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1.
A technique is presented to solve analytically the turbulent diffusion equation for the concentration of a passive contaminant emitted from an elevated continuous source into the atmosphere. A generalized method of solution using Sturm–Liouville and WKB theories is developed to overcome difficulties due to the height‐dependent wind velocity and diffusion coefficient appearing in the diffusion equation. The method presented in this paper is able to derive an asymptotic expression for the concentration obtained from the solution of the atmospheric diffusion equation which involves explicitly inhomogeneous wind velocity and diffusion coefficient. The diffusion equation model derived from this method can be applied in a practical prediction of contaminant concentration in a turbulent atmosphere. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

2.

The management of end-of-life vehicles conserves natural resources, provides economic benefits, and reduces water, air, and soil pollution. Sound management of end-of-life vehicles is vitally important worldwide thus requiring sophisticated decision-making tools for optimizing its efficiency and reducing system risk. This paper proposes an interval-parameter conditional value-at-risk two-stage stochastic programming model for management of end-of-life vehicles. A case study is conducted in order to demonstrate the usefulness of the developed model. The model is able to provide the trade-offs between the expected profit and system risk. It can effectively control risk at extremely disadvantageous availability levels of end-of-life vehicles. The formulated model can produce optimal solutions under predetermined decision-making risk preferences and confidence levels. It can simultaneously determine the optimal long-term allocation targets of end-of-life vehicles and reusable parts as well as capital investment, production planning, and logistics management decisions within a multi-period planning horizon. The proposed model can efficiently handle uncertainties expressed as interval values and probability distributions. It is able to provide valuable insights into the effects of uncertainties. Compared to the available models, the resulting solutions are far more robust.

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3.
This study explores Knowledge Brokerage (KB) aspects of an ex-post Impact Assessment (IA) for the Rural Development Programme (RDP) measure of setting up young farmers, under the Common Agricultural Policy (CAP), at the regional level in Northern Greece. The measure supports the entry of young farmers in agriculture by moving land from older to younger farmers. The aim of the study was to test a set of KB tools for improving the interaction between researchers and policy makers. Our analysis mainly focused on a suite of IA Support Modules to guide practitioners, and on a technical tool kit, a web-based contextualisation platform, to support the IA of the specific test case. Offering a structured approach towards IA, both the Support Modules and LIAISE-KIT allow framing the context, organisation, scheduling and method selection in the light of KB objectives. The evaluation of how IA Support Modules influence the Science Policy Interface (SPI), in the case of the ex-post assessment, demonstrated the high relevance of KB activities for facilitating the interaction between researchers and regional policy makers. The assessment bridges the gap between knowledge producers developing scientific output to be applied in a specific context, and knowledge users, who want clear messages regarding the policy challenges they face. Other conclusions include the need for specific guidelines and training for knowledge users, especially with regard to the use of tools. According to our findings, a consequent application of KB activities is a crucial pre-condition for successfully implementing IAs in future RDP measures.  相似文献   

4.
The exploitation and degradation of natural environments exert intense pressure on important ecosystems worldwide. Thus, it is necessary developing or adapting assessment methods to monitor environmental changes and to generate results to be applied to environmental management programs. The Brazilian Veredas (phytophysiognomies typical to the Cerrado biome) are threatened by several human activities; thus, the aim of the present study is to adapt a rapid assessment protocol (RAP) to be applied to Veredas springs, by using the upper course of the Vai-e-Vem stream watershed (Ipameri County, Goiás State, Brazil). Therefore, several springs in the study site were visited and 11 of them were considered Veredas springs. After the RAP was adapted, the instrument was validated and used to environmentally assess the springs in order to demonstrate its applicability. The present study has provided an instrument of option to monitor Veredas springs.  相似文献   

