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1.
The aim of this paper is to propose a method for coupling national energy models, to identify the dividends of international cooperation in atmospheric pollution abatement and efficient energy use. It indicates, also, how to solve the resulting large‐scale multinational model. It simulates finally a cooperation of four European countries for curbing their carbon dioxide (CO2) emissions. 相似文献
2.
In this paper we apply graph theory in a reserve selection exercise to explore the tradeoffs between maintaining connectivity and minimizing the total area of a protected area network. Rather than focus on a single organism, we used a multi-species approach and looked at the tradeoff curves for organisms with varying dispersal abilities. We first generated the tradeoff curves using a graph-based metric to determine the importance of individual patches for maintaining connectivity. We then performed an analogous set of analyses using patch size as a surrogate measure of importance. 相似文献
3.
The SITES reserve selection system: A critical review 总被引:1,自引:0,他引:1
Numerous models have been put forth to help with the growing demand for the establishment of biodiversity reserves. One site
selection model that has been used in several recent studies is SITES [S.J. Andelman, I. Ball, F.W. Davis and D.M. Stoms,
SITES V 1.0: an analytical toolbox for designing ecoregional conservation portfolios, Unpublished manual prepared for the
nature conservancy, 1999, 1–43. (available at )]. SITES includes two heuristic solvers: based on Greedy and Simulated Annealing. We discuss the formulation of the SITES
model, present a new formulation for that problem, and solve a number of test problems optimally using off-the-shelf software.
We compared our optimal results with the SITES Simulated Annealing heuristic and found that SITES frequently returns significantly
suboptimal solutions. Our results add further support to the argument, started by Underhill [L.G. Underhill, Optimal and suboptimal
reserve selection algorithms, Biol. Conserv. 70 (1994) 85–87], continuing through Rodrigues and Gaston [A.S.L. Rodrigues and
K.J. Gaston, Optimization in reserve selection procedures – why not?, Biol. Conserv. 107 (2002) 123–129], for greater integration
of optimal methods in the reserve design/selection literature. 相似文献
4.
Designing a conservation reserve network with minimal fragmentation: A linear integer programming approach 总被引:1,自引:0,他引:1
In the biological conservation literature, the optimum reserve site selection problem has often been addressed by using the
prototype set covering and maximal covering formulations, assuming that representation of species is the only criterion in
site selection. This approach usually results in a small but highly fragmented reserve, which is not useful for practical
conservation planning. To improve the chances of species' persistence, it may be desirable to reduce habitat fragmentation.
This paper presents a linear integer programming formulation to minimize spatial gaps between selected sites in a reserve
network, which is applied to a data set on breeding birds.
The authors express their willingness to share the database used in this study. Those readers who wish to have access to the
data may contact Robert A. Briers at r.briers@napier.ac.uk. 相似文献
5.
Models for designing habitat reserve networks have focused on minimizing the number of sites necessary to cover each species
one or more times. A solution to this problem is usually one from among a large number of alternative optimal configurations
of sites. This paper develops an iterative method for building reserve networks that produces an optimal solution to the species
set covering problem (SSCP) and also maximizes the number of species covered two or more times, three or more times, and so
on, conditional on the solution to the previous iteration. We refer to this as representational success. Thus, a pareto optimal species set covering is achieved that is preferable to an arbitrary optimal solution to the SSCP. 相似文献
6.
集对分析用于大气环境质量评价 总被引:3,自引:0,他引:3
简述了集对分析用于大气环境质量综合评价的基本思路,介绍了多项污染物联系度表达式中合成同一度、差异度及对立度的计算公式。通过实例说明了计算的方法和步骤。该法应用于大气环境质量评价的结果是合理的,并针对结果进行了讨论。 相似文献
7.
