印度德里城市规划与发展

对印度首都德里的城市演变、城市发展的主要问题和当代城市规划进行了综合的介绍和分析。包含3部分内容：一是德里的城市演变过程,分为12-17世纪的德里七城、1911-1947的英国殖民统治、1947年的印度独立和分裂以及1967年至今的当代城市规划4个时期;二是分析德里当前城市发展面临的主要问题;三是阐述了德里当代城市规划的主要举措以及2002-2021城市总体规划的新战略重点。     

Seasonal and diurnal variations of carbonyl compounds in the urban atmosphere of Guangzhou, China

Seasonal and diurnal variations of carbonyl compounds were investigated at two sampling sites (Liwan and Wushan) in the ambient air of Guangzhou, China. Air samples were collected during 2005 from January to November, and carbonyl compounds were analyzed with HPLC. The results show that carbonyls exhibit distinct seasonal variation. The total concentrations of 21 carbonyls detected ranged from 2.64 to 103.6 μg m⁻³ at Liwan and from 5.46 to 89.9 μg m⁻³ at Wushan, respectively. The average total concentrations of carbonyls at both Liwan and Wushan decreased in order of summer>spring>autumn>winter. Formaldehyde, acetaldehyde, and acetone were the most abundant carbonyl compounds, which accounted for more than 60% of the total concentrations of carbonyls. The mean concentration ratios of summer/winter were all > 1.0 for the total concentrations and the individual carbonyl compound. The diurnal variation of carbonyls was not distinct in this study. The average concentration ratios of formaldehyde/acetaldehyde (C₁/C₂) varied from 0.71 to 1.32 and 0.65 to 1.14 at Liwan and Wushan, respectively, and the average concentration ratios of acetaldehyde/propionaldehyde (C₂/C₃) varied from 5.42 to 7.70 and 5.02 to 13.9 in Liwan and Wushan, respectively. Regarding photochemical reactivity of carbonyls and the ozone production, acetaldehyde, butyraldehyde, formaldehyde, and valeraldehyde account for 75-90% to the total propene-equivalent concentrations, while formaldehyde, acetaldehyde, valeraldehyde, butyraldehyde, and propionaldehyde contribute 89-96% to the total ozone formation potentials (ranging from 105 to 274 μg m^-3). The ozone formation potentials in summer were higher by 1-2 times than those in the other seasons.     

BTEX污染含水层中氧化还原环境的空间变化

采用一维柱实验模拟方法,研究了地下水受BTEX污染过程初期,含水层中顺序氧化还原环境的空间变化规律,并对模拟柱不同高度出水中BTEX各组分的浓度进行监测。结果表明,模拟柱中各氧化还原灵敏性指标的浓度分布呈现以下规律:距离污染源80~98cm处的氧还原环境较强;60~80cm之间硝酸盐还原环境较强;35~60cm之间以铁还原环境为主;24~50cm之间形成硫酸盐还原环境;0~30cm处HCO-3的浓度最低则产甲烷作用较明显。BTEX各组分从模拟柱底部至顶部呈急剧减少规律,其中苯、甲苯、乙苯、对二甲苯和间邻二甲苯的去除率分别达到99.94%、99.96%、99.94%、99.49%和98.3%。     

Sustainable transport and the modernisation of urban transport in Delhi and Stockholm

This article addresses issues of the development of transport systems taking its examples from Delhi and Stockholm. The introduction of the first bus rapid transport corridor in Delhi and the congestion tax in Stockholm is presented and discussed in terms of modernisation and sustainable transport. This paper explores the perceptions of politicians and examines some transport plans in the search for the driving forces for transport policies. The continuing presence of a high proportion of non-motorised modes of transport and use of public transport in Delhi over the past 50 years gives it a greater political opportunity for creating a more inclusive city than Stockholm. Whereas, in Stockholm, awareness of the influence of emissions on climate change makes the inhabitants more inclined to accept fees for the use of city streets where sustainable transport and modernisation of transport systems are seen as key activities, but are perceived and operationalised differently in Delhi and Stockholm. Despite all the differences, some similarities in the development of their urban transport projects have been found. This paper inquires into the planning and operationalisation of transport modernisation and the politics of sustainable transport.     

