随着我国城镇化进程的不断加快，城市内各类风险交织，灾害事故频发，这给城市安全风险监测工作带来很大的挑战，对城市安全风险管控能力提出更高的要求。开展城市区域安全风险评估对防范化解城市安全风险，提高城市风险防范能力至关重要。本文利用风险矩阵（LS）法、层次分析（AHP）法、熵权（EWM）法以及集对分析可变模糊集理论（SPA-VFS）法，构建科学合理的风险评估指标体系，从点（单位）、线（行业）、面（区域）三个角度，对西安市Y区进行综合风险评估。

首先，针对传统风险矩阵法在评估中未考虑救援抵达时间的不足之处，本文在风险矩阵法的基础上增加了补偿系数救援抵达时间，并利用改进风险矩阵法进行单位层面的风险评估。基于实地调研，分析提取区域安全风险的主要影响因素，选取综合全面的评估指标，为构建科学合理区域风险评估指标体系，实现区域风险评估提供基础。

其次，以各重点行业为研究对象，在单位风险评估结果的基础上，利用线性加权法，构建行业风险评估函数模型。通过不同风险等级风险单位的权重占比，得出行业总体风险值，基于层次分析法建立评价指标体系和层次结构模型，利用熵权法确定各行业指标综合权重。基于各行业指标综合权重，以整体区域为研究对象，综合考虑重点行业及区域应急管理能力等多方面影响因素，利用集对分析-可变模糊及理论方法，得出各行业与不同风险等级之间的综合隶属度及相对隶属度，借助置信度准则，得出区域整体风险水平。

最后，本文以西安市Y区为安全风险评估实施对象，通过相关数据收集、分析、统计等，运用城市区域安全风险评估模型，计算出Y区整体风险为低风险。结果表明基于集对分析可变模糊集理论的区域风险评估模型可行性高、实用性强，“点-线-面”三个角度的评估结果相互印证，为区域风险评估提供了新的思路及方法。

综上所述，本文基于改进风险矩阵法、线性加权法以及集对分析可变模糊集理论在点线面三个角度进行区域风险评估，可以为城市安全风险的精准管控提供科学合理的决策依据，提升城市安全水平。

With the continuous acceleration of China's urbanization process, various risks are intertwined in cities, and disasters and accidents occur frequently, which poses great challenges to urban safety risk monitoring and puts higher requirements on urban safety risk control ability. Conducting urban regional safety risk assessment is crucial for preventing and resolving urban safety risks and improving urban risk prevention capabilities. In this thesis, the risk matrix (LS) method, analytic hierarchy process (AHP) method, entropy weight method (EWM), and set pair analysis variable fuzzy set theory (SPA-VFS) method were used to construct a scientific and reasonable risk assessment index system and comprehensively evaluate the risk of the Y area in Xi'an city from three perspectives: point (enterprise), line (industry), and surface (region).

Firstly, based on the shortcomings of traditional risk matrix method in not considering rescue arrival time in evaluation, this thesis added a compensation coefficient for rescue arrival time on the basis of the risk matrix method and used the improved risk matrix method for point-level risk assessment. Based on field investigations, the main influencing factors of regional safety risk were analyzed and selected comprehensive and comprehensive evaluation indicators to provide a basis for constructing a scientific and reasonable regional risk assessment index system.

Secondly, taking each key industry as the research object, a linear weighted function model was constructed based on the point-level risk assessment results to evaluate industry risk. Based on the weight ratio of risk points of different risk levels, the overall industry risk value was obtained. The evaluation index system and hierarchical structure model were established based on the analytic hierarchy process, and the entropy weight method was used to determine the comprehensive weight of each industry index. Based on the comprehensive weight of each industry index, the set pair analysis variable fuzzy set theory method was used to comprehensively consider various influencing factors such as key industry and regional emergency management capabilities, and to obtain the comprehensive membership degree and relative membership degree between each industry and different risk levels. Using the confidence criterion, the overall risk level of the region was obtained.

Finally, taking Y District in Xi'an as the object of safety risk assessment, this thesis collects, analyzes, and statistically processes relevant data. By using the urban regional safety risk assessment model, the overall risk of Y District is calculated to be low. The results show that the regional risk assessment model based on the variable fuzzy set theory and set pair analysis has high feasibility and strong practicality. The evaluation results from the three perspectives of "point-line-surface" mutually confirm each other, providing new ideas and methods for regional risk assessment.

In summary, this thesis used the improved risk matrix method, linear weighted method, and set pair analysis variable fuzzy set theory to conduct regional risk assessment from the perspectives of point-line-surface, providing scientific and reasonable decision-making basis for accurate control of urban safety risks and improving urban safety level.