Safety assessment of shipping routes in the South China Sea based on the fuzzy analytic hierarchy process

The shipping routes of the South China Sea (SCS) are of major significance in global trade and global economy. However, the shipping routes of the SCS are frequently threatened by both natural and manmade factors, such as complex submarine topography, extreme weather, and piracy. Previous studies of shipping safety in the SCS mainly focused on the individual ship safety and broader political policies. For this study, we applied spatial analysis to assess shipping safety along shipping routes. First, we extracted the main shipping routes from spatial analysis of the Voluntary Observing Ships data. Then, we used a qualitative review to choose influencing factors on ship safety in the SCS, for which data were available over a comparable time period. Further, annual and four seasonal criteria systems were developed. After factor normalization and mapping, the annual and seasonal navigation environment risk was evaluated along the shipping routes using the fuzzy analytic hierarchy process and geographic information science, and validated by comparison to actual incident reports. Our study shows that (1) the proposed method is a reasonable method of evaluation of navigation environment risk, at least in the SCS; (2) the majority of the shipping routes run from southwest to northeast, reflecting a linear-direction trend; (3) the risk of navigation environment in the SCS gradually decreases from the north to the south with a V-shape spatial distribution, and varies seasonally; and (4) in terms of shipping risk the four seasons are sorted in an ascending order: spring, winter, summer, and autumn. 2013 Elsevier Ltd. All rights reserved.