投资项目环境影响经济费用效益分析框架

<中华人民共和国环境影响评价法>明确规定要对投资项目进行环境影响评价,并特别规定应对项目环境影响的经济损益进行分析.然而,在目前的项目评价实际工作中,对预期产生较重大环境影响的项目进行经济费用效益分析的工作基本上还是一块空白,原因之一是分析人员对这一新领域十分陌生.本文试图在传统的项目费用效益分析中加入环境影响经济评价元素,提出一个评价框架,希望能够促进项目评价人员与各相关部门和领域的专家,特别是与环境科技人员间的协作,从而推动实际评价工作的开展.     

A method for reliability-based economic design of building structures

In limit states design codes for building structures, the load and resistance factors are derived based on a ‘;target’ reliability index, which is determined based on a code calibration process. It is not clear whether the target reliability index selected through the code calibration is optimal with respect to the cost, because through calibration the structural safety is achieved quantitatively while the economic aspects are only considered qualitatively. The intention of the present paper is to formulate a basic approach to reliability-based economic design, based on structural reliability theory. The focus of the paper is to derive an analytical solution to optimized reliability index. A parametric study is conducted for sensitivity analysis of the optimal reliability index to different variables. Finally, the application of the solution to design codes, i.e. determining load and resistance factors in design formulae, is outlined.

Dans les codes de conception d'états limite se rapportant à la construction des structures de bâtiments, la charge et les facteurs de résistance reposent au départ sur un index de fiabilitié ‘cible’, qui est basé sur un processus de calibrage de code. Il n'est pas possible de savoir si l'index de fiabilitié cible choisi par le calibrage de code est optimal en ce qui concerne le coût parce que lors du calibrage, la sécurité structurelle est évaluée de façon quantitative. L'objectif de cet article est de formuler une appréciation de référence sur la conception reposant sur la fiabilité économique, basée sur la théorie de fiabilité structurelle; le point fort de ce texte est de trouver une solution analytique afin d'optimiser l'index de fiabilité. Une étude paramétrique est conduite pour analyser la sensibilité de la fiabilitié optimale de l'index par rapport aux diffeérentes variables. Au total, est proposée une solution consistant à concevoir des codes, c'est-à-dire la détermination de la charge et des facteurs de résistance sous l'aspect de formules.     

城镇生活垃圾转运系统的经济性研究

通过运用系统论、运筹学等理论,论述建设生活垃圾转运站经济可行的条件以及生活垃圾转运站经济的选址位置,并以福建省建瓯市城区生活垃圾转运系统为例,从经济的角度进行多方案比较,确定其生活垃圾转运系统的布局。     

中国城镇市政设施投融资现状研究

从市政设施含义着手，探讨了我国城镇市政设施投融资改革历程，明晰了各类市政设施归属，指明其民营化的对象，总结了我国推进市政设施民营化的成功实践，并提出了一些改革建议与相关措施。     

国际大都市交通发展战略

本文通过研究分析国际大都市在城市发展过程中碰到的机动化、城市化、信息化和生态化4大问题而采取的相应交通发展战略,对具体城市进行了实例研究,并结合上海交通规划的具体情况进行分析,以期通过本研究为21世纪我国大城市的发展提供参考。     

时空制约下的城市居民活动-移动系统——活动分析法的理论和模型进展

自上世纪80年代以来,活动分析法在西方交通规划、城市研究和地理学等领域中得到了快速发展。活动分析法理论认为出行源于活动,把传统上分离的城市活动系统和出行系统结合起来,形成了城市居民活动-移动系统。国内尚很少文献对活动分析法进行系统综述,因此本文通过评述基于活动分析法的城市活动移动系统的研究在理解行为、交通和空间等方面的作用,以及指导城市规划的意义,提出了具体研究的概念模型。最后归纳和评述了三种基于活动分析法的应用模型：制约模型、决策模型和关系模型。     

CFD analysis of ventilation effectiveness in a public transport interchange

A study was conducted into the ventilation effectiveness of a ventilation system within a public transport interchange (PTI) in Hong Kong. A computational fluid dynamics (CFD), steady state computational model of the PTI was used to investigate and predict the typical pollutant emission pattern for buses. In Hong Kong, the displacement ventilation (DV) scheme is often employed for the PTI. The numerical simulation investigates the effectiveness of the DV system in removing pollutants from the occupied zone. An alternative model is proposed where the supply is located at the ceiling and the exhausts are located at the lower part of the columns. It was found that both systems could adequately ventilate the PTI; however, the ceiling based air supply system is able to provide improved thermal comfort and indoor air quality (IAQ).     

昆明BRT系统适用性分析

阐述了BRT系统的构成要素及特点,结合目前昆明BRT系统实施过程中遇到的困难和问题,介绍了昆明的公共交通现状,对BRT系统在昆明的适用性作了分析,并提出了建设昆明BRT系统的建议.     

公共投资项目评价内容研究

从公共投资项目特点入手进行分析,认为公共投资项目评价与一般投资项目评价在内容上应该有所差异,根据近年来公共投资项目评价的发展趋势--绩效评价,研究了公共投资项目绩效评价的内容.     

