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1.
Jordan NR Slotterback CS Cadieux KV Mulla DJ Pitt DG Olabisi LS Kim JO 《Environmental management》2011,48(1):1-12
Increasingly, total maximum daily load (TMDL) limits are being defined for agricultural watersheds. Reductions in non-point
source pollution are often needed to meet TMDL limits, and improvements in management of annual crops appear insufficient
to achieve the necessary reductions. Increased adoption of perennial crops and other changes in agricultural land use also
appear necessary, but face major barriers. We outline a novel strategy that aims to create new economic opportunities for
land-owners and other stakeholders and thereby to attract their voluntary participation in land-use change needed to meet
TMDLs. Our strategy has two key elements. First, focused efforts are needed to create new economic enterprises that capitalize
on the productive potential of multifunctional agriculture (MFA). MFA seeks to produce a wide range of goods and ecosystem
services by well-designed deployment of annual and perennial crops across agricultural landscapes and watersheds; new revenue
from MFA may substantially finance land-use change needed to meet TMDLs. Second, efforts to capitalize on MFA should use a
novel methodology, the Communicative/Systemic Approach (C/SA). C/SA uses an integrative GIS-based spatial modeling framework
for systematically assessing tradeoffs and synergies in design and evaluation of multifunctional agricultural landscapes,
closely linked to deliberation and design processes by which multiple stakeholders can collaboratively create appropriate
and acceptable MFA landscape designs. We anticipate that application of C/SA will strongly accelerate TMDL implementation,
by aligning the interests of multiple stakeholders whose active support is needed to change agricultural land use and thereby
meet TMDL goals. 相似文献
2.
设计良好的导电回路对真空断路器灭弧性能的提高有着重要的意义。本文首先从结构上分析了三种不同导电回路的优缺点,接着,分析了三种不同导电回路的电动斥力和吹弧磁场,为通过选择不同导电回路,触头直径和开距提高真空断路器灭弧性能提供方法和思路。 相似文献
3.
创新水源型流域污染系统控制科技支撑战略,对我国流域水环境综合治理与管理具有前瞻意义.文章从引导科技支撑发展方向,发展多维流域认知系统,创立流域系统控制知识,创新水源流域环境技术,建立流域水环境经济学与完善流域环境管理体系六个方面构建了水源流域污染系统控制的科技支撑战略体系;从制定水源型流域环境区划、水源型流域安全发展规划、水源型流域环境保护规划与水源型流域保护工程规划四个方面提出了水源型流域污染系统控制科技支撑的战略行动;从转变治理方向、改变治理目标与调整控制范围、优化监控指标等方面提出了水源型流域污染系统控制科技支撑的战略建议. 相似文献
4.
Dick Morris Sue Oreszczyn Christine Blackmore Raymond Ison Stephen Martin 《Local Environment》2006,11(6):683-699
Defining and putting into practice sustainable land use is a complex, systemic problem. Systems models and techniques were used in a study of Herefordshire to clarify the situation and identify the potential for a more locally focused, learning-based approach to land use. Issues included: (i) uncertainty about the boundary of a 'system of sustainable Herefordshire land use'; (ii) the complexity of economic flows in the county and the absence of some critical data; (iii) the importance of the Herefordshire landscape to tourism and the role of agriculture as a determinant of the state of that landscape; (iv) weakness of the institutional linkage between tourism and agriculture; (v) the current lack of inclusion of many relevant stakeholders in concerted action. Factors favouring a learning approach included a strong local identity, local food-related developments, and educational initiatives. Barriers to such an approach included questions of power and landholding, government policies, and attitudes and skills within organizations. These findings are considered in relation to the wider debate over approaches to sustainability. 相似文献
5.
Richard A. Slaughter 《Journal of the American Water Resources Association》2009,45(2):331-342
Abstract: Water marketing is often cited as a means of alleviating the stresses attached to allocation of water use. Frequently, marketing is suggested in a context that implies substitution of competitive markets for the allocation based on the prior appropriation doctrine. This study examines water marketing from the perspective of a transactions cost approach to the private and broad social agreements (contracts) that support water allocation. It examines the major behavioral challenges faced by any contract, and the alternative approaches to those challenges, with respect to water allocation. It also examines the impact of market design on the existence of externalities, costs imposed by transactions on society and individuals not party to the transaction. It finds that the most robust water market designs will be found in systems with sufficient property rights protection to support investment, sufficient hydrologic information to provide accurate analysis of third party effects, conjunctive management of surface and groundwater, and a governance structure capable of administering the rules while not determining outcomes. 相似文献
6.