5.
Integrated assessment (IA) can be defined as a structured process of dealing with complex issues, using knowledge from various scientific disciplines and/or stakeholders, such that integrated insights are made available to decision makers (J. Rotmans, Enviromental Modelling and Assessment 3 (1998) 155). There is a growing recognition that the participation of stakeholders is a vital element of IA. However, only little is known about methodological requirements for such participatory IA and possible insights to be gained from these approaches. This paper summarizes some of the experiences gathered in the ULYSSES project, which aims at developing procedures that are able to bridge the gap between environmental science and democratic policy making for the issue of climate change. The discussion is based on a total of 52 IA focus groups with citizens, run in six European and one US city. In these groups, different computer models were used, ranging from complex and dynamic global models to simple accounting tools. The analysis in this paper focuses on the role of the computer models. The findings suggest that the computer models were successful at conveying to participants the temporal and spatial scale of climate change, the complexity of the system and the uncertainties in our understanding of it. However, most participants felt that the computer models were less instrumental for the exploration of policy options. Furthermore, both research teams and participants agreed that despite considerable efforts, most models were not sufficiently user-friendly and transparent for being accessed in an IA focus group. With that background, some methodological conclusions are drawn about the inclusion of the computer models in the deliberation process. Furthermore, some suggestions are made about how given models should be adapted and new ones developed in order to be helpful for participatory IA. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

6.
In environmental decisions, analysts commonly face substantial uncertainties around stakeholders’ values judgments. Multi-Attribute Value Theory (MAVT), a family of multi-criteria decision analysis techniques, is applied in participative settings to articulate stakeholders’ values in decision-making. In MAVT, value judgments represent the intensity of individuals’ preferences in a set of objectives, which are operationalized as scaling factors or weights. Different sets of weights may express variation in people’s preferences or value judgments. Unfortunately, there are still important methodological gaps regarding how to incorporate uncertainty and the substantial variation commonly encountered in stakeholders’ preferences. This article presents a model of uncertainty that encompasses the dispersion of value judgments in MAVT. To achieve this goal, we draw on info-gap theory, which provides a mathematically grounded method for exploring sensitivity to preference weights when there are relatively high levels of uncertainties. We experimentally tested the uncertainty model in an environmental decision problem. We found that MAVT can use info-gap analysis to deal with multiple value judgments, avoiding exclusive reliance on nominal expected values to inform decisions. We explored a mechanism to explicitly consider the trade-offs between the performance of alternatives and the level of uncertainty that in any specified context a decision maker is willing to accept. Findings emphasize the potential of MAVT to support environmental management decisions, particularly in situations where multiple stakeholders and their contested value judgments have to be considered simultaneously to explore uncertainties around value trade-offs.  相似文献   

7.
Integrated Assessment: an emerging methodology for complex issues   总被引:1,自引:0,他引:1  
Over recent years Integrated Assessment (IA) has been presented as a new and innovative approach to modern decision making. In this paper we explore some of the key features that we consider characterise IA; we present IA as a framework that allows a flexible approach to uncertainty in decision making and to which a broad palette of expertise can contribute. The example of the development of an international agreement to reduce acidic deposition is used to illustrate the current practical status of an IA. The scientific process leading to this agreement has previously been described as IA but we argue that, although it marks a change from traditional approaches, further progress is still required to satisfy the requirements for a successful and durable IA.  相似文献   

8.
Integrated Environmental Assessment (IEA) can be loosely defined as policy‐relevant, multidisciplinary research on environmental issues. Many, diverse activities in this broad field are ongoing, but the approaches lack the structure, standardization and quality control common in disciplinary research. IEA has three stages: “structuring the problem”, “analyzing the problem” and “communicating the findings and insights”. Each stage has its inherent difficulties, not least because problem definition and analysis are neither separable nor unambiguous nor unique. Difficulties are exacerbated in the first and third stages by the necessity for science and policy to work together. Difficulties are exacerbated in the second stage by the necessity of different scientific disciplines to cooperate. The European Forum on Integrated Environmental Assessment is an initiative to improve scientific quality and policy‐relevance of IEA, by organizing two series of workshops, one looking in detail at current and desired scientific practices, the other reviewing current and establishing further applications of IEA to environmental issues in Europe. This revised version was published online in July 2006 with corrections to the Cover Date. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
The concept that a few well chosen, strategically placed, water quality stations can provide valuable scientific information to water managers is common to many countries. Historically within Canada, water quality regional networks (Great Lakes network, Prairie Provinces Water Board network, Long Range Transport of Airborne Pollutants network, etc.) have been successfully operating for many years. This paper will describe the difficulties associated with developing a national water quality network for a country the size of Canada. In particular, it will describe some of the statistical tools presently being used in regional networks which are suitable for a national network, and discuss the need to develop new statistical tools for environmental monitoring in the 1990's.  相似文献   

