Vulnerability analysis of liner shipping networks under cascading failures based on improved coupled map lattice model

With the development of global trade, liner shipping network (LSN) plays a crucial role in global logistics. Assessing their sensitivity to external disturbances and evaluating their vulnerability have become key issues in ensuring the smooth flow of international trade. This paper improves the Coupled Map Lattice (CML) model by integrating the load-capacity model, aiming to reveal the vulnerability characteristics of the LSN and the cascade failure propagation mechanisms under various types of disturbances. The improved model innovatively incorporates port affiliation, inter-port distance, and transportation volume into coupling strength determination, and proposes a constrained load redistribution mechanism that accounts for node capacity, geopolitical ties, and link addition strategies. Through a series of simulation analyses, this paper reveals the impact of different disturbances on network structure and functionality, particularly under scenarios such as system failures, natural disasters, and geopolitical events, highlighting the variation in network vulnerability under these diverse disturbances. This study provides a theoretical foundation for enhancing the stability of LSNs and formulating effective emergency response strategies.