介绍了航空机载产品磁影响测量标准的技术要求和测量方法,深入剖析了磁影响测量的原理,澄清了标准中容易混淆的磁影响限值的确定原则,详细解释了磁强计测量磁影响的方法,经过实践检验,这种磁强计测量航空机载产品磁影响的方法准确可靠。 相似文献
7.
Stijn Speelman Stefano Farolfi Aymen Frija Guido Van Huylenbroeck 《Journal of the American Water Resources Association》2010,46(6):1133-1144
Speelman, Stijn, Stefano Farolfi, Aymen Frija, and Guido Van Huylenbroeck, 2010. Valuing Improvements in the Water Rights System in South Africa: A Contingent Ranking Approach. Journal of the American Water Resources Association (JAWRA) 46(6):1133–1144. DOI: 10.1111/j.1752-1688.2010.00480.x Abstract: In the context of increasing water scarcity, understanding is growing that irrigation water rights are important and that a lack of an effective water rights system constitutes a major reason for inefficient water management. This study carried out a contingent ranking experiment to study how smallholder irrigators in South Africa would value potential changes in water rights. Three specific dimensions of water rights, relevant for the South African case, are considered: duration, quality of title, and transferability. Results indicate that smallholder irrigators are prepared to pay considerably higher water prices if improvements are made in the water rights system. This implies that the proposed interventions in the water rights system would improve the efficiency and productivity of the small-scale irrigation sector. The increased willingness to pay could furthermore also assist the South African government to reach the objective of increased cost recovery. 相似文献
8.
Cochran, Bobby and Charles Logue, 2011. A Watershed Approach to Improve Water Quality: Case Study of Clean Water Services’ Tualatin River Program. Journal of the American Water Resources Association (JAWRA) 47(1):29‐38. DOI: 10.1111/j.1752‐1688.2010.00491.x Abstract: Over the last five years, Clean Water Services developed and implemented a program to offset thermal load discharged from its wastewater facilities to the Tualatin River by planting trees to shade streams and augmenting summertime instream flows. The program has overcome challenges facing many of the nation’s water quality trading programs to not only gain consensus on the frameworks needed to authorize trading, but also provide a broad range of ecosystem services. This paper compares the Tualatin case study with some of the commonly cited factors of successful trading programs. 相似文献
9.
将国内旅游流空间模式研究划分为旅游流圈层结构研究、旅游流时空演化规律研究和旅游流空间场效应分析三个阶段的内容,并重点探讨国内旅游流空间场效应研究的现状.通过文献分析,从基本理论、研究方法和存在的问题三个方面对旅游流空间场效应研究的相关成果进行归纳、总结,力求构建一个国内旅游流空间场效应研究的基本框架,以进一步深化对旅游流空间场效应的认识,扩宽国内旅游流空间模式研究的视野. 相似文献
10.
Ellen Hanak 《Journal of the American Water Resources Association》2007,43(4):1024-1035
Abstract: Rapidly growing regions such as the western United States face difficult challenges in mobilizing new water supplies to meet new demands. Environmental concerns have curtailed the scope for large new surface storage projects, and widespread basin overdraft has limited ground water’s potential as a source of expansion. Drawing on the California experience, this article explores modern water planning approaches, which focus on a portfolio of options including nontraditional sources (recycling, desalination, underground storage) and more efficient use of existing supplies (conservation and water marketing). It reviews the advantages and drawbacks of the elements of the portfolio, provides examples of innovative planning approaches, and assesses the role for supportive government policies. 相似文献
11.
