Study On The Risk Assessment Of Ships'oil Spill

Today, sea pollution is become more and more serious and people pay great attention to the pollution caused by ships. With the prosperity of shipping market and development of ships growing larger, the risk of ships'oil spill accidents is greatly increased in Chinese coast.Therefore employing appropriate method to assess the risk of ships'oil spill, then finding key risk factors and forecasting the harm degree correctly, makes great sense not only for the risk prevention but also for the emergency treatment.In the thesis, the dynamic state of the study on risk assessment models is reviewed.Combining with the need of the reserch, by comparing the technique characteristics of various risk assessment method, the author select Fault Tree Analysis (FTA) and Fuzzy Comprehensive Evaluation as risk assessment methods of this thesis. Then, relevant knowledge on oil spill is introduced, inclouding conversion of oil in the ocean, harm and emergency treatment of ships' oil spill. This set a theoretical foundation.for the below quantitative and qualitative evaluation.On the basis of a large number of documents reading,the fault tree analysis method is employed in the probability assessment study of ships'oil spill.firstly,Combining with accident statistics at home and abroad, the thesis selects caused by collision accident as reaserch subject and establishes the related model.The system risk is analyzed based on the minimum cut sets which are solved using the Semanderes algorithm.With the help of FlaultTree software,and by taking Bohai Bay as an example,we calculate the probability of oil spill accidents and importance degree of every bottom event. According to the analysis, countermeasures of reducing the probability of ships'oil spill are made.The study of assessing the damage degree is another hand of ships' oil spill risk assessment. After the analyses of the sources and composition of oil pollution accidents , the thesis confirme the four factors as key factors in ships' oil spill harm degree analysis. Then the thesis establishe the evaluation index system.The thesis also establishes evaluation model of damage degree on ships' oil spill by analyzing the weight and the subject degree of those factors. Finally, we calculate the damage degree of oil spill with Fuzzy Comprehensive Evaluation, verifies the math model by the oil spill accident in the sea area of the MeiZhou Gulf, and puts forward a general procedure and technique of the evaluationon on damage degree of oil spill. The results indicate that Fuzzy Comprehensive Evaluation is applied to study oil spill risk assessment of ships, which is completely feasible and valid.