稻鸭共作有机农业模式的能值评估

应用能值分析方法对稻鸭共作有机农业模式（模式Ⅰ）和对应的稻麦常规生产模式（模式Ⅱ）进行比较研究,并比较了两种模式的生态经济效益.结果表明,模式Ⅰ的能值效益高,自组织能力、可持续发展能力强,产品安全性高,净能值产出率（EYR）、系统产出能值反馈率（FYE）、能值可持续指标（ESI）分别是模式Ⅱ的1.57、14.1和8.71倍;基于能值的产品安全性指标（EIPS）模式Ⅰ为0,模式Ⅱ为-0.66;模式Ⅰ对环境的压力小于模式Ⅱ,能值投资率（EIR）,环境负载率（ELR）分别是模式Ⅱ的40.1%和18.3%;但模式Ⅰ的经济效益低于模式Ⅱ,其产出、毛收入和净效益分别低于模式Ⅱ15.7%、9.6%和29.6%;以能值 货币价值计算,模式Ⅰ的产投比、毛收入和净收入分别高于模式Ⅱ50%、102.6%和136.4%.随着生产系统的优化和市场对有机食品认知程度的提高,模式Ⅰ的经济效益具有提高的潜力.     

Emergy evaluation of organic rice-duck mutualism system

Rice-duck mutualism is one form of ecological engineering which makes use of the symbiotic relationship between rice and ducks to more effectively utilize materials, reduce chemical fertilizer and pesticide inputs, increase product safety and overall productivity and decrease the pollutants discharged from rice-fields. This is becoming a popular mode for organic rice production in China and it can be used as one measure taken in the drainage area to assist in the ecological rehabilitation of lakes. This study applied the emergy evaluation method to analyze the resource use and environmental impact of organic rice-duck mutualism (mode 1) compared with the conventional wheat/rice rotation system (mode 2) in the same farm to evaluate its sustainability and ecological and economic benefits and provide suggestions for optimizing this system. The results showed that mode 1 produced greater emergy benefits, and had higher self-organization, lower environmental pressure and higher product safety. The net emergy yield ratio (EYR), feedback ratio of yield emergy (FYE) and emergy sustainable index (ESI) of mode 1 were 1.57 times, 14.10 times and 8.71 times those of mode 2, respectively, and the emergy index of product safety (PSI) was 0 in mode 1 and −0.66 in mode 2. The emergy investment ratio (EIR) and environmental loading ratio (ELR) were 40.1 and 18.3% of those of mode 2. The economic benefit of mode 1 was lower than mode 2. The economic output, gross income and net income of mode 1 were 15.7, 10.8 and 35.4% less than those of mode 2, respectively, but using Em$, the output, gross income and net income of mode 1 were 47.4, 161.2, 87.3% higher than mode 2. With the development of markets for organic foods, mode 1 has the potential to achieve better economic benefits.     

A Method for Green Rating of Automobiles

Coherent information about the environmental impacts of a product is essential for pursuing market-oriented approaches to environmental protection. Such green rating information can influence consumers' choices and, by affecting product and corporate images in the marketplace, might also influence technology development and product planning. Automobiles and their supporting industries are the subjects of many environmental policies. Informational approaches to automotive environmental performance, however, have been relatively piecemeal. In the course of developing consumer information and market creation programs for vehicles of higher energy efficiency (an important determinant of environmental performance), the authors felt that it was necessary to address this fragmentation rather than treat efficiency in isolation from other factors. A green rating system was developed based on principles of life-cycle assessment and is usable within the confines of available data that permit discrimination among makes and models. The resulting methodology is applied in a consumer-oriented publication that rates vehicles in the U.S. market. The ratings cover all vehicles and do not constitute an eco-label, although the methodology provides groundwork for developing a label. The background, data issues, analysis, and future research needs for this rating system are described along with a summary of its application.     

Comparisons of ecosystem services among three conversion systems in Yancheng National Nature Reserve

A conceptual framework of internal and external emergy was addressed to integrate ecosystem services evaluation and emergy analysis. Internal emergy yields support the material, structure, and information of the ecosystem, and external emergy is those goods and services related to the outside of the ecosystem. An accounting system was determined from the conceptual framework and applied to the evaluation of ecosystem services of conversion activities in Yancheng National Nature Reserve (YNNR), an international important coastal wetland in Jiangsu Province of China. Three typical conversion systems were selected as study cases: (1) a ragworm culturing system (RCS, located in the core zone of YNNR), (2) a clam culturing system (CCS, located in the buffer zone), and (3) a fishpond system (FCS, located in an experimental zone). Our results showed that the ragworm culturing system was more sustainable than the other two systems; indices of base emergy yield ratio (Beyr), net emergy yield ratio (EYR), eco-services benefits (Bs), emergy sustainable indices (ESI) were more sensitive in the new accounting system; the function of the ragworm culturing system relied more on renewable resources and the other two relied mainly on the economic management; and environmental impact, and external services played a crucial role in the ecological engineering evaluation.     

