生态经济系统可持续发展研究能解决人地关系地域系统中人与自然和谐共处问题。而易学不仅与生态经济系统可持续发展观有着共同哲学核心和理论基础，还具有成熟的理论体系、系统的科学方法以及丰富的实践经验等优势，能以易学视角去解决生态经济系统平衡和人与自然和谐等重要问题。这不仅有利于传承易学，还符合我国生态文明建设方针，更能增添生态经济系统可持续发展研究的新方法，具有重要的理论意义和实际价值。 鉴于此，本研究在“天-地-人”三才架构中分别从思想融合、模型构建和实证研究三方面展开易学视角下生态经济系统可持续发展研究。在思想融合方面，将“天人合一”等易学思想延伸到生态经济系统可持续发展观中，并以“易学人”角度提出生态经济系统可持续发展“易”概念模型；在模型构建方面，将“三才论”等易学方法拓展到生态经济系统可持续发展理论中，旨在能构建出生态经济系统可持续发展“易”模型；并将能值分析、信息熵分析和生态足迹分析等现代科学方法有机整合，意在实现“易”模型的定量研究；在实证研究方面，选取“美丽与发展”共进的呼伦贝尔市为典型区域，对其可持续发展能力进行时空分析。其中，时序分析以呼伦贝尔市为研究尺度，探讨2005~2013年间系统发展变化。空间格局分析则以1km2网格为研究尺度，补充说明时序分析结果。基于此，本研究主要得到以下结论。 生态经济系统可持续发展“易”概念模型可描述为通过生态系统的自然资源供给限制和社会经济系统发展需求产生的阴阳自校手段，在遵循公平原则与和谐原则条件下生态经济系统沿着一定边界约束“通道”实现可持续发展能力逐渐增强的正向演化过程。 生态经济系统可持续发展“易”模型包括“阴阳”模型、“五行”模型和“阴阳-五行”互动模型，可用以阐释生态经济系统的产生机理、子系统作用关系、功能结构、代谢过程和动力学机制。在产生机理和子系统作用关系方面，“阴阳”模型辨别出负熵流和正熵流是阴阳二气，以及生态系统和社会经济系统是阴阳系统，阴阳二气相互运动可影响阴阳系统作用关系；在功能结构与代谢过程方面，“五行”模型识别出生态环境系统、农业系统、工业系统、社会系统和“三废”处理系统，其功能账户又依次为自然资源账户、农业资源账户、工业资源账户、社会资源账户和“三废”再生资源账户，由此构筑成“五行”功能结构系统。生态经济流则按照五行相生方向在不同功能账户间流动与转化，形成生态经济系统新陈代谢过程；在动力学机制方面，“阴阳-五行”互动模型显示出阴阳二气和阴阳系统分别是“五行”功能结构系统可持续发展动力学机制的深层次原因和基本矛盾。相较于传统分析方法来说，“易”模型有机融合过程模拟模型和耦合分析模型，实现了对既能剖析系统内部作用关系又能解析系统整体效应的分析框架的定性定量研究。不仅如此，“易”模型基于“天-地-人”三才各要素间的影响关系，对区域进行空间离散化，解决了生态模型与社会经济模型耦合时尺度匹配问题。这充分说明“易”模型对生态经济系统可持续发展研究具有良好的拓展性与科学性。 基于“易”模型的呼伦贝尔市可持续发展评价结果表明，2005年至2013年期间，系统总熵变变化率均在0附近波动，这显现出呼伦贝尔发展趋势稳定。而且，先由供给侧分析结果可知，生态支撑力指数除2013年外其余年份基本上徘徊于6.40×106km2。再由需求侧分析结果可知，社会经济压力指数因呼伦贝尔市不断推动经济社会发展的缘故，由2005年的3.33×106km2逐年增至2013年的5.80×106km2，增幅达74.20%。终由供需侧衡量结果可知，系统供需指数除2011年为均衡外其余年份均为盈余。基于此，综合分析呼伦贝尔的发展趋势与供需状态，可推测出在2005~2013年间呼伦贝尔生态经济系统发展正处于成熟期阶段且动态平衡。其中，2009~2011年为一般可持续性，其余年份均为强可持续性。此外，1km2网格尺度下的呼伦贝尔市虽然出现局部生态失衡，但大多地区因处于非重要生态功能区而对全市生态安全格局影响甚微，从而不足以影响全市可持续发展能力。由此可见，“易”模型能清晰地且合理地解析呼伦贝尔可持续发展状况，足以证明易学重塑生态经济可持续发展理论方法的科学性与实践性。

Bringing human beings into a harmonious relationship with nature in man-land relationship areal systems can be effected by establishing sustainable eco-economic systems (SES). However, Yi-ology is very similar to the sustainability concept of eco-economic systems (SCES) in philosophy, and it is already a well-established theory, developed by systematic scientific means and rich real-world experience. It may be possible to apply Yi-ology to SES and so solve such important issues as balance of eco-economic systems and harmony between human beings and nature. This not only benefits the heritage of Yi-ology, but also conforms to the guidelines for the construction of ecological civilization in China. It is also a new method for SES, so it has important theoretical and practical values. In view of Yi-ology, SES is here discussed in the context of Three Powers from Human and Nature (TPNH), including commingled ideologies, establishing a model, and performing empirical studies. First, on the matter of commingled ideologies, if the I Ching ideologies (e.g., ideologies about Harmony of Man and Nature) were extended to SCES, it might contribute to the I Ching conceptual model of sustainability within eco-economic systems (ICCMSES) from the Yi-man standpoint. Second, on the matter of building the model, the I Ching methods (e.g., the way of TPNH) can be expanded into the sustainability theory of eco-economic systems (STES). It would be conducive to establishing the I Ching model of sustainability within eco-economic systems (ICMSES). Furthermore, mordern scientific methods can be organically integrated, comprising emergy analysis, information entropy analysis and ecological footprint analysis, and it would be useful for achieving quantitative research of ICMSES. Lastly, on the matter of empirical study, Hulunbuir was selected as a typical region for evaluation of man’s capability for sustainable development. An experiment was carried out in time and space. For the temporal analysis, the city was observed from 2005 to 2013. In terms of the spatial analysis, a 1km2 grid was selected as the observation dimension, supplementing the results of the temporal analysis. Based on this, we drew the following conclusions. ICCMSES was characterized as the evolution of an eco-economic system (EES) involving a progression of increasing