| China is an earthquake-prone country.After an earthquake occurs,it is the key direction of earthquake emergency research to accurately assess the casualties of the earthquake,quickly make an emergency response to the earthquake,and minimize casualties.Earthquake disasters are typical disasters of all types,and the casualties caused not only by the destruction and collapse of buildings,but also by factors such as earthquake secondary disasters.However,the currently used assessment models are not sufficiently regionally targeted,and do not consider the impact of earthquake secondary geological hazards,which may lead to large errors in practical applications.Therefore,it is necessary to analyze the fatal factors of earthquake disasters,and to provide more accurate evaluation methods and models.In this paper,the Zhaotong area is used as the research area,and the lethality matrix of the Zhaotong area is established,and the comprehensive lethality level of the area is considered under the two causative factors of buildings and earthquake secondary landslides.Firstly,the mortality data of people with different intensity in historical earthquake cases in zhaotong area were collected and analyzed,and the mortality matrix based on buildings in Zhaotong area was constructed.Then,the research in the area to set up 45 earthquakes,based on this paper to establish the localization of deadly matrix and preciously existing earthquake death toll to predict landslide data sets,using Arc GIS software related tools to estimate respectively set building under earthquake death toll and the death toll from the earthquake landslide,according to the two-formative factors lead to the death toll,Corresponding to the corresponding position of the localized lethality matrix,the comprehensive lethality level of the region was back-deduced,and the change rule of the comprehensive lethality level was studied.The following conclusions were obtained:(1)Through the fitting analysis of the mortality data of the historical earthquake cases in Zhaotong area,it is found that there is a grouping phenomenon in the historical earthquake cases.The death rate range of the intensity personnel is determined.The grouping characteristics of earthquake cases and the difference in the death rate of people with different intensity in different groups also reflect the difference in the level of regional lethality,that is to say,each earthquake case group corresponds to a group of intensity personnel mortality data and a lethality level.Based on the correspondence between these three,combined with the mortality rate data of the historical earthquake cases collected,under the condition of ensuring that the mortality error between the groups does not exceed ±50%,the historical earthquake cases,the mortality rate of the people with different intensity and the lethality level are divided into 11 groups A-K,and based on the real earthquake case data,the mortality rate data of the intensity personnel of each group are interpolated and calculated,and finally the lethality matrix of the lethality level and the mortality rate of the person with the intensity of the Zhaotong area is constructed.Through the examination of historical earthquake examples,it is found that the evaluation accuracy of the constructed lethality matrix has been improved,and its calculation results are closer to reality.(2)According to the different slopes,the study area is divided into five categories according to the division standard of 10 °,of which the slope of 0 °-20 ° is the widest distribution range.Based on the lethality matrix established in this paper and the prediction model of human death data on seismic landslides established by Bai Xianfu,it is found that the number of deaths caused by buildings and seismic landslides in various slope types under the set earthquake is found that the number of building deaths in the dense area is mainly in the range of 0°-20°,and the number of building deaths gradually decreases with the increase of slope;The number of deaths caused by seismic landslides is also mainly distributed in the range of 0 °-20 °,but when the slope is 20 °-30 °,there is a small peak in the number of landslide deaths.Combined with the spatial distribution of the population in the kilometer grid,it is found that the population in Zhaotong is mainly concentrated in the slope range of0°-20°,indicating that the slope is an important factor affecting the death of earthquake victims.(3)By superimposing the number of people killed by buildings and seismic landslides under the set earthquake,and pushing back to the corresponding position of the fatality matrix,it is found that there is a phenomenon of "jumping gear"(that is,the position in the lethality matrix will move down)in the comprehensive lethality level,which is divided into four situations: Move down zero,one,two and three gears.Through research and analysis,the regional lethality level and the proportion of various slopes were selected as the influence indicators of the comprehensive lethality level change,and the corresponding lethality grade correction model was established,and the historical earthquake case verified that the modified model could improve the assessment accuracy of the areas with more serious secondary geological disasters. |
