perspectives of spatial and multiple criteria choice methods.  相似文献   

16.
Exchange of trace gases between the oceans and the atmosphere affects the atmospheric content and cycling of a range of chemical species which are related to climate change, ozone layer depletion, acid deposition, eutrophication, atmospheric particle formation, photo-oxidants, trace metals and persistent organic pollutants (POPs). The effects and impacts of air–sea exchange of these gases can be local, regional and global. Until now, most of the research has concentrated on the sea–air exchange of trace gases in the open ocean. The flux rates of the trace gases from the coastal waters to the air are much higher than the rates for the open ocean and the contribution of the coastal areas to the total oceanic emissions of these trace gases can be significant on a global scale. This contribution can be as high as 50% and more for nitrous oxide and COS. Concerning the contribution of the trace gas production in the coastal areas to the total global production of these gases, it can be concluded that this contribution seems to be below 2% except for nitrous oxide. However, it should be pointed out that on the local and even regional scale the emissions in the coastal areas can be very important, contributing substantially to the total emission of these gases in a studied area. Thus, there is a need to carry out studies in the future with the aim to provide more accurate understanding of the production and sea–air exchange processes for these gases around the world. Electronic Publication  相似文献   

17.
18.
利用在2010年3月~2011年2月江西省25个中小型湖泊水质监测指标的分析数据,采用综合营养状态指数(TLI)法对调查湖泊进行各季节和全年的营养状态评价,并分别计算在各季节和全年内调查湖泊中发生富营养化的概率。在全年营养状态评价的基础上,运用Bootstrap方法,寻找在不同营养状态下的置信区间,并推断富营养化控制指标的建议值。结果表明,在被调查的湖泊中,春、夏季发生富营养化的概率是接近的,秋季是最高的,冬季是最低的。在春、夏和冬季时,调查湖泊的营养状态以中营养为主;在秋季时,中营养状态湖泊所占比例下降,富营养状态湖泊所占比例上升。在全年中,富营养和中营养状态湖泊所占比例分别为32%和68%。江西省中小型湖泊富营养化控制指标透明度(SD)、总磷(TP)、叶绿素a(Chl a)和高锰酸盐指数(CODMn)等的建议值,分别为044 m、005 mg/L、1000 mg/m3和2 70 mg/L。为湖泊富营养化的分区控制与治理提供基础资料和理论依据  相似文献   

19.
The study focuses on evaluating factors that farmers consider relevant in adopting cassava production in five semi-arid zone of West African countries. The study is based on primary data randomly collected as part of collaborative study of cassava in semiarid zones of Africa (COSCASSA) village level survey from five West African countries namely: Nigeria, Ghana, Chad, Niger and Burkina Faso. This study models effects of farm, farmer and technology specific factors on the decision of semi arid farmers to adopt cassava into their farming system. By way of threshold decision models—Probit and Logit models, the estimation of each country and the pooled data adoption models reveal different adoption models for the countries considered. For each country, different variables appeared as major adoption shifters. Comparatively, the adoption models for Nigeria and whole region appear to have the highest significance variables, being seven in number. This is followed by Chad (6), Ghana (4), and Burkina Faso and Niger with three each. For the variables considered, distance to nearby urban market appears a major adoption shifter in all the country, except for Niger. This is closely followed by contact with extension, variety, pest/disease resistance and livestock feeds, which appear significant in four of the countries. Membership of cooperative societies appears as the least adoption predictor, which is only significant in Chad republic. The study therefore recognizes the importance of varietial characteristics and farmers’ characteristics in acceptance of cassava as a major root tuber crop in the semi arid region of West Africa. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

20.
人类健康风险的定量评估与分析   总被引:1,自引:0,他引:1  
通过深入研究.将人类健康风险解析环境污染、食物安全、疾病流行和医疗保障四个方面。在建立一套评价人类健康风险指标体系的基础上。对40个样本国家进行评估。用聚类分析的方法.将40个国家分为四类,在对每一类国家的人类健康风险特点进行对比发现,在同等经济发展水平下,中国的人类健康风险相对较高。通过分析人类健康风险与经济发展水平的关系得出,人均GNI 1000,3000美元是国家经济发展的关键时期。同样也是改善人类健康状况的关键时期,这一时期国家要高度重视改善人类健康状况。  相似文献   

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