| Our country,which is one of the nations suffering very severe earthquake,is located in the joint of the Pacific Ocean and Himalayan earthquakes.In recent years,with the continuous expansion of urban scale and the rapid development of urban system,the risk of earthquakes in cities has intensified.As the spatial disaster bearing body of earthquake disaster,earthquake disaster will cause very serious economic loss and casualties to the city.It is also one of the hot issues in the international research field that how to correctly grade the urban disaster bearing condition,how to scientifically manage it and how to maintain the sustainable development of the city under the impact of natural disasters.In 2017,the China Earthquake Administration listed "resilient City" as one of the four major plans of earthquake science and technology innovation project,and the proposition of "resilient city" was first formally proposed at the Fifth Plenary Session of the 19 th Central Committee of China.Therefore,from the perspective of urban system,a set of comprehensive evaluation index system of earthquake resilience suitable for urban system is constructed,and on this basis,comprehensive evaluation of resilience of urban system is of great theoretical value and practical significance for cities to resist earthquake disasters and build modern resilient cities.Based on the existing conceptual theories of resilience and urban resilience,this paper analyzes the urban resilience function curve,the seismic resilience function curve of the urban system and the Driving force-State-Response model,and combines the urban economic development status and the location of the seismic zone in northwest China to build a comprehensive evaluation system of urban earthquake resilience in Northwest China,which takes disaster resistance factors,disaster bearing factors and recovery factors as the core.The quantitative methods of each evaluation index are determined.Based on the gray whitening weight function cloud model,the actual data of 14 cities in northwest China were analyzed to verify the rationality and feasibility of the model,and an optimization scheme to improve the seismic toughness of the urban system was proposed.Firstly,the paper explains the relevant theoretical concepts such as toughness and urban toughness.Through the analysis of domestic and foreign research status and national standards and norms,combined with the existing research on the seismic toughness of urban systems and the whole process of earthquake disaster,the paper summarizes the relevant theories and framework system,summarizes the research experience that can be used for reference,and gives the concept of the seismic toughness of urban systems understood in this paper.Secondly,based on the concept of seismic resilience of urban system given in this paper,based on the three stages of urban seismic resistance,absorption and recovery,combined with the four characteristics of sudden earthquake disaster,monolithic,destructive and recurrent characteristics.Description of spatial time sequence characteristics of earthquake disaster occurrence;Function curve of seismic toughness of urban system and description of characteristics of each stage;Relevant national laws,regulations,norms and standards;Representativeness,scientificity,independence,accessibility and other 4 indicators selection principles;Complex and diverse urban system;The evaluation of urban earthquake resilience is affected by multiple factors.Based on the driver-state-response model modified by the seismic process of the urban system,33 secondary indexes from 10 aspects including natural factors,urban system factors,secondary disaster factors,lifeline systems,building structure systems,population factors,social factors,economic factors,planning and management factors,and urban emergency systems are obtained.A comprehensive evaluation index system of seismic toughness of urban system is constructed,and the meaning and quantitative calculation formula of each evaluation index are determined.Based on G1-CRITIC method,the comprehensive weight of indicator was calculated,the gray whitening weight function cloud model was introduced,and the gray cloud model was used to measure the randomness and gryness of futility,so as to realize the conversion between qualitative concept and quantitative data,and get the seismic toughness level of urban system in Northwest China.According to the seismic zone location of cities in northwest China,14 cities are selected as examples.Through literature,materials,yearbooks,reports,etc.,to obtain the actual data of each city index;The comprehensive weight of indicators and the digital characteristics of gray cloud of each toughness level of each city were calculated,and the corresponding gray cloud model diagram was generated.Finally,the comprehensive clustering coefficient of each city in Northwest China was calculated.According to the principle of maximum membership,the seismic toughness grade of each city was determined.Among them,Xi ’an and Lanzhou were rated as Ⅳ,indicating that the city had high seismic toughness.Xianyang,Hanzhong,Tianshui,Zhangye,Xining,Urumqi,Turpan and other seven cities of the city earthquake resilience level is Ⅲ,indicating that the city earthquake resilience is basic;Baoji,Longnan,Haidong,Yinchuan,Guyuan and other five cities are rated Ⅱ,which shows that the city has general toughness.The conclusion is consistent with the fact.The results show that the seismic toughness evaluation system based on urban system has rationality and adaptability.Finally,based on the results of the evaluation model,countermeasures and improvement strategies are proposed to make up for the current deficiencies.It has certain significance for urban system to cope with major earthquake disaster,reconstruction and sustainable development of the city. |
PDF Full Text Request