Tirusew Asefa 《Journal of the American Water Resources Association》2009,45(5):1155-1163
Abstract: While training a Neural Network to model a rainfall‐runoff process, generally two aspects are considered: its capability to be able to describe the complex nature of the processes being modeled and the ability to generalize so that novel samples could be mapped correctly. The general conclusion is that, the smallest size network capable of representing the sample distribution is the best choice, as far as generalization is concerned. Oftentimes input variables are selected a priori in what is called an explanatory data analysis stage and are not part of the actual network training and testing procedures. When they are, the final model will have only a “fixed” type of inputs, lag‐space, and/or network structure. If one of these constituents was to change, one would obtain another equally “optimal” Neural Network. Following Beven and others' generalized likelihood uncertainty estimate approach, a methodology is introduced here that accounts for uncertainties in network structures, types of inputs, and their lag‐space relationships by looking at a population of Neural Networks rather than target in getting a single “optimal” network. It is shown that there is a wide array of networks that provide “similar” results, as seen by a likelihood measure, for different types of inputs, lag‐space, and network size combinations. These equally optimal networks expose the range of uncertainty in streamflow predictions and their expected value results in a better performance than any of the single network predictions. 相似文献
12.
乡村人居环境:人居环境科学研究的新领域 总被引:5,自引:0,他引:5
乡村人居环境是人居环境科学的重要构成部分,随着城市化的快速推进,乡村人居环境日益恶化.人居环境科学研究存在明显缺陷,即人居环境研究的"城市主义"倾向明显,忽视了乡村人居环境研究.分析了开展乡村人居环境研究的重要性和紧迫性,评述了国内外的相关研究成果,提出了乡村人居环境研究的多维视角,即基于农户空间行为的乡村人居环境研究、乡村人居环境的地域文化与发展模式研究、乡村人居环境与空间规划研究、基于"3S"技术的乡村人居环境研究、乡村人居环境的系统理论与发展战略研究. 相似文献
13.
/ Models available in the literature on nutrient uptake, lightavailability, and chlorophyll growth have been suitably modified andintegrated through the computer program CHLORF (written in "C"language), which has the advantage of being amenable to simulation undervarious combinations of input variables. The model has been used forsensitivity analysis in order to identify the most sensitive set ofparameters whose control can form an appropriate basis for evolving pragmaticmanagement strategies. In addition, greenhouse mitigation potential has beencomputed in terms of assimilation of carbon dioxide for a case study ofIndian wetlands.KEY WORDS: Wetland; Nutrient cycling; Modeling; Greenhouse effect 相似文献
14.
Watershed management requires integration of social and ecological understanding. Participatory approaches to planning and management incorporate stakeholder knowledge and understanding. An action research strategy using focus groups with Michigan State University operations units helped generate a soft systems model of watershed impacts of organizational decision-making regarding road de-icing. The results reveal tensions and inconsistencies between the mission and operation of the institution. These tensions are exacerbated by inadequate communication among various elements of the campus watershed management system. The action research approach facilitated the researchers understanding of the complex institutional system and helped identify possible areas for making improvements. Specifically, the researchers were able to facilitate improvement in some linkages between scientists developing campus watershed models and the operations staff responsible for handling many of the inputs being modeled. 相似文献
15.
How to Quantify Sustainable Development: A Risk-Based Approach to Water Quality Management 总被引:1,自引:0,他引:1
Since the term was coined in the Brundtland report in 1987, the issue of sustainable development has been challenged in terms
of quantification. Different policy options may lend themselves more or less to the underlying principles of sustainability,
but no analytical tools are available for a more in-depth assessment of the degree of sustainability. Overall, there are two
major schools of thought employing the sustainability concept in managerial decisions: those of measuring and those of monitoring.
Measurement of relative sustainability is the key issue in bridging the gap between theory and practice of sustainability
of water resources systems. The objective of this study is to develop a practical tool for quantifying and assessing the degree
of relative sustainability of water quality systems based on risk-based indicators, including reliability, resilience, and
vulnerability.
Current work on the Karoun River, the largest river in Iran, has included the development of an integrated model consisting
of two main parts: a water quality simulation subroutine to evaluate Dissolved Oxygen Biological Oxygen Demand (DO-BOD) response,
and an estimation of risk-based indicators subroutine via the First Order Reliability Method (FORM) and Monte Carlo Simulation
(MCS). We also developed a simple waste load allocation model via Least Cost and Uniform Treatment approaches in order to
consider the optimal point of pollutants control costs given a desired reliability value which addresses DO in two different
targets.
The Risk-based approach developed herein, particularly via the FORM technique, appears to be an appropriately efficient tool
for estimating the relative sustainability. Moreover, our results in the Karoun system indicate that significant changes in
sustainability values are possible through dedicating money for treatment and strict pollution controls while simultaneously
requiring a technical advance along change in current attitudes for environment protection. 相似文献
16.
