Elemental Composition of Urban Aerosol Collected in Florence, Italy

An extensive investigation is in progress aiming at the characterisation of the air particulate composition in Florence. For our investigation, we use the external PIXE-PIGE beam facility of the I.N.F.N. Van de Graaff accelerator at the Physics Department of the Florence University. In order to gather information on both the longer- and shorter-time trends of the aerosol elemental composition, we are analysing both long temporal series (about 1 year) of 24-h Millipore filters collected by the health authorities in 3 different sites, and filters collected simultaneously in two of the above sites for about one month, by two streakers with one-hour resolution, providing size fractionation between particle size smaller than 2.5 µm and from 2.5 µm to 10 µm. The streakers sampling period includes two days during which the Municipality of Florence has banned the circulation of non-catalytic cars, due to the increase of NO₂ above the "recommended safety values". We present here the first obtained results for the sampling site located near a heavy traffic road.     

酒泉市城南热岛成因分析

根据遥感资料分析了酒泉市城市热岛的成因。指出建筑空间、污染物、水体都是影响城市热岛的主要因素。     

乌鲁木齐大气微生物污染研究

采用网格布点用自然沉降法同步采样，调查和研究乌鲁木齐建成区大气微生物浓度分布、污染现状及微生物污染类型特征．结果表明：乌鲁木齐市大气微生物以细菌为主导，占微生物总数的７９．５％，真菌约占２０．５％．建成区大气微生物达５级中污染水平．大气微生物污染分布与环境条件和环境质量都有一定关系。     

城市区域环境噪声监测优化布点探讨

应用数理统计中抽样理论，对瑞安市环境噪声监测点进行了优化组合，方法简单易行，兼顾了功能区特征，减少了测点数，并能达到要求的准确性。     

细水雾在城市地下综合管廊内灭火特性的数值模拟研究

近年来,综合管廊逐渐成为城市建设热点,选择合理的灭火系统有利于保障消防安全,但相应的规范中未明确具体的设置参数。因此以某城市综合管廊为研究对象,采用FDS数值模拟软件,研究了管廊通风、雾滴粒径、喷雾流量等因素对细水雾灭火特性的影响,研究结果表明:将细水雾灭火系统与通风系统联动关闭通风可以提升细水雾的灭火效果;在此研究条件下,平均粒径为300μm、喷雾流量为13 L/min的细水雾灭火效果较优。     

基于信息熵和GM(1,1)的上海市城市生态系统演化分析与灰色预测

城市生态系统是典型的"自然-社会-经济系统",城市的可持续发展依托于城市生态系统结构和功能的不断协调与完善.新一轮"城市化"进程中,城市生态系统将面临生态用地减少、环境衰退等诸多挑战,生态环境和经济发展之间的矛盾可能日益突出.因此,把握城市生态系统的演化方向,对于促进城市可持续发展和生态文明建设意义重大.本研究以"国际化大都市"上海市为研究对象,运用"耗散结构理论"和"信息熵"分析模型,构建包括支持型输入熵、压力型输出熵、氧化型代谢熵、还原型代谢熵4方面的"上海市城市生态系统演化指标体系",以统计资料和政府公报为数据来源,对上海市2003—2013年的城市生态系统演化进行了熵变分析;基于集成层次分析法(AHP)和熵权法(EVM)"综合赋权"的"综合发展度"和"协调发展度"模型对城市生态系统可持续发展状况进行了评价;采用"相关分析法"对城市生态系统熵变与可持续发展协同演化过程进行量化分析;并引入GM(1,1)灰色预测模型对上海市城市生态系统(2014—2020)年的演化趋势和方向做出了预测.研究得出以下结论:12003—2013年,上海市城市生态系统"熵流、熵产生和总熵变",均整体呈波动下降趋势.上海市城市生态系统有序度不断提高,总体朝健康态势发展.22003—2013年,上海市城市生态系统总体可持续发展态势良好,不断向健康可持续方向演进;环境与经济整体效益不断提高,但环境与经济发展之间的协调能力近年来有所下降.3上海市城市生态系统(2014—2020)期间的演化趋势预测:城市生态系统整体继续向健康、有序方向演进.城市生态系统可持续发展整体保持协调发展态势,但未来发展协调度可能从"初级协调"衰退为"勉强协调".最后,基于指标"熵权"和熵变时序提出了上海市城市生态系统的针对性优化措施:积极扶持城市生态农业发展,扩大进出口贸易规模,促进娱乐教育文化服务产业增长;进一步提高居民生态环保意识,提倡低碳生活;加强工业"三废"的达标排放,提高资源利用率,巩固城市绿化率,加大环保投资规模.本研究旨在为上海市城市生态系统健康可持续发展和优化调控提供一定的科学参考.     

