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561.
562.
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. 相似文献
563.
James A. Kushlan 《Environmental management》1983,7(3):201-207
An important aspect of developing a philosophical foundation for management of reserves using an ecosystem approach is the exploration of the relationship of ecosystem management strategies to the need for conservation of species of special concern Colonial water birds are species that may deserve special consideration They occur in over 25 US national parks, but in no case do the parks have a monopoly on the total protection or management of these birds As an agency responsible for such populations, the National Park Service engages in activities such as inventory, monitoring, research, and management, using an ecosystem management philosophy Most parks contain only segments of natural ecosystems, and management actions, even those undertaken from an ecosystem perspective, may not be in the best interest of an individual species Management strategies for widely ranging special species require a regional perspective, including plans that take into consideration the differing objectives of the agencies responsible for such species A matrix of the different management strategies in various areas may provide a suitable, perhaps the best, method for protecting special species In practice, any one strategy, such as management of remnant ecosystem patches or intensive single-species management, may not be successful alone 相似文献
564.
Stanley L. Ponce James R. Meiman 《Journal of the American Water Resources Association》1983,19(3):415-419
The demand for more water is increasing throughout the country. Research on upland watersheds clearly demonstrates that water yield can be increased using forest and range management practices. Based on the experience of the past several decades and a review of six papers in a recent AWRA series on water yield augmentation through vegetation management, the following issues and concerns are discussed: predicting increased yields from large basins; economic evaluation of additional flows; court acceptance and need for system models; the legal question of ownership and transferability of increased yields; and management emphasis on private and federal lands. The immediate potential for water yield augmentation is on carefully selected watersheds that have the bio-physical potential to produce high value water under environmentally acceptable multiple use management. We predict water yield management on a broader scale will result from increased pressures to solve the legal and economic issues involved. 相似文献
565.
Robert B. Leonard Donald C. Signor Donald G. Jorgensen John O. Helgesen 《Journal of the American Water Resources Association》1983,19(6):903-912
ABSTRACT: The Dakota aquifer, composed of the Dakota Sandstone and stratigraphically equivalent sandstone units of Cretaceous age, is the upper-most regional aquifer underlying the extensively developed High Plains aquifer of the midwestern United States. The concentration of dissolved solids in ground water of the Dakota aquifer ranges from less than 500 milligrams per liter in calcium bicarbonate type water in the eastern outcrop area to more than 100,000 milligrams per liter in sodium chloride type oilfield brine in the Denver Basin to the west. Preliminary maps showing the distribution of dissolved solids confirm the complex nature of the Dakota aquifer as inferred from stratigraphic and hydraulic evidence. Extensive vertical leakage through confining layers, local recharge at the truncated eastern boundary, and a barrier to recharge along the western edge of the Denver Basin are consistent with the distribution of hydraulic head and dissolved solids. 相似文献
566.
Farrell AE Corbett JJ Winebrake JJ 《Journal of the Air & Waste Management Association (1995)》2002,52(12):1399-1410
Continued interest in improving air quality in the United States along with renewed interest in the expansion of urban passenger ferry service has created concern about air pollution from ferry vessels. This paper presents a methodology for estimating the air pollution emissions from passenger ferries and the costs of emissions control strategies. The methodology is used to estimate the emissions and costs of retrofitting or re-powering ferries with seven technological options (combinations of propulsion and emission control systems) onto three vessels currently in service in San Francisco Bay. The technologies include improved engine design, cleaner fuels (including natural gas), and exhaust gas cleanup devices. The three vessels span a range of ages and technologies, from a 25-year-old monohull to a modern, high-speed catamaran built only four years ago. By looking at a range of technologies, vessel designs, and service conditions, a sense of the broader implications of controlling emissions from passenger ferries across a range of vessels and service profiles is provided. Tier 2-certified engines are the most cost-effective choice, but all options are cost-effective relative to other emission control strategies already in place in the transportation system. 相似文献
567.
Remediation of contaminated land and groundwater is of common international concern. The context and approach taken to the problem are, however, country-specific. A survey of remedial activity occurring within England and Wales over the period 1996-1999 was commissioned by the Environment Agency (for England and Wales) to establish a baseline against which future trends in remedial activity could be judged. This paper: explains the context of contaminated land and groundwater remediation in England and Wales (Britain); provides an overview of the 1996-1999 survey of remedial activity, discussing its findings within its legislative and institutional context; and, discusses the survey results of significance to the management of contaminated land and groundwater internationally. The survey obtained specific data from 367 remediated sites supplemented by general data from a further 1189 contaminated (not necessarily remediated) sites. The survey aimed to be, and was indicative of remediation practice, and did not seek to identify every remediation scheme operating. Previous anecdotal evidences were generally confirmed. Civil engineering-based techniques dominated and were used at 94% of sites with in situ techniques (predominantly vapour extraction-based) on 16% and ex situ on just 5%. Although disposal to landfill was dominant and occurred at over 80% of sites, integrated use of multiple techniques was common. Remediation was predominantly of soil (rather than water), development-based, designed to protect human health and reflected national development-led and 'suitable for use' policies. Lessons of international relevance from the survey and general British experience are drawn concerning remediation technique selection, regulatory and financial support of innovative remediation techniques and demonstration sites, competent use of risk-based approaches to allow pragmatic remediation and effective use of quality guidelines, need for effective guidance to highlight water quality issues, the necessity of post remediation monitoring to prove remediation effectiveness and the keeping of remediation databases. 相似文献
568.
569.
Characteristic levels of metal ions in post dredged sediment and dredged sediments materials of a municipal creek in the Niger
Delta show that significant concentrations of heavy metals are found to be accumulated more on the surface (0–15cm depth)
of the dredged material as compared to the sub surface (15–30cm) and post dredged sediments. The distribution patterns were
in the following order Fe > Mn > Zn > Cu > Pb > Ni > Cd and Fe > Mn > Zn > Pb > Cu > Ni > Cd for the post dredged sediment
and dredged sediment materials respectively. The levels of the various metals were far below the EPA screening levels for
open water disposal, consequently total levels of heavy metal found in these sediments pose no problem by open-water or upland
disposal 相似文献
570.
Basharat A. Pitafi James A. Roumasset 《Journal of the American Water Resources Association》2006,42(6):1441-1450
Abstract: Conserving the watershed can help to preserve ground water recharge. Preventing overuse of available water through pricing reforms can also substantially increase the value of an aquifer. Inasmuch as users are accustomed to low prices, efficiency pricing may be politically infeasible, and watershed conservation may be considered as an alternative. We estimate and compare welfare gains from pricing reform and watershed conservation for a water management district in Oahu that obtains its water supply from the Pearl Harbor aquifer. We find that pricing reform is welfare superior to watershed conservation unless the latter is able to prevent very large recharge losses. Watershed conservation that yields net gains in combination with pricing reform may cause net losses without the pricing reform. If adoption of watershed conservation delays the implementation of pricing reform, the benefits of the latter are significantly reduced. 相似文献