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901.
Regarding various energy and materials flowing in the urban ecosystem and the merit of emergy as an embodied energetic equivalent for integrated ecological economic evaluation, an evaluation framework of emergy-based urban ecosystem health indicators (UEHIem) was established in view of five aspects including vigor, structure, resilience, ecosystem service function maintenance and environmental impact to depict the urban ecosystem health states. Further, set pair analysis (SPA) was employed to assess the urban ecosystem health level based on the UEHIem, by which the approximate degree of real index set to the optimal one was defined and evaluated to describe the relative health state of the concerned urban ecosystems. Choosing twenty typical Chinese cities in 2005 as cases, we evaluated and compared their urban ecosystem health levels based on UEHIem and SPA. The results showed that health levels of Xiamen, Qingdao, Shenzhen and Shanghai are pretty well, while those of Wuhan, Harbin, Yinchuan, Beijing and Urumchi are relatively weak. Moreover, the relative health levels were analyzed by SPA to discern the influences of the mentioned five aspects on the UEHIem. It is concluded that emergy synthesis combined with SPA can serve as an effective relative-measure to compare different ecosystem health levels of urban ecosystems. 相似文献
902.
Urban ecological risk characterization is the final step in risk assessment and an important foundation upon which risk managers build risk aversion, risk control, and emergency handling strategies. In this study, we reviewed present risk characterization methods and proposed a multi-level characterization method for the assessment of urban ecological risks. The new characterization method consists of four elements: urban ecological risk sources, risk source probabilities, assessment endpoint indicators, and assessment endpoint indicator probabilities. Using this method, results of risk assessments can be organized into different levels of detail to meet different risk management goals. 相似文献
903.
The concentrations and characteristics of volatile organic hazardous air pollutants (HAPs) in the urban city of Kaohsiung
from motor vehicles and dense pollutant sources has become a national concern. To continuously monitor volatile organic HAPs,
sampling sites were selected near the four air-quality monitoring stations established by Ethe nvironmental Protection Administration
of Taiwan ROC, namely Nan-tz, Tso-ying, San-min and Hsiao-kang, from north to south. An on-site automated online monitor of
volatile organic compounds (VOCs) was used for continuous monitoring. This study performed two consecutive days of 24-h monitoring
of five volatile organic HAPs form August to October 2005 at the four monitoring sites, which cover the northern, central,
and southern areas of Kaohsiung city. The average monitored concentration was 2.78–4.84 ppb for benzene, 5.90–9.66 ppb for
toluene, 3.62–5.90 ppb for ethylbenzene, 3.73–5.34 ppb for m,p-xylene, 3.38–4.22 ppb for o-xylene, and 4.48–7.00 ppb for styrene. The average monitored concentrations of the major volatile organic HAPs tended to
follow the pattern San-min > Nan-tz > Hsiao-kang > Tso-ying. Among all the species monitored in this study, toluene had the
highest ambient concentration, followed by styrene, m,p-xylene, ethylbenzene, o-xylene, and benzene. The results showed that the concentration at night was higher than that in the day for toluene at Nan-tz,
San-min, Hsiao-kang, and for benzene at Nan-tz and Hsiao-kang. 相似文献
904.
Dave Morgan 《Journal of Environmental Planning and Management》1987,30(1):50-52
The paper describes the development role of the London Docklands Development Corporation and what sort of plan it uses. It describes the government initiative that promoted the regeneration idea and appraises the Dockland's approach. Finally, it discusses local authority involvement in the Urban Development Corporation's initiatives. 相似文献
905.
Gregory KJ 《Environmental management》2002,29(5):620-633
The impact of urbanization on stream channels has been investigated in a range of areas; the degree and extent of the channel
adjustments have been demonstrated; and for a few areas these characteristics have recently been placed into a spatial context.
A method of rapid field survey for depicting the channel network of urban areas in terms of near natural, adjusted, and channelized
systems is illustrated for the urban area of Armidale NSW, for which Armidale Dumaresq Council had prepared a stormwater management
plan. Such a survey could enable channel characteristics and adjustments, as well as water quantity and quality, to be included
in the management plan. Possible options for management to address are suggested for each of the channel categories. A channel
classification system of the kind suggested can provide a basic complement for the further development of the stormwater management
plan, can afford a basis for specifying management alternatives, and can be helpful in demonstrating the options offered for
community consultation. 相似文献
906.
