Study On Spatial Distribution And Consequence Classification Of Maritime Traffic Accidents

Maritime safety has been a hot topic in maritime transportation for a long period. Although the global maritime community has made great efforts to improve maritime safety, maritime traffic accidents still happen from time to time. Studies on the characteristic of maritime accidents contribute to avoiding accidents effectively and assessing the impact of the accidents. This dissertation studies into the spatial distribution and consequence classification of maritime traffic accidents. The main research contents of the dissertation are summarized as follows.(1) Spatial analysis of maritime traffic accidents is implemented by Geographic Information System(GIS) and a general framework of application of GIS to maritime traffic accidents is proposed. Historical data is obtained from Global Integrated Shipping Information System(GISIS) database of IMO. Based on the data, spatial analysis of the accidents is implemented. The hot spots of maritime accidents and the distribution percentage in the coastal areas are calculated on the Arc GIS platform. The result is helpful for the navigation to reduce risk.(2) Accidents are divided into different scenarios according to accident types and ship types. A consequence model is built to analyze the consequence of different scenarios. Through reading accident reports from different sources, the consequences of accidents are collected. The empirical distributions of six different types of consequence are established.(3) Considering the consequence of historical accidents may not be suitable for the situation in the future, relative consequence is proposed to be analyzed. In the dissertation, human casualty in collision is taken as an example. Casualty rate is studied as the statistical target. Because there are many accidents without any human casualty and the probability density decreases as human casualty rate becomes larger, a zero-inflated exponential distribution of human casualty in ship collision is chosen to fit the historical data.(4) A fuzzy expert system is constructed to assess the classification of maritime traffic accidents. The number of fatalities, the number of injuries, environmental impact, and damage to property are the four inputs. The classification result is inferred by the fuzzy inference system based on fuzzy IF-THEN rules. The classification results of fuzzy expert system are more or less the same with the results of traditional method. Accident cases with different classification results by the two methods are explained.Compared with previous literatures, the contribution of the dissertation is summarized as follows.(1) A general framework of application of GIS to maritime traffic accidents is proposed. This method is more convenient and efficient than the traditional statistical method.(2) A zero-inflated exponential distribution of human casualty rate in ship collision is built,which is the first application of zero-inflated exponential distribution to maritime traffic accident analysis. The problem that empirical distribution of human casualty may not be suitable for future accidents is solved by considering the human casualty rate, not human casualty numbers as statistical target. The zero-inflated exponential distribution of human casualty can be used to generate human casualty data when carrying out maritime risk analysis or simulation.(3) A fuzzy expert system is constructed to classify maritime traffic accidents considering four types of consequences: the number of fatalities, the number of injuries, environmental impact, and damage to property. This system contributes to assessing the accidents for the government.