Study On The Influencing Factors Of Typhoon Disaster Preassessment

Tropical cyclones are generated on the subtropical or tropical ocean,with the determination of cyclonic circulation and convection of non-frontal vortex.Typhoon as a tropical cyclone,it often leads to floods,storm surge,debris flow and other disasters after landing.With global warming,the strength of typhoon landing has been increasing year by year.There are complex correlation between typhoon disaster and influencing factors.It is very important to accurately and efficiently extract the key influencing factors to pre-evaluate the typhoon disaster rating.In order to study the correlation factors between typhoon disaster and disaster-causing system,hazard-affected body system and disaster-mitigation system,select key influencing factors for pre-evaluation.The main contents of this paper include the following aspects:In the first part,we use the Monte Carlo method to calculate the copula entropy of influence factors and disaster.And then we analyze the correlation between the single influence factor,the comprehensive index and the disaster.Finally,we use T test to determine a threshold,in order to filter influencing factors which obviously related to the disaster.In the second part,based on the first part of the work,after filtering the influence factors which related to the disaster.We use Isometric Feature Mapping(ISOMAP),Principal Component Analysis(PCA)and the entropy weight to extract the residual influence factors.Then we use the significant correlation factors as input neurons,the disaster level as output neurons,to establish probability neural network model of typhoon disaster pre-assessment in Guangxi.The results show that the average accuracy rate of pre-evaluation model based on Copula entropy and Isometric Feature Mapping is 83.54%,which is the highest.It means that the method of selecting the influencing factors of typhoon disasters is effective and feasible.The pre-assessment results can provide reference for the relevant departments to develop disaster prevention and mitigation policies,that is of practical significance.