Broiler production from the perspective of emergy analysis - environmental impact scenarios

Emergy analysis and optimization for a solar-driven heating and cooling system integrated with air source heat pump in the ultra-low energy building

PDF HTML阅读 XML下载 导出引用 引用提醒 基于能值分析的我国小水电生态影响研究 DOI: 10.5846/stxb201306091484 作者: 作者单位: 北京师范大学环境学院 水环境模拟国家重点实验室,北京师范大学环境学院 水环境模拟国家重点实验室,北京师范大学环境学院 水环境模拟国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: Emergy evaluation for ecological impacts of small hydropower in China Author: Affiliation: State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:如何系统定量地评价小水电开发过程所引起的景观变化、河流局部断流等生态影响,是平息争议、进行合理规划与开发小水电前提之一。运用能值分析方法,以贵州省赤水市观音岩水电站为例,将小水电建设、运行的资源投入,以及河道中水流的时空改变所导致生态服务功能的损失纳入核算体系,对其生态影响进行综合定量评估。从2010年的实际结果来看,由于河流断流,导致水坝下游生态系统服务功能的能值损失为2.77×1018sej,占到了系统建设运行总投入的44.84%,其中重点保护鱼种在影响河段的生境破坏是最大的能值损失。若不考虑下游生态系统服务功能损失,系统的环境负载率为1.92,可持续性指标为1.22;而考虑下游生态影响之后,系统环境负载率增大至4.26,可持续性指标减小为0.34。研究表明,小水电的开发必须遵循适度开发、规划优先,保障河流最基本的生态需水底线,是协调小水电开发和河流健康矛盾、追求小水电持续发展的刚性要求。 Abstract:In China, most of the small hydropower (short for SHP) plants are currently seeking for benefits in power generation and economic revenue with little consideration of environmental flows for ecosystems, causing great impacts on river ecosystem services in the downstream of the dams. Negative ecological impacts of small hydropower have drawn increasing attention from the public. This paper used emergy analysis, one of the ecological energetic accounting methods, to evaluate the overall ecological impacts of construction and operation of small hydropower and took Guanyinyan hydropower plant in Chishui City, northwest of Guizhou Province as an example. Having capabilities in accounting multiple forms of energy and materials both from environmental and economic points of view on a common energy basis, the method of emergy analysis was widely used for supporting the evaluation of agricultural, wetlands and urban systems and was proved to be a useful tool for evaluating the overall performance of a mixed ecological and economic systems. The related indices and ratios based on emergy flows such as emergy yield ratio (EYR), environmental loading ratio (ELR) and emergy sustainability index (ESI) can be used for characterizing resource consumptions, environmental impacts and overall system sustainability. Through incorporating losses of the downstream ecosystem services into the operation cost of the power production system, the results showed that the studied system was supported by a total emergy of 6.18×1018sej in 2010 to produce 2.26×1013J of electricity, of which the downstream ecosystem service losses was the largest among multiple marginal costs, accounting for 44.84% of total ecological economic cost. The losses of ecosystem service mainly included those due to biodiversity losses (especially rare species losses) and climate regulation losses, with 2.77×1018 and 4.63×1013 sej/a respectively. Without considering the ecosystem service losses, the ELR of the studied system was 1.92 and the ESI was 1.22. However, when considering ecosystem service losses, the ELR of the studied system increased to 4.26, which was much larger than those of large hydropower generation projects in Mekong River or those in Korea, showing an increased pressure on local environment. And the value of ESI decreased to 0.34, which was much lower than 1, indicating that the studied power production system was not sustainable. Furthermore, the results suggested that the degradation of river ecosystem in the downstream of the dam during operation period greatly reduced the sustainability of the system. Thus, for a small hydropower, occupying environmental flows of the downstream and the development pattern at the expense of the ecosystem approach would be unsustainable. Sufficient environmental flows would be essential to the river ecosystem in the downstream, especially for maintaining the aquatic biodiversity. Environmental-friendly and social harmonious development of water resources would be necessary to achieve sustainable development for small hydropower. Relevant authorities should strengthen the planning and management of water resources development to ensure the sustainability of small hydropower and the health of river ecosystem. In addition, this paper reflected that emergy analysis, as a measure of the environmental support and the work to keep ecosystem sustainability, is an effective tool that is capable of providing an integrative assessment, and then provide a basic for the sustainable development of small hydropower. 参考文献 相似文献 引证文献

