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11.
Sawicka-Kapusta K Zakrzewska M Bajorek K Gdula-Argasińska J 《Environment international》2003,28(8):691-698
The influence of Cracow's urban pollution on small forest ecosystems was studied during 1998-2000. Seven sites located at different distances from the Cracow conurbation and from busy road were selected. Two sites were situated 26 and 31 km from Cracow town along an eastern transect, the other five-3, 8, 14, 26 and 35 km respectively, from Cracow-along a southern transect. At the beginning of September, five litter traps were set at each site. The quantity of litter fall, along with percentage composition of each species, were estimated for an area of 1 m(2). The concentration of Cd, Pb, Cu, Zn and Fe in the litter fall and the input of these metals to the forest floor were determined. The input of cadmium ranged from 84 microg m(-2) at Kornatka in 1998 to 382 microg m(-2) at Bonarka in 2000. The input of lead was about 10 times higher than cadmium and varied from 406 microg m(-2) at Weglówka in 1998 to 3717 microg m(-2) at Bonarka in 2000. Input of Cu, Zn and Fe to the forest floor showed the similar tendency. During 1998-2000, the highest heavy metal concentrations in the litter fall and their impact on the forest floor were always found at sites close to the Cracow conurbation and, in the eastern transect, close to a steel works. Input of metals to the forest floor tended to decrease with increasing distance from the centre of Cracow. 相似文献
12.
The present article, based on a study of five village ecosystems, assesses the energy efficiency of rain-fed agriculture in
a dry tropical environment and the impact of agricultural activity on the surrounding natural ecosystems. Agronomic yield
is insufficient to meet the food requirement of the human population, hence 11.5%–49.7% of the required amount of food grains
are imported from the market. Energy requirements of five studied agroecosystems are subsidized considerably by the surrounding
forest in the form of fodder and firewood. Natural ecosystems supply about 80%–95% of fodder needs and 81%–100% of fuelwood
needs. The output-input ratio of agriculture indicated that, on average, 4.1 units of energy are expended to obtain one unit
of agronomic energy. Of this, 3.9 units are supplied by the natural ecosystem. In addition, 38% of the extracted firewood
is marketed. The illegal felling and lopping of trees result in ever-increasing concentric circles of forest destruction around
the villages and together with excessive grazing results in savannization. The forests can be conserved by encouraging fuelwood
plantations (0.7 ha/ha cultivated land) and developing village pastures (1.6 ha/ha cultivated land) and reducing the livestock
numbers. Agricultural production in the region can be stabilized by introducing improved dry farming techniques such as intercropping,
planned rainwater management, and adequate use of fertilizers. 相似文献
13.
Liz Heywood Richard Skeffington Paul Whitehead Brian Reynolds 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):391-397
Critical loads have been used to develop international agreements on acidifying air pollution abatement, and within the UK and other countries, to develop national policies for pollution abatement. The Environment Agency (England and Wales) has regulatory obligations to protect sites of high conservation value from the threat of acidification, and hence requires a practical methodology for acidification assessments at the site-specific scale. The Environment Agency has therefore posed the question: Are the national critical load exceedance models sufficiently robust to form the basis for methods to assess harm to individual sites or are they only useful for national policy development? In order to provide one measure of the appropriateness of applying the models at the site-specific scale we incorporated estimates of uncertainty in both national and site-specific data into the calculation of critical load exceedance for individual sites. The exceedance calculations use data from a wide range of sources and the accuracy of the exceedance will be influenced by the accuracy of the input data sets. Using Monte Carlo methods to incorporate the uncertainty in the input data sets into the calculation a distribution of critical load exceedance values is generated rather than a single point estimate. This paper compares uncertainty analyses for coniferous forested sites in England and Wales using both national scale and site-specific data sets and uncertainty ranges. 相似文献
14.
当前经济研究中对环境问题越来越重视,已经有多种不同方法可以用来研究材料和物质流在经济中的运转,物流分析模型(SFA)就是其中一种。本文将SFA应用于一个单一的,假设的污染问题中,这样以实践的方式来评价模型的结果。结果显示,SFA模型能够发现潜在的或预料不到的物质流和排放物,并能发现在将来某一时候会引起经济和环境问题的积累。 相似文献
15.
