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511.
Over the last decade the Great Smoky Mountains National Park (GSMNP) has experienced a tremendous increase in visitation, especially in backcountry camping. In 1976 there were an estimated 117,500 backcountry visitor nights, with a peak of 16,865 visitor nights in April. The high use season extends from March to October. Visitation tends to be concentrated in certain sections of the park and at specific sites. The Appalachian Trail, which includes about 8 percent of the maintained trail mileage, carried 32 percent of the visitor nights in 1976.Campsite disturbance is also concentrated in specific sites and sections of the park. Maximum camping disturbance per km of maintained trail was 3,400 m2 for the sites on the Appalachian Trail. Shelter sites have more visitation per site and more total disturbance per site than open campsites, but shelters tend to have less intensive disturbance, such as bare soil, because they concentrate trampling impacts. Visitation levels were strongly correlated with disturbances such as bare soil at open campsites. Visitation was significantly correlated to the number of firepits at shelter sites but not to other types of disturbance. Regressions indicate that for each additional visitor night at a site (annual average), one can expect an additional 9 m2 of total disturbance and 1 m2of bare soil. The distance of a site from the nearest road was not significantly correlated with damage or visitation. Elevation was correlated to visitation levels, especially in the case of the shelters. More legal sites and large illegal sites are in mesic forest types. Illegal camping accounted for 10 percent of the total camping disturbance.The data imply that the suggested removal of shelters will require redistribution of visitor use or replacement developments, such as tent platforms, in order to mitigate damage. Zone camping is a possible alternative but presents difficulties because campers may concentrate in certain plant communities and topographic positions.  相似文献   
512.
ABSTRACT: Arizona's water pollution control program is based on authorties of Arizona Revised Statutes and Public Law 92–500, the Federal Water Pollution Control Act Amendments of 1972. The primary areas of this program are monitoring, facility inspections, plan review, planning, discharge permits and grants for the construction of publicly-owned waste water treatment facilities. The discharge permit program deals with control of point-source discharges and is administered by the United States Environmental Protection Agency. The planning and construction grants programs are administered by the State Water Quality Control Council and are implemented by the Bureau of Water Quality Control, which serves as staff to the Council. There are several challenges that face the State in this program. First is the adaptation of the “eastern law” to deal with Arizona's water quality problems. Second is to address problems caused by a long history of “laissez-faire” environmental quality management. Third is a mutual cooperation and coordination among the many entities involved in water resources management. Areas of particular interest in the State's program is the process setting water quality standards and the involvement of people of diversified backgrounds in the field of areawide planning under Section 208 of the Federal Water Pollution Control Act, which is primarily concerned with non-point sources of water pollution.  相似文献   
513.
No energy technology is risk free when all aspects of its utilization are taken into account. Every energy technology has some attendant direct and indirect health and safety concerns. Solar technologies examined in this paper are wind, ocean thermal energy gradients, passive, photovoltaic, satellite power systems, low- and high-temperature collectors, and central power stations, as well as tidal power. For many of these technologies, insufficient historical data are available from which to assess the health risks and environmental impacts. However, their similarities to other projects make certain predictions possible. For example, anticipated problems in worker safety in constructing ocean thermal energy conversion systems will be similar to those associated with other large-scale construction projects, like deep-sea oil drilling platforms. Occupational hazards associated with photovoltaic plant operation would be those associated with normal electricity generation, although for workers involved in the actual production of photovoltaic materials, there is some concern for the toxic effects of the materials used, including silicon, cadmium, and gallium arsenide.Satellite power systems have several unique risks. These include the effects of long-term space travel for construction workers, effects on the ozone layer and the attendant risk of skin cancer in the general public, and the as-yet-undetermined effects of long-term, low-level microwave exposure. Hazards may arise from three sources in solar heating and cooling systems: water contamination from corrosion inhibitors, heat transfer fluids, and bactericides; collector over-heating, fires, and out-gassing and handling and disposal of system fluids and wastes. Similar concerns exist for solar thermal power systems. Even passive solar systems may increase indoor exposure levels to various air pollutants and toxic substances, eitherdirectly from the solar system itself or indirectly by trapping released pollutants from furnishings, building materials, and indoor combustion.Operated by Union Carbide Corporation under contract W-7405-eng-26 for the U.S. Department of Energy.  相似文献   
514.
Populations of introduced European wild boar, feral pigs, and combinations of both types (all Susscrola L.) inhabit thirteen areas in the National Park Service system. All parks have relatively stable populations, with the exception of Great Smoky Mountains National Park, which reported a rapidly expanding wild boar population. Suspected and documented impacts were apparently related to pig densities and sensitivity of the ecosystem; the three largest units with dense wild pig populations reported the most damage. Overall, wild pigs are a relatively minor problem for the Park Service; however, problems are severe in at least three parks, and there is potential for invasion of wild boars into several additional parks in the Appalachian Mountains. More specific information is needed on numbers of wild pigs and their impacts in the various parks.  相似文献   
515.
