环境物品的经济价值评估方法:条件价值法

系统地介绍了西方国家常用的１种评价环境物品（公共物品）的方法——条件价值法。在大量文献和作者已有研究的基础上,解释了环境物品的特征和价值含义,综述了条件价值法的概念、特点和总体框架内容,分析了该方法中出现的偏差类型,总结了该方法在国际国内的已有应用,提出其应用潜力和应用前景     

Learning abatement costs: On the dynamics of the optimal regulation of experience goods

We study the introduction of new technologies when their costs are subject to idiosyncratic uncertainty and can only be fully learned through individual experience. We set up a dynamic model of clean experience goods that replace old polluting consumption options and show how optimal regulation evolves over time. In our base setting where social and private learning incentives coincide, the optimal tax on the polluting consumption is increasing over time. We show, however, that if social and private learning incentives diverge because the private discount rate exceeds the social discount rate, it may be optimal to temporarily increase the tax rate beyond net marginal external damages to induce more learning before reducing the tax rate to the steady state level. Alternatively, one could complement the tax with subsidies for first-time users which can be phased out over time. Similar results apply if consumers have biased expectations. We therefore give a rationale for introductory subsidies on new, clean technologies and non-monotonic tax paths from a perspective of consumer learning.     

城市公共安全规划理论与方法的探讨

分析了进行城市公共安全规划研究的意义和理论基础,并对了城市公共安全规划的方法进行了探讨。     

粤东山区土壤环境与蔬菜反夏栽培研究

以粤东丰顺县下八乡山区为例,根据其土壤、气候与环境特点,对蔬菜反夏栽培的适宜品种、播种期、轮作形式及各种配套技术措施进行了多年的试验研究。试验及推广的结果表明,种植反季节蔬菜及实行稻菜轮作的经济效益都比种植水稻高;新植茶园间套种蔬菜也有较高的经济效益。     

武汉月湖近代沉积物中的硅藻组合与环境关系研究

采集武汉月湖2处近代沉积物,分析了沉积硅藻组合与其环境关系,共发现24属83种硅藻。结果表明：2个柱状沉积物中硅藻优势属为小环藻属、直链藻属、舟形藻属、Cyclostephanos属。Z-1钻孔共有20属61种硅藻,Z-2钻孔共有24属68种硅藻。Z-1钻孔优势种为梅尼小环藻（Cyclotella meneghiniana）、颗粒直链藻（Aulacoseira granulata）、Navicula porifera、Cyclostephanos tholifomis。Z-2钻孔优势种为梅尼小环藻、颗粒直链藻、舟形藻（Navicula sp.）、Cyclostephanos invisitatus。就硅藻密度分布而言,总趋势上层最多,平均7.14×10^5～58.65×10^5 ind.g-1,中层其次,平均0.08×10^5～13.98×10^5 ind.g-1,下层最少,平均0.24×10^5～0.64×10^5 ind.g-1。硅藻种数最少的样品出现在沉积物中层,梅尼小环藻、颗粒直链藻、舟形藻、Navicula porifera、Cyclostephanos tholifomis、Cyclostephanos invisitatus的组合可以指示湖泊水体环境出现富营养化。通过探讨分析影响硅藻分布的环境因素,为恢复月湖近代水环境演化过程提供了依据。     

WTO框架下重构农村公共服务体系的探讨

我国已经加入WTO后,由于在谈判过程中我国在农业方面的让步比较大,如果不利用“绿箱政策”加强农村公共服务体系建设,农业和农村经济的竞争力必然大大下降．“绿箱”政策是一种问接式的保护政策,不在《农业协议》限制之列,而且“绿箱”政策中许多条款都涉及到保护本国农业的可持续发展能力,得到了各国的一致赞同．因此,我国有必要对农村公共服务体系的改革与发展历程进行一次系统清理,在此基础上认真总结正反两方面的经验和教训,重新构筑农村公共服务体系。     

Spatial sampling and the environment: some issues and directions

In this paper we summarize research issues for spatial environmental sampling stemming from a NISS/USEPA workshop held on 21-22 September 1994 at Chapel Hill, NC.     

Endosulfan in the Chinese environment: monitoring and modeling

This paper reviews the usage and emissions of endosulfan, the newest member of the persistent organic pollutants (POPs), in China, and its fate and behavior in Chinese environment. Endosulfan usage in China has been estimated to be approximately 25700 t between 1994 and 2004. Concentrations of endosulfan in different environmental compartments in China, such as air, soil, water, and biota, but focusing at air and surface soil, have been summarized. Concentrations of total endosulfan in surface soil across China were ranged from below detection limit (BDL) to 19000 pg·g^?1 dry weight (dw), with geometric mean of 120 pg·g^?1dw. The results indicated that endosulfan sulfate had highest concentration in Chinese soil, followed by ??- and ??-endosulfan. Air concentrations of endosulfan in China were ranged 0?C340 pg·m^?3 for ??-endosulfan and 0?C121 pg·m^?3 for ??-endosulfan, with high concentrations occurred in the cotton production areas. Gridded usage inventories of endosulfan on a fine gridded system with a 1/4° longitude by 1/6° latitude resolution were compiled, from which, emission to air and residues in soil of endosulfan were calculated in each grid by using a modified simplified gridded pesticide emission and residue model (SGPERM), an integrated modeling system combining mathematical model, database management system, and geographic information system. Total emissions were around 10800 t from 1994 to 2004. Based on the emission and residue inventories, concentrations of ??- and ??-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell, which are in general consistent with the published monitoring data.     