Marlen D. Eve Kris M. Havstadt Walter G. Whitford Marlen D. Eve 《Environmental monitoring and assessment》1999,54(3):205-227
Considerable evidence documents that certain changes in vegetation and soils result in irreversibly degraded rangeland ecosystems. We used Advanced Very High Resolution Radiometer (AVHRR) imagery to develop calibration patterns of change in the Normalized Difference Vegetation Index (NDVI) over the growing season for selected sites for which we had ground data and historical data characterizing these sites as irreversibly degraded. We used the NDVI curves for these training sites to classify and map the irreversibly degraded rangelands in southern New Mexico. We composited images into four year blocks: 1988–1991, 1989–1992, and 1990–1993. The overlap in pixels classified as irreversibly degraded ranged from 42.6% to 84.3% in year block comparisons. Quantitative data on vegetation composition and cover were collected at 13 sites within a small portion of the study area. Wide coverage reconnaissance of boundaries between vegetation types was also conducted for comparisons with year block maps. The year block 1988–1991 provided the most accurate delineation of degraded areas. The rangelands of southern New Mexico experienced above average precipitation from 1990–1993. The above average precipitation resulted in spatially variable productivity of ephemeral weedy plants on the training sites and degraded rangelands which resulted in much smaller areas classified as irreversibly degraded. We selected imagery for a single year, 1989, which was characterized by the absence of spring annual plant production in order to eliminate the confounding effect of reflectance from annual weeds. That image analysis classified more than 20% of the rangelands as irreversibly degraded because areas with shrub-grass mosaic were included in the degraded classification. The single year image included more than double the area classified as irreversibly degraded by the year blocks. AVHRR imagery can be used to make triage assessments of irreversibly degraded rangeland but such assessment requires understanding productivity patterns and variability across the landscapes of the region and careful selection of the years from which imagery is chosen. 相似文献
8.
D. G. M. Senevirathna G. Achari J. P. A. Hettiaratchi 《Environmental Modeling and Assessment》2007,12(1):1-11
Errors associated with the closed flux chamber technique, used to measure surface emissions from landfills, were investigated
by using a combination of numerical modeling and laboratory studies. A transient-state, advective–dispersive–reactive model
was developed and used in conjunction with its steady-state version to quantify the errors associated with closed flux chambers.
In developing the model, all four major gases, CH4, O2, CO2, and N2, and the oxidation of CH4 to CO2 were considered. Laboratory experiments were conducted on a monolayered as well as a two-layered landfill cover system to
calibrate and verify the model. The model was used to develop a plot of the percentage errors associated with closed flux
chambers of different dimensions and surface flux rates. 相似文献
9.
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11.
The treatment of solid waste is currently one of the major environmental problems facing municipalities. Thousands of tonnes of waste are generated each day, requiring a large area for disposal purposes. It is difficult to find suitable areas for the construction of such sanitary landfills as numerous criteria must be met, and landfill sites vary considerably in terms of their sophistication. The selection criteria for landfill sites should be as simple as possible, and with this in mind, we have evaluated a large number of random cases for the suitability of the site for landfill purposes using the recently advocated fuzzy approach. Using the fuzzy classification, we have attempted to develop a simple classification which uses only certain point values for available attributes. A normalized average of such attributes based on the proposed classifier is further evaluated using additionally generated random data sets. The results appear to be encouraging and indicate that the present classifier can be used as a substitute for the fuzzy-based ranking of landfill sites. 相似文献
12.
The choice of the energy storage technology involves multiple criteria that need to be simultaneously considered in the energy planning process. The development of sustainable energy system requires to take into account not only technical characteristics of storage technologies but also to pursue sustainability issues. The paper aims to perform not-site-specific sustainability assessment of the main types of energy storage technologies (mechanical, chemical, electrochemical and thermal) based on the developed advanced multi-criteria technique. The paper follows the vein of the coordinated Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and extends it to the interval environment. A geometric integer programming model is introduced to identify the interval for the degree of coordination. The proposed method is, therefore, able to handle uncertainty and coordinate performance of the alternatives with respect to multiple criteria. Sustainability assessment of energy storage technologies is performed based on the most important technological, economic, environmental and social criteria. The results showed that the most sustainable energy storage technologies are mechanical and thermal ones (utility scores range in between 1 and 0.75). The remaining technologies exhibit utility scores of 0.69 at most. The least appealing options are electrochemical storage technologies. 相似文献
13.
