Study on the impact of sea level rise on the tsunami hazard in the South China Sea

This study employs numerical simulation methods to investigate the disastercausing mechanisms of tsunamis in the South China Sea and their coupled effects with sea level rise. Using the GeoClaw shallow water equation model, the study simulated the impact of different sea level heights (SLH)—0 m, 1.0 m, 1.5 m, and 2.5 m—on tsunami wave amplitudes in the South China Sea and surrounding regions under M w 8.0 and M w 9.35 earthquakes. The results indicate that earthquake magnitude has a nonlinear amplifying effect on wave amplitudes, compared to an M w 8.0 earthquake, wave amplitudes at observation points increase by 10–40 times under a M w 9.35 earthquake; Sea level rise significantly enhances tsunami disaster intensity. For the M w 9.35 earthquake, wave amplitude differences accumulate with increasing sea level, with wave amplitude differences reaching 0.2 m in central Philippines and along the Chinese mainland coast; Tsunami hazard exhibit spatial heterogeneity, with the largest wave amplitudes near Taiwan Island, northern Philippines, and the northern South China Sea, while the central and southern South China Sea exhibit smaller wave amplitudes; Coastal cities face significantly increased flood risks under sea level rise scenarios. This study reveals the patterns of sea level rise's impact on tsunami hazards in the South China Sea, recommending optimized monitoring systems and enhanced coastal infrastructure resilience for high-risk areas, providing scientific basis for hazard prevention and long-term planning in the South China Sea region.