生态安全的概念与环境安全、生态修复、生态保护等均相关，本质是从生产、消费、资源节约、生态环境等方面提升人类的福祉，并出于对经济、社会、生态、环境等方面的综合评估与安全阈值设定，才产生了生态安全的概念。对生态安全概念的理解是与研究者的背景、经验、认知、文化等相关，也与不同国家、地区经济发展和快速城市化、自然资源的损失和退化、以及由此可能对人类健康产生不利影响等相关，因此，对该概念的理解在东西方研究中有明显的差别。城市系统人口众多、问题复杂，城市生态安全是区域和国家生态安全的基础和核心，相比更大尺度的生态系统而言，城市生态系统更加脆弱和不稳定，因此有必要对城市及更大尺度地区形成跨尺度的生态安全分析框架，并提出相关评估方法，充分体现城市中密集化的资源管理、人类福祉、生物多样性等综合问题。

本论文首先综述了近二十年来城市生态安全的定义、边界和研究内容，并深入分析了东西方由于文化、背景、经验、认知等方面的差异形成对这个概念的分野。相比于西方学者的理解，东方学者对于城市生态安全的理解更加宏大，其相关主题包括生态风险评估和生态安全、生态安全预警、生态系统保护与恢复及生态安全格局等，并形成了相对应的方法学体系。随着城市化进程的加快，城市生态安全问题变得日益突出，这表明城市生态安全研究的范畴包含了资源安全、经济安全、国家安全等更多的指标。但现有的城市生态安全中生态方面的指标仍存在一些量化问题，仅适用面积或足迹等难以区分不同生态系统类型及不同的生态功能，反映的城市生态安全多停留在数量上，缺少在品质方面的考虑。

进一步，为了完整性的反映城市生态安全中生态量、质方面的指标，本研究使用能值分析方法分类计算多种生态系统服务，并提供加和原则。能值分析方法以生态系统服务为评价终点，不仅直接关注城市生态本身，而且可以作为统一量纲，打通城市内的不同生态系统类型，为城市生态安全研究提供既考虑数量、有考虑品质的相关指标。本论文选取中国地级以上342个城市，利用能值分析方法计算2018年各城市的生态指标，并进一步从文献中获得这些城市经济方面、社会方面和环境方面的共包括了36指标的城市生态安全指标体系，进行指标的排序分析和相关性分析。并使用UMAP聚类分析工具，通过概率分布来进行城市聚类分析。UMAP聚类分析工具通过分析单元格或数据之间的邻接单元数量和最小距离，对指标进行合并或分离，形成2018年中国地级以上城市的聚类格局。

总体而言，本研究综述了城市生态安全的基本概念、边界和内容，分析比较了适用条件、评估方法和指标体系，并以生态系统服务作为城市生态安全分析的评估重点，构建全新生态指标体系，并结合其他经济、社会、环境指标，形成了城市生态安全分析框架。该研究可为城市尺度的生态安全评估提供理论、框架和方法工具。

Ecological Security known as Environmental Security, Ecological Restoration, Ecological Protection, portrayed with different names in different regions of the world, but with similar concept and similar analysis that can support and assist the well-being of human on the cards of their consumption, conservation of its resources. The similar concept is engraved for the integrated purpose of economic, Social, ecological understanding. These all understandings and integrated purposes described above are influence of the Researchers experience related to the extensive economic development and urbanization, the consequential loss and degradation of natural resources and resulting environment pollution that may adversely affect human health. Urban ecological security being the basis and core of regional and national ecological security and also as a populous and complex ecological study, urban ecosystem is more fragile and unsteady, therefore there is a need to develop a sense about the security of an urban surrounding and its repercussion, that need to be either resolved or predicted in order to create that safe environment for mankind along with the ecological diversity. To have an understanding of ecological security with context to the urbanization, we need to know the tools used and methods applied for the concentration of the ecological security in context to the human wellbeing and resource management and its densifying paradigm.

The Paper Focuses on the research advancement and its analysis for the past two decades, that has been termed as the most focused and concerned decade related to environment and its security and the boundaries that defines that security level. In context to the above protection and its statement in the last two decades the Eastern researchers have been countering several problems related to the urbanization, some of the major advancement in its research topic i.e. Ecological risk assessment and ecological security, Ecological security warning, Ecological security protection and Restoration and most important and significantly on ecological security pattern, which are all countered as the tools for the ecological security, along with the acceleration of urbanization, regional ecological security issues have become increasingly prominent, which shows a complex relationship between the sources that counters it, and urban ecological security. The large context of ecological security plays the same important role with political security, economic security, and national security, in which the existing research is still primitive in their abilities to resolve ecological security problem concentrated and more related to the national security. With rapid development of society and economy, more and more problems on ecological security stand out.

Also, to completely explain and identify the indicator system, emergy method is used in order to calculate the ecological service values and providing such a framework which not only focuses more on the ecological aspect of the environment but also it provides an integrated structure for the indicator system, thus providing more and more information related to the cities analysis, a total of 342 cities were selected across China to calculate and analyze their indicator system based on the ESV accounting method through emergy. The data analyzed explained several aspects of cities under study in terms of their ranking from top and bottom both, and benefited in accounting the term and number of cities according to their ranking system, the data shows the evaluation of Chinese cities in 2018. One more evaluation tool to analyze such large quantity of cities with almost 36 indicators was the UMAP plotting tool, which calculated and analyzed the data using exponential probability distribution in high dimensional, i.e., the dimensional reduction analysis of such large data combined and portrayed in form of clusters, showing the cities with similar data values to be clustered along side each other, the UMAP used two of the main hyperparameters such as the n-neighbors and min distance between the cells or data to be analyzed, amongst which we can see in the evaluation analysis, that the cities with economic and social indicators are grouped with one another i.e., Shanghai, Beijing, Tianjin, Guangdong, Shandong, which clearly shows their increased evaluation structure and cluster in the UMAP software due to their similar aspects and characteristics in the indicators, whereas the same cities mentioned above also listed at the top in terms of environmental indicators, which depicts the analysis under pollution and their surroundings, but if we look at the cluster formation in the UMAP structure for the ecological indicators, we get to know the benefits of the western and western northern part of China, which are much feasible and abundant in terms of their ecological factors and aspects, and this helped a lot in understanding the pattern of cities across China for the year 2018 and can be used for any futuristic research approach in terms of time trend or pattern analysis, this study framework focused mainly on providing an integrated approach for sustainable study and provided a clear meaning in terms of the core of urban ecological security. Overall, the whole study applies to give a basic understanding of urban ecological security and then , provides the importance and significance of the topic under consideration with various conditions, tools and theories and concludes with a beneficial framework approach which not only focuses the other aspects of study such as economic, social and environment, but primarily states upon the ecological aspect, thus signifying the importance of ecological security in today’s world and its contribution in today’s increasing environmental issues.