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Securing flows for environmental purposes from an already fully utilized river is an impossible task--unless users are either coerced into freeing up water, or offered incentives to do so. One sensible strategy for motivating users to liberate volumes is to offer them economic compensation. The right amount for that compensation then becomes a key environmental management issue. This paper analyses a proposal to restore and maintain ecosystems on a stretch of the Río Conchos in northern Mexico, downstream from a large irrigation district that consumes nearly all local flows. We present here estimates of environmental flow requirements for these ecosystems and compute compensation figures for irrigators. These figures are derived from crop-specific irrigation water productivities we statistically estimate from a large set of historical production and irrigation data obtained from the district. This work has general implications for river ecosystem management in water-stressed basins, particularly in terms of the design of fair and effective water sharing mechanisms.  相似文献   

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Incorporation of aesthetic considerations in the process of landscape planning and development has frequently met with poor results due to its lack of theoretical basis, public involvement, and failure to deal with spatial implications. This problem has been especially evident when dealing with large areas, for example, the Adirondacks, Scenic Highways, and National Forests and Parks. This study made use of public participation to evaluate scenic quality in a portion of the Niagara Escarpment in Southern Ontario, Canada. The results of this study were analyzed using thevisual management model proposed by Brown and Itami (1982) as a means of assessing and evaluating scenic quality. Themap analysis package formulated by Tomlin (1980) was then applied to this assessment for the purpose of spatial mapping of visual impact. The results of this study illustrate that it is possible to assess visual quality for landscape/management, preservation, and protection using a theoretical basis, public participation, and a systematic spatial mapping process.  相似文献   

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瑞典的生态税收规模较大,种类较多,并具有特色,主要是对能源及其他与环境有关的税基的征税。近年我国能源的消耗量逐渐增大,以及废旧电池等对环境污染较大,应该借鉴瑞典的经验,开征独立的环境保护税,并配合其他措施,将取得的税收用于环境的保护。  相似文献   

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Economic sustainability or intergenerational equity entails maintaining social well-being by decisions about investments in different types of assets. Under certain conditions, consumption can be sustained by depleting resources, or various kinds of natural capital, while building up other kinds of capital. Theoretically, the choices involve the use of a set of accounting prices. The question becomes one of finding and implementing accounting prices that express the roles of the various capital goods in achieving the objective of the economy.Hartwick's rule holds that an economy can be sustained if the value of the total, net investment in the economy, evaluated at those accounting prices, is zero. The rule applies to a special, abstract economic model which expresses a social objective different from the discounted-utilitarian objective on which national accounting is based. Different objectives give rise to different accounting prices. Because the prices may not be right, the zero net-investment rule using available national-accounting prices cannot generate a condition for sustaining an economy.Still, environmental accounting is a tool which, used prudently, can make an important contribution to social decision-making. This paper expands upon these ideas by discussing the incorporation of natural resource and intangible environmental costs and benefits into green accounting at the firm as well as the economy level. Common techniques of mine valuation and standard corporate accounting are the bases for this extension to the valuation of and accounting for decisions concerning the environment.  相似文献   

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We performed a sociocultural preference assessment for a suite of ecosystem services provided by the Kiamichi River watershed in the south‐central United States, a region with intense water conflict. The goal was to examine how a social assessment of services could be used to weigh tradeoffs among water resource uses for future watershed management and planning. We identified the ecosystem services beneficiaries groups, analyzed perception for maintaining services, assessed differences in the importance and perceived trends for ecosystem services, and explored the perceived impact on ecosystem services arising from different watershed management scenarios. Results show habitat for species and water regulation were two ecosystem services all beneficiaries agreed were important. The main discrepancies among stakeholder groups were found for water‐related services. The identification of potential tradeoffs between services under different flow scenarios promotes a dynamic management strategy for allocating water resources, one that mitigates potential conflicts. While it is widely accepted the needs of all beneficiaries should be considered for the successful incorporation of ecosystem services into watershed management, the number of studies actually using the sociocultural perspective in ecosystem service assessment is limited. Our study demonstrates it is both possible and useful to quantify social demand of ecosystem services in watershed management.  相似文献   

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Studies show a direct relationship between occurrence of asthma and increases of particulate matter in the air. Private transportation is found to be a significant contributor to this problem. The objective of this article is to explore this link between air pollution, asthma and vehicular dependency in order to provide recommendations for health and transport policy. This article focuses on the survey of literature on the relationship between vehicular air pollution and asthma; combining it with the literature on vehicular dependency or ‘car culture’ in the global context and in The Netherlands. This article exposes the imbalance of power between patient groups and polluting industries, and the government failure to protect the weaker party can be explained by corporate pressures. It will be argued that since air pollution is tied to the corporate support for the car industry and vested interests in promoting a ‘car culture’, strategic policy that claims to be concerned with public health should explicitly link the present pattern of mobility to public health. This article concludes with a recommendation for raising environmental health awareness by explicitly linking vehicular dependency to respiratory health through a combination of holistic and citizenship education.  相似文献   

