Analyzing the cost effectiveness of Santiago, Chile's policy of using urban forests to improve air quality

Santiago, Chile has the distinction of having among the worst urban air pollution problems in Latin America. As part of an atmospheric pollution reduction plan, the Santiago Regional Metropolitan government defined an environmental policy goal of using urban forests to remove particulate matter less than 10 microm (PM(10)) in the Gran Santiago area. We used cost effectiveness, or the process of establishing costs and selecting least cost alternatives for obtaining a defined policy goal of PM(10) removal, to analyze this policy goal. For this study, we quantified PM(10) removal by Santiago's urban forests based on socioeconomic strata and using field and real-time pollution and climate data via a dry deposition urban forest effects model. Municipal urban forest management costs were estimated using management cost surveys and Chilean Ministry of Planning and Cooperation documents. Results indicate that managing municipal urban forests (trees, shrubs, and grass whose management is under the jurisdiction of Santiago's 36 municipalities) to remove PM(10) was a cost-effective policy for abating PM(10) based on criteria set by the World Bank. In addition, we compared the cost effectiveness of managing municipal urban forests and street trees to other control policies (e.g. alternative fuels) to abate PM(10) in Santiago and determined that municipal urban forest management efficiency was similar to these other air quality improvement measures.     

我国城市大气污染现状与特点

中国城市化和工业化的快速发展与能源消耗的迅速增加，给中国城市带来了很多空气污染问题。20世纪70年代期间，煤烟型污染排放成为中国工业城市的特点；80年代，许多南方城市遭受严重的酸雨危害；近年来，汽车尾气排放的NOx、CO及随后形成的光化学烟雾，使得许多大城市的空气质量恶化。城市空气污染影响着城市居民的健康和城市的发展。为控制空气污染和保护大气环境质量，我国政府已经实施了许多规划。本文概述了当前中国城市特别是重点城市的空气质量状况，描述一些主要城市空气污染物包括总悬浮颗粒、PM10、PM2．5、SO2、酸雨、NOx/NO2的特点。尽管采取了很多应对措施，但目前我国城市的空气质量依然不容乐观，文中还讨论了未来城市空气污染控制面临的问题。     

汶川地震极重灾区震后10年环境承载力评估

采用大气污染物超标指数、水污染物浓度超标指数、污染物浓度综合超标指数等3个指标,针对汶川地震极重灾区10个县市,评价了区域环境系统对社会经济系统的支撑能力。结果表明:10个县市中,环境承载力超载的县市有7个,接近超载的县市有3个。其中,9个县市的大气存在环境质量问题,4个县市的水环境质量存在问题,整个区域大气环境质量改善形式更为严峻。10县市的大气污染物中,O₃、PM_2.5、PM₁₀普遍超标或接近超标,是影响区域大气质量的主要因素。在3指标中,又以PM₁₀和PM_2.5超标情况最为严重。大气污染在10个县市中具有明显的区域特征。都江堰市、彭州市、安县、绵竹市、什邡市等环成都城市圈的5县市大气污染物浓度超标指数普遍高于远离成都经济中心的5县市。根据影响水质的水污染物性质,及水环境影响因子排序分析,彭州市、什邡市在COD_Cr、P、N-NH₃上有较高载荷,平武县在CODMn、DO两因子上载荷较大;汶川县的主要水环境影响因子是BOD5。根据在水污染因子上的载荷,10县市水污染特征归为集中污染型和面源污染型,以及混合污染三种类型。     

城市空气质量达标规划编制中的关键技术及其案例应用

本文结合重庆市空气质量限期达标规划编制案例,介绍了城市空气质量达标规划编制中的几个关键技术及其具体应用,包括本地化污染源排放清单编制、污染物来源解析、污染物排放形势预测与减排潜力分析以及大气环境容量核算等。本地化污染源排放清单是城市空气质量达标规划编制的基础,针对现有污染源制定科学合理的减排方案是达标规划的核心内容。分析不同区域的污染物组分浓度特征、污染源贡献以及未来污染排放形势预测,有助于识别出制约未来空气质量达标的关键因素及污染源。基于污染源减排潜力和污染传输矩阵制定的污染源减排方案更具合理性和可行性,应用空气质量模型估算大气环境容量可为规划目标可达性提供依据。     

Woody Vegetation Composition and Structure in Peri-urban Chongming Island, China

Chongming, the world’s largest alluvial island, is located within the municipality of Shanghai, China. Recent projects have now linked peri-urban Chongming to Shanghai’s urban core and as a result will soon undergo substantial changes from urbanization. We quantitatively analyzed the structure and composition of woody vegetation across subtropical, peri-urban Chongming as a basis for sustainable management of these rapidly urbanizing subtropical ecosystems elsewhere. We used 178 permanent, random plots to statistically and spatially analyze woody plant composition and tree structure across the 1,041 km² of Chongming. A total of 2,251 woody plants were measured comprising 42 species in 37 genera. We statistically and geospatially analyzed field data according to land uses and modeled air pollution removal by trees. Average tree diameter at breast height, total height, and crown widths on transportation land uses were greater than other land uses. These same values were lowest on forest land use and greater tree cover was associated with areas of increased anthropogenic activity. Less than 20 % of the woody vegetation was exotic and a species richness index was significantly different between land uses due to legacy effects. Composition of agriculture and forest land uses were similar to residential and transportation. Tree cover across Chongming was also estimated to annually remove 1,400 tons of air pollutants. We propose that this integrated and quantitative method can be used in other subtropical, peri-urban areas in developing countries to establish baseline trends for future sustainability objectives and to monitor the effects of urbanization and climate change.     