10.
对于企业的环境风险管理,目前多侧重于风险发生后的应急机制的建立。探讨了如何拓展环境风险管理的思路,结合项目管理和企业管理的全过程,将环境风险管理细化并融入对企业日常的环境管理和企业自身的日常管理之中,减少管理成本,从环保部门和企业双方将环境风险的发生概率降低到最低程度,实现整体安全。  相似文献   

11.
Uncertainty is an inherent part of impact assessment (IA), and can vary in type and source. However, according to previous research, uncertainty is rarely explicitly acknowledged and handled in IA, indicating that it is a challenging issue in practice. This paper adds to the current research body a study of EIA in Greenland, which includes a document study of EIA reports as well as white papers and summaries from public hearings. The study findings are in line with previous results, finding a limited explicit acknowledgement of uncertainty, although uncertainty is indicated through implicit language use. The study also finds that various tools are applied, which could be used for handling uncertainty, including sensitivity analysis, monitoring and worst-case estimates. However, often these tools are not used systematically, and it is not transparent whether they are targeted at handling uncertainty. Regarding the examination of materials from hearing processes, there is little evidence that uncertainty is part of the discussions. These results initiate discussions of how choices of whether and how to acknowledge and handle uncertainty are made, and how consciously participants in the process make these choices.  相似文献   

12.
Monitoring the condition of natural resources in US national parks   总被引:1,自引:0,他引:1  
The National Park Service has developed a long-term ecological monitoring program for 32 ecoregional networks containing more than 270 parks with significant natural resources. The monitoring program assists park managers in developing a broad-based understanding of the status and trends of park resources as a basis for making decisions and working with other agencies and the public for the long-term protection of park ecosystems. We found that the basic steps involved in planning and designing a long-term ecological monitoring program were the same for a range of ecological systems including coral reefs, deserts, arctic tundra, prairie grasslands, caves, and tropical rainforests. These steps involve (1) clearly defining goals and objectives, (2) compiling and summarizing existing information, (3) developing conceptual models, (4) prioritizing and selecting indicators, (5) developing an overall sampling design, (6) developing monitoring protocols, and (7) establishing data management, analysis, and reporting procedures. The broad-based, scientifically sound information obtained through this systems-based monitoring program will have multiple applications for management decision-making, research, education, and promoting public understanding of park resources. When combined with an effective education program, monitoring results can contribute not only to park issues, but also to larger quality-of-life issues that affect surrounding communities and can contribute significantly to the environmental health of the nation.  相似文献   

13.
In this article, we describe the design and development of a quantitative, geospatial risk assessment tool intended to facilitate monitoring trends in wildfire risk over time and to provide information useful in prioritizing fuels treatments and mitigation measures. The research effort is designed to develop, from a strategic view, a first approximation of how both fire likelihood and intensity influence risk to social, economic, and ecological values at regional and national scales. Three main components are required to generate wildfire risk outputs: (1) burn probability maps generated from wildfire simulations, (2) spatially identified highly valued resources (HVRs), and (3) response functions that describe the effects of fire (beneficial or detrimental) on the HVR. Analyzing fire effects has to date presented a major challenge to integrated risk assessments, due to a limited understanding of the type and magnitude of changes wrought by wildfire to ecological and other nonmarket values. This work advances wildfire effects analysis, recognizing knowledge uncertainty and appropriately managing it through the use of an expert systems approach. Specifically, this work entailed consultation with 10 fire and fuels program management officials from federal agencies with fire management responsibilities in order to define quantitative resource response relationships as a function of fire intensity. Here, we demonstrate a proof-of-concept application of the wildland fire risk assessment tool, using the state of Oregon as a case study.  相似文献   

14.
With the adoption of the Berlin Mandate, developed countries are being asked to set emission limits for the early decades of the next century. The size of the reductions is currently the subject of international negotiations. This paper is intended to contribute to the analysis and assessment phase leading up to the adoption of new targets and timetables. However, we take a somewhat different approach than that suggested by the Berlin Mandate. Rather than focus exclusively on the next steps by developed countries, we view the issue from the perspective of the Convention's ultimate objective, the stabilization of atmospheric concentrations. We examine what might constitute costeffective strategies for limiting CO2 concentrations to alternative levels. We then explore the implications for nearterm mitigation decisions and for longterm participation by the developing countries.  相似文献   