Emergy as a Life Cycle Impact Assessment Indicator

Founded in thermodynamics and systems ecology, emergy evaluation is a method to associate a product with its dependencies on all upstream environmental and resource flows using a common unit of energy. Emergy is thus proposed as an indicator of aggregate resource use for life cycle assessment (LCA). An LCA of gold mining, based on an original life cycle inventory of a large gold mine in Peru, is used to demonstrate how emergy can be incorporated as an impact indicator into a process‐based LCA model. The results demonstrate the usefulness of emergy in the LCA context. The adaptation of emergy evaluation, traditionally performed outside of the LCA framework, requires changes to the conventional accounting rules and the incorporation of uncertainty estimations of the emergy conversion factors, or unit emergy values. At the same time, traditional LCA boundaries are extended to incorporate the environmental processes that provide for raw resources, including ores. The total environmental contribution to the product, doré, is dominated by mining and metallurgical processes and not the geological processes forming the gold ore. The measure of environmental contribution to 1 gram (g) of doré is 6.8E + 12 solar‐equivalent Joules (sej) and can be considered accurate within a factor of 2. These results are useful in assessing a process in light of available resources, which is essential to measuring long‐term sustainability. Comparisons are made between emergy and other measures of resource use, and recommendations are made for future incorporation of emergy into LCA that will result in greater consistency with existing life cycle inventory (LCI) databases and other LCA indicators.     

LEED v4: Where Are We Now? Critical Assessment through the LCA of an Office Building Using a Low Impact Energy Consumption Mix

Various green building rating systems (GBRSs) have been proposed to reduce the environmental impact of buildings. However, these GBRSs, such as Leadership in Energy and Environmental Design (LEED) v4, are primarily oriented toward a building's use stage energy consumption. Their application in contexts involving a high share of renewable energy, and hence a low‐impact electricity mix, can result in undesirable side effects. This paper aims to investigate such effects, based on an existing office building in Quebec (Canada), where more than 95% of the electricity consumption mix is renewable. This paper compares the material impacts from a low‐energy context building to material considerations in LEED v4. In addition to their contributions to the building impacts, material impacts are also defined by their potential to change impacts with different material configurations. Life cycle assessment (LCA) impacts were evaluated using Simapro 8.2, the ecoinvent 3.1 database, and the IMPACT 2002+ method. The building LCA results indicated higher environmental impact contributions from materials (>50%) compared to those from energy consumption. This is in contrast with the LEED v4 rating system, as it did not seem to be as effective in capturing such effects. The conclusions drawn from this work will help stakeholders from the buildings sector to have a better understanding of building environmental profiles, and the limitations of LEED v4 in contexts involving a low‐impact energy mix. In addition, this critical assessment can be used to further improve the LEED certification system.     

A semantic study of the Emergy Sustainability Index in the hybrid lifecycle-emergy framework

Emergy-based indicators are claimed to be useful outcomes of the emergy evaluation framework, which aims at guiding decision-makers toward environmental sustainability. The calculation of the Emergy Sustainability Index (ESI), in particular, seems widely consensual among emergy scholars, but several variants actually exist in the scientific literature, which may lead to different interpretations or misunderstanding of the ESI result. This paper proposes a semantic study of two variants in both components of the ESI (the Emergy Yield Ratio and the Environmental Loading Ratio, respectively EYR and ELR), to enhance standardization and reproducibility in the calculation of emergy indicators. It is shown that ESI can be consistently defined at the level of the production site as well as from a lifecycle perspective, although several case studies in the literature use an intermediary version with inconsistent system boundaries. A recent definition of lifecycle-oriented EYR is made operational by the development of an algorithm to be implemented in the emergy accounting software SCALE. However, the classification of foreground inputs needs further precision. ESI is also decomposed using partial derivatives, in order to analyze the influence of each input category and retrieve generic recommendations. These multiple outcomes demonstrate the added value of hybrid lifecycle-emergy evaluation to identify specific potential actions toward enhancing ESI of human activities.     

