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51.
Neil L. Drobny 《Journal of the American Water Resources Association》1971,7(6):1180-1193
Applications of linear programming to water quality and water quantity problems are discussed, and a fairly comprehensive sample of recent literature in these areas is reviewed. Basic elements of linear programming are also discussed. Emphasis is placed on the elements of linear programming that make it a useful tool for analyzing water resource problems and the basic features of various water resource problems that render them amenable to meaningful analysis by linear programming. 相似文献
52.
Graduated licensing has been implemented in many U.S. states to reduce teenage driver crash involvement. The goal is to introduce teenagers gradually to driving before allowing full, unrestricted licensure. Tennessee, one of the states that introduced graduated licensing, implemented a program to influence both driving by teenagers during the learner stage and restrictions imposed by parents after licensure. In addition to a standard welcome letter, booklets and reminder cards were mailed to parents of teenagers who had just obtained their learner's permits. The booklets and cards were designed to assist parents in becoming more actively involved in their children's driving experiences. The effects of three different approaches (welcome letter only, letter plus booklet, and letter plus booklet plus reminder cards) on parental involvement, teenage crashes, and teenage citations were assessed based on telephone interviews with parents. Although the parents said the booklets and reminder cards were helpful and should continue to be sent to other parents, there were no discernible effects on teenage practice driving and reported parental involvement during the learner stage. Nor was there any measurable influence on restrictions imposed by parents after licensure. It is unknown whether the standard welcome letter affected parental involvement, but overall supervised driving exceeded the state requirements by a substantial margin. 相似文献
53.
Resource managers require objective methodologies to optimize decisions related to forest road deactivation and other aspects of road management, especially in steep terrain, where road-related slope failures inflict extensive environmental damage. Decision analysis represents a systematic framework that clearly identifies real options and critical decision points. This framework links current decisions with expected future outcomes and provides advantages such as a common currency to systematically explore the liability consequences of limited budget expenditures to road deactivation and other road-related activities. Furthermore, the decision framework prevents the analysis from becoming hopelessly entangled by the vast number of possibilities generated by the alternative occurrences, magnitudes, and consequences of landslide/debris flow events and provides the information required for the first step of an adaptive management process. Here, a structured analysis of potential environmental risks for a road deactivation project in coastal British Columbia, Canada is presented. The application of decision analysis generates a ranking of the expected benefits of proposed deactivation activities on various road sections. The ranking distinguishes between road sections that offer high expected benefit from those that offer moderate to low expected benefit. Seventeen of 171, 100–m road segments accounted for 18% of the cumulative cost and 98% of the cumulative expected net benefits from road deactivation. Furthermore, the cost of deactivating a section of road is related to the expected benefit from such deactivation, thus providing the basis for more effective resource allocation and budgeting decisions. 相似文献
54.
Abstractions of surface and groundwater for irrigation in Scotland are currently subject to control in only two small catchments. Under the terms of the EU Water Framework Directive, it will be necessary to introduce new legislation to control abstractions elsewhere. To help in the development of appropriate policy for Scotland a study has been carried out to examine the significance of irrigation and the effectiveness of different types of control strategies in terms of the economics of potato cropping and stream hydrology in Scotland. This paper presents the findings of the hydrological study and highlights some of the spatial and temporal issues that need to be considered in the selection of control mechanisms, if they are to be successful in achieving objectives for environmental improvement.The study was focussed on two catchments in the east of Scotland, the Tyne and West Peffer. The effectiveness of several different abstraction control strategies was examined to see how stream flows in the catchment would be modified by their implementation. The results of the study demonstrated that the West Peffer catchment in particular is significantly affected by irrigation abstractions. Control mechanisms based on allowable monthly abstraction volumes and flow-based abstraction bans would be of considerable help in restoring stream flows to their natural levels, but would modify the hydrological regime in slightly different ways. A spatial analysis of stream flows demonstrated that implementation of controls based on a single monitoring point may be ineffective at maintaining acceptable levels of flow throughout the catchment and that this may require a tighter control at the monitoring point. 相似文献
55.
