欧洲的氮状况

欧洲(不包括前苏联)的氮收支表明,欧洲氮循环加速的三个主要驱动力是肥料生产(14MtN/a)、矿物燃料燃烧及其它工业(3.3MtN/a)和各种产品中的氮输入(7.6MtN/a).本文估计了欧洲粮食、能源和工业产品系统中活性氮元素的各种泄漏,评估了它们对人类健康及水陆生态系统的影响.考虑到氮流转中的可能后果,未来欧洲有关封闭氮循环和减少活性氮泄漏的环境政策措施最好集中于三个主要驱动力.在确定氮排放上限和制定氯流控制的综合政策方面,如肥料使用、输入和氮水平,临界负载可能是非常有用的工具.     

Sharing environmental space: the role of law,economics and politics

The concept of ‘environmental space’ has been put forward as a means for providing specific meaning to sustainability. The concept combines the idea of the existence of environmental limits with a strong principle of environmental justice. It has been used as a basis for the development of sustainable action plans for many European countries, and has attracted political interest. However, thus far, the concept has found limited application by governments. The paper identifies and discusses several issues that need to be addressed for the environmental space approach to be implemented. Three main options for the institutionalization of the approach are discussed: within the legal‐constitutional framework (as rights and obligations), within the economic system (as environmental property rights), and through green planning (as specific objectives and targets contained in national environmental plans or strategies). The paper discusses the ability of the three options to deal with the issues identified, assessing their relative advantages and disadvantages, and to what extent these options are complementary. Finally, conclusions are drawn about the viability of the concept of ‘environmental space’.     

NUTRIENT CONCENTRATION CRITERIA AND CHARACTERIZATION OF PATTERNS IN TROPHIC STATE FOR RIVERS IN HETEROGENEOUS LANDSCAPES1

ABSTRACT: A method is demonstrated for the development of nutrient concentration criteria and large scale assessment of trophic state in environmentally heterogeneous landscapes. The method uses the River Environment Classification (REC) as a spatial framework to partition rivers according to differences in processes that control the accrual and loss of algae biomass. The method is then applied to gravel bed rivers with natural flow regimes that drain hilly watersheds in New Zealand's South Island. An existing model is used to characterize trophic state (in terms of chlorophyll a as a measure of maximum biomass) using nutrient concentration, which controls the rate of biomass accrual, and flood frequency, which controls biomass loss. Variation in flood frequency was partitioned into three classes, and flow data measured at 68 sites was used to show that the classes differ with respect to flood frequency. Variation in nutrient concentration was partitioned at smaller spatial scales by subdivision of higher level classes into seven classes. The median of flood frequency in each of the three higher level classes was used as a control variable in the model to provide spatially explicit nutrient concentration criteria by setting maximum chlorophyll a to reflect a desired trophic state. The median of mean monthly soluble reactive phosphorus and soluble inorganic nitrogen measured at 68 water quality monitoring sites were then used to characterize the trophic state of each of the seven lower level classes. The method models biomass and therefore allows variation in this response variable to provide options for trophic state and the associated nutrient concentrations to achieve these. Thus it is less deterministic than using reference site water quality. The choice from among these options is a sociopolitical decision, which reflects the management objectives rather than purely technical considerations.     

Public perceptions of equity in environmental policy: Traffic emissions policy in an english urban area

A promising new pathway for research on environmental justice is understanding public perceptions of justice or equity around a range of issues. Here we focus on policies intended to reduce air pollution from road traffic. We ask different urban communities, distinguished by the quality of local air and by socio-economic status, to judge the equitability of policies intended to reduce traffic emissions, both in terms of the environmental benefits of the policies and allocating the financial burden of paying for improvements. In the latter case, we are interested not only in the popular principles of equity that emerge, but also in whether a trade-off might exist between such principles of equity and the overall effectiveness and cost of the policy.     

Social impact evaluation of the US Resource Conservation and Recovery Act

Debate over environmental policy often focuses on social impacts of those policies, but few empirical studies examine the impacts of environmental regulations once they are implemented. A quasi-experimental design based on survey data is used to assess the social impacts of the US Resource Conservation and Recovery Act (RCRA) on the West Virginia chemical industry. Changes in employment, manufacturing process, product line, and manufacturing costs are evaluated. RCRA seems to have produced changes in manufacturing processes, but we find no statistically significant impacts on.jobs, product line, or manufacturing costs.     

MULTISCALE RIVER ENVIRONMENT CLASSIFICATION FOR WATER RESOURCES MANAGEMENT1

ABSTRACT: River Environment Classification (REC) is a new system for classifying river environments that is based on climate, topography, geology, and land cover factors that control spatial patterns in river ecosystems. REC builds on existing principles for environmental regionalization and introduces three specific additions to the “ecoregion” approach. First, the REC assumes that ecological patterns are dependent on a range of factors and associated landscape scale processes, some of which may show significant variation within an ecoregion. REC arranges the controlling factors in a hierarchy with each level defining the cause of ecological variation at a given characteristic scale. Second, REC assumes that ecological characteristics of rivers are responses to fluvial (i.e., hydrological and hydraulic) processes. Thus, REC uses a network of channels and associated watersheds to classify specific sections of river. When mapped, REC has the form of a linear mosaic in which classes change in the downstream direction as the integrated characteristics of the watershed change, producing longitudinal spatial patterns that are typical of river ecosystems. Third, REC assigns individual river sections to a class independently and objectively according to criteria that result in a geographically independent framework in which classes may show wide geographic dispersion rather than the geographically dependent schemes that result from the ecoregion approach. REC has been developed to provide a multiscale spatial framework for river management and has been used to map the rivers of New Zealand at a 1:50,000 mapping scale.     

Constructing land-use maps of the Netherlands in 2030

The National Environmental Assessment Agency of the RIVM in the Netherlands is obliged to report on future trends in the environment and nature every 4 years. The last report, Nature Outlook 2, evaluated the effects of four alternative socio-economic and demographic scenarios on nature and the landscape. Spatially detailed land-use maps are needed to assess effects on nature and landscape. The objective of the study presented here was how to create spatially detailed land-use maps of the Netherlands in 2030 using the Environment Explorer, a Cellular Automata-based land-use model to construct land-use maps from four scenarios. One of these is discussed in great detail to show how the maps were constructed from the various scenario elements, story lines and additional data and assumptions on national, regional and local land-use developments. It was the first time in the history of our outlooks that consistent, spatially detailed land-use maps of the Netherlands for 2030 were constructed from national economic and demographic scenarios. Each map represents a direct reflection of model input and assumptions. The maps do not show the most probable developments in the Netherlands but describe the possible change in land use if Dutch society were to develop according to one of the four scenarios. The large (societal) uncertainties are reflected in the total set of future land-use maps. The application of a land-use model such as the Environment Explorer ensures that all relevant aspects of a scenario, i.e. economic and demographic developments, zoning policies and urban growth, are integrated systematically into one consistent framework.