Lifespan of Commodities,Part I

Lifespan is an essential parameter for the accounting and analysis of material stocks and flows, one of the main research topics in industrial ecology. Lifespan is also important as a parameter that portrays the current and historical situation of industrial metabolism, which is an area of interest to industrial ecologists. In the present article, the available information from various reports on product lifespan was reviewed. Although we found a large number of data for many durables, the definition of lifespan in published articles varied, which limited our ability to compare reported values. We therefore first defined lifespan and then compared the international and historical data. We compiled more than 1,300 data sets from various sources and identified some differences among the types of goods and among regions. With the reviewed data noted in this article, we established a database, named LiVES (Lifespan Database for Vehicles, Equipment, and Structures), and will disclose it on the Internet to share the information.     

Lifespan of Commodities,Part II

Lifespan of commodities is essential information for material flow analysis and material stock accounting. Lifespan data is available in the literature; however, it varies in definition and in methodology employed. This article reviews and categorizes different types of lifespan distribution and distribution estimation methodologies, and investigates the relationship and differences between lifespan definitions and estimation methodologies. Lifespan distribution of commodities can be classified into five types from two perspectives: base year for which the distribution is drawn, and vertical axis of the distribution. The methodologies for estimating lifespan distribution were classified into four types and the details of each methodology and the relationship to the definition of lifespan were also clarified. This article also examines differences in actual lifespan data—between the types of distribution, the definitions, and the employed methodologies—by comparing reported data in literature. Any of the four methodologies are theoretically applicable and provide the same value of a lifespan; however unless accurate data such as census statistics are available, lifespan data can vary, and therefore we must be very cautious about the representativeness of sample data.     

以材料“创造”土地？——中国城市化进程的一个重要特征

中国快速城市化进程的一个重要特征是以土地为载体,通过大量投入钢铁、水泥等建材大规模修建城市建筑和基础设施,创造出大量的城市生产和生活空间。利用1985—2010年中国省级行政单元城市建成区总面积、城市居住用地总面积、城市住宅总面积和城市住宅建筑材料总使用量等数据,识别城市扩张模式,揭示中国城市化进程中土地、建筑面积及其构筑材料三者间的关系。研究表明2000年是中国城市扩张的重要分界点,2000年之前中国各省份的城市建成区总面积、城市住宅总面积和城市住宅建筑材料总使用量均较小且省份间差异不大,2000年之后三者迅速增长且省份间差异逐渐扩大。在地区尺度上,三者均呈现东部地区最高、中部次之、西部最低的特点,地区内部差异则表现为东部地区最大、西部次之、中部最小的特征。大多数省份的城市住宅总面积及其构筑材料总量随着城市建成区的扩张而增长,表明城市在发展初期以扩大建成区和水平扩张为主。随着城市化水平的不断提高,城市内部空间重组和用地置换导致高层建筑逐步替代了原有的单层或低矮建筑,城市扩张的方向由依赖土地的水平扩张转向以大量使用建筑材料为基础的垂直扩张,使得许多省份的城市住宅总面积逐渐超过辖区内居住用地总面积。这种以建筑材料\"创造\"出更多\"土地\"的城市垂直扩张在满足人们对城市生产和生活空间需求的同时,有利于节约土地资源和保护生态空间,但需要以消耗更多的建筑材料并承担建筑材料在开采、制造、运输、使用和废弃过程中所造成的环境影响为代价。     

