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651.
Devils Lake, located in a closed basin in northeastern North Dakota has over a century-long history of highly fluctuating water levels. The lake has risen nearly 25 feet (7.7 m) since 1993, more than doubling its surface area. Rising water levels have affected rural lands, transportation routes, and communities near the lake. In response to rising lake levels, Federal, state and local agencies have adopted a three-part approach to flood damage reduction, consisting of (1) upper basin water management to reduce the amount of water reaching the lake, (2) protection for structures and infrastructure if the lake continues to rise, and (3) developing an emergency outlet to release some lake water. The purpose of this study was to provide information about the net regional economic effects of a proposed emergency outlet for Devils Lake. An input-output model was used to estimate the regional economic effects of the outlet, under two scenarios: (1) the most likely future situation (MLS) and (2) a best case situation (BCS) (i.e., where the benefits from the outlet would be greatest), albeit an unlikely one. Regional economic effects of the outlet include effects on transportation (road and railroad construction), agriculture (land kept in production, returned to production sooner, or kept in production longer), residential relocations, and outlet construction expenditures. Effects are measured as changes in gross business volume (gross receipts) for various sectors, secondary employment, and local tax collections. The net regional economic effects of the proposed outlet would be relatively small, and consideration of these economic impacts would not strengthen the case for an outlet.  相似文献   
652.
近年来 ,恐怖袭击事件威胁着城市公共安全 ,给人们的精神和心理造成极大的创伤和痛苦 ,已引起各国政府、各大媒体的广泛关注。笔者分析了城市公共安全的特点 ,研制了恐怖内心思想的智能阅读车 (IRV) ,通过对进入公共场所的人群进行快速 (数秒内 )检测人体生理参数 (3项指标 ) ,阅读人群的心理、生理、行为特征 ,快速地识别出恐怖分子 ,解决了安全预警滞后的问题 ,建立公共安全的常规通道 (或非常规通道 )。研究与开发的目的是从传统的被动防范转变到主动预控 ,为解决国内外防恐和反恐难题提供了一种新方法。  相似文献   
653.
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   
654.
ABSTRACT: Precipitation, streamflow, and population data were analyzed over the 1941–1990 period to determine whether changes in stormflows and net (post. minus pre-rainstorm) stormflows, associated with warm-season large rainstorms, were similar for two urbanized northeastern Illinois basins. Warm season large rainstorms were defined as April through October rainfall events in which ? 5.1 cm occurred in a 48-hour period over the basin. To minimize differences associated with varying large rainstorm amounts over time, the net sthrmflow for each event was divided by the large rainstorm amount. This ratio, Ui, indicated that the two urbanized basins experienced significant, yet different, increases (102 percent and 49 percent) in flow amount per centimeter of rainfall from 1941–1965 to 1966–1990. Results of a regression analysis between Ui and population showed that the increase in Ui per 100,000 increase in population ranged from 0.59 to 0.67 m3s-1 per cm of rainfall for the two basins. These results demonstrate the varying degree of change that urban planners can expect in stormflows associated with large warm season rainstorms for areas undergoing urbanization.  相似文献   
655.
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   
656.
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   
657.
Flooding and the susceptibility to flood damage inherent in all land uses constitute the flood hazard. Resolution of the hazard while properly recognizing flood plain environmental attributes within the context of overall community or area needs is the essence of comprehensive flood plain management. The traditional approach–flood control–has effected modification of only the flooding component of the hazard whether it be coastal or inland. Until recently Federal programs have overlooked the possibilities of modifying the susceptibility component, for which the major responsibility lies with non-Federal interests. Beginning with actions in the TVA area, the latter is now being strongly encouraged through Federal programs and actions notably the Flood Plain Management Services and Survey Programs of the Corps of Engineers, those stemming from Executive Order 11296, and those required for eligibility under the National Flood Insurance Act of 1968. Flood plain management objectives must be stated in planning, e.g., economic efficiency, reduction in threat to life and health, environmental improvement, and regional development, to permit proper evaluation of the optional means and approaches for achieving them.  相似文献   
658.
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   
659.
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   
660.
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   
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