Atmospheric levels of BTEX compounds during the 2008 Olympic Games in the urban area of Beijing

The hourly concentrations of BTEX (Benzene, Toluene, Ethylbenzene, m,p-Xylene and o-Xylene) in the urban area of Beijing were measured during July-October 2008, covering the periods of the 2008 Olympic Games and Paralympic Games. The atmospheric BTEX were pre-concentrated on Tenax-TA tubes, and analyzed by GC-PID (Gas Chromatography with Photo Ionization Detector) after thermal desorption. During the games, the mean daytime concentrations of benzene, toluene, ethylbenzene, m,p-xylene and o-xylene were 2.37, 3.97, 1.92, 3.51 and 1.90 μg/m³, respectively, and were 52.8%, 63.9%, 56.4%, 56.8% and 46.9%, respectively lower than those after the games. The significantly positive correlation between BTEX and CO as well as the ratio of benzene/toluene suggested that the vehicle exhaust was the major source of BTEX during the whole investigated period. The extremely high ratios of ethylbenzene to m,p-xylene (E/X) were mainly observed at noontime in haze days, indicating that photochemical reactions were highly active under these typical days.     

Effects of urbanisation on the quality of the urban runoff for Delhi watershed

The current paper is the first study to report quality of urban runoff, focusing on the diffuse sources contributing to pollutant loads in the Delhi watershed. The quality of stormwater runoff from the urban watershed of Delhi was evaluated to assess the effects of different land-use practices on pollutant concentrations. Six sites within the Delhi watershed with different land-use characteristics were selected. The microbial quality of the urban runoff from sub-catchments of Delhi watershed is very poor with Faecal Coliform (FC) levels varying between 6 and 7 log orders. There was a good correlation between the chemical and biological quality of urban runoff with land-use characteristics such as impervious land and population density. Except for chemical oxygen demand all other parameters in urban runoff were found to exceed the effluent discharge standards set by the National River Conservation Directorate (NRCD), India. The public health risks associated with exposure to urban runoff via different routes have also been qualitatively estimated.     

Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Xiamen, China

An intensive sampling program was conducted from October 2008 to September 2009 at the five different environmental sites in Xiamen, Fujian Province, to study the spatial and temporal characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in the gaseous and particulate phase, respectively. The PAHs concentrations at different sites were quite distinct during four seasons. The average concentrations of PAHs in winter were about 8.4 times higher than those in spring, and the concentrations of background were 0.56 times lower than those of industrial area. In addition, the higher temperature in summer affected the particle/gas partitioning of PAHs and led to the higher concentrations of gaseous PAHs. Diagnostic ratios of PAHs, which were employed to indicate the primary sources of PAHs in Xiamen, showed that the traffic vehicle exhaust was the largest contributor and the primary source for PAHs in Xiamen, especially in urban area; while the stationary combustion processes, such as petrochemical factories and power plants, were mainly responsible for PAHs sources in the industrial areas. The health risk of PAHs in the particulate phase was higher than those of the gaseous phase at the five sampling sites. The average toxic equivalent (BaP_eq) of the benzo[a]pyrene values for PAHs were 0.14, 0.32, 1.38 and 3.59 ng m^− 3 in spring, summer, autumn and winter, respectively. Furthermore, the results of average BaP_eq in all four seasons indicated that the health risks of particulate PAHs were higher than those of the gaseous PAHs at different sampling sites.     