David Fowler Rognvald Smith Jennifer Muller John Neil Cape Mark Sutton Jan Willem Erisman Hilde Fagerli 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):41-47
Emissions of sulphur and oxidized nitrogen compounds in Europe have been reduced following a series of control measures during
the last two decades. These changes have taken place during a period in which the primary gases and the wet deposition throughout
Europe were extensively monitored. Since the end of the 1970s, for example land based sulphur emissions declined by between
90 and 70% depending on the region. Over the same period the total deposition of sulphur and its partitioning into wet and
dry deposition have declined, but the spatial pattern in the reduction in deposition differs from that of emission and has
changed with time. Such non-linearities in the emission-deposition relationship are important to understand as they complicate
the process of assessing the effects of emission reduction strategies. Observed non-linearities in terrestrial sulphur emission-deposition
patterns have been identified in north west Europe due to increases in marine emissions, and are currently slowing the recovery
of freshwater ecosystems. Changes in the relative amounts of SO2 and NH3 in air over the last two decades have also changed the affinity of terrestrial surfaces for SO2 and have therefore changed the deposition velocity of SO2 over substantial areas. The consequence of this effect has been the very rapid reduction in ambient SO2 concentration in some of the major source areas of Europe, where NH3 did not change much. Interactions between the different pollutants, generating non-linearities are now being incorporated
in long-range transport models to simulate the effects of historical emission trends and to provide projections into the future.
This paper identifies non-linearities in emission deposition relationships for sulphur and nitrogen compounds in Europe using
data from the EMEP long-rang transport model and measured concentration fields of the major ions in precipitation and of SO2 and NO2 in surface air. 相似文献
56.
Clay Schoenfeld 《The Environmentalist》1981,1(2):117-122
Summary How do we inculcate that mass conservation literacy necessary to fuel the public and private quest for ecological survival. One such approach would establish on appropriate university campuses Integrated Resource Management Education Centers. Such centers would focus on the problem of translating resource management policies and plans into action on the landscape through (a) the collation of information about, and the preparation of practical materials on, restoring the quality of the environment, (b) informal instruction and technical assistance carried out directly to local governments, regional instrumentalities, and citizen groups, (c) the refresher education of key practitioners brought back to the campus for work in natural resource policy implementation, and (d) research in adult education theory and practice.Clay Schoenfeld is Professor of Journalism and Mass Communication, Affiliate Professor of Wildlife Ecology, Chair of the Center for Environmental Communication and Education Studies, and Director of Inter-College Programs at The University of Wisconsin-Madison. Schoenfeld is perhaps best known as the author of 20 books and over 200 national journal and magazine articles. He is a past president of three national associations in the fields of university administration and environmental education. 相似文献
57.
58.
Donald R. Field Neil H. Cheek 《Journal of the American Water Resources Association》1974,10(6):1218-1227
ABSTRACT: Participation in water-based recreation activities does not arise in random fashion nor simply as a result of having a water resource immediately available. Neither do individuals and groups engage in the same activities or a specific activity in the same way. The purpose of the present paper is to describe an alternative framework whereby differences among recreation users can be identified. Prior to this time, research directed toward understanding participation patterns at a recreational site have emphasized the activities while ignoring the human behavior factors which determine how participation arises. People consider recreation sites to be leisure settings in which the definition of such places has a broader socio-cultural meaning than that the site was designed. These definitions are reflected within the context of the social group and can be observed in the subsequent orientation to leisure and play. When activities are considered in the context of a human group, differences in participation patterns can be discovered. 相似文献
59.
Rhys Worrall David Neil David Brereton David Mulligan 《Journal of Cleaner Production》2009,17(16):1426-1434
Sustainable development practices have become an integral part of most major mining companies’ business activities. However, the history of mining and the negative impacts it has had on the natural and social environment mean future mining activities, rightly or wrongly, will be judged against the legacies of the past and current poor performers. Legacy mine land, defined here as land which has been mined and is now being used for another purpose, or is orphaned, abandoned or derelict and in need of remedial work, is one management challenge that will be judged in the context of sustainable development. Globally, millions of such sites exist. Having criteria against which to measure progress toward or away from sustainable development goals is a key to delivering results. The aim of this research was to develop a sustainability criteria and indicators framework to suit the particular needs of legacy mine land. The resulting framework consists of 14 criteria and 72 indicators. 相似文献
60.