两种典型养鸡模式的能值分析

畜禽养殖的有机化过程被认为是实现养殖业持续发展与保障食品安全的重要途径.运用能值分析方法对两种典型养鸡模式——家庭有机饲养和林地散养进行了系统分析,并结合Castellini等人对意大利所做的同类研究(工业规模化笼养和草地散养)进行了横向对比.结果表明,林地散养生产系统的能值产出率为1.11,与家庭有机饲养系统相近,而在环境负载率和可持续发展能力方面的表现,均差于家庭有机饲养生产系统,说明林地散养模式尽管通过提高系统生产空间,理论上接近畜禽养殖的有机化理念,但由于大量的禽舍建筑、医药及其饲料等方面的外部资源输入,反而使得系统的环境负载率提高,可持续性大大下降.与意大利的结果比较发现,我国两个养殖系统的社会经济成本高、对外部不可再生资源的依赖程度较高,有机化目标并没有很好的实现.因此,我国现有的有机化畜禽养殖方式和外部制度都有待进一步改进和创新.     

城市可持续发展能力的能值评价新指标

能值理论、方法克服了传统能量与经济分析方法的诸多缺憾,为城市可持续发展的研究提供了全新的视角。但作为一种新兴的理论,其评价指标,尤其是针对城市可持续发展能力的综合评价指标尚不完善。从生态经济效益及环境影响的全面表达角度,剖析了国际现行可持续发展能值指标(ESI)的不足之处,并在此基础上拓展构建了新的可持续发展能值指标(EISD)。以珠江三角洲中山市1996～2000年的发展动态为例进行了案例研究。结果表明,新拓展的可持续发展能值指标．在系统效益评价中考虑了系统能值产出的实际经济效果,在环境影响评价中同时考虑了系统的消耗影响和排放影响,可以更全面明晰的评价城市系统的可持续发展能力、状态及其成因,为系统的优化指明方向。     

Specific emergy of cement and concrete: An energy-based appraisal of building materials and their transport

Use and production of building materials, such as cement and concrete, is a major cause of global ecological problems with special reference to the overexploitation of non-renewable natural resources due to high temperature production processes, fossil fuels combustion, extraction of raw materials and non-recycling. In this paper, an environmental accounting method was applied to the production of cement and concrete in order to evaluate its dependence on natural resources even non-renewable and heavily relied on external inflows. The main steps of the production process (1) cement production, (2) transport of materials and (3) concrete mixing, were assessed by the emergy analysis (spelled with an “m”). This was performed to measure the amount of environmental resource use in terms of equivalent solar energy, extending the energy hierarchy principle to building materials. The resulting unit emergy values of cement and concrete were compared with previous emergy assessments in order to highlight how emergy analysis is sensitive to local context and reference system's boundaries. An Emergy Investment Ratio (EIR) was assessed and presented as a synthetic indicator of sustainability. Results showed a high dependence of cement and concrete production on external resource flows. Furthermore, the high value of EIR suggested a weak competitive capacity due to a high sensitivity to external instabilities.     

Provincial level-based emergy evaluation of crop production system and development modes in China

This paper presented a multi-objective indicator system for the performance evaluation of crop production system based on emergy method. Eight emergy indicators were selected to analyze the crop production system in the 31 provinces of mainland China to compare intensive use, scale management, investment density, environmental pressure, output benefit, output density, output per capita, and economic benefit. This paper conducted a comparison of each indicator in different provinces, and divided the 31 provinces into 10 groups by cluster analysis. The results show that: the crop production system among provinces has a significant difference and it is summarized into 10 development modes; with the development of modern agriculture, Chinese crop production system still complies with the input–output balance; the majority of provinces cannot achieve win-win between economic investment and environmental health; most of the underdeveloped provinces with high productivity may not be able to obtain good economic benefit; there is a significant positive correlation between the scale management degree and emergy output per capita in the crop production system; 10 development modes and policy suggestions are deduced. It is concluded that emergy-based multi-objective indicators can serve as an effective method in the evaluation of crop production system.     

Emergy analysis for the environmental sustainability of an inshore fish farming system

The emergy concept was used to evaluate the environmental sustainability of the rearing process of Gilthead Sea Bream (Sparus aurata) in an inshore fish farming system in Gulf of La Spezia (Italy, Northwestern Mediterranean). Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for the examined fish farm calculated from the emergy evaluation were compared with those of three other systems producing fishes: two intensive fish farming systems producing, respectively, salmons (Salmo salar) and tilapia (Tilapia mariae), the third system producing again S. aurata but in a semi-natural extensive manner. The emergy evaluation showed that the rearing of fishes in a sheltered area of Mediterranean Sea imposes a large stress on the environment. The greatest contributions to the emergy needed for production were due to fingerlings purchased and goods and services provided that are two external, non-renewable inputs to the system. The strong dependence of external contributions and the relative inability at exploiting local natural resources affect strongly the level of environmental sustainability of the productive process.     

