Temporal features of non-accident critical events impact from tides around the Yangtze Estuary and adjacent coastal waters

Abstract

Applying non-accident critical events (NACEs) as an alternative measuring method to assess ship collision risk has become popular in recent years. NACEs has shown temporal features in different waters. This study uses the quaternion ship domain method to identify NACEs around the Yangtze Estuary and adjacent coastal waters from the Automatic Identification System (AIS) data in October 2019. The results indicate that NACEs show different temporal features in estuaries and coastal waters. The relationship between tides, channel types and ships is discussed. In addition, we established a statistical method for the occurrence time of NACEs and the state of tides according to the half-tide level and the nearest time. The outcomes of this study provide a direction for exploring the relationship between NACEs and environmental conditions, which is also instructive for the study of the causes of ship accidents.

A Domain-Based Model for Identifying Regional Collision Risk and Depicting Its Geographical Distribution

“…The proposed model was not limited by the statistical period and can allow maritime surveillance operators to better understand the collision risk in a water area in real time. When the experiment was extended by using a larger range of data, from 16 June 2022 to 30 June 2022, a similar phenomenon was observed in the near miss map, depicted by using the method in [14], as shown in Figure 22. In addition, the proposed model was also compared with the near miss model proposed in [14].…”

“…The model in [22] found it difficult to fully and accurately identify the collision risk in such situations, while the proposed model, which additionally considered the traditional collision avoidance parameters on the basis of the SDOR, had an advantage in collision risk identification in such scenarios. In addition, the proposed model was also compared with the near miss model proposed in [14]. The model was used to calculate near misses at 1300 on 24 June 2022, and the distribution map is shown in Figure 21.…”

“…The model proposed in this article was also used to calculate the collision risk at this moment and the distribution map is shown in Figure 14b. By comparing the two figures, we found that the model in [14] only determined a near miss by the threshold of the impact factors of the collision risk, and thus studied the collision risk in the water area. In other words, it only determined whether there was a near miss or not.…”

“…The logistic regression method is used to evaluate the near miss index, and the risk in the Busan Port and Busan New Port is visualized accordingly. Yao et al [14] have conducted a study on the characteristics of potential collision events in the Yangtze River estuary and adjacent waters based on a quaternion ship domain method, one which can detect non-accident critical events and provide information support for marine spatial planning and management. Cui [15] has analyzed the temporal distribution of near misses in the Qiongzhou Strait based on the concept of ship domain and conducted a kernel density analysis of ship positions in different encounter situations where near misses occur.…”

“…Additionally, we used the methods in [14,22] to identify the collision risk in the studied water area within a 15-day period for comparison. The resultant maps are depicted in Figure 13.…”