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41.
ABSTRACT: The concentrations of iron and sulfate in community water supplies are a concern for a number of areas in southwestern Minnesota. This study used the contingent valuation method to determine how much consumers would be willing to pay to improve their drinking water quality. On average, individuals were willing to pay US$5.25 per month (in 1995 U.S. dollars) to reduce the level of iron and US$4.33 per month to reduce the level of sulfate in their water to the USEPA's secondary standards for drinking water quality. Respondents with negative perceptions of their drinking water quality were willing to pay more to improve water quality. The aggregate annual willingness to pay (WTP) for all consumers in community water systems in southwestern Minnesota that were out of compliance with water quality standards were estimated to be US$2.4 million and US$2.0 million (in 1995 dollars) for reducing the levels of iron and sulfate, respectively. Yet the total WTP of consumers who use small community water systems may not be enough to pay the full cost of providing improved water in those systems. Economies of scale in water treatment and difficulties in financing improvements mean that technical innovation, government assistance, or institutional changes may be needed to improve water quality in these areas.  相似文献   
42.
Asymmetric regulation of a global pollutant between countries can alter the competitiveness of industries and lead to emissions leakage, which hampers countries’ welfare. In order to limit leakage, governments consider supporting domestic trade-exposed firms by subsidizing their investments in abatement technology. The suppliers of such technologies tend to be less than perfectly competitive, particularly when both emissions regulations and advanced technologies are new. In this context of twin market failures, we consider the relative effects and desirability of subsidies for abatement technology. We find a more robust recommendation for upstream subsidies than for downstream subsidies. Downstream subsidies tend to increase global abatement technology prices, reduce pollution abatement abroad and increase emission leakage. On the contrary, upstream subsidies reduce abatement technology prices, and hence also emissions leakage.  相似文献   
43.
为分析共因失效对高速铁路接触网系统的影响,将二元决策图(Binary Decision Diagram,BDD)与共因失效理论引入到接触网系统可靠性分析中。利用逻辑相邻优先组合法(Logic Neighbor Priority Connect,LNPC)将高速铁路接触网系统的故障树模型转化为BDD模型并求取其可靠度表达式,利用隐式方法对考虑了共因失效的接触网系统可靠度进行计算,利用MATLAB绘制考虑共因失效和不考虑共因失效情况下接触网系统可靠度变化曲线。研究结果表明:提出的分析方法适用于接触网系统的可靠性分析,为接触网系统的可靠性分析提供了一定的理论依据。  相似文献   
44.
Understanding human perspectives is critical in a range of conservation contexts, for example, in overcoming conflicts or developing projects that are acceptable to relevant stakeholders. The Q methodology is a unique semiquantitative technique used to explore human perspectives. It has been applied for decades in other disciplines and recently gained traction in conservation. This paper helps researchers assess when Q is useful for a given conservation question and what its use involves. To do so, we explained the steps necessary to conduct a Q study, from the research design to the interpretation of results. We provided recommendations to minimize biases in conducting a Q study, which can affect mostly when designing the study and collecting the data. We conducted a structured literature review of 52 studies to examine in what empirical conservation contexts Q has been used. Most studies were subnational or national cases, but some also address multinational or global questions. We found that Q has been applied to 4 broad types of conservation goals: addressing conflict, devising management alternatives, understanding policy acceptability, and critically reflecting on the values that implicitly influence research and practice. Through these applications, researchers found hidden views, understood opinions in depth and discovered points of consensus that facilitated unlocking difficult disagreements. The Q methodology has a clear procedure but is also flexible, allowing researchers explore long‐term views, or views about items other than statements, such as landscape images. We also found some inconsistencies in applying and, mainly, in reporting Q studies, whereby it was not possible to fully understand how the research was conducted or why some atypical research decisions had been taken in some studies. Accordingly, we suggest a reporting checklist.  相似文献   
45.
Transport projects have numerous consequences for the environment, society and economy, and thus an EU Directive has stated a number of impacts that need to be assessed prior to any major intervention. This paper is set in a Danish context where the EU requirements have been adopted in the Environmental Impact Assessment (EIA) regulation along with national requirements. In recent years, however, the EIAs have been criticised for an inconsistent inclusion of impacts and unclear assessment process. A selection of EIAs is for this reason reviewed and compared to the EU Directive and corresponding works in Sweden and the UK to identify potential opportunities for improvements. From the literature study, an overview table with all potential relevant impacts for transport projects is set up to assist the EIA process. For the sake of simplicity and transparency, the impacts selected from this table should, however, be further reduced in number to ensure that only the most important impacts are included in the process. To further increase simplicity and transparency in the EIA process, a novel framework for assessing different types of impacts is proposed. In this framework, a comprehensive decision support tool involving stakeholders is in focus. The framework is supplemented with a procedure for generating objectives and presenting results in an appropriate way to the many stakeholders involved. The impacts overview table and the assessment techniques are applied to a case study to illustrate the process, and finally, conclusions and perspectives for future work within the field are set out.  相似文献   
46.