基于能值分析的厦门城市代谢可持续性评估

生态城市建设是中国城市转型发展的关键节点,对中国生态文明和新型城镇化发展具有推动作用。研究以中国典型的生态城市厦门市为例,基于城市代谢框架结合能值分析法,对厦门市代谢系统进行各项能值流的核算,构建2010-2017年厦门市能值指标评估体系,选用可持续发展指数、可持续发展能值指标、城市健康水平能值指数3项指标综合评价其生态可持续性,选取部分能值指标与珠海市、深圳市进行对比分析,以期为中国生态城市的可持续发展提供科学参考。结果表明：（1）2010-2017年,厦门市总能值呈上升趋势,2017年的总能值为2.51×10²⁴ sej,是2010年总能值的1.65倍,货币流能值显著增加,废弃物流能值下降。能值自给率由98.30%逐渐递增至99.20%,能值产出率由8.30%逐渐递增至15.20%,环境承载率小于3,属于环境低负荷状态。（2）厦门市可持续发展指标处于1-10之间,表明其生态经济系统具有活力和发展潜力,可持续发展能值指标由2010年的3.67增加至2017年的7.76,表明厦门市的可持续发展性能愈来愈好,城市健康水平能值指数由2010年的6.21上升至2017年的25.80,表明厦门市生态系统处于健康可持续发展的状态。（3）厦门市与珠海市、深圳市的能值指标对比分析表明,厦门市与珠海市均处于富有经济活力与生态可持续发展潜力阶段,且厦门市代谢系统的可持续发展水平整体优于珠海市与深圳市。（4）总体来看,厦门城市代谢系统处于可持续发展阶段,生态城市的建设有利于厦门市实现生态经济的可持续发展,研究对同类型生态城市的建设与可持续发展具有理论参考价值。     

旅游生态系统能值研究进展

能值分析是以能值为基准,通过能值转换率,有效测度与评价生态系统及经济系统中不同类型的物质流、能量流、货币流及其相互关系的方法。旅游生态系统是特殊类型的人地关系地域系统,是以旅游活动为中心的"自然、经济、社会、旅游"复合系统,利用能值方法进行旅游能值研究可以为旅游可持续发展提供科学建议。通过对国内外相关研究重要文献的梳理,从旅游能值研究尺度与类型角度,分析了国内外相关研究进展,并通过与农业、工业系统的能值研究对比分析,目前研究在理论推进、要素选择、指标构建、方法集成等4个方面,旅游生态系统能值研究存在特殊性,并从理论、方法、内容等3个角度,提出了今后旅游能值研究的方向,以期推动旅游系统能值研究的深入。     

山西省农业生态经济系统能值分析

采用能值分析方法对2005年山西省农业生态经济系统的投入产出状况、运行效率和环境负荷进行了系统分析.结果表明：2005年,山西省农业生态系统仍处于主要依赖人力有机能和环境资源的传统农业阶段;研究区系统能值投资率（EIR）为1.07,能值产出率（EYR）为0.99,环境负载率（ELR）为6.55;在农业结构调整方面,畜牧业取得了长足发展,而小杂粮、蔬菜和干鲜果的能值产出仍较小,远未成为优势产业;研究区农业生态系统整体的回报效率较低,承受的压力较大.山西省今后应继续转移农业剩余劳动力、控制人口增长,同时加大农业科技辅助能值投入、提高环境资源的利用效率,使系统能值的投入产出向高水平发展.     

The emergy ecological footprint for small fish farm in China

Mariculture, especially cage aquaculture remains a growing, vibrant and important production sector for high protein food in coastal regions in China. A quantitative evaluation of the mariculture system is an essential step to documenting its’ sustainability. The method of emergy ecological footprint is applied to evaluate the environmental sustainability of an offshore small fish farm (Great Marine fish farm, GMFF) in the East China Sea. All input needed to support fish farming were accounted and converted into biological space, to estimate the natural capital demand for the rearing process in terms of global hectares. The emergy ecological footprint of GMFF was 1953.19 ha, meaning that nearly 2000 ha of ecologically productive lands were needed to support the fish framing. The largest component of emergy ecological footprint was forage (1183.64 ha), which took up 60.60% of the total footprint; the second and third largest footprint components were fingerlings and fuel. In a word, emergy ecological footprint can serve as a practical and meaningful tool for comparing and monitoring the environmental impact of fish farming. The strong dependence of external contributions of exploiting the wild fish resources affects strongly the level of environmental sustainability of fish farming.     

