基于指标体系的风险建模与评估是目前灾害风险分析与评估中应用最广泛的方法.本文首先分析评价不同学者的地震灾害风险评估指标体系;在此基础上,选取指标体系相对简单的城市防震减灾能力法和考虑因素较多的地震灾害风险系数法对乌鲁木齐市各区县开展地震灾害风险评估.评估结果表明:不同评价方法的侧重点不同,造成评估结果有一定的差异性,评估体系指标大而全并不意味着评估结果更加合理.地震灾害风险评估指标体系的建立需要兼顾可操作性、实用性、全面性及可量化性等要求.%At present,risk modeling and assessments based on an index system are widely used to assess and analyze earthquake risk.In this paper,various index systems for seismic risk assess-ment are compared and analyzed.Most of the index systems include three parts:risk,vulnerabili-ty,and disaster bearing capacity.As a whole,index systems have tended to become more elaborate and complex,especially the parts related to disaster preparation,emergency response,and management,which belong to the disaster bearing capacity set.Evaluating the effects of different index systems is the primary step when using or improving them.In order to compare different in-dex systems in a general sense,two typical methods were chosen and applied to Urumqi city.One is the ability for urban earthquake disaster reduction method,whose index system is relatively simple and macroscopic;the other is the seismic risk index method,which includes many more detailed factors.Earthquake hazard risks for each district in Urumqi city were evaluated using the methods above.By comparing the results we reached the following conclusions:(1 )evaluating results from different index systems does not coordinate well because each one has its ownresearch focus.For example,the ability for urban earthquake disaster reduction method focuses on seismic disaster,which relates to two of its three criteria,whereas the seismic risk index method not only considers disasters,but also considers ways and means to mitigate them.So,the results embody their own characters.(2 )Regarding the development of the evaluation system,one notable phenomenon is that the index sets become increasingly huge and complicated.Although more indexes may express the earthquake mitigation ability of cities more comprehensively,the extraction and quantification of those indexes is a big challenge.Moreover,the determination of some indexes relies on personal experience and j udgment,which can lead to a shift away from the original trend.An index system with more detailed and comprehensive factors will not always attain better,reasonable,and valid results.A sound,efficient,and effective index system must be a combination of ease of manipulation,utility,and accuracy.
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