绿色化学研究与生态环境保护

绿色化学是指利用一系列原理来降低或消除在化工产品的设计、生产及应用中有害物质的使用和产生的科学。它致力于从源头上制止污染物的生成。文章从非传统的绿色原材料、溶剂、试剂、催化剂、安全化学品及合成方法方面综述了绿色化学的研究进展。绿色化学从材料和能源的内在性质上面对生态环境问题的挑战，在分子水平上设计结构及其相关的性质，通过减少内在的危害而使生态系统的发展具有可持续性。发展绿色化学是实现生态环境保护的途径。     

Trade liberalization, corruption, and environmental policy formation: theory and evidence

This study explores the linkages between trade policy, corruption, and environmental policy. We begin by presenting a theoretical model that produces several testable predictions, including: (i) the effect of trade liberalization on the stringency of environmental policy depends on the level of corruption; and (ii) corruption reduces environmental policy stringency. Using panel data from a mix of developed and developing countries from 1982 to 1992, we find evidence that supports these conjectures. We view these results as representing an attempt at understanding the myriad of complex relationships that exist in an open economy.     

Trace elements in the human environment: Problems and risks

Early studies on the possible influences of environmental geochemistry and health were concerned with major diseases such as cancer or multiple sclerosis. They were generally confined to simple comparisons of geochemical and epidemiological maps and corresponding rural areas. Subsequently, studies of dental health produced evidence for the roles of environmental fluoride, selenium, molybdenum and lead in the aetiology of caries. In recent decades lead has been closely studied. Most people in the western world live in urban areas, rather than rural areas, and research on lead has yielded much information on the distribution of the element in streets, parks and gardens of cities and in the home environment. The role of lead in human health has thereby been better understood. Cadmium, selenium and aluminium are good candidates for future study but success will depend on applying appropriate methods of investigation and here the experiences from research on lead are a valuable model to follow.This paper is based on a keynote lecture at the start of the SEGH conference.     

DDT isomers and metabolites in the environment: an overview

It is known for decades that the isomeric composition of organic pollutants can be influenced substantially by environmental processes such as biotransformation or transfer between compartments. This accounts also for the pesticide 2,2,-bis(4-chlorophenyl)-1,1,1-trichloroethane, better known as p,p′-DDT, and its accompanied substitution isomer 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1,1-trichloroethane (o,p′-DDT). Although many studies followed the environmental fate of DDT, only very few publications reported on quantitative data of both o,p′- and p,p′-isomers. Therefore this condensed review describes evidence for remarkable changes and shifts in o,p′-/p,p′-ratios of DDT-related compounds. The application of isomer-specific analysis remains dominantly on emission source apportionment, for example, to differentiate DDT and dicofol emission. Only very few studies linked observed isomer shifts to aspects of environmental processes, such as (1) volatility from soil to air, (2) environmental stability in soil or (3) bioaccumulation in fishes. Additionally, several studies failed to use isomer-specific interpretation in order to obtain more detailed insight into environmental processes, for example, for observed isomer shifts during air–water fluxes. The o,p′-/p,p′-ratios of DDT and its main metabolite DDD have been detected more or less on the same level, whereas the isomers of the second main metabolite DDE were definitely depleted by the o,p′-isomer in all environmental compartments, indicating a general isomer-specific differentiation during DDT metabolism.     

黄河源头生态环境变化的遥感监测及驱动因素

利用1990年、2000年和2004年的TM卫星影像数据研究表明,近10 a来,黄河源头玛多县生态环境状况变化剧烈,主要表现为沼泽、滩涂、河流、湖泊等湿地萎缩干涸,所占比例持续减少,表明水源涵养力减弱.同时,沙地、盐碱地和不宜林草荒地等劣质土地的增加使天然草地破碎化程度加大;而天然草地、林地和宜林草荒地比例持续增加,说明在21世纪初以来的暖湿化气候背景下,黄河源头-玛多县生态环境呈良性发展态势.分析认为气温、降水、蒸发、冻土等自然因素,以及超裁过牧、滥采乱挖和草地鼠害等人类活动是导致黄河源头生态环境变化的共同驱动因素,其中又以气候因子为主导,与冻土环境及水文条件相互影响.     

Contribution of Nitrogen Species to the Surface Aquifers of Volcanic Areas: The Island of Vulcano (Italy)

Ammonium and nitrate concentrations have been investigated in water samples from the wells in the island of Vulcano, (Italy). Systematic observations, extended over a period of five years, have verified different trends in the changing concentrations of both species. Nitrate ion is considered as contributed to the unconfined upper ground aquifer by the surface environment, while for ammonium ion a deep origin appears more likely. Significant changes in the activity of the volcanic system appear to affect the distribution of ammonium only, while nitrate levels do not display any important variation.     