应用能值分析方法,通过能值转换率,把深圳市3个农场生态经济系统的能量流、物质流、货币流和信息流转化为统一量纲——能值。在绘制能值系统概图和编制能值分析表的基础上,建立能值评价指标体系对3个系统的能值输入结构、生产效率、环境负载和可持续发展状况等进行分析和比较。此外,比较经济指标与能值分析结果,并采用情景分析对农场未来发展做出预测。能值分析方法不仅考虑环境及其服务功能对经济生产的贡献,同时能值交换率和能值产出率把系统经济流入和产出纳入分析过程,结合环境和经济评价,可用于综合分析农场生态效益和经济效益。研究结果表明:西丽果场是可持续发展能力最高的农场,碧岭现代农业科技园次之,而山海农场的可持续发展能力最低。都市农场应该大比例利用可更新资源,努力发展农业生产,并且积极提升农业的技术含量。在此基础上,控制规模合理地发展旅游经济,走高科技农业生态旅游之路。;The ability to transform different types of resource flows in energy, physical, capital and information into a unified standard-emergy-makes emergy analysis is an appropriate tool for evaluating and comparing the structural characteristics of input, production efficiency, environmental load, economic viability and the overall sustainability of agricultural ecological-economic systems. The systems studied were Biling Modern Agricultural Technology Park (Biling Park), Xili Orchard and Shanhai Farm in Shenzhen, China. Based on a general emergy system diagram and emergy analysis table, we constructed an emergy evaluation system to analyze and compare these three farms. As for emergy input structure, Xili Orchard mainly relied on renewable resources, which accounted for 50.2% of its total emergy input; Biling Park and Shanhai Farm depended mostly on purchased nonrenewable input. Xili Orchard had the lowest environment load ratio (ELR) value because of its relatively high renewable resources input and low level of purchased nonrenewable resource input. Unlike Xili's situation, Shanhai Farm's ELR value had the highest ELR because of its relatively low level of renewable resource input and high level of purchased nonrenewable resource input. The emergy indices for sustainable development (EISD) value were 12.70, 2.47, and 0.52 for Xili Orchard, Biling Park and Shanhai Farm, respectively. Although Shanhai Farm had a relatively high emergy exchange ratio (EER), strong pressure on the environment limited its sustainability. Also, we compared the economic index analysis with emergy analysis and found them to be consistent with each other. Xili Orchard had the highest economic output/input ratio and benefits density, while Shanhai Farm had the lowest values. The results show Xili Orchard was the most efficient system and Shanhai Farm was the least efficient system from both economically and ecologically. We then used scenario analysis to predict how the three farms would develop in the next ten years. The outlook for Biling Park gives it a bright future and an enormous potential for development. However, if the Shanhai Farm continues expanding its tourism resources blindly without making an effort to develop basic agricultural production, its pressure on the environment would continue to increase, preventing it from achieving sustainability. Xili Orchard was the most sustainable, followed by Biling Park and Shanhai Farm as least sustainable. Emergy analysis was found to be an efficient method for evaluating ecological and economic benefits of these farms, because it not only accounted for the environment's support and contribution to these agricultural systems, but also linked the environment and economic evaluation with the Emergy Exchange Ratio (EER) and Emergy Yield Ratio (EYR). Emergy analysis is a bridge between economics and ecology. Emergy analysis will help show managers of city farms they should strive to make the best use of renewable resources which will facilitate agricultural production; city farms should also actively incorporate high technology agriculture into their operations and understand the scientific system standards. They can then develop tourism rationally. In summary, city farms should seek out new agricultural systems which combine high levels of technology and with ecological tourism.

Economic, environmental and multi objective optimization of a clean tri-generation system based co-firing of natural gas and biomass: An emergy evaluation

Sustainability assessment of bioethanol and petroleum fuel production in Japan based on emergy analysis

This study presents a quantitative and ecological benefit evaluation of the Baiyangdian wetland in China between the years 2000 and 2006. Methods of EMERGY analysis were applied to illustrate the wetland ecosystem, to evaluate the economic and environmental inputs and consequent yields, and to assess the sustainability of the Baiyangdian wetland. The indicators for the integrated ecological and economic system, such as EMERGY yield ratio (EYR) (7.51), EMERGY investment ratio (EIR) (4.52), environmental loading ratio (ELR) (2.92), EMERGY exchange ratio (0.41), and EMERGY sustainable indicator (ESI) (2.57) were calculated, compared, analyzed, and discussed. The non-renewable investment in Baiyangdian was greater than renewable investment, leading to the unsustainable development of the system. High EYR indicated that the Baiyangdian integrated system had created huge profits for its people, while ELR and ESI revealed that human behavior has been a heavy burden on the environment, and countermeasures should be taken by the Chinese government to relieve and resolve these problems. Potential management methods were also proposed in this paper.

The article presents a brief description and criticism of the current state of the emergy analysis for wastewater treatment plants (WWTP) and a new index for the assessment of environmental facilities. As well as in the analysis of economic systems, the assessment of systems and plants for the protection of the environment, provided in the literature, is based on the calculation of basic emergy indices (the emergy yield ratio (EYR) isthe ratio of the sum of renewable kinds of emergy, non-renewable ones and purchased or free resources to the emergy of purchased resources; the environmental loading ratio (ELR) is defined as the ratio of the sum of nonrenewable and imported (purchased) emergy to renewable emergy; the emergy sustainability index (ESI) equal to the ratio of economy (EYR) to depletion (ELR) determines the degree of viability of the facility), which does not take into consideration a fundamental difference of production facilities and facilities designed to protect the environment from pollution. The environmental performance of the facilities, calculated as the ratio of the difference between the emergy estimates of preventable damage and caused damage to the preventable damage, must serve as the main emergy index for the assessment of treatment facilities.

