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891.
于鲁冀  何青  赵晴 《四川环境》2010,29(5):40-45
根据函数单调性特点及模糊识别中最大贴近度原则,分别从距离函数和关联函数两方面对物元可拓法在城市环境可持续发展综合评价过程中存在的不足进行了改进。距离函数改进后,能够真实地反应变量与区间的关系;关联函数改为贴近度函数后,评价结果中不再出现负值,易于级别的判定。采用改进后的物元可拓法建立了城市环境可持续发展综合评价的多级物元模型,对城市环境可持续发展现状进行了综合评价,结果表明该方法更快捷,评价结果能更客观地反映城市环境可持续发展现状。  相似文献   
892.
Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content.  相似文献   
893.
太湖流域是我国城市化高度发达地区,城市化的发展有力地促进了区域经济的增长,但同时对原有河流水系造成了较大冲击,从而对生态环境造成了很大影响。苏州市是太湖流域城市化发展最为典型的城市之一,近几十年来城市化的快速发展导致区域河网萎缩,水系连通受阻。为此运用图论和GIS的方法探讨了水系结构与河流连通变化。研究表明:(1)近50 a来,苏州市中心区河流总长减少了约84 km,河网密度下降了约197%;(2)研究区二、三级河流持续减少,一级河流不断增加,呈明显的主干化趋势;(3)河流结点数和河链数均呈下降趋势,且1980s到2009年的变化幅度要比1960s到1980s的变化幅度大;(4)水系连通度由1960s的4215下降到1980s的4017,到2009年下降为3361,呈明显的减小趋势  相似文献   
894.
A source attribution study was performed to assess the contributions of specific pollutant source types to the observed particulate matter (PM) levels in the greater Cairo Area using the chemical mass balance (CMB) receptor model. Three intensive ambient monitoring studies were carried out during the period of February 21–March 3, 1999, October 27–November 27, 1999, and June 8–June 26, 2002. PM10, PM2.5, and polycyclic aromatic hydrocarbons (PAHs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. Major contributors to PM10 included geological material, mobile source emissions, and open burning. PM2.5 tended to be dominated by mobile source emissions, open burning, and secondary species. This paper presents the results of the PM10 and PM2.5, source contribution estimates.  相似文献   
895.
Cities are major contributors to global emissions, producers of waste and consumers of resources such as energy, water and food: implementing green development strategies is hence a core challenge of modern city-planning. The attention of research has been focusing on the development of energy efficient, low carbon strategies, yet city decision-makers need truly integrated approaches, as the one proposed by the water-energy-food Nexus. The purpose of our paper is to investigate whether it is possible to take one step in this direction by extending existing approaches to energy efficiency strategies to progressively include other priority resources, in particular water. To test this hypothesis we have taken a robust and well accepted methodology, the ELCC (Economics of Low Carbon development strategies for Cities) developed by SEI and CCCEP, and we have extended it to the case of demand side water efficiency strategies for cities. We have then applied the adapted ELCC framework to the case study of the domestic sector of the city of Bologna (Italy), identifying and prioritizing several efficiency measures. Measures were evaluated through their capital investment, annual values of savings, payback period and reduction in consumption, and then aggregated in different scenarios in order to highlight potential urban investments and to showcase a possible approach to the prioritization of demand side water efficiency measures. The results show that, with an upfront investment of € 17 million, a feasible subset of Bologna’s households could be equipped with five selected cost-effective measures, generating annual savings of € 10.2 million and reducing the total domestic water consumption of 34% by 2020 compared to the 2012 initial value. With additional € 28.5 million, households could be equipped with more costly appliances reaching an overall water reduction of 37% by 2020. Our findings confirm that it is possible to successfully extend current approaches to urban energy efficiency strategies to include demand side water efficiency, adding an important building block to the construction of an integrated Nexus-based approach to green development strategies at the city-level. We encourage further tests to confirm the robustness of the methodology.  相似文献   
896.
Most accounts of urban green space governance originate in cities where such initiatives have been successful. Meanwhile, there is too little information on cities where such initiatives develop with more difficulty. In order to overcome the problems that such cities face, their situations need to be studied more carefully to facilitate peer comparisons. This article provides an account of urban green space governance in three cities in Poland (Krakow, Lodz, Poznan), where environmental protection is still quite far down on the list of political priorities. With the use of a social network analysis we looked at the extent of relationships between different stakeholders and the roles of different actors within the network. The results indicate that the network's collaboration potential is barely used and that cross-sectoral collaboration is especially deficient. In particular, public institutions hold a relatively strong position and downplay the role of other actors. More collaboration is necessary and the potential bridging role of NGOs should be used to a larger extent. However, this requires more openness and trust within the network.  相似文献   
897.
