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401.
Charles S. ReVelle Justin C. Williams John J. Boland 《Environmental Modeling and Assessment》2002,7(2):71-80
Five classes of zero–one programming models for discrete facility location problems are compared to counterpart models for the selection of conservation reserves. The basic problem of siting facilities to cover demand for services is analogous to the problem of selecting reserves to support species diversity. The classes of models include the set covering and maximal covering models, as well as models for backup and redundant coverage. Issues of reliability and uncertainty are addressed by chance constrained covering models and maximal expected covering models. Exact and heuristic solution approaches are discussed. Multi-objective and economic issues are considered. 相似文献
402.
Two basic requirements, low bias and high precision, are necessary for generating reliable estimates for the load from point and nonpoint sources of pollution. Biases and low precision can be the result of using a bad sampling design and/or inadequate method of estimation. The effects of biases can be reduced at the design stage prior to the data collection or at the data anlysis stage. This paper discusses the statistical issues involved in generating adequate load estimations using recently published point source discharge data from the Niagara River to illustrate these issues. 相似文献
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Integrating Temporal Inequality into Conservation Planning to Improve Practice Design and Efficacy 下载免费PDF全文
Mark R. Williams Kevin W. King Chad J. Penn 《Journal of the American Water Resources Association》2018,54(5):1039-1054
In contrast to spatial inequality, there are currently no methods for leveraging information on temporal inequality to improve conservation efficacy. The objective of this study was to use Lorenz curves to quantify temporal inequality in surface runoff and tile drainage, identify controls on nutrient loading in these flowpaths, and develop design flows for structural conservation practices. Surface runoff (n = 94 site‐years) and tile drainage (n = 90 site‐years) were monitored on 40 fields in Ohio. Results showed, on average, 80% of nitrate‐nitrogen, soluble reactive phosphorus (P), and total P loads occurred between 7 and 12 days per year in surface runoff and between 32 and 58 days per year in tile drainage. Similar temporal inequality between discharge and load provided evidence that loading was transport‐limited and highlighted the critical role hydrologic connectivity plays in nutrient delivery from tile‐drained fields. Design flow criterion for sizing structural practices based on load reduction goals was developed by combining Lorenz curves and flow duration curves. Comparing temporal inequality between fields and the Maumee River, the largest tributary to the western Lake Erie Basin, revealed challenges associated with achieving watershed load reduction goals with field‐scale conservation. In‐field (i.e., improved nutrient and water management), edge‐of‐field (i.e., structural practices), and instream practices will all be required to meet nutrient reduction goals from tile‐drained watersheds. 相似文献
405.
Jesper Madsen James Henty Williams Fred A. Johnson Ingunn M. Tombre Sergey Dereliev Eckhart Kuijken 《Ambio》2017,46(2):275-289
An International Species Management Plan for the Svalbard population of the pink-footed goose was adopted under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds in 2012, the first case of adaptive management of a migratory waterbird population in Europe. An international working group (including statutory agencies, NGO representatives and experts) agreed on objectives and actions to maintain the population in favourable conservation status, while accounting for biodiversity, economic and recreational interests. Agreements include setting a population target to reduce agricultural conflicts and avoid tundra degradation, and using hunting in some range states to maintain stable population size. As part of the adaptive management procedures, adjustment to harvest is made annually subject to population status. This has required streamlining of monitoring and assessment activities. Three years after implementation, indicators suggest the attainment of management results. Dialogue, consensus-building and engagement among stakeholders represent the major process achievements. 相似文献
406.
Clare McCausland 《Journal of Agricultural and Environmental Ethics》2014,27(4):649-662
In this paper I defend a theory of welfare rights for nonhuman animals. I do this by demonstrating that a well-established framework for protecting the interests of farm animals, the ‘Five Freedoms of Animal Welfare’, is already functioning just as a set of rights. To support this claim I adopt a common approach to detecting evidence for deontological reasoning and look at the structural features of rights. I first consider Hohfeld’s system of legal rights and consider whether the Five Freedoms may be understood as liberties or claim rights, before making a more successful comparison with side constraints and an interest theory of rights as understood by Nozick and Raz. I also respond to a likely objection that it is not possible to have some welfare rights without a right to freedom from exploitation. The argument therefore contributes to breaking down the stubborn division between ‘animal welfare’ and ‘animal rights’. 相似文献
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