- eMergy Evaluation: a Multi-Scale Optimum Tool for Visioning Sustainability   381 kb by    Li, Dong | uriel_li@yahoo.com.cn    Short Outline Emergy analysis and its optimum principle help planners and decision-makers to shape a sustainable visioning strategy of urban development. The analytical results show evidences of how to promote urban vision by individual projects. Abstract In spite of its recent argument, Urban SUstainability (USU) becomes the core issue of all of the stakeholders throughout the world. By cross-questioning past short-sighted developments, people realize there is a need for a tool to evaluate urban projects comprehensively. The key is not only for economic profits, but also for the externalized costs and the gained sustaining capability. Many methods working at different scales have been introduced by the scientific community. However, the perfection of methodological integrality and comparability among different projects or scales is still not accomplished. eMergy Analysis (EMA) provides a common ¡°track¡± framework for accounting projects at disparate space-time scales, where emergy represents natural and economic values of products and services with a simple, universal unit. Besides, an energy-based hierarchical picture of self-organizing urban systems and its optimum evolving mechanism is advanced in emergy theory, Maximum Power Principle (MPP). It indicates the whole system will take the predominance by increasing its emergy inflows and improving its internal structure, etc.. People get a clearer view of the good and the bad impacts of urban projects at larger scales, as the deviation to designed target, by referring to EMA and MPP. For accumulating urban assets, EMA and MPP help the planners and the decision makers to shape a sustainable visioning strategy of urbanization. In this article, a general EMA study framework for urban projects will be discussed, from context analyzing to decision supporting. Then by employing the MPP, different development scenarios are evolved and compared. The case study, building material recycling strategy in Beijing as a icon of Circular Economy, is investigated synthetically for demonstrating how urban vision being driven by specific projects and how the demanding identity and capability being built up. Keywords emergy, urban sustainability, decision supporting Case Study presented on the ISOCARP Congress 2007: Urban Trialogues   Click to open the full paper as pdf document   Click to send an email to the author(s) of this paper