Integrating cost-benefits analysis and life cycle assessment of green roofs: a case study in Florida

Abstract

Multiple environmental benefits can be achieved by using a green roof instead of conventional roofs. To better understand the LCA and cost-effectiveness of a green roof, a case study was performed. Two energy models, one with conventional white roof and the other with green roof, were created using eQUEST software to compare the influence of green roof on building energy consumption. The results indicated that the application of a green roof reduced annual space heating and cooling electricity consumption by 9500 kWh (2.2 kWh per square meter). The LCA shows that by using an extensive green roof in lieu of a conventional white roof the LCA measures at the product, construction, and end-of-life stages increased due to the use of additional layers. However, these increases are offset by the reduction of LCA measures at the use stage such that the overall environmental impacts of green roof is less than that of conventional roof. To find out the cost-effectiveness of green roof, a 50-year cost-benefits analysis was conducted. The analysis showed that the net savings of the green roof is negative compared to the white roof it replaced due to its higher initial cost and follow on maintenance cost.     

基于能值的天山北坡经济带农牧系统可持续性评估

应用能值分析理论和方法,对新疆天山北坡经济带农牧业生态经济系统进行了分析和评价,通过一系列的能值指标定量分析了该地区的农牧业系统的能值流动。结果表明:环境资源对农牧业系统的贡献很大,环境资源能值占总能值利用的79.2%,高于全国农业系统平均值(13%);净能值产出率为4.81,高于我国平均值(0.27),说明该区域农牧系统生产有一定的竞争优势;农牧业产品的宏观经济价值大于市场价值,这是由于农牧业生产中有相当大一部分环境资源无偿投入所致;环境负载率指标为0.373,低于我国农业系统的环境负载率(2.8),环境压力较小;可持续发展指数为12.90,有较好的发展潜力,据此,提出了一系列促进区域农业可持续发展的产业结构调整措施。     

Emergy and economic evaluations of four fruit production systems on reclaimed wetlands surrounding the Pearl River Estuary,China

Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The goal of this study was to apply ecological engineering principles to fruit production system designs to maximize total emergy benefits and sustainability. The evaluations considered input structure, production efficiency, environmental impacts, economic viability and sustainability. The market effects on emergy exchange were assessed both for purchasing the inputs to production and for selling the fruit. These market effects were also considered in the evaluation of sustainability by using the Emergy Index for Sustainable Development (EISD), which was evaluated with and without taking the change in natural capital (i.e., soil organic matter) into consideration. The results showed that all three of the newly introduced systems are much more sustainable than the traditional banana production system. The guava production system had the highest value of the Emergy Sustainability Index (ESI = 0.40). The high price of wampee gave it the highest economic yield/cost ratio (4.87) and EISD (0.73). Emergy and economic evaluations are complementary methods, with emergy analysis shedding more light on environmental support and impacts of the production systems not considered in the market value, and economic analysis focusing on the effects of markets on fruit production. The Emergy Exchange Ratio (EER) was proposed as a bridge between emergy and economic evaluations for specific systems and/or processes.     

Development of concepts for human labour accounting in Emergy Assessment and other Environmental Sustainability Assessment methods

Human labour is central to the functioning of any human-influenced process. Nevertheless, Environmental Sustainability Assessments (ESAs) do not systematically include human labour as an input. Systematic omission of labour inputs in ESAs may constitute an unfortunate, significant bias in favour of labour intensive processes and a systematic underestimation of environmental impacts has implications for decision-making. A brief review of the evaluation of human labour in ESAs reveals that only Emergy Assessment (EmA) accounts for labour as standard. Focussing on EmA, we find, however, that there is no agreement on the calculation method for labour. We formalise the calculation of human labour unit emergy values (UEVs) as being the ratio between the emergy resource basis of the labour system and a proxy for labour, with or without allocation to account for different qualities of labour. The formalised calculation approach is demonstrated using examples from the literature (USA, with allocation based on educational level; Ghana, with allocation based on income level; the World, with no allocation). We elaborate on how labour may be considered as endogenous or exogenous to the studied system, and how inputs can be categorised as direct labour taking place in the system under study and indirect labour occurring upstream in the supply chain associated with the studied system. With appropriate modifications, the formalised calculation approach and the distinction between direct and indirect labour may be transferred to other ESA methodologies. Concerning EmA, we recommend that product UEVs should systematically be calculated with and without labour, and that working hours rather than salary should be used when accounting for labour inputs. We recognise that there is a risk of double counting of environmental impacts when including labour. We conclude, however, that it can be ignored for most production systems, since only a negligible fraction of emergy already accounted for is likely to be included in the emergy flow from labour inputs.