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991.
Four sediment cores collected in the Seine River basin and dated between 1916 and 2003 were analyzed for lead concentrations and isotopic composition. In all four cores, the measured Pb concentration (up to 460 mg kg−1) lies significantly above the natural background (27-40 mg kg−1), although a significant decrease (down to 75 mg kg−1) was observed during the second half of the 20th century which can be explained by the reduction of lead emissions. The 206Pb/207Pb ratio measured in these samples indicates that the main source of Pb used in the Paris conurbation is characterized by a “Rio Tinto” signature (defined as 206Pb/207Pb = 1.1634 ± 0.0001). A high contribution, up to 25%, from the leaded gasoline (characterized by 206Pb/207Pb = 1.08 ± 0.02) is revealed in the Seine River downstream Paris, indicating that lead from the leaded gasoline is preferentially released to the river.The dominating Pb signature in the Paris conurbation that is currently sampled through incinerators fumes (206Pb/207Pb = 1.1550 ± 0.0005) and waste water treatment plant (206Pb/207Pb = 1.154 ± 0.002), represents a mixture of highly recycled lead from the Rio Tinto mine and lead from leaded gasoline (imprinted by the low 206Pb/207Pb of the Broken Hill mine). This signature is called “urban” rather than “industrial”, because it is clearly distinct from the Pb that is found in areas contaminated by heavy industry, i.e. the heavy industries located on the Oise River which used lead from European ores characterized by high 206Pb/207Pb ratios (∼1.18-1.19) and possibly a minor amount of North American lead (206Pb/207Pb ratios > 1.20). The “urban” signature is also found in a rural area upstream of Paris in the 1970’s. At the Seine River mouth in 2003, Pb with an urban signature represents 70% of the total Pb sediment content, with the 30% remaining corresponding to natural Pb. 相似文献
992.
A Quantitative Review of Urban Ecosystem Service Assessments: Concepts,Models, and Implementation 总被引:3,自引:0,他引:3
Dagmar Haase Neele Larondelle Erik Andersson Martina Artmann Sara Borgström Jürgen Breuste Erik Gomez-Baggethun Åsa Gren Zoé Hamstead Rieke Hansen Nadja Kabisch Peleg Kremer Johannes Langemeyer Emily Lorance Rall Timon McPhearson Stephan Pauleit Salman Qureshi Nina Schwarz Annette Voigt Daniel Wurster Thomas Elmqvist 《Ambio》2014,43(4):413-433
Although a number of comprehensive reviews have examined global ecosystem services (ES), few have focused on studies that assess urban ecosystem services (UES). Given that more than half of the world’s population lives in cities, understanding the dualism of the provision of and need for UES is of critical importance. Which UES are the focus of research, and what types of urban land use are examined? Are models or decision support systems used to assess the provision of UES? Are trade-offs considered? Do studies of UES engage stakeholders? To address these questions, we analyzed 217 papers derived from an ISI Web of Knowledge search using a set of standardized criteria. The results indicate that most UES studies have been undertaken in Europe, North America, and China, at city scale. Assessment methods involve bio-physical models, Geographical Information Systems, and valuation, but few study findings have been implemented as land use policy.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-014-0504-0) contains supplementary material, which is available to authorized users. 相似文献993.
Green infrastructure (GI) and ecosystem services (ES) are promoted as concepts that have potential to improve environmental planning in urban areas based on a more holistic understanding of the complex interrelations and dynamics of social–ecological systems. However, the scientific discourses around both concepts still lack application-oriented frameworks that consider such a holistic perspective and are suitable to mainstream GI and ES in planning practice. This literature review explores how multifunctionality as one important principle of GI planning can be operationalized by approaches developed and tested in ES research. Specifically, approaches developed in ES research can help to assess the integrity of GI networks, balance ES supply and demand, and consider trade-offs. A conceptual framework for the assessment of multifunctionality from a social–ecological perspective is proposed that can inform the design of planning processes and support stronger exchange between GI and ES research. 相似文献
994.
Heavy Metal Monitoring Using Bivalved Shellfish from Zhejiang Coastal Waters, East China Sea 总被引:2,自引:0,他引:2
The interest of culturing bivalved shellfish (including mussels, clams, oysters etc.), has increased in recent years, but
the consumption has been hampered both by high levels of heavy metals and toxic algae. The levels of heavy metals (Hg, Cd,
Pb, Zn, Cu and As) were determined in soft tissues of different shellfish from Zhejiang coastal waters, East China Sea. The
average concentrations of the heavy metals analyzed exhibited the following decreasing order: Zn > Cu > As > Cd > Pb > Hg.
Comparison of heavy metals concentrations among species indicated that Bivalves clearly have significant potential as useful
bioindicators; however, the results indicated that no one species is universally suitable, as is true of any organism used
in these studies. The distribution of the metals was also investigated along the Zhejiang coast, which the results showed
the mean concentration of Hg and Cd detected did not vary greatly and presented a similar spatial pattern at different sampling
stations, the concentrations of Zn and Pb were highly variable at different sampling sites. The amounts of heavy metals in
soft tissue of shellfish were also compared with those from the related species from other seas in China and world marine
waters. The results suggested that the coastal area might be considered relatively unpolluted with heavy metals and the concentrations
of metals in shellfish also below the seafood safety limits for human consumption. 相似文献
995.
