The Environmental Impact Assessment (EIA) procedure should predict and identify the major impacts of a project development that may cause specific spatial and temporal effects. Early in the EIA, the scoping stage provides all the relevant information on the impacts of the project alternatives. In particular, potential effects on the territorial network such as habitat connectivity loss and accessibility improvements should be taken into account in the various proposed layout alternatives when evaluating transport infrastructure projects. However, several authors have identified deficiencies in practice. The aim of this article is to provide a methodology for the assessment of these territorial impacts using adequate indicators in the early stages of the EIA procedure.
The proposed method is based on a comparison of a range of alternative layouts for a railway line linking two population centres, using indicators calculated with geographic information systems. The methodology was applied to a case study – the rail link between Huelva (Spain) and Faro (Portugal) – and the high speed rail (HSR) and conventional rail were evaluated in different layouts. The method was effective in spatially identifying significant impacts on accessibility improvements, which occurred closer to the cross border area. The conventional railway alternatives have similar accessibility values to the HSR. The results also reveal that connectivity loss is not limited to the area around the infrastructure, but extends throughout the territory. The results are at variance with the initiative proposed by Spanish and Portuguese transport decision-makers, and raise the possibility of selecting a conventional railway option. An adequate territorial evaluation methodology enables the new action to be correctly assessed, and supplies the information required to propose the most suitable alternative from a socio-economic and environmental standpoint, regardless of whether this proposal was initially included in the transport policy. 相似文献
Assessing the sustainability of complex development processes requires multi-causal and integrated analyses. We develop a
system-based methodology, rooted in interdisciplinary discussion and consensus building between 15 experts, to construct a
multi-causal diagram which examines the sustainability of the Argentine Pampas′ process of agriculturization. The resulting
diagram includes 25 factors and provides a big-picture of the multiple dimensions and interrelations affecting sustainability.
According to this examination, the increasing concentration of production and the incorporation of technological innovations,
triggered by economic and institutional factors, are the cause of environmental distresses and social changes, whose consequences
for sustainability are still highly disputed. Nevertheless, the symptoms of both environmental and social unsustainability
are more evident in the case of the extra-Pampean regions than in the Pampas. This suggests that the Pampean agriculture model
should not be transferred to these regions without substantial modifications. The experts did not reach consensus on whether
the agriculturization process is overall sustainable or unsustainable. Lack of consensus revolved mainly around opposing perspectives
regarding the significance of the threats to environmental sustainability. The magnitude of socio-distributive unbalance and
loss of rural jobs were also contentious. Yet, the paper shows how the exercise of building a joint causal diagram was undoubtedly
helpful for linking piece-meal disciplinary facts, brought in from all fronts, into a comprehensive and coherent picture.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
Background, aim, and scope In this work, the potential for using olive-mill solid waste as an organic amendment for biochemical and biological restoration
of a trichloroethylene-contaminated soil, which has previously been stabilized through vermicomposting processes, has been
explored.
Materials and methods Trichloroethylene-contaminated water was pumped into soil columns with a layer of vermicompost at 10-cm depth (biobarrier
system). The impacts of the trichloroethylene on the microbial community were evaluated by determining: (1) the overall microbial
activity (estimated as dehydrogenase activity) and enzyme activities related to the main nutrient cycles (β-glucosidase, o-diphenoloxidase, phosphatase, urease, and arylsulphatase activities). In addition, isoelectric focusing of the soil extracellular
humic-β-glucosidase complexes was performed to study the enzymatically active humic matter related to the soil carbon cycle.
(2) The soil bacterial diversity and the molecular mechanisms for the bacterial resistance to organic solvents were also determined.
For this, polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) was used to detect changes in bacterial
community structure and PCR-single-strand conformational polymorphism (SSCP) was developed and optimised for detection and
discrimination of the resistance-nodulation-division (RND) genes amplified from the contaminated soils.