Recent extreme weather events worldwide have highlighted the vulnerability of many urban settlements to future climatic change. These events are expected to increase in frequency and intensity under climate change scenarios. Although the climatic change may be unavoidable, effective planning and response can reduce its impacts. Drawing on empirical data from a 3-year multi-sectoral study of climate change adaptation for human settlements in the South East Queensland region, Australia, this paper draws on multi-sectoral perspectives to propose enablers for maximising synergies between disaster risk reduction and climate change adaptation to achieve improved planning outcomes. Multi-sectoral perspectives are discussed under four groups of identified enablers: spatial planning; cross-sectoral planning; social/community planning; and strategic/long term planning. Based on the findings, a framework is proposed to guide planning systems to maximise synergies between the fields of disaster risk reduction and climate change adaptation to minimise the vulnerability of communities to extreme weather events in highly urbanised areas.  相似文献   
898.
There is a lack of information on urban heat island impact on the thermal environment due to low populated urban sprawl, although densely populated urban sprawl impact has been identified by several researchers. The Takamatsu area has recently developed in a low populated urban sprawl style without any increase in population. This paper examined the impact of a low populated urban sprawl on the thermal environment through an analysis of the last 30 years data set and investigated the contribution of vegetation fraction and population density to the temperature trend. As a consequence, it was shown that one of the most significant causative factors of temperature increase is an expansion of non-vegetated area even without population growth. This result implied that vegetated zones should be maintained in urban areas in order to realize sustainable urbanization.  相似文献   
899.
To improve quality of life as well as the adaptive capacity in the city of Rotterdam over the past 15 years there has been a lot of focus on improving green infrastructure and finding new ways for integrated planning. As many cities face similar challenges they are looking for novel approaches in urban ecosystem governance. The Rotterdam case can be an interesting example but can also reveal new questions to be researched.Before local policies and projects where developed a regional and urban green blue vision of how to improve overall quality of life using green infrastructure were developed. This provided policy frameworks for politicians, policymakers and other actors. Later on the same was done with Urban Waterplan 2, using the Rotterdam Watercity 2030 vision document as a basis. This vision was the result of a stakeholder based planning process which was made for the International Architecture Biennale 2005. Within these frameworks many interesting projects have been built and tested in the city and city region; ranging from a) a roof park over a railway yard to connect neighbourhoods to the waterfront, to b) water squares and c) digging new waterways with connected walking and biking routes. To go from projects to an overall implementation at city level required tools and approaches for better decision making. For the ‘Dakpark’ project as well as for the Zomerhofkwartier, the first climate proof neighbourhood in the city, stakeholder sessions were held and plans were drawn together with urban planners and landscape architects. To feed these processes even better and to know what would be an optimal solution for certain challenges, city data were studied and linked to scalable GIS mapping in the ‘smart city planner’. This tool gives the decision maker the possibility to quickly have an overview of an area and can be used in a stakeholder process to provide relevant additional information and to define joint projects. The tool makes it possible to do this for all 90 neighbourhoods in the city.Overall the urban ecosystem governance in the city of Rotterdam has – with trial and error- lead to a series of innovative projects. The next steps are acceleration and scaling up to city and regional level. Valuing the crucial role of green blue infrastructure for several aspects of the quality of life in cities are paramount.  相似文献   
900.
The urban landscape is comprised of many land uses, none more intensively managed than turfgrass; however, quantification of nutrient losses from specific land uses within urban watersheds, specifically golf courses is limited. Nitrate (NO(3)-N) and dissolved reactive phosphorus (DRP) were measured on a golf course in Austin, TX, USA from April 1, 1998 to March 31, 2003. NO(3)-N and DRP concentrations measured in storm flow were significantly greater exiting the course compared to those entering the course. Significant differences were also measured in baseflow NO(3)-N concentrations. The measured loading from the course was 4.0kg NO(3)-Nha(-1)yr(-1) (11% of applied) and 0.66kg DRPha(-1)yr(-1) (8% of applied). The resulting concentrations contributed by the course were 1.2mgL(-1) NO(3)-N and 0.2mgL(-1) DRP. At these levels, NO(3)-N poses minimal environmental risk. However, the DRP concentration is twice the recommended level to guard against eutrophication.  相似文献   
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