Research On Collision Risk In Precautionary Area Based On Variable Weight Vague Set GCA-TOPSI Method

Since the 21 st century,the process of globalization has been accelerating,and economy of China has developed rapidly.The shipping industry is playing an irreplaceable role in the world trade transportation and development.80% of the world’s cargo transportation is realized by sea transportation,and sea transportation accounts for more than 90% of trade transportation of China.In recent years,the number of large ships is increasing,especially some new super large ships,which brings new challenges to maritime transport safety.Maritime safety issues are not only related to the safety of the lives and property of the crew,but also related to the country’s economic development.The implementation of the Ships’ Routeing plays an important role in improving the maritime traffic environment.However,as one of its measures,the precautionary area still has problems such as traffic convergence,large number of ships and complex traffic flow.The safety problems are more prominent,and it is the area where ship collision accidents occur frequently.Therefore,this article conducts research on the precautionary area,determines the safety level,and provides a reference for the safe navigation of ships.Firstly,based on the research of characteristics of precautionary area and water traffic conflict,this paper define water traffic conflict on basis of summarizing the predecessors’ research.The function factors of traffic conflict in the precautionary area and the necessity and feasibility of applying water traffic conflict in the collision risk research in precautionary area are analyzed and the theory of traffic conflict is introduced into the research model of collision risk in precautionary area.Secondly,based on the research and improvement of the existing models,an improved collision risk assessment model of GCA-TOPSIS(Grey Correlation Analysis;Technique for Order Performance by Similarity to Ideal Solution)based on Vague Set is established.This model can take into account the difference and correlation between the evaluation objects and various levels as well as the ambiguity of risk levels.The water traffic conflict is introduced into the evaluation model and the index system of the precautionary area evaluation model based on traffic conflict is established.In part to determine important index weights in the model,this paper take four methods to determine the basis weight from different angles,on the basis of the four weight will be the basis of the combination to determine the optimal combination weights,and on the basis of the combination weights is introduced into the variable weight method is applicable to precautionary area,through the index of the true state of dynamic adjustment of weight to establish a more reasonable weight system and evaluation model.In order to verify the validity of the evaluation model,a validation model based on the improved SPA method was established in this paper.Through the analysis of traffic conflicts and other influencing factors in the actual water area,the results of the evaluation model and the validation model were compared and analyzed to verify the validity.Finally,according to the output results of the actual water area,combined with the theory of traffic conflict,the measures for safe navigation of ships in the precautionary area are proposed,which can provide reference for seafarers and traffic control personnel,reduce the occurrence of collision,and ensure the smooth implementation of Ships’ Routeing.It can also provide ideas for the design and planning of Ships’ Routeing and improve the safety of ship navigation in the precautionary area from the source.