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251.
This study examines sustainability indicators using the sustainability report of the Finnish Ministry of Agriculture and Forestry as the case study. The report is a compilation of indicators designed to assess the sustainability of natural resource management. The interviews with the users revealed, however, that the indicators have not been particularly effective in informing the actors or in affecting their behaviour. Clearly, the informative value of the indicators has been overrated and the complexity of the information transfer has been underestimated. At least partly, the difficulties were due to the obscurity of the indicator-concept itself and consequently to their improper use. First, the statistics with the objective state-of-affairs information should be distinguished from the indicators that are always related to policy discussion. In addition, the technical and communicative use of the indicators should be distinguished from each other as they have different relationship between the information, policy values and the associated activities.  相似文献   
252.
Lake Zapotlán is a small (1100 ha) lake in Jalisco state, western Mexico. Two communities are located within the basin (Ciudad Guzman, population ~93,000 and Gomez Farías, population ~12,000). The lake has a productive fishery (annual harvest between 200 and 570 tonnes) comprising tilapia and carp. Extensive beds of rooted and floating Typha latifolia are found in the lake and are used in local handicraft activities. The lake receives untreated sewage from both communities and, as a result, has elevated levels of nutrients and coliform bacteria. Local human health issues, as a possible consequence of this pollution, have been identified. This paper describes a process of identifying potential indicators of ecosystem health, to be used as a management tool in developing a sustainability plan for the lake and its basin.  相似文献   
253.
Many cities' municipal governments have made some version of “sustainability” an explicit policy goal over the past two decades. Previous research has documented how the operationalisation and conceptualisation of sustainability in urban sustainability plans vary greatly among cities, particularly with respect to environmental justice. This article reports on whether and how large American cities incorporate environmental justice into their urban sustainability indicator projects. Our findings suggest that while there has been an increase in the number of cities incorporating environmental justice elements into sustainability plans since the early 2000s, their conceptualizations and implementations of sustainability remain highly constrained. The paucity of evaluative tools suggests that environmental justice efforts are potentially losing traction in public debate over macro-scale sustainability concerns (e.g. climate change) or the need for regionally competitive environmental amenities (e.g. parks). This paper concludes with suggestions for revising existing sustainability plans to better reflect environmental justice concerns.  相似文献   
254.
In this paper, the power output of the cycle is taken as objective for performance optimization of an irreversible regenerated closed Brayton cycle coupled to constant-temperature thermal energy reservoirs in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulae about the relations between power output and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the regenerator, the irreversible compression and expansion losses in the compressor and turbine, and the pressure drop loss in the piping. The maximum power output optimization is performed by searching the optimum heat conductance distribution corresponding to the optimum power output among the hot- and cold-side heat exchangers and the regenerator for the fixed total heat exchanger inventory. The influence of some design parameters, including the temperature ratio of the heat reservoirs, the total heat exchanger inventory, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the optimum heat conductance distribution and the maximum power output are provided. The power plant design with optimization leads to smaller size including the compressor, turbine, and the hot- and cold-side heat exchangers and the regenerator.  相似文献   
255.
Although very often used, the concept of sustainable development has not yet been perceived pragmatically. Due to its process nature, in this paper, we argue that sustainable development is a process in which the essential feedback loops, or Viability Loops as we name them, in the system in question are kept healthy and functional. This process deals with evolutionary changes with the end point not known in advance. According to this perception, measurement of sustainable development does not make sense. Rather, we should look for the process indicators to monitor systems for sustainable development. The purpose of the paper is to develop a methodology to deal with monitoring systems for sustainable development and its practice in an urban water system. Using a system dynamics approach, the paper adopts a systemic monitoring framework based on the idea of Viability Loops to define process indicators to monitor systems for sustainable development. To illustrate the application of the framework, its practice in the urban water system of Tehran, the capital of Iran, is provided as an example. The example of the urban water supply system of Tehran is given as a case study, albeit with some unavailable data. Here, four typical viability loops are discussed. The results of this application show that the flows of informative signals are lacking. Adopting the process indicators, we can see the gaps between the public perceptions of water abundance, the costs of water provision and energy utilizations, and what is going on in the reality are getting wider. That indicates that the viability loops are not functional enough to produce effective changes to offset the reinforcing mechanisms. The sustainable development of the system is impaired due to the persistence of those reinforcing mechanisms.  相似文献   
256.
