Systematic Risk Assessment of Seawater Intrusion in Ports: Assessment Framework and Empirical Analysis

Multiple factors, including global climate change and rising sea levels, increase the frequency and intensity of seawater intrusion. However, most previous studies have not regarded seawater intrusion as a typical accident for systematic safety risk assessment. In view of this, this paper comprehensively employed the fault tree model, the “Man-Machine-Material-Method-Environment” system theory, the Bayesian network model, and the Attack-Defense game theory to conduct qualitative and quantitative analyses concerning seawater intrusion. The main research results were as follows: the fault tree model was applied to sort the hazard-inducing factors from the perspectives of nature and humans, which were further categorized based on the theoretical framework of the “Man-Machine-Material-Method-Environment” (4M1E) theory. Based on the Bayesian network model, and incorporating assessments of the existing defense conditions of the target port, the occurrence probability of seawater intrusion at the port was calculated as 3.05%. Simultaneously, the influence weights of the 4M1E factors on seawater intrusion were quantified; environmental and mechanical factors ranked as the top two contributors, accounting for 57.79% and 29.70% of the total impact, respectively. Utilizing the Attack-Defense game theory, two key risk evolution paths of seawater intrusion were identified, with occurrence probabilities of 7.627‰ and 4.164‰. Typical disaster cases clarified the underlying mechanisms by which these key risk paths triggered seawater intrusion, and targeted prevention and control measures were proposed accordingly. The research findings can not only deepen the systematic understanding of seawater intrusion as a typical marine disaster but also provide technical references for governments and enterprises to optimize their risk management systems.