Developing an Environmental Indicator System for Sustainable Development in China: Two Case Studies of Selected Indicators

Environmental indicator systems are a fundamental tool in quantifying the environmental component of sustainable development. They are useful because they quantify the status and trends of key environmental parameters and provide information on the environment that allows authorities and communities to make informed decisions. This article analyzes the basic framework for Chinese environmental indicator systems and presents a “core” set of environmental indicators. In our research, we used a theme approach to develop the environmental indicator systems. We performed two case studies of selected indicators. In the first, we used an urban ambient air pollution composite index and an urban ambient air pollution indicator for three main pollutants to examine trends in urban air pollution in China from 1990 to 2000 at regional and national levels. The results indicate that China has made some progress towards controlling urban air pollution, but must do more in order to reach acceptable pollution levels. We think that an aggregated index and disaggregated indicators have important complementary roles in the policy-making processes. In the second case study, we developed and constructed a grassland degradation index that aggregates information on the extent and severity of grassland degradation. Taking the Xilinhaote region of Inner Mongolia as the study area, we calculated this index by combining remote-sensing data, a geographical information system (GIS), and field investigation. Based on these results, we provide recommendations regarding further development and measurement of environmental indicators in China.     

北京市大气污染物排放现状分析及治理对策研究

通过对北京市2000—2004年间大气污染物排放情况的考察和研究，着重分析了二氧化硫等大气污染物的排放现状以及大气污染物排放强度指标变化的原因并与国内主要城市及美国大气污染物排放指标进行了对比。结果表明，北京市大气污染物强度在国内处于较低水平，但与发达国家相比，仍有相当的差距，并提出了治理大气污染的对策。     

Interaction Between the Environment and Animals in Urban Settings: Integrated and Participatory Planning

In urban ecosystems, the ecological system has become completely unbalanced; this, in turn, has led to an increase in well-known problems such as air pollution, ground pollution, and water pollution. This imbalance has also led to the growth and spread of pathogens harmful to man, animals, and plants. Urban sustainability indicators, both global and local, also “indicate” the percentage of population, but these refer only to the human population, not the animal population. Cities need good waste, water, and air management, effective traffic planning, and good zoning of businesses, crafts, and services; over and above these activities, cities also need for planning to take into account the existence of pets (dogs, cats, and etc.) and nonpet animals (insects, birds, mice, etc.). Cities tend to be designed around humans and “on a human scale,” without taking into account the fact that a huge animal population is living side by side with people. That explains why overcrowding tends to go hand in hand with urbanization; all these populations, including humans, need to adapt to new spaces and often need to drastically change their behavior. This is a fact that must be included when drafting sustainable city plans. The supposed strategy is that of “integrated-participatory” control of the interactions between the environment and animals in the cities. Strategy will focus on the development of integrated approaches and tools for environment and animal management in the context of urban settings. This will require such specific methods as ecological balance sheets and ecoplans for the planning, management, and control of the interrelation among environment, animal, and public health. The objective is to develop a better understanding of urban biodiversity and of urban ecosystem functioning, in order to understand and minimize the negative impacts of human activities on them. The research will focus on assessing and forecasting changes in urban biodiversity, structure, function, and dynamics of urban ecosystems, with relationships among society, economy, biodiversity, and habitats.     

Evaluation of seasonal scale first flush pollutant loading and implications for urban runoff management

This study investigated how the occurrence and magnitude of first flush events in stormwater may influence the effective management of urban runoff pollution. To facilitate the understanding of the first flush phenomenon on a seasonal scale, the City of San Jose, CA carried out an investigation between May 1997 and April 2000 to characterize concentrations of pollutants in local waterbodies during eight storm events. The purpose of the investigation was twofold: (1) To determine if concentrations of specific constituents in stormwater runoff are elevated during the first substantial storm of the wet season, and (2) To identify the physical and environmental conditions surrounding such events. Concentration data for total and dissolved metals, pesticides, polyaromatic hydrocarbons, anions, total suspended solids, total organic carbon, conductivity, gasoline and diesel, and volatile and semi-volatile organics were collected at over 25 sites. Monitoring data analysis focused on identifying physical and environmental conditions yielding increased levels of pollutants during the first substantial storms of the rainy season compared to other storm events. Quantitative analysis focused on metals and anions because most observations for other constituents were below detectable levels. The results suggest that first flush phenomena did not occur consistently throughout most of the stations investigated. The results further suggest that there are specific combinations of site and storm conditions that result in a first flush effect with respect to dissolved metals. Based on the results of this and related investigations, implications for urban runoff management are discussed. For example, if dissolved metals are of principal concern, it may be worthwhile to optimize existing control strategies to minimize pollutant loading from storms that are preceded by an extended dry period.     

衡水市区大气污染经济损失估算

衡水市区的大气污染对人体健康、农业、建筑材料造成的经济损失是巨大的。运用修正的人力资本法、生产率变动法、成果参照法等环境经济学方法,计算出衡水市区1996-2000年各年的大气污染经济损失。以2000年为例,衡水市区大气污染经济损失为1.23亿元,相当于研究区域每人损失510元,其中大气污染引起的人体健康经济损失为12079万元,农业经济损失85.4万元,建筑材料经济损失175万元。由于认识、数据搜集、技术上的原因,本研究给出的经济损失数据只是一个半定量的供宏观思考的结论,可看作是实际损失的下限值。