This article discusses a methodology for assessing and rankinga predefined universe of objects to assist in the selectionof suitable areas for the construction of sanitary landfills.The methodology is, in principle, for universal application. Its development was initially based on the `Value Analysis' methodology and then on the `Fuzzy Eigenvector Method', or `Fuzzy Logic' as it is sometimes referred to. The focus of thestudy herein is on the comparative appraisal of a group ofelements which are part of the guidelines to be adopted whendetermining the choice of the most suitable site for a sanitarylandfill. This set of guidelines includes technical, economical,environmental, social and political aspects. As an example of themethodology proposed, four different areas were chosen. They werestudied to determine which is the most appropriate site for thedevelopment of a new solid waste fill site. The results for thesefour areas, together with the functions chosen and functionweights, are presented here. 相似文献
14.
Bas van Ruijven Jeroen P. van der Sluijs Detlef P. van Vuuren Peter Janssen Peter S. C. Heuberger Bert de Vries 《Environmental Modeling and Assessment》2010,15(3):175-188
Uncertainties in energy demand modelling originate from both limited understanding of the real-world system and a lack of
data for model development, calibration and validation. These uncertainties allow for the development of different models,
but also leave room for different calibrations of a single model. Here, an automated model calibration procedure was developed
and tested for transport sector energy use modelling in the TIMER 2.0 global energy model. This model describes energy use
on the basis of activity levels, structural change and autonomous and price-induced energy efficiency improvements. We found
that the model could reasonably reproduce historic data under different sets of parameter values, leading to different projections
of future energy demand levels. Projected energy use for 2030 shows a range of 44–95% around the best-fit projection. Two
different model interpretations of the past can generally be distinguished: (1) high useful energy intensity and major energy
efficiency improvements or (2) low useful energy intensity and little efficiency improvement. Generally, the first lead to
higher future energy demand levels than the second, but model and insights do not provide decisive arguments to attribute
a higher likelihood to one of the alternatives. 相似文献
15.
A variety of decision models have been formulated for the optimal selection of nature reserve sites to represent a diversity
of species or other conservation features. Unfortunately, many of these models tend to select scattered sites and do not take
into account important spatial attributes such as reserve shape and connectivity. These attributes are likely to affect not
only the persistence of species but also the general ecological functioning of reserves and the ability to effectively manage
them. In response, researchers have begun formulating reserve design models that improve spatial coherence by controlling
spatial attributes. We review the spatial attributes that are thought to be important in reserve design and also review reserve
design models that incorporate one or more of these attributes. Spatial modeling issues, computational issues, and the trade-offs
among competing optimization objectives are discussed. Directions for future research are identified. Ultimately, an argument
is made for the development of models that capture the dynamic interdependencies among sites and species populations and thus
incorporate the reasons why spatial attributes are important. 相似文献
16.
Efficiency,costs and trade-offs in marine reserve system design 总被引:1,自引:0,他引:1
With marine biodiversity conservation the primary goal for reserve planning initiatives, a site's conservation potential is
typically evaluated on the basis of the biological and physical features it contains. By comparison, socio-economic information
is seldom a formal consideration of the reserve system design problem and generally limited to an assessment of threats, vulnerability
or compatibility with surrounding uses. This is perhaps surprising given broad recognition that the success of reserve establishment
is highly dependent on widespread stakeholder and community support. Using information on the spatial distribution and intensity
of commercial rock lobster catch in South Australia, we demonstrate the capacity of mathematical reserve selection procedures
to integrate socio-economic and biophysical information for marine reserve system design. Analyses of trade-offs highlight
the opportunities to design representative, efficient and practical marine reserve systems that minimise potential loss to
commercial users. We found that the objective of minimising the areal extent of the reserve system was barely compromised
by incorporating economic design constraints. With a small increase in area (<3%) and boundary length (<10%), the economic
impact of marine reserves on the commercial rock lobster fishery was reduced by more than a third. We considered also how
a reserve planner might prioritise conservation areas using information on a planning units selection frequency. We found
that selection frequencies alone were not a reliable guide for the selection of marine reserve systems, but could be used
with approaches such as summed irreplaceability to direct conservation effort for efficient marine reserve design. 相似文献
17.