Emergy analysis of biogas production and electricity generation from small-scale agricultural digesters

Sustainability assessment of bioenergy at different scales: An emergy analysis of biogas power production

The demand for energy has increased gradually over the past few years. As a result, the reserve of petroleum-based fuels is depleting continuously which led to thinking about an alternative energy source. This resulted in the increased popularity of biofuel, which is an alternative and renewable source of energy. This study aims to investigate whether biodiesel production from different edible oil crops is sustainable enough to replace conventional fuels. In this work, emergy analysis has been used to study the sustainability of edible oil crops-based biodiesel production. Wheat germ, groundnut and cottonseed oils produced from edible oil crops have been considered in the present study. Based on the data availability, the study area considered in the present work is the state of Maharashtra, India. Three different processes of biodiesel production have been studied in this work, namely alkali-catalysed, acid-catalysed and lipase-catalysed transesterification processes. The emergy performance indicators such as emergy sustainability index (ESI), emergy investment ratio (EIR), emergy renewability (%R), emergy yield ratio (EYR), environmental loading ratio (ELR) and environmental impact ratio (EVR) are then evaluated for each of the considered biodiesels derived from edible oil crops. The sustainability of the considered biodiesels is then evaluated based on a comparative assessment considering these emergy performance indicators. Based on the emergy analysis, it is found that irrespective of the transesterification processes considered, the wheat germ oil is found to be the most preferable edible oil for the production of biodiesel as it has lowest transformity value. On the contrary, cottonseed oil is the least preferred edible oil as it has the highest transformity value. Similarly, based on the values of emergy indices, it is observed that irrespective of the transesterification processes considered, the biodiesel derived from cottonseed oil crop is found to be the most sustainable followed by biodiesel derived from groundnut oil crop and the biodiesel derived from wheat germ oil crop is found to be least sustainable.

Comprehensive evaluation and optimization of agricultural system: An emergy approach

Improved emergy indices for the evaluation of industrial systems incorporating waste management

Emergy evaluation of biofuels production in Thailand from different feedstocks

Sustainable forestry production systems, such as certified forestry, re- duced impact logging or sustainable forest management, have become an important part of tropical countries’ strategy to oversee their forest re- sources. Particularly, certification of forest products has become a widely adopted practice as a response to a growing international concern over the ecological and economic sustainability of harvesting natural tropical forests because of the benefits on reducing excessive and unnecessary construction of forest roads, reducing excessive use of heavy machinery, diminishing excessive collateral damage, and improving the inefficient milling processes and wasting of residues. To accomplish the aim of this study, which is to compare conventional and certified forestry we used a systems analysis tool that could integrate various benefits of certified forestry including, stand age, wood harvest, soil losses and economic gain or loss. We found that the affected area under uncertified logging practices is twice the area of certified forestry because conventional prac- tices require more roads, more logging decks and more skid trails. Also, the rate of soil erosion between uncertified logging (154 Mg/ha/yr) and certified logging (66 Mg/ha/yr) is different. Based on these data, we es- timated that the total emergy removed from certified forests was 40% less than the forest under conventional forestry. The fact that certification does a better job of preserving forest while removing wood was also demonstrated through the Environmental Loading Ratio (ELR). We also found that certification leaves forests with a 30% better chance to recover after logging because less wood is removed. But forestry using certifica- tion showed a lower Emergy Yield Ratio (EYR) because the lower yield and the extra cost of certification. Certification is also favored for the higher price for certified wood in international markets. Then, when Bo- livia exports uncertified wood, it obtains a positive benefit, but lower than using uncertified wood domestically (EYR = 20.4). In other words the worst thing the country could do is certify wood for their domestic market and sell uncertified wood abroad.

Clay brick is a commonly used building material in China. Due to the enormous land destruction and excessive consumption of resources, such as materials and energy in the manufacture of clay brick, it is important to study its overall sustainability, i.e., in terms of impact on the environment, services, and economy. In this study, emergy analysis is employed, which offers a holistic perspective, unlike typical environmental studies. A series of emergy indices such as renewability rate (R%), nonrenewability rate (N%), unit emergy values (UEVs), emergy yield ratio (EYR), environmental loading ratio (ELR), and emergy sustainability index (ESI) were used to study manufacturing of clay brick. In addition to calculating UEVs of clay brick manufacturing in China (7.18 × 1012 sej/kg), our detailed analysis shows that the nonrenewable resources and imported energy have a dominant impact on the emergy contribution (50.6%) and within the nonrenewable resources, clay is the foremost item, accounting for 33.5% of local emergy inputs. Given different electricity UEVs, the change ranges of clay brick system UEVs are 14.9% (scenario 1), 7.24% (scenario 2), 8.91% (scenario 3), and 6.94% (scenario 4). Furthermore, several policy suggestions are discussed for improving the sustainability of the evaluated system, involving the energy structure adjustment, recycling material replacement, and promotion of energy-saving systems.