Mass concentrations of BTEX inside air environment of buses in Changsha,China

In order to estimate the mass concentrations of benzene (B), toluene (T), ethylbenzene (E) and xylenes (X) inside air environment of buses and to analyze the influencing factors of the BTEX pollution levels, 22 public buses were investigated in Changsha, China. The interior air was collected through activated charcoal adsorption tubes and then the air samples were analyzed with thermally desorbed gas chromatograph. The mass concentrations ranged from 21.3 to 106.4 μg/m³ for benzene, from 53.5 to 266.0 μg/m³ for toluene, from 19.6 to 95.9 μg/m³ for ethylbenzene and from 46.9 to 234.8 μg/m³ for xylenes. Their mean values were 68.7, 179.7, 62.5 and 151.8 μg/m³, respectively. The rates of buses tested where the interior concentrations exceeded the limit levels of Chinese Indoor Air Quality Standard were 45.5% for toluene and 13.6% for xylenes. The BTEX levels increased when in-car temperature or relative humidity rose, and decreased when car age or travel distance increased. The BTEX concentrations were higher in leather trims buses than in non-leather trims ones, in air-conditioned buses than in non-air-conditioned ones, and in high-grade buses than in low-grade ones. According to the analysis of multiple linear regression equation, car age and in-car temperature were two most important factors influencing the BTEX pollution levels in the cabins of public buses.     

Spatial and temporal variation of particle number concentration in Augsburg, Germany

Epidemiological studies on health effects of outdoor air pollution are largely based on a single monitoring site to estimate the exposure of people living in urban areas. For such an approach two aspects are important: the temporal correlation and the spatial variation of the absolute levels of concentrations measured at different sites in an urban area. Whereas many studies have shown small spatial variability of fine particles in urban areas, little is known on how well a single monitoring station could represent the temporal and spatial variation of ultrafine particles across urban areas. In our study we investigated the temporal and spatial variation of particle number concentration (PNC) at four background sites in Augsburg, Germany. Two of them were influenced by traffic, one was placed in the outskirts of the city. The average PNC levels at two urban background sites with traffic impact were 16,943 cm(-3) and 20,702 cm(-3), respectively, compared to 11,656 cm(-3) at the urban background site without traffic impact (ratio 1.5 to 1.8). The Spearman correlation coefficients between the monitoring sites were high (r>0.80). The pronounced differences in absolute PNC levels suggest that the use of a single monitoring station in long-term epidemiological studies must be insufficient to attribute accurate exposure levels of PNC to all study subjects. On the other hand, the high temporal correlations of PNC across the city area of Augsburg implicate that in epidemiological time-series studies the use of one single ambient monitoring site is an adequate approach for characterizing exposure to ultrafine particles.     

Spatial and temporal analysis of urban flood risk assessment

Urban flood risk assessment requires quantification of uncertainty that is spatially and temporally variable. This paper presents a new approach to urban flood risk assessment by: (a) integrating objective and subjective uncertainties and (b) providing full insight into spatial and temporal change of flood risk. A 1-D storm sewer model and a 2-D surface flow model are integrated to describe the dynamic interactions between overland flow on the streets and flow through the storm sewer network. The fuzzy set theory approach is used to assess spatial and temporal variability of urban flood damage, and the acceptable level of partial flood damage. The spatial and temporal variability of fuzzy performance indices: (i) combined reliability-vulnerability; (ii) robustness and (iii) resiliency, are generated as the outcome of the urban flood risk analysis. The methodology is illustrated using the residential community of Cedar Hollow (London, Ontario, Canada) as a case study.     

Spatial and temporal trends of volatile organic compounds (VOC) in a rural area of northern Spain

Ambient concentrations of volatile organic compounds (VOCs) were measured at 40 rural sampling points in Navarre (northern Spain). Air samples were collected by means of sorbent passive sampling and analyzed by thermal desorption (TD) and gas chromatography/mass-selective detector (GC/MSD). A total of 140 VOCs were identified during the study, which was carried out between May to October 2004 for a total of a 10 biweekly sampling campaigns. Concentrations of benzene, toluene, ethylbenzene, m/p-xylenes, o-xylene (BTEX) and 1,3,5-trimethylbenzene were determined in order to investigate their temporal and spatial distributions. Geostatistical analysis pointed to traffic as the main emission source of these compounds. Supporting this idea, BTEX and nitrogen oxides concentrations were found to be highly significantly correlated (r = 0.495, P = 0.001), whereas a strong negative correlation between BTEX and ozone was also observed (r = -0.355, P = 0.025). The concentrations for the BTEX group were similar to the values that have been previously reported for other rural areas.     

