Analysis of impact of typhoon track and intensity on cage aquaculturearea in sea area of Maniao Bay

Extreme waves and currents generated by the passage of typhoons have an important impact on the cage culture area. In order to assess the degree of hazard of typhoons with different paths and intensities on the large-scale aquaculture areas with in-cell nets in Maniao Bay, Hainan, we constructed a wave-current coupling model based on the Holland wind field model and the Delft3D software, and the model was validated by using observational data. The typhoon paths were categorized into four types based on the paths and landfall locations of the historical typhoons, and "Rammasun", "Kompasu", "Vongfong" and "Ted" were selected as the representative typhoons of the four types of paths. Seventy-two typhoon processes were reconstructed by translating and changing the typhoon intensity, and we simulated the process of change in the wave current field during the typhoon, obtained the statistics of different paths and intensity of the typhoon transit process of the maximum effective wave height and current velocity in the Maniao Bay aquaculture area, which were used as an assessment of the strength of the influence of the Maniao Bay nets aquaculture area, the strength of the impacts of the factors. Moreover, we analyzed theimpacts of different paths and typhoon intensities on the net box aquaculture area, and proposed the range of warning paths during the transit of typhoons of different intensities. The results show that among the four types of typhoon paths, the first type of typhoon paths had the widest and greatest impacts on the net-pen aquaculture area, in which the maximum effective wave height in the net-pen aquaculture area under the R4 path was higher than 5.5 m, and the maximum current velocity was more than 1.5 m·s⁻¹ under the 'super typhoon' category, which severely affected the aquaculture area; the second and third types of typhoon paths had the greatest impacts on the net-pen aquaculture area. Most of the paths of Category II and III typhoons had less moderate impacts on the net-pen culture area; and the paths of Category IV typhoons had basically no impacts on the net-pen culture area under the intensity of each typhoon.