Study On Life Vulnerability Of Earthquake Disaster

China has been a country with many earthquakes since ancient times,and it is also one of the countries with the most serious earthquake disaster losses in the world.In recent years,destructive earthquakes have caused serious loss of life.The in-depth study of the vulnerability of earthquake disasters not only improves the accuracy of quantitative assessment of earthquake disaster risk but also plays an important role in emergency rescue after earthquake.This study takes the life loss data of earthquake disasters in China from 1966 to2016 as the research object.Based on the GIS platform,the life loss of earthquake disasters in China is analyzed from time distribution,spatial distribution,different magnitudes and population density.The results show that:On the whole,the loss of life in earthquake disasters in mainland China is frequent and highly concentrated.In the spatial distribution,the overall presentation of small and medium earthquakes in the more earthquake-prone provinces has a smaller loss of life,and in the less earthquake provinces the loss of life is rather large..In addition,the distribution of loss of life in earthquake disasters is significantly affected by population density.It is bounded by the demarcation line“Hu Huanyong Line”,which shows that the east is high and the west is low,which is contrary to the frequency of earthquakes.Based on the analysis of the spatial-temporal characteristics of earthquake life loss,this paper systematically collected the death data of 51 earthquakes in China,and evaluated the applicability of five representative seismic hazard models.The study result shows that:(1)The majority of the assessment results for the five representative models are basically reasonable when the earthquake magnitude is lower than 5.5;when earthquake magnitude ranges between 5.5 and 6,the results of the five types of evaluation models with small errors and within a reasonable range are models based on epicenter intensity and specific regions;when the earthquake magnitude is equal to or higher than 7,the assessment model with specific applicable scopes and expert experience are generally required to obtain relatively accurate assessment results,which,however,contains large errors.(2)The life vulnerability models in earthquake disasters are not applicable to the assessment of life loss of earthquakes occurring directly beneath the city.(3)The life vulnerability models in earthquake disasters is divided spatially in typical regions of China,and the assessment results are obviously regionally differentiated.Combining the current model applicability evaluation results and the seismic parameters,the epicentral intensity,the earthquake area(intensity?VI),the population density,and difference between the epicentral intensity and the seismic intensity tolerable by the constructions are selected to construct the life vulnerability model of earthquake disaster.The construction of the life vulnerability model divides the mainland China into the Northwest(Xinjiang,Qinghai,Ningxia,Gansu,Shaanxi),Southwest(Sichuan,Guizhou,Yunnan,Tibet,Chongqing),and the eastern region(mainly the“Hu Huanyong”line east in addition to the western provinces)the population density is divided into groups.The northwestern region is divided into 20people/km~2 or less,20-60 people/km~2 and 60 people/km~2 or more,and the southwest region is divided into population density below 60 persons/km~2,60 to 150 people/km2and 150 people/km~2 or more.Since the eastern region is east of the“Hu Huanyong”line and the population distribution is relatively dense,but the earthquake frequency is low.There are few historical earthquake cases recorded by the death toll,and there are fewer sample data that can be used as model construction.Therefore,in order to ensure the earthquake disaster in the eastern region.The accuracy of the life vulnerability model is no longer grouped by population density.On this basis,the multivariate nonlinear regression method is used to establish the life vulnerability model of earthquake disasters,and the validity of the model is verified by historical earthquake cases.