印度德里酒店综合体之地域化设计

一、项目概况及设计目标 印度德里酒店建筑综合体包括酒店、商场和公寓三组建筑，设计的客房量为300床，包括住宿、餐饮、娱乐、购物等功能。总建筑面积15800m^2。建筑用地平整外形东西短南北长，处于街区十字交叉口的西北端，视野开阔。     

Utility reforms in developing countries: Learning from the experiences of Delhi

The power sector reforms of Delhi, the capital of India presents an interesting case in the evolution of power sector reforms in India, targeting improvements in distribution side. The Delhi reform design has benefitted from the experience of an earlier partially successful experiment in the state of Orissa. The reform format has tried many new ideas such as defining Aggregate Technical and Commercial (AT&C) losses, auctioning of Discoms based on highest AT&C loss reduction, direct privatization and transitory support provision. In the span of a little more than a decade from the year 2002, there has been tangible progress on many fronts. Other utilities planning the reforms may benefit from this experience. However, newer challenges such as an unexpected increase in power purchase costs with limited scope of passing these costs to the end customers seem to have emerged in the recent years. The paper ends with a cautionary note that for any utility not having access to lower cost power, the distribution reforms will reach a dead-end unless a competitive market is created at the generation side too.     

Urinary BTEX, MTBE and naphthalene as biomarkers to gain environmental exposure profiles of the general population

The aim of this work was to evaluate urinary benzene, toluene, ethylbenzene, m+p-xylene, o-xylene (BTEX), methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and naphthalene (NAP) as biomarkers of exposure to environmental pollutants. Personal air and urine samples from 108 subjects belonging to the Italian general population were compared. Urinary profiles were obtained by headspace gas chromatography-mass spectrometry. BTEX, MTBE, ETBE and NAP median airborne exposures during a 5-h sampling were 4.0, 25.3, 3.8, 9.3, 3.4, 3.4, < 0.8, and 3.4 µg/m³, respectively. Meanwhile, median urinary levels, as geometric means of three determinations were: 122, 397, 74, 127, 43, 49, < 15, and 46 ng/L, respectively. Urinary benzene and toluene concentrations were 4.6- and 1.2-fold higher in smokers than in non-smokers. For most chemicals, significant positive correlations between airborne exposure (log-transformed) and the corresponding biological marker (log-transformed) were found, with Pearson's r values for correlation, ranging from 0.228 to 0.396. Multiple linear regression analysis showed that the urinary level of these chemicals was influenced by personal airborne exposure, urinary creatinine, and urinary cotinine, with R² 0.733 for benzene. Urinary chemicals are useful biomarkers of environmental exposure. Given the ease of rapidly obtaining urine samples, they represent a non-invasive alternative to blood chemical analysis. The possibility of obtaining urinary exposure profiles makes this method an appealing tool for environmental epidemiology.     

Occurrence and fate modeling of MTBE and BTEX compounds in a Swiss Lake used as drinking water supply

Emissions of fuel components from boating use on multiple-use lakes and reservoirs are of high concern with regard to the drinking water supply from such water bodies. We report results of a detailed study on the occurrence, sources and fate of aromatic hydrocarbons and methyl tert-butyl ether (MTBE) in a typical holomictic lake, Lake Zurich, that supplies drinking water for the largest Swiss city. Emphasis of the investigation was on the fuel oxygenate MTBE, which was found in concentrations up to 1.4 microg/L in the epilimnion and up to 0.05microg/L in the hypolimnion of the lake. The concentration difference was due to the stratification of the lake during the boating season with very limited water exchange across the thermocline. MTBE and BTEX nearly completely volatilized before vertical lake mixing occurred in winter. Spatial and temporal variations of MTBE concentrations in the lake were observed and successfully predicted using two complementary box models (MASAS Light and Aquasim). The drinking water supply from holomictic lakes is not at risk for the scenarios studied if water is extracted from well below the thermocline. Since emissions of unburned gasoline into such water bodies are caused predominantly by boating activities, restrictions of highly emitting two-stroke engines could substantially reduce the MTBE and BTEX load of the epilimnion during the boating season.     

