生态文明与农业发展

农业作为国民经济的基础,是生态文明的重要内容,其文明程度直接体现生态文明程度.生态文明建设给农业经营提出了更高的要求,也为农业生产的发展指明了方向.充分认识生态文明建设与农业生产的关系,加强农业相关人员的生态文明教育和农业环保法制建设,实施更加科学、文明的农业经营方式将对促进农业的可持续发展和生态文明建设发挥积极的作用.     

Long Term Trends in Concentration of Major Pollutants (SO<Subscript>2</Subscript>, CO,NO, NO<Subscript>2</Subscript>, O<Subscript>3</Subscript> and PM<Subscript>10</Subscript>) in Prague – Czech Republic (Analysis of Data Between 1992 and 2005)

To assess the effect of changes in traffic density and fuels used for heating at the beginning of the 1990s, 1992–2005 monthly averages of PM₁₀, SO₂, NO₂, NO, CO and O₃ from Prague, the Czech capital, were analyzed together with long term trends in emissions of major pollutants, fuel consumption and number of vehicles registered in Prague. The data from all monitoring stations were retrieved from the database of the state automated monitoring system. Correlation coefficients between ambient monthly averaged temperature and all pollutants of concern showed distinct seasonal trends. The results showed that while SO₂ and to some extent also CO concentrations dropped namely in the first half of the analyzed period (1992–1997) as a result decreased fossil fuel consumption for local heating, the behaviour of other pollutant concentrations followed a different pattern. PM₁₀ concentrations decreased during the beginning of the 1990s but showed a sign of increase after 2000. Concentrations of ozone and NO₂ did not reveal any significant change throughout the whole studied period. It can be concluded that during the studied period traditional urban sources of pollution, such as coal and oil combustion, lost their importance but were simultaneously substituted by pollutants from automotive transport (namely PM and NO₂) making the problem of air quality even worse.     

我区城市污水处理程度探讨

建立城市污水处理厂处理污水,是城市发展的必然趋势,而处理级别及处理后水的去向及用途是关系到环境保护和资源得到充分利用的关键,针对我区干旱缺水,灌溉农业特征及天然水域的特点,就污水处理级别排水的用途提出一些看法。     

城市生活垃圾生命周期管理

生命周期评价是一种全面的环境管理工具,具有潜在的发展前景。０它通过对产品,产品系统,工艺活动整个生命周期的环境影响环境改善的机会进行评价。根据国际环境毒理与化学学会１９９３年和ＩＳＯ１４０００环境管理体系中关于生命周期评价的技术框架,本文应生命周期评价在城市生产垃圾管理系统中的作用及管理系统的清单分析,影响评价和改善评价进行研究。     

城市轨道交通噪声评价方法及其限值的研究

根据城市轨道交通噪声时、空分布特点及污染规律,对轨道交通噪声评价量作了分析研究,提出了列车通过时的最大声级作为城市轨道交通噪声的评价量,并根据噪声时问分布特性曲线提出了与之相对应的等效声级简易计算方法.通过对上海轨道交通3号线沿线居民区的主、客观调查,得到主观烦恼度阈值和干扰睡眠阈值,提出了适用于我国城市轨道交通的环境噪声限值(建议).     

A method for evaluating transport energy consumption in suburban areas

Urban sprawl is a major issue for sustainable development. It represents a significant contribution to energy consumption of a territory especially due to transportation requirements. However, transport energy consumption is rarely taken into account when the sustainability of suburban structures is studied. In this context, the paper presents a method to estimate transport energy consumption in residential suburban areas. The study aimed, on this basis, at highlighting the most efficient strategies needed to promote awareness and to give practical hints on how to reduce transport energy consumption linked to urban sprawl in existing and future suburban neighborhoods. The method uses data collected by using empirical surveys and GIS. An application of this method is presented concerning the comparison of four suburban districts located in Belgium to demonstrate the advantages of the approach. The influence of several parameters, such as distance to work places and services, use of public transport and performance of the vehicles, are then discussed to allow a range of different development situations to be explored. The results of the case studies highlight that traveled distances, and thus a good mix between activities at the living area scale, are of primordial importance for the energy performance, whereas means of transport used is only of little impact. Improving the performance of the vehicles and favoring home-work give also significant energy savings. The method can be used when planning new areas or retrofitting existing ones, as well as promoting more sustainable lifestyles regarding transport habits.     

Carbon Monoxide Concentration in a Street Canyon of Buenos Aires City (Argentina)

The analysis of three years of 8-h CO concentration values registered in a deep street canyon downtown shows high frequency of values that exceed WHO health protection guidelines. An inverse relationship between opposing percentiles of the distributions of CO concentrations and mean wind speed could be found. Data also showed a variation of mean CO values with prevailing wind direction. The averaged concentration value obtained when the sampler probe is on the leeward side is lower than the obtained when it is on the windward wall. A preliminary explanation of this feature may be related to the advection of polluted air from a high traffic density area nearby.     

Numerical Simulations of the Urban Roughness Sub-Layer : A First Attempt

Most of the mesoscale models use roughness parameters to characterise the ground and to compute the surface stress. As the experimental determinations of the urban roughness parameters are rare and not very reliable, a new methodology based on microscale numerical simulations is presented here and the first results from two-dimensional simulations with different roof shapes are analysed.Firstly, it appears that the roof shape has a large influence : large difference in the Reynolds stress profile and in the roughness sub-layer thickness, enhancement of the exchanges at the roof level by buildings with attic. It also appears that the fetch necessary to obtain a constant flux layer is unrealistic compared to the real spatial homogeneity of quarters in European cities. Consequently, a new parameterisation of the urban ground-induced friction is to be developed without reference to the constant flux layer theory.     

城市土壤重金属污染及其生态环境效应

对城市土壤中重金属的来源、空间分布特征、化学形态、在不同介质间的迁移转化及其污染的生态环境效应等近年来的研究进展进行了回顾,指出今后的研究重点是建立城市土壤重金属污染风险评价和标准体系,并应对重金属在城市环境中的迁移转化机制及城市土壤质量演变与郊区之间的关系开展研究。