Abdul-Wahab SA 《Environmental management》2004,34(3):372-382
The CAL3QHC model was used to predict carbon monoxide (CO) concentrations from motor vehicles at an existing urban intersection (Star Cinema in Muscat area, Oman). The CO concentrations predicted from the model were compared with those measured in the field. Predicted average CO concentrations were found to compare favorably with measured values obtained at all eight receptors considered within the modeled intersection. In general, the comparison indicates good agreement with some underprediction for CO. For receptor 6, the model overpredicts the average CO concentration. This overprediction is associated with the presence of trees and green area in the location of receptor 6. In general, the measurements and the model results indicated that the highest CO concentrations were found to occur close to the intersection and, hence, a decrease in the concentration levels was seen as the distance from the road increased. The results indicated that the levels of CO were well below the ambient air quality standard and that probably no health risk was present in areas adjacent to the star cinema intersection. However, the predicted worst-case 1-h CO concentrations assuming inversion atmospheric stability conditions (class F) and wind speed of 1 m/s indicated that the levels of CO were close to or higher than the Omans National Ambient Air Quality Standards (NAAQS) value of 35 ppm at all receptors considered. The results of this study are useful in transport development and traffic management planning.Published online. 相似文献
907.
Evaluation of Heritage Trees for Conservation and Management in Guangzhou City (China) 总被引:1,自引:0,他引:1
Jim CY 《Environmental management》2004,33(1):74-86
The recent fast pace of urbanization in China and other developing countries has exerted pressure on urban trees, which constitute a key urban environmental asset. The most outstanding trees should be treated as natural-cum-cultural heritage. Guangzhou Citys growth has threatened its rich urban-tree endowment, a diversified assemblage of 200,000 trees represented by 254 species and located in three major habitats: roadside, park, and institutional grounds. Mainly based on age and performance, 348 trees were officially designated as heritage specimens. They were evaluated in the field for tree dimensions, habitat, performance, and landscape contribution, to establish enhanced conservation and management strategies. With only 25 species, heritage trees were dominated by five cultivated natives and encompass some of the citys rare species; some common urban-forest species were not represented. Older districts and roadside habitats, despite their compact town plan and limited growing space, had the largest tree dimensions and largest share of heritage trees. Many heritage trees were large with long life expectancy and the potential for biomass expansion, and had pivotal cityscape impacts where they occur. Old neighborhoods, traditional haven for the arborescent treasure, are being changed by construction activities and periodic typhoon and windstorm damages. Increasing development density could degrade the heritage trees and their growing space, and reduce tree quality and life span. Upgrading the statutory-administrative systems and arboricultural care can enhance long-term survival of the precious natural-cum-cultural heritage. The experience of Guangzhou in identifying and preserving its high-quality urban trees can provide management strategies for other cities. 相似文献
908.
城市轨道交通行车安全保障信息系统的研究 总被引:5,自引:4,他引:1
在分析城市轨道交通安全系统现状的基础上 ,笔者阐述了建立行车安全保障信息系统的必要性 ;提出需先期建立综合调度指挥中心 ;而后 ,重点介绍了作为该中心基本组成部分的行车安全保障信息系统及其各个子系统的构成情况 ;进而对监测子系统的设计进行初步研究。城市轨道交通行车安全保障信息系统可以增强事故处理实时性 ,也可在一定程度上减轻事故损失 ,从而指导安全管理工作 ,同时也是提高城市轨道交通自动化水平的一个创新性探索。 相似文献
909.
城市安全规划的可视化技术研究 总被引:13,自引:4,他引:9
李彪 《中国安全科学学报》2003,13(11):28-31
城市安全规划是提高城市安全水平的重要手段 ,笔者分别介绍了利用GIS(地理信息系统 )技术实现安全规划可视化的方法 ;介绍了以安全规划对象的可视化组织、安全规划对象的可视化编辑、安全规划结果可视化、危险源危险性可视化等方面的研究成果。该系列成果及其应用有利于安全规划工作的自动化、智能化和工作绩效的提高。 相似文献
910.
城市轨道交通的振动和噪声及其控制的研究 总被引:11,自引:4,他引:7
地铁、轻轨等城市轨道交通会给市民和旅客带来便捷 ,同时也会给沿线的居民和建筑物带来振动及噪声等环境污染的公害。笔者分析了振动和噪声的控制与评价标准和预测方法 ,针对城市轨道交通的振动和噪声的特点和传播规律 ,从声源的控制、振动传播与声传播控制以及承受物控制 3个方面 ,提出了相应的控制措施和途径 相似文献