Spatial variation of urban soil geochemistry in a roadside sports ground in Galway, Ireland

Characterization of spatial variation of urban soil geochemistry especially heavy metal pollution is essential for a better understanding of pollution sources and potential risks. A total of 294 surface soil samples were collected from a roadside sports ground in Galway, Ireland, and were analysed by ICP-OES for 23 chemical elements (Al, Ca, Ce, Co, Cu, Fe, K, La, Li, Mg, Mn, Na, Ni, P, Pb, S, Sc, Sr, Th, Ti, V, Y and Zn). Strong variations in soil geochemistry were observed and most elements, with the exception of Cu, Pb, P, S and Zn, showed multi-modal features, indicating the existence of mixed populations which proved difficult to separate. To evaluate the pollution level of the study area, the pollution index (PI) values were calculated based on a comparison with the Dutch target and intervention values. None of the concentrations of metal pollutants exceeded their intervention values, indicating the absence of serious contaminated soil, and the ratios to target values were therefore employed to produce the hazard maps. The spatial distribution and hazard maps for Cu, Pb and Zn indicated relatively high levels of pollution along the southern roadside extending almost 30 m into the sports ground, revealing the strong influence of pollution from local traffic. However, heavy metal pollution was alleviated along the eastern roadside of the study area by the presence of a belt of shrubs. Therefore, in order to prevent further contamination from traffic emissions, the planting of hedging or erection of low walls should be considered as shields against traffic pollution for roadside parks. The results in this study are useful for management practices in sports and parks in urban areas.     

Capability of Nocardia nova found in activated sludge to use synthetic BTEX as sole source of carbon and energy

Benzene and its derivatives, toluene, ethylbenzene and xylenes (BTEXs) are volatile monocyclic aromatic compounds which are widely distributed in nature and highly hazardous to human and animal health. The species belonging to the genus Nocardia are filamentous bacteria widely present in the flocs of activated sludge. They lead to the formation of foams and bulking sludge, which disrupt the sludge settling properties and thus reduce the quality of the purified water. The aim of our study is to isolate from these filamentous bacteria in the activated sludge, indigenous strains of Nocardia able to use the BTEX as the sole source of carbon and energy. Two isolation media were used to isolate the Nocardia species found in the activated sludge samples taken from the Ibn Ziad (Constantine-Algeria) wastewater treatment plant. The results show that five strains that morphologically resemble Nocardia have been isolated. The strain named (S) was identified by the sequencing of its 16S rRNA gene as Nocardia nova. This strain was the only isolate capable of growing under laboratory conditions, on BTE (m-o-p) X added at concentrations of 1500 mg/L each. Such a result can be used in the bioremediation of aquatic or terrestrial ecosystems contaminated by these compounds, using this bacterium as a bio-augmentation agent.     

Spatial and temporal variation in indicator microbe sampling is influential in beach management decisions

Fecal indicator microbes, such as enterococci, are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection, which are driven by environmental parameters, impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictive of the presence of Staphylococcus aureus, a skin pathogen. Over a ten-day period, hydrometeorologic data, hydrodynamic data, bather densities, enterococci levels, and S. aureus levels including methicillin-resistant S. aureus (MRSA) were measured in both water and sand. Samples were collected hourly for both water and sediment at knee-depth, and every 6 h for water at waist-depth, supratidal sand, intertidal sand, and waterline sand. Results showed that solar radiation, tides, and rainfall events were major environmental factors that impacted enterococci levels. S. aureus levels were associated with bathing load, but did not correlate with enterococci levels or any other measured parameters. The results imply that frequencies of advisories depend heavily upon sample collection policies due to spatial and temporal variation of enterococci levels in response to environmental parameters. Thus, sampling at different times of the day and at different depths can significantly impact beach management decisions. Additionally, the lack of correlation between S. aureus and enterococci suggests that use of fecal indicators may not accurately assess risk for some pathogens.