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The next stage in the process will be to obtain the views of as many people working in as many different fields as possible, to see whether the proposed scheme suits their needs and how it should be modified. With a few modifications, such a scheme could easily be appended to an existing land cover classification scheme, such as the FAO system, greatly increasing the usefulness and accessability of the results of the landcover classification.  相似文献   

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Consumer concerns pop up. They are relatedto the safety of agrifood products for people, foranimals, and for the environment as well as the socialand ethical implications of certain agrifoodproduction methods. At first sight, the WTO agreementand the SPS and TBT agreements appear to offersufficient legal scope to deal with these concerns andresolve trade conflicts. The events of recent years,however, have shown the limitations of theseagreements in dealing with cultural differencesbetween nations and in dealing with the social andpolitical pressure on national governments to lay downrestrictive, trade distorting measures. It is vitalthat we consider the dynamic relationship betweennational governments, civil society, and the market.In the United States, Canada, and Europe, thisrealization is growing. We propose that these issuesshould be studied by experts in several disciplines:technical experts, hygiene experts and veterinarians,public administration experts, lawyers, philosophers,ethicists, sociologists, and, of course, economists.To unite these disciplines and provide a platform fordiscussion in the light of international tradeliberalisation, the cultural identity of distinctcommunities, and the functioning of the democraticnation state an international network is needed. Wetherefore propose establishing a network to explorethe issues and dynamics described above. The networkshould be international and interdisciplinary withparticipants, initially, from science and government.The purpose of the network would be to present newperspectives to the negotiating parties in the nextWTO round. The first steps to development of thisnetwork have since been taken and an initial group hasbeen established.  相似文献   

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Options for National Parks and Reserves for Adapting to Climate Change   总被引:2,自引:2,他引:0  
Past and present climate has shaped the valued ecosystems currently protected in parks and reserves, but future climate change will redefine these conditions. Continued conservation as climate changes will require thinking differently about resource management than we have in the past; we present some logical steps and tools for doing so. Three critical tenets underpin future management plans and activities: (1) climate patterns of the past will not be the climate patterns of the future; (2) climate defines the environment and influences future trajectories of the distributions of species and their habitats; (3) specific management actions may help increase the resilience of some natural resources, but fundamental changes in species and their environment may be inevitable. Science-based management will be necessary because past experience may not serve as a guide for novel future conditions. Identifying resources and processes at risk, defining thresholds and reference conditions, and establishing monitoring and assessment programs are among the types of scientific practices needed to support a broadened portfolio of management activities. In addition to the control and hedging management strategies commonly in use today, we recommend adaptive management wherever possible. Adaptive management increases our ability to address the multiple scales at which species and processes function, and increases the speed of knowledge transfer among scientists and managers. Scenario planning provides a broad forward-thinking framework from which the most appropriate management tools can be chosen. The scope of climate change effects will require a shared vision among regional partners. Preparing for and adapting to climate change is as much a cultural and intellectual challenge as an ecological challenge.  相似文献   

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A mechanistic understanding of the effects of nutrient enrichment in lotic systems has been advanced over the last two decades such that identification of management thresholds for the prevention of eutrophication is now possible. This study describes relationships among primary nutrients (phosphorus and nitrogen), benthic chlorophyll a concentrations, daily dissolved oxygen (DO) concentrations, and the condition of macroinvertebrate and fish communities in small rivers and streams in Ohio, USA. Clear associations between nutrients, secondary response indicators (i.e., benthic chlorophyll and DO), and biological condition were found, and change points between the various indicators were identified for use in water quality criteria for nutrients in small rivers and streams (<1300 km2). A change point in benthic chlorophyll a density was detected at an inorganic nitrogen concentration of 0.435 mg/l (±0.599 SD), and a total phosphorus (TP) concentration of 0.038 mg/l (±0.085 SD). Daily variation in DO concentration was significantly related to benthic chlorophyll concentration and canopy cover, and a change point in 24-h DO concentration range was detected at a benthic chlorophyll level of 182 mg/m2. The condition of macroinvertebrate communities was related to benthic chlorophyll concentration and both minimum and 24-h range of DO concentration. The condition of fish communities was best explained by habitat quality. The thresholds found in relationships between the stressor and the response variables, when interpreted in light of the uncertainty surrounding individual change points, may now serve as a framework for nutrient criteria in water quality standards.  相似文献   