基于STIRPAT模型的中国城镇生活能源消费影响因素研究

为探究人口规模、收入水平、消费倾向、节能政策和技术等因素对中国城镇生活能源消费的影响,基于拓展的STIRPAT模型并运用2000~2013年中国省际面板数据对各影响因素的效应进行评估。结果显示:城镇生活能源强度、城镇居民消费倾向、人均可支配收入、城镇化率、总人口、政策综合力度6个因素的增长率每变化1%,将会引起城镇生活能源消费量增长率0.9322%、0.8537%、(0.559 2+0.169 2 ln DI)%、0.599 8%、0.408 0%、-0.012 0%的变化,表明除节能政策外,其余5因素均正向促进城镇生活能耗增长。其中生活能源强度对城镇生活能耗影响最大,节能政策虽会抑制城镇生活能耗增长,但作用较为微弱。政府需继续加强节能政策综合实施力度,从而实现生活能源消费领域的节能减排。     

Practicalities of participation in urban IWRM: Perspectives of wastewater management in two cities in Sri Lanka and Bangladesh

As the demand for water in cities increases, the quantity of wastewater being produced is growing at a phenomenal rate. If resources are to be managed effectively, a new paradigm is required for urban wastewater management. This paper reviews the initial findings of a participatory action planning process for managing wastewater for agricultural use. It finds that such processes need considerable facilitation, capacity building and knowledge sharing, but that if a plan can be devised that meets the needs of the stakeholders, even if some compromise is required, then certain stakeholders are likely to take responsibility for specific aspects. This may not meet the entire integrated water resources management (IWRM) vision of the plan but provided the plan is developed in such a way that incremental implementation will be beneficial then this will produce some success and may stimulate further cooperation.     

The impacts of urban sprawl on ecological connectivity in the Montreal Metropolitan Region

Urban sprawl is a widely recognized phenomenon in many major cities worldwide and is a significant land use planning and management issue. This process has many impacts on the ecological function and structure of the landscape. In this article, we analyze the effects of urban sprawl on the ecological patterns and processes in the Montreal Metropolitan Region (MMR) between 1966 and 2010. The dispersed sprawl of low-density urban areas within the territory during this period sharply increased the fragmentation of the territory, isolating the few remaining natural spaces and decreasing their ecological connectivity and, ultimately, biodiversity. The results obtained clearly show that land-use changes that occurred in the MMR have caused profound changes in landscape properties, both structurally and functionally, and especially from 1981 to 2010. In 1966, around 45% of the land had a high or very high level of connectivity, and almost 38% in 1981. By 2010 only 6.5% of the landscape was connected and 73% of the territory possessed no or low connectivity.     

Street canyon ventilation and atmospheric turbulence

Operational models for pollutant dispersion in urban areas require an estimate of the turbulent transfer between the street canyons and the overlying atmospheric flow. To date, the mechanisms that govern this process remain poorly understood. We have studied the mass exchange between a street canyon and the atmospheric flow above it by means of wind tunnel experiments. Fluid velocities were measured with a Particle Image Velocimetry system and passive scalar concentrations were measured using a Flame Ionisation Detector. The mass-transfer velocity between the canyon and the external flow has been estimated by measuring the cavity wash-out time. A two-box model, used to estimate the transfer velocity for varying dynamical conditions of the external flow, has been used to interpret the experimental data. This study sheds new light on the mechanisms which drive the ventilation of a street canyon and illustrates the influence of the external turbulence on the transfer process.