729 / 2024-09-19 10:50:10

Terrain changes of the gravel-sand beach under the super typhoon “Yagi”

super typhoon “Yagi”,gravel-sand beach,hydrodynamic

Events with strong driving forces have a significant impact on coastal geomorphological changes. To study the impact of strong typhoons on the geomorphic evolution process of gravel-sand beach coasts, topographic data, as well as waves, currents, and water level data in Fangpo Village, Xuwen city, were collected during the passage of the super typhoon "Yagi" in 2024. The results show that during the typhoon event, the highest water level at the observation point was about 2.0 m, the maximum wave height reached 1.5 m, the maximum significant wave height was about 1.1 m, the corresponding wave period is about 6.5 s, and the maximum current velocity is about 0.45 m/s. After the typhoon, the sediment on the beach surface became coarse, gathering a large amount of coral and shell debris, and some large coral blocks. At the same time, a clear accumulation zone of coral shell debris appeared on the beach surface, while elevation data showed significant erosion on some parts of the beach surface. For the area with gravels at low water levels, the bed elevation change is relatively small. The research results show that gravels have strong resistance to typhoons, while sandy beaches respond more significantly to typhoon events.