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201.
Bentrup G 《Environmental management》2001,27(5):739-748
Collaborative planning processes have become increasingly popular for addressing environmental planning issues, resulting
in a number of conceptual models for collaboration. A model proposed by Selin and Chavez suggests that collaboration emerges
from a series of antecedents and then proceeds sequentially through problem-setting, direction-setting, implementation, and
monitoring and evaluation phases. This paper summarizes an empirical study to evaluate if the Selin and Chavez model encompasses
the range of factors important for the establishment and operation of collaboration in watershed planning from the perspective
of the planning coordinator. Analysis of three case studies of watershed based planning efforts in the Intermountain West
suggests the model realistically describes some of the fundamental collaborative elements in watershed planning. Particularly
important factors include the involvement of stakeholders in data collection and analysis and the establishment of measurable
objectives. Informal face-to-face dialog and watershed field tours were considered critical for identifying issues and establishing
trust among stakeholders. Group organizational structure also seems to play a key role in facilitating collaboration. From
this analysis, suggestions for refining the model are proposed. 相似文献
202.
/ Marginal aquatic systems (wetlands) of the Po River (Italy) have become the target of a renewed interest because of their value for recreation, natural reserves, and deposits of sand. To preserve these sites, wise management must be the objective of local administrations. In this paper a strategy for the sustainable use of 11 wetlands is presented. It uses simple economic analysis and multiple criteria techniques and provides suggestions to promote sustainability in terms of conservation of natural resources, economic self-sufficiency, and minimization of potential conflicts about the use of the wetlands. In the understanding that sustainability is framed in a long-term perspective, stability analysis is also considered and performed by means of loop analysis, a qualitative technique. Conditions for stability are then discussed about management opportunities. 相似文献
203.
Determination of Q1, an unknown organochlorine contaminant, in human milk, Antarctic air, and further environmental samples 总被引:2,自引:0,他引:2
Vetter W Alder L Kallenborn R Schlabach M 《Environmental pollution (Barking, Essex : 1987)》2000,110(3):6188-409
Q1, an organochlorine component with the molecular formula C(9)H(3)Cl(7)N(2) and of unknown origin was recently identified in seal blubber samples from the Namibian coast (southwest of Africa) and the Antarctic. In these samples, Q1 was more abundant than PCBs and on the level of DDT residues. Furthermore, Q1 was more abundant in seals from the Antarctic than the Arctic. To prove this assumption, gas chromatography-electron-capture negative ion mass spectrometry (GC/ECNI-MS), which is sensitive and selective for Q1, allowed for screening of traces of Q1 even in samples with particularly high levels of other organochlorine contaminants. Q1 was isolated by high-performance liquid chromatography (HPLC) from a skua liver sample. A 1:1 mixture with trans-nonachlor in electron-capture detectors (ECDs) was used to determine the relative response factor with ECNI-MS. The ECNI-MS response of Q1 turned out to be 4.5 times higher than that of trans-nonachlor in an ECD. With GC/ECNI-MS in the selected ion-monitoring mode, four Antarctic and four Arctic air samples were investigated for the presence of Q1. In the Antarctic air samples, Q1 levels ranged from 0.7 to 0.9 fg/m(3). In Arctic air samples, however, Q1 was below the detection limit (<0.06 fg/m(3) or 60 ag/m(3)). We also report on high Q1 levels in selected human milk samples (12-230 microg/kg lipid) and, therefore, suggested that the unknown Q1 is an environmental compound whose origin and distribution should be investigated in detail. Our data confirm that Q1 is a bioaccumulative natural organochlorine product. Detection of a highly chlorinated natural organochlorine compound in air and human milk is novel. 相似文献
204.
After the flooding in 2002 European governments provided billions of Euros of financial assistance to their citizens. Although there is no doubt that solidarity and some sort of assistance are reasonable, the question arises why these damages were not sufficiently insured. One explanation why individuals reject to obtain insurance cover against natural hazards is that they anticipate governmental and private aid. This problem became to be known as “charity hazard”. The present paper gives an economic analysis of the institutional arrangements on the market for natural disaster insurances focusing on imperfections caused by governmental financial relief. It provides a theoretical explanation why charity hazard is a problem on the market for natural disaster insurances, in the way that it acts as an obstacle for the proper diffusion and therefore the establishment of natural hazard insurances. This paper provides a review of the scientific discussion on charity hazard, provides a theoretical analysis and points out the existing empirical problems regarding this issue. 相似文献
205.
Chemical Treatments of Natural Fiber for Use in Natural Fiber-Reinforced Composites: A Review 总被引:2,自引:0,他引:2
Xue Li Lope G. Tabil Satyanarayan Panigrahi 《Journal of Polymers and the Environment》2007,15(1):25-33
Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced composites have increased and opened
up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However,
the main disadvantages of natural fibers in composites are the poor compatibility between fiber and matrix and the relative
high moisture sorption. Therefore, chemical treatments are considered in modifying the fiber surface properties.
In this paper, the different chemical modifications on natural fibers for use in natural fiber-reinforced composites are reviewed.