Conservation decision makers commonly use project‐scoring metrics that are inconsistent with theory on optimal ranking of projects. As a result, there may often be a loss of environmental benefits. We estimated the magnitudes of these losses for various metrics that deviate from theory in ways that are common in practice. These metrics included cases where relevant variables were omitted from the benefits metric, project costs were omitted, and benefits were calculated using a faulty functional form. We estimated distributions of parameters from 129 environmental projects from Australia, New Zealand, and Italy for which detailed analyses had been completed previously. The cost of using poor prioritization metrics (in terms of lost environmental values) was often high—up to 80% in the scenarios we examined. The cost in percentage terms was greater when the budget was smaller. The most costly errors were omitting information about environmental values (up to 31% loss of environmental values), omitting project costs (up to 35% loss), omitting the effectiveness of management actions (up to 9% loss), and using a weighted‐additive decision metric for variables that should be multiplied (up to 23% loss). The latter 3 are errors that occur commonly in real‐world decision metrics, in combination often reducing potential benefits from conservation investments by 30–50%. Uncertainty about parameter values also reduced the benefits from investments in conservation projects but often not by as much as faulty prioritization metrics.  相似文献   
47.
童莉  贾学桦  姜华  曹亮  王立 《环境科学与技术》2012,(12):121-125,138
2008年6月颁布的《制浆造纸工业水污染物排放标准》(GB 3544-2008)与原标准(GB 3544-2001)相比,增加了控制排放的污染物项目,污染物排放控制要求也大幅提高,传统的废水二级生化处理工艺已不能满足新标准要求。文章通过梳理和分析调研及现场监测的资料和数据,提出目前制浆造纸企业通过有效的技术改造和升级,增加废水三级深度处理流程,在加强管理的情况下可以实现废水稳定达标排放。但不可避免会增加企业建设和运营成本,大中型制浆造纸企业尚可接受,对小型企业的冲击则相对较大。同时提出目前制浆造纸企业废水处理仍存在一些技术和管理方面的问题,尚需通过制定技术规范、强化环境监管、深入开展相关基础研究等多方面对策,优化制浆造纸行业结构调整,确保行业污染物减排。  相似文献   
48.
传统的基于GIS建立的土地适宜性评价系统缺乏对空间问题决策的支持能力,而GIS与DSS技术集成建立土地适宜性评价决策系统一方面可以实现对空间数据的管理和分析,另一方面可以利用模型进行辅助决策,有利于解决与空间有关的决策问题。以MapInfo Professional 6.0为基础平台,以Visual 〖XC夏敏字1.TIF,JZ〗6.0为开发工具,建立了一个土地适宜性评价决策支持系统,该系统包括数据库系统、模型库系统、知识库系统以及人机接口4个部分,具有数据输入输出、图属互查、数据空间分析和辅助决策等功能。系统成功应用于南京市江宁区淳化镇农地适宜性评价实践中,应用结果表明系统能为决策者提供多种决策方案,同时又集成了GIS的数据管理和空间分析功能,满足土地适宜性评价的要求,有推广使用的价值。  相似文献   
49.
In this work we present a method for risk-informed decision-making in the physical asset management context whereby risk evaluation and cost-benefit analysis are considered in a common framework. The methodology uses quantitative risk measures to prioritize projects based on a combination of risk tolerance criteria, cost-benefit analysis and uncertainty reduction metrics. There is a need in the risk and asset management literature for a unified framework through which quantitative risk can be evaluated against tolerability criteria and trade-off decisions can be made between risk treatment options. The methodology uses quantitative risk measures for loss of life, loss of production and loss of property. A risk matrix is used to classify risk as intolerable, As Low As Reasonably Practicable (ALARP) or broadly tolerable. Risks in the intolerable and ALARP region require risk treatment, and risk treatment options are generated. Risk reduction benefit of the treatment options is quantified, and cost-benefit analysis is performed using discounted cashflow analysis. The Analytic Hierarchy Process is used to derive weights for prioritization criteria based on decision-maker preferences. The weights, along with prioritization criteria for risk reduction, tolerance criteria and project cost, are used to prioritize projects using the Technique for Order Preference by Similarity to Ideal Solution. The usefulness of the methodology for improved decision-making is illustrated using a numerical example.  相似文献   
50.
It is widely accepted that wetland ecosystems are under threat worldwide. Many communities are now trying to establish wetland rehabilitation programs, but are confounded by a lack of objective information on wetland condition or significance. In this study, a multi-criteria decision-making method, TOPSIS (the Technique for Order Preference by Similarity to Ideal Solution), was adapted to assist in the role of assessing wetland condition and rehabilitation priority in the Clarence River Catchment (New South Wales, Australia). Using 13 GIS data layers that described wetland character, wetland protection, and wetland threats, the wetlands were ranked in terms of condition. Through manipulation of the original model, the wetlands were prioritized for rehabilitation. The method offered a screening tool for the managers in choosing potential candidate wetlands for rehabilitation in a region.  相似文献   
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