Urban Metabolism of Paris and Its Region

The article presents the results of a research project aimed at (1) examining the feasibility of material flow analysis (MFA) on a regional and urban scale in France, (2) selecting the most appropriate method, (3) identifying the available data, and (4) calculating the material balance for a specific case. Using the Eurostat method, the study was conducted for the year 2003 and for three regional levels: Paris, Paris and its suburbs, and the entire region. Applying the method on a local scale required two local indicators to be defined in order to take into account the impact of exported wastes on MFA: LEPO, local and exported flows to nature, and DMC_corr, a modified domestic material consumption (DMC) that excludes exported wastes (and imported ones if necessary). As the region extracts, produces, and transforms less material than the country as a whole, its direct material input (DMI) is lower than the national DMI. In all the areas, LEPO exceeds 50% of DMI; in contrast, recycling is very low. The multiscale approach reveals that urban metabolism is strongly impacted by density and the distribution of activities: the dense city center (Paris) exports all of its wastes to the other parts of the region and concentrates food consumption, whereas the agricultural and urban sprawl area consumes high levels of construction materials and fuel. This supports the use of MFA on an urban and regional scale as a basis for material flow management and dematerialization strategies and clearly reveals the important interactions between urban and regional planning and development, and material flows.     

The Sankey Diagram in Energy and Material Flow Management

The Sankey diagram is an important aid in identifying inefficiencies and potential for savings when dealing with resources. It was developed over 100 years ago by the Irish engineer Riall Sankey to analyze the thermal efficiency of steam engines and has since been applied to depict the energy and material balances of complex systems. The Sankey diagram is the main tool for visualizing industrial metabolism and hence is widely used in industrial ecology. In the history of the early 20th century, it played a major role when raw materials were scarce and expensive and engineers were making great efforts to improve technical systems. Sankey diagrams can also be used to map value flows in systems at the operational level or along global value chains. The article charts the historical development of the diagrams. After the First World War the diagrams were used to produce thermal balances of production plants for glass and cement and to optimize the energy input. In the 1930s, steel and iron ore played a strategic role in Nazi Germany. Their efficient use was highlighted with Sankey diagrams. Since the 1990s, these diagrams have become common for displaying data in life cycle assessments (LCAs) of products. Sankey diagrams can also be used to map value flows in systems at the operational level or along global value added chains. This article, the first of a pair, charts the historical development. The companion article discusses the methodology and the implicit assumptions of such Sankey diagrams.     

The Sankey Diagram in Energy and Material Flow Management

The Sankey diagram is an important aid in pointing up inefficiencies and potential for savings in connection with resource use. This article, the second of a pair, examines the use of Sankey diagrams in operational material flow management. The previous article described the development of the diagram and its use in the past.
Simple Sankey diagrams follow the requirement of conservation of energy or mass and allow a physical view of production systems. Advanced diagrams integrate stocks of materials beside the flows or show the different (ecological) quality of the materials. For the purpose of management, however, a further step is necessary: to illustrate the economic value of the energy and material flows and to use information from cost accounting. The use of flow charts showing added value or the costs of energy and material flows is particularly important for production systems. This article describes examples of each of these uses as well as assumptions that must be taken into account for Sankey diagrams to be used as an effective aid for decision-making in business and public policy.     

‘Habitat’ Suitability Index Mapping for Industrial Symbiosis Planning

By ‘working with the willing’, the National Industrial Symbiosis Programme (NISP) has successfully facilitated industrial symbiosis throughout the United Kingdom and, in the process, delivered significant economic and environmental benefits for both Programme members and the country as a whole. One of the keys to NISP's success is that, unlike failed attempts to plan and construct eco‐industrial systems from scratch, the Programme works largely with existing companies who have already settled in, developed, and successfully operate within a given locale. This article argues that existing and mature industrial systems provide the best prospects for identifying opportunities for, and ultimately facilitating, industrial symbiosis. Due to levels of diversification and operational fundamental niches that, in the fullness of time, develop within all industrial systems, industrially mature areas are deemed to be industrial symbiosis ‘conducive environments’. Building on the conservation biology concept of a habitat suitability index, the article presents a methodology for comparing a potential site for eco‐industrial development to a known baseline industrial ‘habitat’ already identified as being highly conducive to industrial symbiosis. The suitability index methodology is further developed and applied to a multi‐criteria evaluation geographic information system to produce a ‘habitat’ suitability map that allows practitioners to quickly identify potential industrial symbiosis hotspots (the methodology is illustrated for England). The article concludes by providing options for the development of symbiosis suitability indices and how they can be used to support the facilitation of industrial symbiosis and regional resource efficiency.