Chemical treatments including alkali, silane, acetylation, benzoylation, acrylation, maleated coupling agents, isocyanates,
permanganate and others are discussed. The chemical treatment of fiber aimed at improving the adhesion between the fiber surface
and the polymer matrix may not only modify the fiber surface but also increase fiber strength. Water absorption of composites
is reduced and their mechanical properties are improved. 相似文献
206.
P. H. Anderson M. W. Lefor W. C. Kennard 《Journal of the American Water Resources Association》1980,16(2):248-255
ABSTRACT: The delineation of inland wetlands requires close field examination of the biological and physical gradients (transition zones) between wetlands and bordering uplands. As part of a study on the detection and delineation of inland wetlands in eastern Connecticut by remote sensing techniques, this effort was designed to investigate vegetation distribution and composition and selected physical and chemical properties of the soils of wetland to upland transition zones in deciduous wetland forests. Field research was conducted during the growing season of 1975 within a test area consisting of the 45 mi2 Town of Mansfield, Connecticut. Changes in vegetation composition and structure, soil pH, and soil water content were determined along line transects extended over wetland to upland transition zones. Differences in soil pH occurred along the transects but were of such magnitude that they probably have little impact on plant distribution. There were significant changes in soil water content along the wetland to upland gradients. Discriminant analysis applied to statistical “index of abundance” data describing vegetation distribution among the various zones (wetland, transition, upland) showed which plant species best distinguish wetlands from uplands. Of the criteria studied, vegetation composition and distribution, soil water content, and relief are the most useful criteria for delineating deciduous wetland forests. 相似文献
207.
New York City’s extensive municipal park system is home to forests, wetlands, and grasslands that provide important ecological and social benefits to the city’s population. While efforts and programs exist to restore and protect these spaces, management recommendations are complex due to variable conditions in urban natural areas. To advance the management of urban natural areas, the first comprehensive ecological assessment was conducted through a collaborative effort across 4000 ha of natural areas within New York City parkland. Field and spatial data were collected and analyzed to identify the extent of forests, the types of forests, and their conditions. This approach will help guide decision-making and prioritization of natural area management at the regional level by developing unique quantitative targets for urban forests. This project serves as an example of collaboration between private and public institutions advancing the governance of urban natural areas to achieve citywide conservation and policy goals. 相似文献
208.
Several international initiatives, including the European Biodiversity Strategy to 2020, promote the identification and mapping of ecosystems as basic tools for the conservation of biodiversity and related services. On coarse scales, the spatial representation of ecosystems is usually based on broad land cover categories that largely overlook important ecological and biogeographic features of the biotic communities they are meant to exemplify. This paper presents a nationwide ecosystem mapping approach that promotes a degree of thematic detail, which is more suited than that found in the continental maps to meeting biodiversity conservation targets in Italy. The approach is based on the rationale that current and potential vegetation cover are valuable proxies for outlining ecosystems. The resulting Ecosystem Map of Italy includes 43 types of forest ecosystems instead of the 5 woodland, forest and other wooded land types recognized at the European level. We outline the expected advantages of this enhanced thematic detail for a number of conservation purposes and highlight how the resulting maps may help to meet biodiversity conservation targets at the national level. In particular, we refer to the assessment of conservation status, the definition of restoration priorities, the planning of green infrastructure and the identification of collapse risks for the ecosystems identified. Comprehensively, the definition, characterization and assessment of ecosystem types represent the carrying structure of the recently launched national system of natural capital accounting. 相似文献
209.
填料在自由水面人工湿地中的应用 总被引:4,自引:0,他引:4
本文通过对深圳市某橡胶厂自行设计造的自由水面人工湿地的调查研究,分析了在人工湿地中采用填料代替植物的工作特性,并论证了土壤-植物-微笑一这样一个生态系统是传统自由水面湿地处理系统实现其处理污水功能的核心。 相似文献
210.
Fabio Orecchini 《Sustainability Science》2007,2(2):245-252
Human society consumes resources that it is not able to reproduce. Human activities are still based on “open cycles,” starting
from a condition of natural environmental balance and reaching an environmental imbalance. The challenging scope of scientific
and technological research towards sustainability appears clear if it is based on this analysis: to find development systems
based on “closed cycles” of resources. The challenging objective of realizing closed cycles leads to a definition of sustainability
that indicates the path to sustainable development, as well as stating the general principle. It also provides a key to the
qualitative measurement of sustainability. This means that the sustainability level of a system can be measured by measuring
its capacity to avoid the consumption of resources. Zero consumption is a necessary condition for sustainability, and brings
about as a side effect the highly desired “zero-waste” result. Materials entering the proposed endless scheme pass through
the process of usefulness without losing their capacity to feed the system again after being used. Thus, the concept of “consumption”
itself is replaced by one of “use” when resources are inserted into closed loops capable of feeding human development. The
application of the closed cycle sustainability criterion particularly displays its feasibility, and a theoretical guiding
role, in the energy sector. Energy vectors such as hydrogen and electricity enable the closure of the energy resources loop
by effectively approaching the objective of “zero consumption” (and the side result of “zero waste”) through already demonstrated
technological solutions. 相似文献