Markus Kirkilionis 《Environmental Modeling and Assessment》1997,2(4):297-306
The paper discusses the importance of understanding structural perturbations of models used in mathematical biology, where we mainly focus on ecology and dynamical systems. We describe first briefly the classical modeling strategy and the derivation of model structures. Structural perturbations are then discussed, mainly in the framework of ODEs. We give some examples how insights obtained from this type of model could be transfered to other kinds of models. Finally we propose an alternative modeling strategy characterized by a systematic investigation of a models neighbourhood in an appropriately chosen model class. 相似文献
18.
2013年4月至2015年4月,利用红外触发自动相机开展保护区野生动物的监测研究,在保护区内的9个水源地布设了红外相机进行监测。监测期间共拍摄到照片73 421张,共记录到35种野生动物,其中兽类13种,鸟类22种,包括野骆驼、藏野驴、雪豹以及胡兀鹫、金雕、高山秃鹫等国家Ⅰ级保护动物。拍摄率最高的前5种食草动物分别是野骆驼、藏野驴、鹅喉羚、岩羊、盘羊,也是保护区观测区域中分布最广泛的物种。其中,野骆驼在9个位点都被拍到照片,是水源地占优势地位的物种。 相似文献
19.
The performance of four mathematical models (hockey stick, biexponential, first-order double exponential decay, and first-order two-compartment) was evaluated to describe the dissipation kinetics for 4-n-nonylphenol (4-n-NP) and bisphenol-A (BPA) in groundwater-aquifer material slurry under aerobic and anaerobic conditions conducted under controlled laboratory conditions. The fit of each model to the measured values under both conditions was tested using an array of statistical indices to judge the model's ability to fit the measured datasets. Corresponding 50% (DT(50)) and 90% (DT(90)) dissipation values for each compound were numerically obtained and compared against each model. The model derived DT(50) values in groundwater-aquifer material ranged from 1.06 to 1.24 (4-n-NP) and 0.341 to 0.568 days (BPA) under aerobic condition, while they were 2- to 4-fold higher under anoxic condition. DT(90) values for 4-n-NP ranged anywhere between 2.3 and 4.45 days under both conditions, while DT(90) values for BPA ranged from around 1 day to as high as 12 days under both conditions tested. A visual examination of the measured and fitted plots as well as the statistical indices showed that, with the exception of the hockey stick model, the models performed satisfactorily. Despite having only 3 parameters, the biexponential model could describe the dissipation kinetics very well and this was supported by the statistical indices generated for each case. 相似文献
20.
Coupling GIS and mulitvariate approaches to reference site selection for wadeable stream monitoring 总被引:1,自引:0,他引:1
Geographic Information System (GIS) was used to identify potential reference sites for wadeable stream monitoring, and multivariate analyses were applied to test whether invertebrate communities reflected a priori spatial and stream type classifications. We identified potential reference sites in segments with unmodified vegetation cover adjacent to the stream and in >85% of the upstream catchment. We then used various landcover, amenity and environmental impact databases to eliminate sites that had potential anthropogenic influences upstream and that fell into a range of access classes. Each site identified by this process was coded by four dominant stream classes and seven zones, and 119 candidate sites were randomly selected for follow-up assessment. This process yielded 16 sites conforming to reference site criteria using a conditional-probabilistic design, and these were augmented by an additional 14 existing or special interest reference sites. Non-metric multidimensional scaling (NMS) analysis of percent abundance invertebrate data indicated significant differences in community composition among some of the zones and stream classes identified a priori providing qualified support for this framework in reference site selection. NMS analysis of a range standardised condition and diversity metrics derived from the invertebrate data indicated a core set of 26 closely related sites, and four outliers that were considered atypical of reference site conditions and subsequently dropped from the network. Use of GIS linked to stream typology, available spatial databases and aerial photography greatly enhanced the objectivity and efficiency of reference site selection. The multi-metric ordination approach reduced variability among stream types and bias associated with non-random site selection, and provided an effective way to identify representative reference sites. 相似文献