Spatial Analysis for Vessel Collision Risk Assessment
In order to estimate the risk of vessel collision, vessel encounters are studied, which is an important intermediate phase in the collision events. The closest point of approach (CPA) between two encounter wessels is an important indicator to judge the degree of collision risk. The amount of vessel encounters can be used for risk assessment of vessel collision. When CPA=0, it means that two encounter vessels have collided; when CPA is very small, but two vessels have not collided, it can be considered that a near miss accident has occurred; when the CPA is less than a certain value, for example, 0.5 nautical miles, although there may be neither a collision nor a near miss accident, it is still considered that there is a great risk of collision between vessels. Therefore, spatial analysis based on CPA can be used to evaluate the risk of vessel traffic and to support the investigation of vessel collision avoidance behavior, the planning and rationalization of marine traffic, and the evaluation of potential risk of traffic in busy or complex water areas.