sustainability along the frontier of a restricted channel, which was established by the Yin-Yang self-correcting mechanism between ecological supplies and economic needs on the premise of equitable and harmonious principles. ICMSES consisted of the Yin-Yang model (YYM), the Five-Elements model (FEM), and the interactive model between Yin-Yang and the Five-Elements (IMYYFE). These explain the effects of induced mechanisms, subsystem interactions, functional architecture, metabolic processes, and dynamic mechanisms on EES. First, on the matter of induced mechanisms and subsystem interactions, YYM indicated that negative entropy and positive entropy were Yin energies and Yang energies, respectively, and ecosystems and socioeconomic systems were Yin systems and Yang systems, respectively. The relative movement between Yin energies and Yang energies affected the interaction between the Yin and Yang systems. Second, on the matter of functional architecture and metabolic processes, the FEM identified an ecological environment system, agricultural system, industrial system, social system, and three types of waste treatment systems. Moreover, its functional accounts comprised natural resource accounts, agricultural resource accounts, industrial resource accounts, social resource accounts, and three types of waste renewable resource accounts. In this way, these formed the functional structure of the Five-Elements system (FSFES). The eco-economic flow moved and changed in the orientation of action among five elements in these functional accounts, forming the metabolic processes of ESS. Lastly, on the matter of dynamic mechanisms, IMYYFE indicated that Yin-Yang energies and Yin-Yang systems were profound causes of and basic contradictions of dynamic mechanisms affecting the sustainable development of FSFES. Compared with traditional analytical methods, ICMSES organically integrated the process simulation model and the coupled-analysis model to achieve qualitative and quantitative analysis on the analytical framework, which could analyze for the system of both internal interactions and overall effects. Additionally, ICMSES was based on influence relationships among elements of TPHN, spatially discretizing the region, and solving the problem of scale matching when coupled with the ecological model and the socio-economic model. This showed that ICMSES had a satisfying scalability and scientific performance in terms of SES. The results of evaluating sustainability in Hulunbuir based on ICMSES showed that from 2005 to 2013, the total entropy change rate of the system fluctuated around 0, indicating the stable development trend of Hulunbuir. Moreover, from the analysis results on the supply side, it could be seen that the eco-supporting capacity index, except for in 2013, was hovering at 6.40×106km2. Then, from the analysis of the demand side, it could be seen that due to the continuous economic and social development of Hulunbuir, the socio-economic pressure index increased from 3.33×106km2 in 2005 to 5.80×106km2 in 2013, namely an increase of 74.20%. Furthermore, from the measurement results of the supply and demand side, it could be seen that the supply and demand index was surplus except for in 2011 when the supply and demand was balanced. Based on this and comprehensive analysis on Hulunbuir's development trends and supply and demand conditions, it could be inferred that the development of the Hulunbuir's EES from 2005 to 2013 was at a mature stage and dynamically balanced, among which the development was generally sustainable from 2009 to 2011 and strongly sustainable for the remaining years. Meanwhile, while there was regional eco-imbalance on a 1km2 grid scale, locating the unimportant eco-functional zoning, we detected little effect on ecological safety patterns and sustainability capability in Hulunbuir. In this way, we not only reasonably and clearly analyzed the sustainable development status of Hulunbuir using ICMSES but also established that Yi-ology could be used to improve STES in a scientific and practical manner.