Results Vermicompost reduced, with respect to the unamended soil, about 30% of the trichloroethylene leaching during the first month
of the experiment. Trichloroethylene had a marked negative effect on soil dehydrogenase, β-glucosidase, urease, phosphatase,
and arylsulphatase activities. Nevertheless, the vermicompost tended to avoid this toxic effect. Vermicompost also displays
stable humic-β-glucosidase complexes that increased the extracellular activity related to C-cycle in the contaminated soils.
The isoelectric focusing technique showed a more biochemically active humic matter in the soil sampled under the vermicompost.
The behaviour of the three main phyla of bacteria isolated from the DGGE bands was quite different. Bands corresponding to
Actinobacteria disappeared, whereas those affiliated with Proteobacteria remained after the trichloroethylene contamination. The disappeared Actinobacteria became visible in the soil amended with the vermicompost. Bands corresponding to Bacteriodetes appeared only in columns of contaminated soils. In this study, six types of RND proteins were detected by PCR-SSCP in the
natural soil, three in the trichloroethylene-contaminated soil and 7/5 in trichloroethylene-contaminated soil above/below
the vermicompost in the biobarrier columns. Trichloroethylene tended to reduce or eliminate all the clones detected in the
uncontaminated soil, whereas new efflux pumps appeared in the biobarrier columns.
Discussion Although enzymes incorporated into the humic substances of vermicomposted olive wastes are quite stable, trichloroethylene
also inhibited the background levels of the soil extracellular β-glucosidase activity in the amended soils. The decrease was
less severe in the biobarrier system, but in any case, no relation was found between the levels of trichloroethylene in soil
and extracellular β-glucosidase activity, or between the latter and the quantity of humic carbon in soils. The isoelectric
focusing technique was carried out in the humic fraction to determine whether the loss of activity occurred in overall extracellular
β-glucosidase or in that linked to stable humic substances (humic–enzyme complexes). The contaminated soils showed the lower
enzyme activities, whereas contaminated and amended soils presented greater quantity of focalised (and therefore stable) humic
carbon and spectra heterogeneity: very different bands with higher enzyme activities. No clear relationship between trichloroethylene
concentration in soil and diversity of the bacterial population was noted. Similar patterns could be found when the community
structures of bacteria and microbial activity were considered. Since the use of the dehydrogenase assay has been recognised
as a useful indicator of the overall measure of the intensity of microbial metabolism, these results could be attributed to
PCR-DGGE methodology, since the method reveals the presence of dominant populations regardless of their metabolic state. Trichloroethylene
maintained or even increased the number of clones with the DNA encoding for RND proteins, except for the contaminated soil
located above the vermicompost. However, the main effect of trichloroethylene was to modify the structure of the community
in contaminated soils, considering the type of efflux pumps encoded by the DNA extracted from soil bacteria.
Conclusions Trichloroethylene inhibited specific functions in soil and had a clear influence on the structure of the autochthonous bacterial
community. The organic matter released by the vermicomposted olive waste tended to avoid the toxic effect of the contaminant.
Trichloroethylene also inhibited the background levels of the soil extracellular β-glucosidase activity, even when vermicompost
was present. In this case, the effect of the vermicompost was to provide and/or to stimulate the humic-β-glucosidase complexes
located in the soil humic fraction >104, increasing the resistance of the enzyme to the inhibition. The bacterial community from the soil presented significantly
different mechanisms to resistance to solvents (RND proteins) under trichloroethylene conditions. The effect of the vermicompost
was to induce these mechanisms in the autochthonous bacterial community and/or incorporated new bacterial species, able to
grow in a trichloroethylene-contaminated ambient. Coupled biochemical and molecular methodologies are therefore helpful approaches
in assessing the effect of an organic amendment on the biochemical and biological restoration of a trichloroethylene-contaminated
soil.
