Research on numerical simulation of typhoon waves with different return periods in nearshore areas: case study of Guishan island Waters in Guangdong province, China

China is one of the countries that are most severely affected by typhoon waves. Typhoon waves often cause catastrophic economic losses and human casualties in the nearshore and offshore areas of China. Risk assessments of nearshore typhoon wave disasters are of great practical significance for the prevention and mitigation of typhoon wave disasters in coastal areas. This study proposes a method of assessing the risks of typhoon wave disasters. The coupled ADCIRC and SWAN model is employed to establish a high-precision numerical model for the study area, which is then used to simulate the process of historical typhoon wave disasters, followed by a statistical analysis of the risk of disasters at the grid scale using the frequency analysis method. The modelling method is empirically analysed, taking the coastal waters from Guishan Island to Zhuhai City, Guangdong Province, as the study area. The processes of 249 typhoon wave disasters in this area were simulated, and the wave height distribution in the 100 m grid of the study area with different return periods calculated. The obtained results can serve as a basis for the development of a methodology for the assessment of typhoon wave disaster risk in coastal areas and could provide a basis for research on disaster-causing mechanisms associated with nearshore waves on the hazard-bearing body. The method proposed in this study can also be applied to other nearshore coastal waters.