Availability and bio-accessibility of metals in the clay fraction of urban soils of Sevilla 总被引:2,自引:0,他引:2
Madrid F Díaz-Barrientos E Madrid L 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):605-610
The availability of Cd, Cr, Cu, Ni, Mn, Pb and Zn present in the finest size particles of urban soils is studied by comparing the concentrations in the clay fraction with those extracted from the whole soil by either single-extraction or sequential extraction method. Many metals are preferentially present in the finest particles as compared to coarser fractions. This is true for most metals studied, except Mn and, perhaps, Cd. Those metals present in the clay fraction are often in easily bio-accessible forms, especially Cu, Pb and Zn. The results suggest that bio-accessible forms of these three metals are distributed among the three sequential fractions, and even the fraction considered as ‘residual’ is also bio-accessible to a significant extent. The statistical analysis shows some distinctions among metals that are compared to the ‘urban’, ‘natural’, or intermediate behaviour of the various metals as proposed earlier in the literature. 相似文献
996.
Measuring revealed and emergent vulnerabilities of coastal communities to tsunami in Sri Lanka 总被引:4,自引:0,他引:4
This paper presents the important findings of a study undertaken in two selected tsunami-affected coastal cities in Sri Lanka (Batticaloa and Galle) to measure the revealed and emergent vulnerability of coastal communities. International risk studies have failed to demonstrate the high vulnerability of coastal communities to tsunami in Sri Lanka. Therefore, indirect assessment tools to measure pre-event vulnerability have to be complemented by assessment tools that analyse revealed and emergent vulnerability in looking at the aftermath and impact patterns of a real scenario, as well as in examining the dynamics of disaster recovery in which different vulnerabilities can be identified. The paper first presents a conceptual framework for capturing vulnerability within a process-oriented approach linked to sustainable development. Next, it highlights selected indicators and methods to measure revealed and emergent vulnerability at the local level using the examples of Batticaloa and Galle. Finally, it discusses the usefulness and application of vulnerability indicators within the framework of reconstruction. 相似文献
997.
城市发展与水环境污染的研究 总被引:1,自引:0,他引:1
本文研究了城市发展与水环境污染的关系。运用灰色关联分析表明,对水污染排放的影响程度大小依次为:人口密度(γ1=0.4456)工业发展(γ3=0.3498)环保投入(γ2=0.2656)。通过弹性系数预测法分析了上海废水排放与人均GDP的发展趋势。 相似文献
998.
Assessing the ecosystem service of air pollutant removal by urban trees in Guangzhou (China) 总被引:7,自引:0,他引:7
In Chinese cities, air pollution has become a serious and aggravating environmental problem undermining the sustainability of urban ecosystems and the quality of urban life. Besides technical solutions to abate air pollution, urban vegetation is increasingly recognized as an alternative ameliorative method by removing some pollutants mainly through dry deposition process. This paper assesses the capability and monetary value of this ecosystem service in Guangzhou city in South China. The results indicated an annual removal of SO(2), NO(2) and total suspended particulates at about 312.03Mg, and the benefits were valued at RMB90.19 thousand (US$1.00=RMB8.26). More removal was realized by recreational land use due to a higher tree cover. Higher concentration of pollutants in the dry winter months induced more removal. The lower cost of pollution abatement in China generated a relatively subdued monetary value of this environmental benefit in comparison with developed countries. Younger districts with more extensive urban trees stripped more pollutants from the air, and this capacity was anticipated to increase further as their trees gradually reach final dimensions and establish a greater tree cover. Tree cover and pollutant concentration constitute the main factors in pollutant removal by urban trees. The efficiency of atmospheric cleansing by trees in congested Chinese cities could be improved by planting more trees other than shrubs or grass, diversifying species composition and biomass structure, and providing sound green space management. The implications for greenery design were discussed with a view to maximizing this ecosystem service in Chinese cities and other developing metropolises. 相似文献
999.
The modification of soil composition in the urbanized area of Ankara due to wet-dry deposition and pollution-derived particles from the atmosphere is investigated by analyzing 120 surface soil samples, collected from the urbanized area and its un-urbanized surrounding, for major, minor and trace elements. Concentrations of elements from human activity (e.g. Cd, Pb, Cr, Zn, Cu and Ca) in the urbanized area were higher than their corresponding concentrations in global average soil and soil in un-urbanized areas outside the urbanized area. Metal contents in soil were very high in densely populated districts and around some industrial facilities. The only exception was Pb distribution, which was more dispersed, due to the nature of motor vehicle emissions. Alteration of the Cd, Zn, Cu and Cr content of soil was confined to the inhabited and industrial areas, whereas enrichment factors of these elements were close to unity in the remaining study area. Factor analysis identified two polluted soil factor associations. One factor includes elements, such as Zn and Cd, which had high factor scores in inhabited areas and the other factor (high loading of Pb) represents soil polluted by motor vehicle emissions. 相似文献
1000.
We investigated Bayesian networks to classify urban land use from satellite imagery. Landsat Enhanced Thematic Mapper Plus (ETM(+)) images were used for the classification in two study areas: (1) Marina del Rey and its vicinity in the Santa Monica Bay Watershed, CA and (2) drainage basins adjacent to the Sweetwater Reservoir in San Diego, CA. Bayesian networks provided 80-95% classification accuracy for urban land use using four different classification systems. The classifications were robust with small training data sets with normal and reduced radiometric resolution. The networks needed only 5% of the total data (i.e., 1500 pixels) for sample size and only 5- or 6-bit information for accurate classification. The network explicitly showed the relationship among variables from its structure and was also capable of utilizing information from non-spectral data. The classification can be used to provide timely and inexpensive land use information over large areas for environmental purposes such as estimating stormwater pollutant loads. 相似文献