Recommendations and perspectives Since the main biochemical and biological effects of the organic amendment on the contaminated soil seem to be the incorporation
of biochemically active humic matter, as well as new bacterial species able to grow in a trichloroethylene-contaminated ambient,
isoelectric focusing and PCR-SSCP methodologies should be considered as parts of an integrated approach to determine the success
of a restoration scheme. 相似文献
Joostella strains are emerging candidates for biosurfactant production. Here such ability was analyzed for Joostella strain A8 in comparison with Alcanivorax strain A53 and Pseudomonas strain A6, all previously isolated from hydrocarbon enrichment cultures made of polychaete homogenates. In pure cultures Joostella sp. A8 showed the highest stable emulsion percentage(78.33%), hydrophobicity rate(62.67%), and an optimal surface tension reduction during growth in mineral medium supplemented with diesel oil(reduction of about 12 mN/m), thus proving to be highly competitive with Alcanivorax and Pseudomonas strains. During growth in pure culture different level of biodegradation were detected for Alcanivorax strain A53(52.7%),Pseudomonas strain A6(38.2%) and Joostella strain A8(26.8%). When growing in consortia,isolates achieved similar abundance values, with the best efficiency that was observed for the Joostella-Pseudomonas co-culture. Gas-chromatographic analysis revealed an increase in the biodegradation efficiency in co-cultures(about 90%), suggesting that the contemporary action of different bacterial species could improve the process. Results were useful to compare the efficiencies of well-known biosurfactant producers(i.e. Pseudomonas and Alcanivorax representatives) with a still unknown biosurfactant producer, i.e. Joostella, and to confirm them as optimal biosurfactant-producing candidates. 相似文献
The key to any QSAR model is the underlying dataset. In order to construct a reliable dataset to develop a QSAR model for pesticide toxicity, we have derived a protocol to critically evaluate the quality of the underlying data. In developing an appropriate protocol that would enable data to be selected in constructing a QSAR, we concentrated on one toxicity end point, the 96 h LC50 from the acute rainbow trout study. This end point is key in pesticide regulation carried out under 91/414/EEC. The dataset used for this exercise was from the US EPA-OPP database. 相似文献
The social pillar has often been treated as an ‘add on’ in sustainable development studies, and analyses of its ‘proactivity’ in economic, environmental, and social transformations to sustainability outcomes are scant. The present paper looks at the social dimension as a key driver of sustainable development. Social factors in the farming system in southeast Spain are analyzed to show how family farms and their networks can integrate socio-economic and eco-social goals, promoting the generation of synergies and trade-offs between the dimensions of sustainability. This study contributes to existing debate on the role of family farms in the framework of European rural development. 相似文献
Environmental Geochemistry and Health - A theoretical pattern for Fe and As co-precipitation was tested directly in a groundwater natural system. Several monitoring wells were sampled to identify... 相似文献
In a previous paper, we reported that juvenile barn swallows (Hirundo rustica) trapped during the autumn migratory season and tested in modified Emlen funnels under overcast conditions can use magnetic
information for compass orientation, although they did not orient toward the expected migratory direction. To further investigate
this behaviour, in the present paper, we report the results of two series of displacement experiments performed on juvenile
barn swallows belonging to two different roost sites [Massaciuccoli Lake (ML) and Terzo Cavone (TC)] and tested using the
same protocol as that previously adopted. On the whole, the outcome of the ML and TC experiments was quite different with
respect to (a) the degree of bird activity within the funnel (substantially lower for TC) and (b) the effect of the experimental
displacement on the directional preferences of the tested subjects (not detectable in TC, while evident in ML swallows). Taken
together, these results suggest that migrating swallows could react differently to the experimental tests depending on the
roost site where they were caught. Indeed, TC swallows, trapped in southern Italy, close to the seacoast, and characterized
by fairly large amounts of fat stores, mainly broke off their migratory activity or reoriented their directional preferences
toward inland sites, possibly in search of more profitable habitats. On the other hand, ML swallows, trapped about 660 km
to the north and characterized by lower amounts of fat stores, apparently tried to compensate for the experimental displacement.
Living organisms and ecosystems have been shown to be sensitive to very weak signals originating very far away. The dynamics governing these phenomena is discussed in the framework of Quantum Field Theory. This phenomenon gives an indication on the dynamics responsible for the exchange of information in ecosystems. The peculiar role of coherent water is stressed. It is shown that energy is able to travel in a coherent medium in form of solitons, without any losses. 相似文献