Mark Coeckelbergh David J. Gunkel 《Journal of Agricultural and Environmental Ethics》2014,27(5):715-733
In this essay we reflect critically on how animal ethics, and in particular thinking about moral standing, is currently configured. Starting from the work of two influential “analytic” thinkers in this field, Peter Singer and Tom Regan, we examine some basic assumptions shared by these positions and demonstrate their conceptual failings—ones that have, despite efforts to the contrary, the general effect of marginalizing and excluding others. Inspired by the so-called “continental” philosophical tradition (in particular Emmanuel Levinas, Martin Heidegger, and Jacques Derrida), we then argue that what is needed is a change in the rules of the game, a change of the question. We alter the (pre-) normative question from “What properties does the animal have?” to “What are the conditions under which an entity becomes a moral subject?” This leads us to consider the role of language, personal relations, and material-technological contexts. What is needed then in response to the moral standing problem, is not more of the same—yet another, more refined criterion and argumentation concerning moral standing, or a “final” rational argumentation that would be able to settle the animal question once and for all—but a turning or transformation in both our thinking about and our relations to animals, through language, through technology, and through the various place-ordering practices in which we participate. 相似文献
17.
18.
ENVIRONMENTAL AUDITING: A Synoptic Approach for Assessing Cumulative Impacts to Wetlands 总被引:1,自引:0,他引:1
/ The US Environmental Protection Agency's Wetlands ResearchProgram has developed the synoptic approach as a proposed method forassessing cumulative impacts to wetlands by providing both a general and acomprehensive view of the environment. It can also be applied more broadly toregional prioritization of environmental issues. The synoptic approach is aframework for making comparisons between landscape subunits, such aswatersheds, ecoregions, or counties, thereby allowing cumulative impacts tobe considered in management decisions. Because there is a lack of tools thatcan be used to address cumulative impacts within regulatory constraints, thesynoptic approach was designed as a method that could make use of availableinformation and best professional judgement. Thus, the approach is acompromise between the need for rigorous results and the need for timelyinformation. It is appropriate for decision making when quantitative,accurate information is not available; the cost of improving existinginformation or obtaining better information is high; the cost of a wronganswer is low; there is a high demand for the information; and the situationcalls for setting priorities between multiple decisions versus optimizing fora single decision. The synoptic approach should be useful for resourcemanagers because an assessment is timely; it can be completed within one totwo years at relatively low cost, tested, and improved over time. Anassessment can also be customized to specific needs, and the results arepresented in mapped format. However, the utility of a synoptic assessmentdepends on how well knowledge of the environment is incorporated into theassessment, relevant to particular management questions.KEY WORDS: Cumulative impact assessment; Landscape ecology; Regionalprioritization 相似文献
19.
Matthew A. Leach Ausilio Bauen Nigel J. D. Lucas 《Journal of Environmental Planning and Management》1997,40(6):705-724
This study develops a modelling framework within which the effects of technology choice and policy on the sustainability of cities may be assessed. A life cycle accounting system for environmental impacts is combined with systems analysis, to represent the flows of resources into cities, the wastes and pollution generated and the technological choices available in an urban environment. The approach is demonstrated through a case study of the demand for paper and management of wastepaper. The case study questions the applicability for paper of the accepted 'hierarchy' of waste management techniques; incineration imposes lower environmental costs than recycling, and consequently lower total costs under some circumstances. 相似文献
20.
Without any incentive to clean up a contaminated site, remediation is often delayed until the site owner is compelled to act by regulatory agencies. In such a context, the selected technology is typically the one that will reach the remediation goals as quickly as possible. Unfortunately, this criterion is often met by overly expensive technologies, resulting in high and sometimes unaffordable total remediation costs, leading to a remediation with a negative net benefit. This study examines the effects of time constraint and benefit value on the optimal remediation strategy for a diesel-contaminated site. This strategy is developed using the technico-economic model METEORS, which takes into account the technology’s effectiveness, the uncertainty of the level of contamination, and the possibility of reducing this uncertainty through either an additional characterization (before selecting and applying a technology) or the monitoring of the remediation technology (during its use). Results of simulations with both economic and temporal constraints support a proactive approach to site remediation. 相似文献