15.
An index system developed for Louisiana lakes was based on correlations between measurable water quality parameters and perceived lake quality. Support data was provided by an extensive monitoring program of 30 lakes coordinated with opinion surveys undertaken during summer 1984. Lakes included in the survey ranged from 4 to 735 km2 in surface area with mean depths ranging from 0.5 to 8.0 m. Water quality data indicated most of these lakes are eutrophic, although many have productive fisheries and are considered recreational assets. Perception ratings of fishing quality and its associated water quality were obtained by distributing approximately 1200 surveys to Louisiana Bass Club Associaton members. The ability of Secchi disc transparency, total organic carbon, total Kjeldahl nitrogen, total phosphorus, and chlorophyll a to discriminate between perception classes was examined using probability distributions and multivariate analyses. Secchi disc and total organic carbon best reflected perceived lake conditions; however, these parameters did not provide the discrimination necessary for developing a quantitative risk assessment of lake trophic state. Consequently, an interim lakes index system was developed based on total organic carbon and perceived lake conditions. The developed index system will aid State officials in interpretating and evaluating regularly collected lake quality data, recognizing potential problem areas, and identifying proper management policies for protecting fisheries usage within the State.  相似文献   

16.
Reliable and frequent information on groundwater behavior and dynamics is very important for effective groundwater resource management at appropriate spatial scales. This information is rarely available in developing countries and thus poses a challenge for groundwater managers. The in situ data and groundwater modeling tools are limited in their ability to cover large domains. Remote sensing technology can now be used to continuously collect information on hydrological cycle in a cost-effective way. This study evaluates the effectiveness of a remote sensing integrated physical modeling approach for groundwater management in Indus Basin. The Gravity Recovery and Climate Experiment Satellite (GRACE)-based gravity anomalies from 2003 to 2010 were processed to generate monthly groundwater storage changes using the Variable Infiltration Capacity (VIC) hydrologic model. The groundwater storage is the key parameter of interest for groundwater resource management. The spatial and temporal patterns in groundwater storage (GWS) are useful for devising the appropriate groundwater management strategies. GRACE-estimated GWS information with large-scale coverage is valuable for basin-scale monitoring and decision making. This frequently available information is found useful for the identification of groundwater recharge areas, groundwater storage depletion, and pinpointing of the areas where groundwater sustainability is at risk. The GWS anomalies were found to favorably agree with groundwater model simulations from Visual MODFLOW and in situ data. Mostly, a moderate to severe GWS depletion is observed causing a vulnerable situation to the sustainability of this groundwater resource. For the sustainable groundwater management, the region needs to implement groundwater policies and adopt water conservation techniques.  相似文献   

17.
Impact assessment (IA) tools are targeted at decisions and decision-making in theory and in practice. Often described as decision support instruments, most IA are driven by the grand purpose of providing for informed decision-making. In practice this often means IA tends to be more concerned with the information to be provided than with the outcomes of IA and its relevance to the decision(s), and decision-makers(s) to which it should be targeted. Decisions and decision-making are, however, understood in many different ways, and actors involved in decision-making may therefore act widely different with diverse results. Therefore, distinguishing which decisions, and to which decision-makers IA are targeted at, is arguably indispensable to enhance IA effectiveness. Based on an overview of decision-making theory, this paper searches for the understanding of decision and decision-making in IA by exploring how it is conceived in guidance documents. Guidance documents have a prominent role in defining IA practice, and the explicit and implicit recognition of decision-making in guidance is therefore relevant to investigate in order to understand how IA relates to decision-making. With a focus on guidance documents related to the European Union Directive on environmental assessment of plans and programmes, this paper scrutinises four guidance documents and discusses the implications of the identified understandings of decision-making to the practice of IA. The key finding of this paper is that legislation-oriented guidance documents appear to miss to reflect the different forms of decision-making, and primarily depicts decision-making as a single, often timeless and faceless moment. The implications for practice are discussed including reflection on how to describe the nature of decision-making in guidance documents.  相似文献   

