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571.
复合工程系统灾害反应分析与系统控制 总被引:2,自引:0,他引:2
防灾工程研究正在循着结构、系统、复合工程系统的轨迹向前迈进。本文综述了复合工程系统灾害反应分析方法与灾场系统控制的研究进展。着重介绍了离散事件动态系统的基本方法及其在复合工程系统地震灾害研究中的应用。指出了这一方向近期内的可能进展。 相似文献
572.
The Hydrologic Engineering Center (HEC-1) model was used to construct synthetic hydrographs for isolated interior urban floods.
Flood peak and lag time were very well preserved in simulated flows. Total volume was not adequately expressed. Lag time varied
inversely with both urban development and storm intensity. Peak discharge varied with storm intensity, but this variability
was well defined only at very high urbanization levels. An 175% increase in storm intensity produced a change of about 15%
in peak discharge. Claims for flood damage correlated well with estimates of peak flow and lag time combined. Other measures
of flood experience also correlated with the two features. Within the range of storms utilized, urban development factors
consistently outranked storm intensity as a determining factor in flood damage. 相似文献
573.
Removal of atmospheric particles by leaves and twigs of urban trees: Some preliminary observations and assessment of research needs 总被引:3,自引:0,他引:3
This paper reviews the various lines of evidence that support the hypothesis that above-ground plant parts remove particulates from the atmosphere. Some scanning electron microscope observations of the particulate burden on leaves of London planetree are discussed. The authors present an outline of the kinds of research required to support or reject the hypothesis that urban woody plants are important air filters. 相似文献
574.
Numerous undeveloped and ecologically diverse tracts of land within urban communities in the United States are presently being utilized for a variety of unsupervised recreational activities. The present use and perceived value of residual open spaces adjacent to the Palisades to residents of four communities in northeastern New Jersey was assessed. The results of our survey suggest that parks and open space represent a city service that is not as highly valued as other more visible services, that respondents desire a diversity of recreational experiences, that existing parks and open space provide a narrow range of recreational benefits to users, that benefits of existing parks extend primarily to the provision of active pursuits, and that undeveloped residual open spaces are valued for and provide opportunities for a variety of passive pursuits.Residual open spaces are a resource that contributes towards meeting the aesthetic and recreational needs of city residents. Failure by planners and decision-makers to recognize the value and utility of such tracts of land may result in their destruction and in the loss of a resource which provides a range of recreational opportunities that is not adequately provided by formal parks and open spaces.Paper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, Rutgers University, New Brunswick, New Jersey.This work was performed as a part of NJAES Project No. 17501, Urban Forestry: Planning and Management of Residual Open Space, supported by the New Jersey Agricultural Experiment Station and by a grant from the Consortium for Environmental Forestry Studies sponsored by the U.S. Department of Agriculture, Forest Service, Northeast Forest Experiment Station. 相似文献
575.
The use and development of natural resources is becoming a critical concern, especially considering the economic development and stability of the world money market. The question here is one of resources as a political weapon. As resources become more scarce, it becomes necessary to make greater intensive use of resources that are presently available. One dimension that has been missing is the development of urban areas. Resources in this domain have been abused and the question now is how to incorporate these types of decisions into land-use planning to refurbish urban areas. Planning is the key to use of a resource. The world can no longer afford crisis planning. The key dimension to future success in resource problems is preventive planning. 相似文献
576.
Terry D. Edgmon 《Journal of the American Water Resources Association》1979,15(5):1341-1352
ABSTRACT: The thesis of this paper is that the citizen participation process provides necessary, but not sufficient conditions to affect substantive change in federal water resource management agencies' planning and decisionmaking. That is, in its present form, the citizen participation process has been observed to occur outside of the normal decision arenas of federal resource management agencies. The paper reviews concepts of citizen participation and defines some theoretical problems inherent with them. Then, a strategy for the structuring of a citizen participation process is proposed. This strategy is based upon the notion that citizen support for federally sponsored programs are essential if such projects are to be implemented. Therefore, an approach which integrates citizen valves with those held by other institutions and the agency is suggested. In conclusion, the relevancy of actively developing and including citizen input to the water resource planning process is illustrated by a discussion of three cases of the Corps of Engineers and Urban Studies planning process, in different metropolitan regions. 相似文献
577.
A. Dennis Lemly 《Environmental management》1982,6(4):343-352
Five single-treatment methods used to stabilize seeded areas at urban and highway construction sites (asphalt-tacked straw, jute netting, mulch blanket, wood chips, excelsior blanket) were tested for their ability to control erosion of red clay soils by comparisons with exposed sites and multiple treatments. Sediment in runoff from experimental plots was characterized during low and high intensity precipitation from natural rainfall episodes during April, May, and June. Reductions in the total sediment concentration of runoff ranged from 28 percent (asphalt-tacked straw, 50 percent slope) to 90 percent (multiple treatments, 40 percent slope), with 85 percent of the eroded material composed of particles <0.04 mm in diameter. Larger size fractions were effectively reduced by all treatments tested regardless of slope (70 percent decrease). Established grass cover exceeded 90 percent on all plots after 60 days, but sediment release remained similar, attributable to high intensity rainfall, poor establishment of root systems, and piping on plots treated with tacked straw or jute netting. Results indicate that current stabilization methods shift sediment compostion toward a smaller particle size, causing single treatments to be minimally effective for controlling erosion of the major component of red clay soils. Because small particles have the greatest direct effect on aquatic biota, certain impacts of sedimentation may not be measurably lessened by single treatments in regions where red clays predominate even though the total sediment load is reduced by as much as 75 percent. Clearly, a multiple-treatment approach offers significantly greater control of erosion on red clay soils, however, current economic and construction policy represents a substantial deterrent to implementation. 相似文献
578.
R. H. Williams 《Journal of Environmental Planning and Management》1986,29(2):87-89
Recent discussion of Enterprise Zones in England has been concerned with attributing development to the financial package of incentives operating, rather than the simplified planning régime, the author reconsiders the question of the significance of the new forms of planning procedure and suggests that, in the long term, the experiment will have lasting significance for the planning system itself. 相似文献
579.
Senecal G 《Environmental management》2002,30(1):46-58
This article assesses the City of Montréal's éco-quartier program from the viewpoint of managing the urban environment and
improving living environments. It evaluates the actual achievements of the program, looking especially at the ability of local
communities to take effective action to improve their living environments, while under the guidance of the associations mandated
to manage the program at the local level. Our research concentrated on three main areas: a) the development of the City of
Montréal's environmental program; b) the effectiveness of the éco-quartiers in carrying out their mandate; c) the actual impacts
of the program in improving living environments. 相似文献
580.