水上个体救生具性能要求的比较研究   总被引:1,自引:0,他引:1  
针对ISO ,IMO ,BS ,MIL ,JIS ,我国GB及JT等具有代表性的技术标准和规范 ,分析和研究了水上个体救生具的整体救生性能、主体材料性能和属具性能要求 ,在进行比较研究的基础上 ,结合国情 ,对于我国水上个体救生具性能改进和技术标准完善 ,提出了建议并指出了发展方向  相似文献   
257.
This paper proposes the concept of cumulative eco-intensity with which environmental or sustainability indicators are related to the added value of economic activities. The intensities are passed on recursively from supplier to supplier and thus make it possible to include upstream and downstream effects along the supply and waste disposal chain. The process is applied to whole companies and (by contrast with LCA) not to individual products. At comparatively low expenditure for the individual companies, it allows vertical comparisons along the value-adding chain and horizontal comparisons among companies or production locations. This provides a decision-making aid for a company seeking to fulfil its ecological or sustainability responsibility in the entire production and supply chains.  相似文献   
258.
The main objectives of this work focus, firstly, on a review of the current existent methodologies to estimate air quality modelling uncertainty, and, secondly, in the preparation of guidelines for modelling uncertainty estimation, which can be used by local and regional authorities responsible for air quality management. From the application exercise, it was concluded that it is possible to define a subset of statistical parameters able to reproduce the general uncertainties estimation. Concerning the quality indicators defined by EU directives, the results show that the legislated uncertainty estimation measures are ambiguous and inadequate in several aspects, mainly in what concerns the error measures for hourly and daily indicators based on the highest observed concentration. A relative error at the percentile correspondent to the allowed number of exceedances of the limit value was suggested and tested, showing that is a more robust and appropriate parameter for model performance evaluation.  相似文献   
259.
Maps of pollutants concentration are usually generated by means of interpolation and extrapolation methods. The quality of the results depends mainly of the number of permanent or temporary measuring stations. This paper deals with a method for the virtual densification of the network of stations. The method creates "virtual measuring stations". It aims at improving the quality of interpolation by increasing the number of data on pollutant concentration. The virtual stations are determined by the means of a classification method applied to each pixel of the area under concern. Discriminating elements are pollutants emission classes, land cover types, urban morphological indicators created to this purpose and distance to major roads. A first implementation was made for particulate matter (PM) for the city of Strasbourg (France) using thin-plates spline interpolation method in Arcview 9 GIS. The relative Root Mean Square Error decreases from 49% for five input stations down to 15% for the virtual stations.  相似文献   
260.
真实储蓄率与可持续发展研究   总被引:1,自引:0,他引:1  
随着全球经济高速发展,地球上的环境却持续恶化,由于经济与环境相互牵制又相互促进,如何实现经济不断增长并能有效保护环境,即实现“可持续发展”成为目前大家普遍关注的问题,本文分析了真实储蓄概念的提出,认为真实储蓄率是基于传统国民经济核算以上两方面的缺陷而提出的。并进一步解释了真实储蓄率的概念,绿色GDP和真实储蓄的关系,及真实储蓄,可持续收入(SI)及生态国民生产净值(EDP),可持续经济福利指标(ISEW)和真实发展指数(GPI)几种货币化的可持续发展指标的相互关系,认为真实储蓄是一种比较实用的衡量可持续发展的综合指标。  相似文献   
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