Major drainage basins within the Angeles National Forest in southern California USA are aggregated into zones of homogeneous wildland fire damage-potential using multivariate statistical techniques. Mathematical models are utilized to examine the policy implications of ongoing and projected fuel management strategies in different Forest zones based on simulated impacts of fuelbreak construction and maintenance upon two proxies for future damage-potential: the expected area burned and an index of relative value used by Forest planners. Alternative strategies for future fuelbreak investments are evaluated based on model outcomes.  相似文献   
516.
Predicting the multiple pathways of plant succession   总被引:4,自引:0,他引:4  
Classical concepts view succession as a deterministic, mechanistic regeneration of the disturbed community, and thus have limited applicability to fire-prone ecosystems, A recently developed multiple pathway succession model appears to have more realism and applicability in frequently disturbed ecosystems. It includes a set of species-specific attributes that are vital to reproduction and survival, and permits variable succession pathways depending on the stand's age (and thus species composition) when disturbed. Examples from Australia and the northern Rocky Mountains (USA) are presented, as are approaches to refining and improving the model.  相似文献   
517.
A trend is presently under way to streamline the compliance requirements of the National Environmental Policy Act of the United States through cooperative assessment procedures. Since the law was enacted in 1970, however, participants in the assessment process have tended to settle disagreements by adversarial rather than cooperative means. This study focuses on a highly acclaimed environmental assessment procedure undertaken by the U.S. Steel Corporation for its proposed $4.0 billion Lakefront Steel Plant. Survey research data were gathered to measure the underlying management philosophy perceived by interorganizational representatives, who attended a series of Technical Team meetings designed to coordinate the assessment effort and to open communication channels. A social psychological scale of behavioral dimensions was adapted from Likert to define the composition and the extent of cooperation at these meetings. A newly constructed scale was used to measure the quantity and quality of representation by each of the major organizations involved. Informal interviews were conducted with project participants to obtain further insight into member interaction. Results indicate that democratic problem solving was in evidence but also suggest a preference by respondents for improved procedures. The paper outlines areas of concern voiced by respondents and offers the means for improving the operating procedures of similar interorganizational environmental assessments.  相似文献   
518.
/ The Council on Environmental Quality's (CEQ's) principal aims in implementing the National Environmental Policy Act (NEPA) are (1) to reduce paperwork, (2) to avoid delay, and most importantly (3) to produce better decisions that protect, restore, and enhance the environment. This paper presents four strategies for improving the NEPA process along with tools that can be used to implement each strategy. The tools include guidelines for project management and problem definition, tips for acquiring existing information and identifying issues of public concern, worksheets on how to identify and analyze potential impacts on resources, ideas for enhancing NEPA documents, and a NEPA process checklist. The tools can be used at various stages of the NEPA process and provide a toolbox of guidelines and techniques to improve implementation of the NEPA process by focusing the pertinent information for decisionmakers and stakeholders. KEY WORDS: National Environmental Policy Act; NEPA; Environmental impact assessment; Ecosystem management  相似文献   
519.
In 1979, the Pinelands Commission was established as a regional land-use planning and regulatory agency charged with the implementation of a Comprehensive Management Plan (CMP) for the Pinelands National Reserve (New Jersey, USA). The CMP was created to balance land preservation and development interests in the Reserve. Because water-quality degradation from developed and agricultural landscapes is associated with changes in the composition of biological communities, monitoring landscape changes provides one of the most direct measures of the impact of land-use policies on the Pinelands ecosystem. In this study, we prepared detailed, land-cover maps within randomly selected aerial-photograph plots for a major watershed in the Reserve. We used these land-cover maps to quantify changes in landscape composition and structure (i.e., patch size, patch area, and number of patches) and characterize land-cover transitions in the basin between 1979 and 1991. Because the study period represented the first 12 years of the regional-planning effort in the Reserve, we evaluated the relationship between land-cover transitions and Commission management-area designations which permit different land-use intensities. Although the landscape composition was similar in 1979 and 1991, we found an increase in the total area and number of developed-land, managed-grassland, and barren-land patches. An increase in the number of patches and a decrease in the total area and median and third-quartile patch sizes for forest land and for all patches regardless of cover type indicated that fragmentation of forest land and the landscape as a whole occurred during the study period. The major land-cover transitions that occurred during the period were the loss of forest land to development and associated cover types and the conversion of one agricultural type to another. Overall, land-cover transitions during the period were found to be consistent with the Commission management-area designations, which indicated that the regional-planning effort has been successful in directing human activities to appropriate areas of the basin.  相似文献   
520.
关于“质量”的内涵 ,在物理学、哲学和经济学等方面有其不同解释。而生产的产品“质量”不仅包括其特殊功能指标 ,还包括其安全性、可靠性、使用寿命。它涉及生产者、使用者或消费者的生命安全与健康 ,甚至影响市场竞争与繁荣、社会稳定与文明、国民经济建设与可持续发展。因此 ,质量的安全问题在安全科学领域 ,在安全科技界 ,在市场流通和消费领域 ,一直为人们所关注。优质的物质产品必然是以人为本的、安全的、无害的 ,也必然是安全科技、环保科技含量很高的产品。笔者对以上领域关于“质量”的问题进行了研究 ,对经济学方面的质量与效益的内涵 ;质量与经济效益的关系、提高质量的途径和方法等问题进行探讨 ,阐述了自己的观点和看法。  相似文献   
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