18.
Metals have been central to the development of human civilisation from the Bronze Age to modern times, although in the past, metal mining and smelting have been the cause of serious environmental pollution with the potential to harm human health. Despite problems from artisanal mining in some developing countries, modern mining to Western standards now uses the best available mining technology combined with environmental monitoring, mitigation and remediation measures to limit emissions to the environment. This paper develops risk screening and prioritisation methods previously used for contaminated land on military and civilian sites and engineering systems for the analysis and prioritisation of chemical risks from modern metal mining operations. It uses hierarchical holographic modelling and multi-criteria decision making to analyse and prioritise the risks from potentially hazardous inorganic chemical substances released by mining operations. A case study of an active platinum group metals mine in South Africa is used to demonstrate the potential of the method. This risk-based methodology for identifying, filtering and ranking mining-related environmental and human health risks can be used to identify exposure media of greatest concern to inform risk management. It also provides a practical decision-making tool for mine acquisition and helps to communicate risk to all members of mining operation teams.  相似文献   

19.
One of the principal tools used in the integrated assessment (IA) of environmental science, technology and policy problems is integrated assessment models (IAMs). These models are often comprised of many sub‐models adopted from a wide range of disciplines. A multi‐disciplinary tool kit is presented, from which three decades of IA of global climatic change issues have tapped. A distinction between multi‐ and inter‐disciplinarity is suggested, hinging on the synergistic value added for the latter. Then, a hierarchy of five generations of IAMs are proposed, roughly paralleling the development of IAMs as they incorporated more components of the coupled physical, biological and social scientific disciplines needed to address a “real world” problem like climatic change impacts and policy responses. The need for validation protocols and exploration of predictability limits is also emphasized. The critical importance of making value‐laden assumptions highly transparent in both natural and social scientific components of IAMs is stressed, and it is suggested that incorporating decision‐makers and other citizens into the early design of IAMs can help with this process. The latter could also help IA modelers to offer a large range of value‐containing options via menu driven designs. Examples of specific topics which are often not well understood by potential users of IAMs are briefly surveyed, and it is argued that if the assumptions and values embedded in such topics are not made explicit to users, then IAMs, rather than helping to provide us with refined insights, could well hide value‐laden assumptions or conditions. In particular, issues of induced technological change, timing of carbon abatement, transients, surprises, adaptation, subjective probability assessment and the use of contemporary spatial variations as a substitute for time evolving changes (what I label “ergodic economics”) are given as examples of problematic issues that IA modelers need to explicitly address and make transparent if IAMs are to enlighten more than they conceal. A checklist of six practices which might help to increase transparency of IAMs is offered in the conclusions. Incorporation of decision‐makers into all stages of development and use of IAMs is re‐emphasized as one safeguard against misunderstanding or misrepresentation of IAM results by lay audiences.  相似文献   

20.
Monitoring long-term change in forested landscapes is an intimidating challenge with considerable practical, methodological, and theoretical limitations. Current field approaches used to assess vegetation change at the plot-to-stand scales and nationwide forest monitoring programs may not be appropriate at landscape scales. We emphasize that few vegetation monitoring programs (and, thus, study design models) are designed to detect spatial and temporal trends at landscape scales. Based primarily on advice from many sources, and trial and error, we identify 14 attributes of a reliable long-term landscape monitoring program: malpractice insurance for landscape ecologists. The attributes are to: secure long-term funding and commitment; develop flexible goals; refine objectives; pay adequate attention to information management; take an experimental approach to sampling design; obtain peer-review and statistical review of research proposals and publications; avoid bias in selection of long-term plot locations; insure adequate spatial replication; insure adequate temporal replication; synthesize retrospective, experimental, and related studies; blend theoretical and empirical models with the means to validate both; obtain periodic research program evaluation; integrate and synthesize with larger and smaller scale research, inventory, and monitoring programs; and develop an extensive outreach program. Using these 14 attributes as a guide, we describe one approach to assess the potential effect of global change on the vegetation of the Front Range of the Colorado Rockies. This self-evaluation helps identify strengthes and weaknesses in our program, and may serve the same role for other landscape ecologists in other programs.  相似文献   

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