Organic farmers in islands: Agricultural management and attitude towards the environment

SUMMARY

This study explores differences among organic farmers who live in islands and have isolated small-size operations. The relationships between farmers' characteristics and attitudes and farm management were interpreted by studying how they manage their land, their attitudes towards the environment and alternative farming systems, and their involvement in organic farming. The research was carried out using questionnaires addressed to organic farmers on the island of Thassos. Nonlinear canonical correlation was applied for data analysis. This information could contribute to adjustment of policy decisions for on-farm diversification. Agricultural policy makers should approach organic farmers in northern Thassos (productive irrigated olive orchards with gentle slopes) by enacting standards to reduce the cost of alternative plant protection methods and promoting their products in order to maintain and expand organic farming. They should also approach organic farmers in southern Thassos (less productive, dry cultivated olive orchards with steep slopes, overgrazed and often abandoned) by providing them with the necessary information and appropriate agricultural know-how to effectively manage their farms. Organic farmers with stable off-farm income are more aware of environmental values and consider that they risk less than others in order to gain the benefits of alternative farming systems. However, they should attend training programmes to achieve economic success to allow them to continue farming organically.     

Industrial organic contaminants: identification,toxicity and fate in the environment

Industrialization and urbanization in the more economically developed countries and also in emerging and developing nations have led to an intensive and still increasing use of water resources. The involved chemical contamination led to a deterioration of aquatic systems in many areas. Industries are important pollution sources and the discharged wastewaters may contain very diverse and potentially harmful organic compound groups. We therefore present here a comprehensive review of the current state of knowledge of organic contaminants from industrial wastewaters. The available studies proved the heterogenic chemical composition of industrial wastewaters, even from the same industry branches, and the presence of heterogenic organic contaminant mixtures from industrial sources in aquatic systems. We conclude that our knowledge of the chemical composition of industrial wastewaters and the occurrence of industrial organic contaminants in the environment is as yet very limited. A combination of chemical and toxicological methods enabled the identification of toxic organic constituents in industrial wastewaters. Chemical evaluations of industrial contamination linked to surveys of environmental impacts could relate toxic effects of field samples to the presence of specific contaminants. Exposure experiments in the field proved the bioaccumulation and toxicity of several industrial compounds. Ecological surveys in industrial areas combined with a comprehensive chemical characterization and toxicity evaluation are so far missing. Some of the identified organic contaminants are related to characteristic industrial production processes, and their presence in water, sediment or biota indicates the input of specific industrial wastewaters. Accordingly, these compounds can be used as industrial markers. We suggest the proceeding application of the marker concept, as markers are useful to verify the input of specific industrial wastewaters to aquatic systems and to investigate the spatial distribution of the emission. Such information helps to disentangle different emission sources for the subsequent investigation of potential impacts in the environment.     

Urban geochemical mapping studies: how and why we do them

Geochemical mapping is a technique rooted in mineral exploration but has now found worldwide application in studies of the urban environment. Such studies, involving multidisciplinary teams including geochemists, have to present their results in a way that nongeochemists can comprehend. A legislatively driven demand for urban geochemical data in connection with the need to identify contaminated land and subsequent health risk assessments has given rise to a greater worldwide interest in the urban geochemical environment. Herein, the aims and objectives of some urban studies are reviewed and commonly used terms such as baseline and background are defined. Geochemists need to better consider what is meant by the term urban. Whilst the unique make up of every city precludes a single recommended approach to a geochemical mapping strategy, more should be done to standardise the sampling and analytical methods. How (from a strategic and presentational point of view) and why we do geochemical mapping studies is discussed.

珠江三角洲地区典型菜地土壤与蔬菜重金属分布特征研究

通过对珠江三角洲地区的广州市、佛山市、江门市和惠州市典型菜地土壤和蔬菜中重金属（Pb、Cr、Cd、As和Hg）含量及其土壤中有效态（Pb、Cr、Cd）含量的调查,分析蔬菜重金属污染状况与土壤重金属含量的相关性,探讨了土壤重金属含量、有效态含量与土壤理化性质的相关性。结果表明,菜地土壤主要受Pb、Cd、Hg污染。Pb、Cd主要以轻度污染为主;而Hg污染在广州市菜地土壤以轻度污染和重度污染为主,佛山市菜地土壤以中度污染和重度污染为主,江门市和惠州市菜地土壤以轻度污染为主。蔬菜主要受Pb、Cd、Hg污染,少数蔬菜受到Cr污染,但并未检测出蔬菜受As污染。蔬菜中重金属含量与土壤中Pb、Cr、Cd的总量、有效态含量之间呈显著正相关关系,与土壤中As、Hg的总量无显著相关性。土壤中Pb、Cr含量与土壤有机质含量、黏粒含量、粉粒含量均达到显著相关。土壤中有效Pb与有效锰含量呈显著负相关关系,土壤中有效Cr含量与土壤粘粒含量、有效铁含量呈极显著正相关关系。