Application of Geographic information system to calculate the probability of piracy occurrence

This paper shows a successful application of Geographic information system to maritime safety. Pirate is a main threat to maritime safety. It is a critical problem to calculate the probability of encountering pirates for a trip. This paper proposes a GIS based method to estimate the probability using historical data from International Maritime Bureau (IMB) and the United Nations Conference on Trade and Development (UNCTAD). At first, it is assumed that the probability is equal everywhere in the sea. The average probability of piracy is calculated. Then, an adjusting coefficient is proposed to revise the probability of piracy in each trip. The adjusting coefficient of each trip is related to the average number of piracy in every grid which is calculated in Geographic Information System (GIS) and come across by the trip. Finally, a case study of a trip from Shanghai to the Republic of Kenya is used to illustrate the application of the proposed method. The results show the average probability of encountering pirates in 2012 is 0.0216% when a ship travels a thousand miles. The adjusted probability of encountering pirates for the case is estimated to be 1.62%.