Safety Of Navigation In And Out Of The Harbour Under The Poor Visibility Situations

In recent years, with the industrialization process of our country continuously develops, the weather was affected by a lot due to the serious pollution problem of atmospheric environment. The increasing of haze weather greatly impacted on ships’ port navigation which not only posed a significant threat on the safety of ships’port navigation, but also seriously affected the resources utilization of ports and waterways. In this paper, in order to improve the utilization rate of ports and waterways on the premise of safety, A study on the risk of ships’port navigation in the condition of restricted visibility has been made, which provide a minimum visibility distance in acceptable safety condition of ships’port navigation to be the theory evidence of related policy.First of all, this paper summarized both domestic and foreign research status of navigation in fog and did the statistical analysis on some important ports. Then, the fuzzy comprehensive evaluation method was selected to evaluate the risk of ships’port navigation in the condition of restricted visibility. According to the analytic hierarchy process, evaluation factor set were divided into three levels. The first level was divided into three factor sets, namely ship status set, navigation environment set and crew psychological pressure value set according to the system engineering idea of human-ship-environment. Next, the evaluation factor set was divided into seven second level factors and twenty-two third level factors. In the meantime, the evaluation index set was divided into five levels, in which the weight of each index was determined by using AHP.In the end, the fuzzy comprehensive evaluation model was established.The model was verified in sixth chapter. It concluded that the navigation risk of Tianjin port under specific visibility distance of 500m and 1000m were all in an acceptable range.