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A composite index, based on function analysis and including thirteen sub-indices, was developed to assess the overall quality of urban and urbanized beaches in the Mediterranean area. The aggregation of components and sub-indices was based on two questionnaires completed by beach users and experts. Applying the new Beach Quality Index (BQI) demonstrated that the quality of beaches could be improved. In general, the strongest aspects of the beaches assessed were those related to short-term user demand, and the weakest were those related to the consequences of human pressure on the area, in particular, erosion problems. The composite index is intended to be used together with Environmental Management Beach Systems (EMBs) as a hierarchical management scorecard and in monitoring programs. This new tool could also make planning more proactive by synthesizing the state of the most important beach processes.  相似文献   

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在中央一系列刺激经济措施相继出台后,民间投资的滞后已开始影响经济复苏的步伐。为此,国家发改委日前开始拟定一份旨在鼓励和促进民间投资的相关文件,目前正在征求意见过程中。  相似文献   

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Agricultural P transport in runoff is an environmental concern. An important source of P runoff is surface-applied, unincorporated manures, but computer models used to assess P transport do not adequately simulate P release and transport from surface manures. We developed a model to address this limitation. The model operates on a daily basis and simulates manure application to the soil surface, letting 60% of manure P infiltrate into soil if manure slurry with less than 15% solids is applied. The model divides manure P into four pools, water-extractable inorganic and organic P, and stable inorganic and organic P. The model simulates manure dry matter decomposition, and manure stable P transformation to water-extractable P. Manure dry matter and P are assimilated into soil to simulate bioturbation. Water-extractable P is leached from manure when it rains, and a portion of leached P can be transferred to surface runoff. Eighty percent of manure P leached into soil by rain remains in the top 2 cm, while 20% leaches deeper. This 2-cm soil layer contributes P to runoff via desorption. We used data from field studies in Texas, Pennsylvania, Georgia, and Arkansas to build and validate the model. Validation results show the model accurately predicted cumulative P loads in runoff, reflecting successful simulation of the dynamics of manure dry matter, manure and soil P pools, and storm-event runoff P concentrations. Predicted runoff P concentrations were significantly related to (r2=0.57) but slightly less than measured concentrations. Our model thus represents an important modification for field or watershed scale models that assess P loss from manured soils.  相似文献   

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Ensuring the persistence of at-risk species depends on implementing conservation actions that ameliorate threats. We developed and implemented a method to quantify the relative importance of threats and to prioritize recovery actions based on their potential to affect risk to Mojave desert tortoises (Gopherus agassizii). We used assessments of threat importance and elasticities of demographic rates from population matrix models to estimate the relative contributions of threats to overall increase in risk to the population. We found that urbanization, human access, military operations, disease, and illegal use of off highway vehicles are the most serious threats to the desert tortoise range-wide. These results suggest that, overall, recovery actions that decrease habitat loss, predation, and crushing will be most effective for recovery; specifically, we found that habitat restoration, topic-specific environmental education, and land acquisition are most likely to result in the greatest decrease in risk to the desert tortoise across its range. In addition, we have developed an application that manages the conceptual model and all supporting information and calculates threat severity and potential effectiveness of recovery actions. Our analytical approach provides an objective process for quantifying threats, prioritizing recovery actions, and developing monitoring metrics for those actions for adaptive management of any at-risk species.  相似文献   

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Comparing Onsite and Offsite Methods for Measuring Norms for Trail Impacts   总被引:1,自引:0,他引:1  
This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwang-Ju, Korea. For the overall photo evaluation method (OPEM), respondents rated the acceptability of bare soil area for each of a series of photographs. For the specific photo evaluation method (SPEM), respondents selected a photograph that illustrated the largest acceptable proportion of bare soil area from a series of 10 photographs. Overall, there were no substantial differences in maximum acceptable impacts between onsite (onsite-I visitor group surveyed at the actual trail points and onsite-II departing visitor group surveyed at the exit area) and offsite (students surveyed in a laboratory setting) groups for the two norm measurement alternatives (OPEM and SPEM). Subjects’ difficulty ratings were low for both methods, and there were no substantial differences in norms between individuals with high and low levels of experience at the park. The offsite method appears to be substitutable for onsite methods in this particular study area, which is a frontcountry setting with a relatively simple range of recreation opportunities. Implications and further studies are discussed.  相似文献   

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Call for Papers

Rolex Calls for Entries to 11th Awards for Enterprise and Extends Deadlines for All Countries  相似文献   

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Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method's impacts on analytical results. The U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQ(D/F)) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQ(D/F) values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQ(D/F) values derived in the same fashion from traditional HRMS analysis. These results would have placed >90% of the samples within the same concentration intervals using ranges of <0.05, 0.05-0.50, 0.50-5, and >5ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQ(D/F), indicating that TOC is not a reliable indicator of TEQ(D/F) concentrations.  相似文献   

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