The Wounded Trauma Characteristics And Modeling Study Based Two Tornadoes In China

BackgroundOn June 23,2016,an EF4(Enhanced Fujita 4)tornado occurred in Yancheng City,Jiangsu Province,killing 99 people and injuring 846 people.This is China's worst tornado in the past half century.On August 11,2017,an F3(Fujita 3)tornado occurred in Chifeng City,Inner Mongolia Autonomous Region,killing 5 people and injuring 58 people.According to the statistics of the International Disaster Database(EM-DAT),the frequency of global meteorological disasters(tornadoes,haze,and extreme temperatures)increased from 1900 to 2016,and the number of deaths increased.The threat of tornadoes to human life is worthy of attention.At present,researches on the occurrence of tornado injuries at abroad mostly focus on the cross-sectional survey.There is no systematic analysis on the process of tornado injuries and related modeling studies.Considering China's special geography and humanities environment,the characteristics of tornado injuries are unknown,so it is necessary to carry out relevant research.Purpose and SignificanceBased on two surveys of tornadoes in Yancheng and Chifeng,the construction of the data base of tornado injuries is conducive to finding out the characteristics of tornado injuries;the construction of the data base of tornado victims is conducive to the identification of the impact factors of tornado injuries.Based on the multi-agent modeling approach,we build a AnyLogic-based tornado trauma model and fill in the model gap of the tornado trauma study.By carrying out model simulation and model intervention tests,it is beneficial to improve the trauma prevention strategies for the tornado victims.Materials and Methods(1)Based on the records of tornado wounded patients in 6 hospitals in Yancheng and Chifeng,the injury characteristics were studied from three aspects: injury sites,injury types,and injury severity.The AIS(Abbreviated Injury Scale)was used to score the injury severity.Based on different disaster areas and EF scale areas in Yancheng City,geographical information systems(GIS)and non-parametric test methods were used to analyze the difference of the wounded density and injury severity between different regions of the tornado.(2)Based on surveys of victims in Yancheng and Chifeng,Chi-square test and logistic regression were used to analyze the influencing factors of the injury from three aspects: demographic characteristics,affected environment,and individual behavior.(3)Based on Multi-agent modeling method and AnyLogic simulation modeling software,a tornado trauma model was constructed and model simulation and intervention tests were conducted.Results and Conclusions(1)Trauma characteristics and GIS distribution of the tornado wounded.From the comparison of two tornadoes,the injury severity and the proportion of infections were higher in Yancheng.The top three injury sites were head,body surface,lower limb injuries in Yancheng,and the top three injury sites were head,upper limbs,and lower limbs in Chifeng.The top three injury types were soft tissue injuries,fractures,and organ injuries both in Yancheng and Chifeng.The proportion of seriously wounded(AIS>=5)in Yancheng was 2.5%,while there were no serious wounded in Chifeng.The serious injuries were mainly in head,spine and chest.The demographic characteristics of the wounded population show that the middle-aged or elderly over 45 years of age and young people less than 18 years of age occupied a large proportion,and the age distribution of the wounded was a “dumbbell-shaped”(ie,the age distribution of the wounded presented a large proportion of two heads and a small proportion in the middle).The wounded density in areas with higher damage and higher EF scale was higher,but there was no statistical difference in injury severity in different areas(p>0.05),suggesting that the deployment of medical rescue forces after the disaster should be based on the principle of "different number at the same speed"(ie,deploy medical staff at the same speed to different regions but deploy different numbers of medical staff).(2)Factors influencing the trauma of victims of tornadoes.Judging from the comparison of two tornadoes,the “hardware” facilities,such as the level of income and the ability to find safe buildings,had a significant impact on the injury in high-intensity Yancheng Tornado(p<0.05).And the “software” behavior,such as individual behavior,exercise awareness,had a significant impact on the injury in low-intensity Chifeng Tornado(p<0.05).Individual effective evacuation behavior needs to be judged according to the tornado level,and depends on effective warning time.Vctims should be strengthened in the science education for disaster prevention and reduction,and their awareness and ability in disaster prevention should be improved.Different from other studies,this study found that there is no statistical difference in the probability of injury among indoor and outdoor victims(p>0.05),but the higher the degree of collapse,the higher the probability of injury(p<0.05).This suggests that the role of house to tornado victims depends on it's wind resistance.It couldn't be considered that houses are a protective factor in all situation.The collapsed building can not only protect the victims but also is an important cause of the victims' injuries.So the building's wind resistance should be improved.(3)Building of the tornado trauma model using AnyLogic.Based on Multi-agent modeling theory,we defined three types of agents: victims,tornadoes,and houses,as well as their behavioral rules.The logical relationship between early warning time,personal behaviors and other factors was systematically analyzed to clarify the traumatic mechanisms of tornado trauma.Using AnyLogic simulation modeling software,a tornado trauma wound model was constructed to realize the computerization of the model.(4)Model simulation based on the tornado trauma model.Based on the survey data of two tornadoes in Yancheng and Chifeng,the trauma process of the two tornadoes was dynamically simulated.We compared the test results and the disaster results and verified the stability and reliability of the model.(5)Intervention tests based on the tornado trauma model.From the early warning time,personal behavior and house collapse,three types of nine groups of intervention tests were carried out.It was found that the number of wounded people was increased as the victims were running away.Early warning can effectively reduce the number of wounded people.The more serious the collapse of the house,the greater the number of wounded.Policy Suggestions(1)Pay attention to the data on the wounded and victims of the tornadoes.The wounded with head injury,spine injury,chest injury are critically injured patients,and the prevention and treatment of organ trauma and infectious trauma should given attention.(2)The deployment of medical rescue forces after a tornado disaster should be based on the principle of "different number at the same speed"(ie,deploy medical staff at the same speed in different regions but deploy different numbers of medical staff)to improve the estimation of potential medical needs and improve the overall rescue efficiency.(3)Considering the tornado disaster prevention measures,we should improve the wind resistance of houses in tornado areas,strengthen early warning of tornado disasters,carry out disaster prevention publicity and education for residents,and increase their awareness and capabilities of disaster avoidance.