Research On Urban Disaster Carrying-bodies Earthquake Risk Assessment And Losses

Natural disaster is an important object of all kinds of risk management, and it’s widely noted by the fields of disaster reduction and relief at home and aboard. With the challenge of urbanization, urban cities are faced with increased natural disaster hazard, the vulnerability of disaster-carrying bodies is higher, once the natural disaster happened, the cities will suffer a great loss. Earthquake usually happens suddenly and is highly interactive. After the earthquake, the cities are suffered heavy losses both in society and economy, such as heavy casualties, productivity impairment, and disaster-carrying capability of environment went down. Therefore, if we try to know the reasons of losses and find out the factors impacted the losses, we can work better in earthquake prevention and disaster relief.In this research, the vulnerability of disaster-carrying bodies and the hazards of earthquake are two dimensions of the earthquake risk and analysis the factors of losses in Wenchuan Earthquake, then come up with some measures of earthquake risk management.At first, urban earthquake risk factors are based on vulnerability and hazard. The project collected data of each province about4000years to analysis the earthquake hazard, the percentage of earthquake which has more than6.0Ms is the index to assessment the hazard. And then, the index system of urban disaster-carrying bodies’vulnerability is established, which about engineer indexes and non-engineer indexes, the variable fuzzy clustering is used to assess the vulnerability.Then, the research modified the traditional risk matrix method, identified the level classification criteria for the vulnerability of disaster-carrying bodies and the earthquake hazard, then the two variables are input into the risk matrix and got the urban earthquake risk level. Data of some municipalities and provincial capitals are adopted in the case study, the results show that most cities’earthquake risk is in the general level. The cities with low earthquake risk are almost located in the eastern coastal areas, which have advanced economy, and have occurred less destructive earthquakes in the history; But western cities have high vulnerability and backward economy, are regularly shaken by earthquakes, therefore, they have high earthquake risks.At last, based on DEA-Tobit model, the index system of urban earthquake loss is proposed, and the data of the10very heavy disaster areas in Wenchuan Earthquake is chosen as the objects. First, the hazard of earthquake is used as input indexes together with the loss of earthquake is as output indexes, and compute the hazard bearing efficiency of disaster-bearing counties; Then, With the efficiency being the dependent variable in the Tobit model, a regression analysis was taken on the reasons that relief capacity and resist capacity mainly influence the scale of loss. The results show that vulnerability of economic, society and environment and the disaster relief capacity of urban are the key factors of urban earthquake loss.