多种型式防水屋面的成本效益对比分析

对普通的平屋面、架空隔热屋面、坡屋面、倒置式屋面、蓄水屋面和种植屋面,按照常见的工艺做法,分别剖析了各自的成本构成和节能效益。通过比较6种屋面的等额年费用,得出坡屋面为最经济节能的屋面,但如果综合考虑生态节能效益,则种植屋面为最佳屋面型式。在工程实践中应该结合具体情况选择合适的屋面型式。     

剩余住房公积金保值增值的投资决策优化分析

通过分析住房公积金起始年到供需平衡点出现年份之前的若干年的动态投资过程以及动态投资的风险,运用Markowitz资产组合理论和Sharpe资产定价模型,设计了投资风险最小化模型作为住房公积金动态投资决策优化模型。     

Economic feasibility study for wastewater treatment: A cost-benefit analysis

Water resource management should be made from a multidisciplinary perspective. In this sense, economic research into the design and implementation of policies for the efficient management of water resources has been emphasized by the European Water Framework Directive (WFD). Cost-benefit analysis (CBA) is one of the more widely accepted economic instruments since it is a rational and systematic decision-making support tool. Moreover, the wastewater treatment process has significant associated environmental benefits. However, these benefits are often left uncalculated because they have no market value. In this paper, using the concept of shadow price, a quantification of the environmental benefits derived from wastewater treatment is made. Once the environmental benefits are estimated and the economic costs of the treatment processes are known, a CBA is made for each of the wastewater treatment plants (WWTPs) under study. In this way, a useful economic feasibility indicator is obtained for WWTP operation.     

Influence of movements on contaminant transport in an operating room

The influence of persons' movements on contaminant transport during an orthopedic surgical operation is examined. Orthopedic surgical operations require an ultra clean environment usually provided by a LAF device (laminar airflow). During hip replacements bone cement is sometimes applied. Due to practical reasons cement mixing is performed outside the LAF area. During the cement transport from the mixing location to the surgeon there is a potential risk of bacterial transport to the clean zone. This phenomenon is examined by smoke visualization and computational fluid dynamics (CFD). The movements are modeled by CFD using distributed momentum sources as well as a turbulent kinetic energy source. A significant risk of contaminant transport from the less clean zone to the ultra clean zone is found. The results indicate that it is possible to simulate the influence of movements using a relatively simple CFD model that considers the significant influence of a transient phenomenon in an approximate way. PRACTICAL IMPLICATIONS: In real-life ventilated enclosures like operating rooms movements take place. Persons' movements may influence the local flow field as well as the contaminant field substantially. Most often movements are ignored in simulations due to the complexity of the phenomenon. This paper presents an indirect and simple method to consider the influence of movements that may enable modelers to include this important phenomenon in the engineering application of CFD. This may improve practical risk assessment--for instance risk assessment of unintended transport of bacteria during orthopedic surgical operations that may jeopardize the hygiene.     

乌鲁木齐市公共交通现状分析及对策研究

指出了随着经济的发展和城市的扩大,城市交通问题日益严重,为促进乌鲁木齐市公共交通更快更好发展,基于乌鲁木齐市公共交通调查资料,分析了乌鲁木齐市公共交通现状,并提出了发展对策。     

赣州市电子地图及公交查询功能的实现

以赣州市区电子地图为例介绍了采用MapObject控件，集成国际上比较先进的GIS软件开发技术，以Dijkstra算法为基础理论实现公交查询功能的过程，该查询系统与同类系统相比速度提高了一倍，以提高城市道路网的管理效率。     

Incorporating agglomeration economies in transport cost-benefit analysis: The case of the proposed light-rail transit in the Tel-Aviv metropolitan area

Abstract.  The economic evaluation of transport projects relies primarily on the impact of the project on road users. Economic benefits are calculated from a reduction in the aggregate value of time saved by the users, as well as from savings on vehicle-operation and maintenance costs, reducion in traffic accidents, and more recently the negative environmental impacts that ensued. Most often the analysis assumes fixed demand. Major mass-transit systems, like the new Light Rail Transit (LRT) currently proposed for the Tel-Aviv Metropolitan Area (TAMA) in Israel, are expected to generate substantial new (induced) traffic. This development will most likely enhance the agglomeration forces at work in major urban concentrations. Agglomeration economies could lead to an upward shift in the production function of the metropolitan area, thus generating substantial additional benefits for the transport project. This article presents the methodology used to estimate the benefits derived from agglomeration economies induced by the aforementioned proposed new LRT in the TAMA. An estimate is made of the increase in the number of employees in the CBD owing to the proposed LRT and their potential contribution to the total annual production of the CBD. Agglomeration economies could add a significant amount of additional benefit to the transport project. In our case study the extent of these benefits increased the benefit-cost ratio from 1.15 to 1.40.     

Quantitative assessment of groundwater vulnerability using index system and transport simulation, Huangshuihe catchment, China

Groundwater vulnerability assessment has been an increasingly important environment management tool. The existing vulnerability assessment approaches are mostly index systems which have significant disadvantages. There need to be some quantitative studies on vulnerability indicators based on objective physical process study. In this study, we tried to do vulnerability assessment in Huangshuihe catchment in Shandong province of China using both contaminant transport simulations and index system approach. Transit time of 75% of hypothetical injected contaminant concentration was considered as the vulnerability indicator. First, we collected the field data of the Huangshuihe catchment and the catchment was divided into 34 sub areas that can each be treated as a transport sub model. Next, we constructed a Hydrus1D transport model of Huangshuihe catchment. Different sub areas had different input values. Thirdly, we used Monte-Carlo simulation to improve the collected data and did vulnerability assessment using the statistics of the contaminant transit time as a vulnerability indicator. Finally, to compare with the assessment result by transport simulation, we applied two index systems to Huangshuihe catchment. The first was DRASTIC system, and the other was a system we tentatively constructed examining the relationships between the transit time and the input parameters by simply changing the input values. The result of comparisons between the two index systems and transport simulation approach suggested partial validation to DRASTIC, and the construction of the new tentative index system was an attempt of building up index approaches based on physical process simulation.