Wenjing Lu Yawar Abbas Muhammad Farooq Mustafa Chao Pan Hongtao Wang 《Frontiers of Environmental Science & Engineering》2019,13(2):30
16.
Soraya María Ruiz Peñalver Mercedes Rodríguez Molina José Antonio Camacho Ballesta 《Waste management (New York, N.Y.)》2014,34(1):3-11
The paper industry has a relatively high degree of reliance on suppliers when compared to other industries. Exploring the role of the paper industry in terms of consumption of intermediate inputs from other industries may help to understand how the production of paper does not only generate waste by itself but also affects the amount of waste generated by other industries. The product Life Cycle Assessment (LCA) is a useful analytical tool to examine and assess environmental impacts over the entire life cycle of a product “from cradle to grave” but it is costly and time intensive. In contrast, Economic Input Output Life Cycle Assessment Models (IO-LCA) that combine LCA with Input–Output analysis (IO) are more accurate and less expensive, as they employ publicly available data. This paper represents one of the first Spanish studies aimed at estimating the waste generated in the production of paper by applying IO-LCA. One of the major benefits is the derivation of the contribution of direct and indirect suppliers to the paper industry. The results obtained show that there was no direct relationship between the impact on output and the impact on waste generation exerted by the paper industry. The major contributors to waste generation were the mining industry and the forestry industry. 相似文献
17.
地震灾害产业关联间接经济损失评估 总被引:4,自引:0,他引:4
地震灾害破坏了一个城市或地区的经济体系的均衡运行状态,震后“残余”的生产能力资源必须经过一段时间的重新调整,才能达到某一新的、较低程度的均衡水平。本文利用投入产出分析法,从机会成本的观点,对调整阶段的生产能力资源“呆滞”损失即产业关联损失进行了评估。 相似文献
18.
《Environmental Forensics》2013,14(3-4):303-321
In the last decade, PETROBRAS has experienced some significant oil spills cases and the PETROBRAS Research Center has played an important role in the company emergency response program by characterizing the spilled oil, monitoring the affected ecosystem, determining the fate of the oil in the environment, and, subsequently, helping the company in assessing the environmental damage. This paper presents the use of advanced chemical analytical techniques (GC/FID, P&T/GC/PID and GC/MS) in some Brazilian oil spill studies in order to determine fractions and individual petroleum hydrocarbons in different matrices such as water, groundwater, sediment, sand, fish and the spilled oil itself. The spill studies encompassed crude and fuel oil releases on land and coastal ecosystems, related to the incidents in Guanabara Bay (Rio de Janeiro), Barigui and Iguassu Rivers (Parana) and Sao Sebastiao Channel (Sao Paulo). Total petroleum hydrocarbons (TPH), n -alkanes, isoprenoids, unresolved complex mixtures (UCM), volatile monoaromatic compounds--benzene, toluene, ethylbenzene and xylenes (BTEX), parent and alkylated homologues polycyclic aromatic hydrocarbons (PAH), and terpanes and steranes were characterized for determining correlation to the spilled oil and other known oil sources and environmental assessment. Some of the acute ecotoxicity data for water and sediment samples is also presented. 相似文献
19.
Zhang K Wang JZ Liang B Zeng EY 《Environmental pollution (Barking, Essex : 1987)》2011,159(6):1510-1515
Sediment samples collected from downstream of the Dongjiang River, a highly urbanized river network within the Pearl River Delta of South China, were analyzed for 28 polycyclic aromatic hydrocarbons (PAHs). Total concentrations of 28 PAHs, 16 priority PAHs designated by the United States Environmental Protection Agency (USEPA) and the seven carcinogenic PAHs classified by the USEPA ranged from 480 to 4600, 100 to 3400 and 10 to 1700 ng/g dry weight, respectively. Principal component analysis-based stepwise multivariate linear regression showed that sediment PAHs were predominantly derived from coal combustion, refined fossil fuel combustion and oil spills, accounting for 37%, 32% and 23%, respectively, of the total loading. The levels of sediment PAHs remained steady from 2002 to 2008, during which fossil fuel consumption had doubled, probably reflecting efforts to control PAH emissions from fossil fuel combustion. Finally, use of natural gas and liquefied petroleum gas in automobiles should be encouraged to improve environmental quality. 相似文献