Numerical study of water exchange through Qiongzhou Strait under the conditions of typhoon

WANG Xiao; LOU Angang; ZHANG Xueqing; LOU Qi

doi:10.13984/j.cnki.cn37-1141.2026.01.001

Abstract：The Qiongzhou Strait is located between Hainan island and the Leizhou peninsula in China,and the water transport through the Strait plays an important role in the circulation structure in the northern part of the Beibu gulf.Typhoons are frequent in the area.To understand the influence of ty-phoons on water exchange through the Strait,typical typhoons Sarika(2016),Kalmaegi(2014)and Rammasun(2014)were selected to simulate the material transport and water exchange characteristics of the Qiongzhou Strait under the influence of typhoons.The results showed that the residual current direction in the Qiongzhou Strait in summer was from east to west;Typhoons(Kalmaegi,Rammasun)passing over the northern part of Hainan island changed the direction of the residual current in the Qiongzhou Strait from west to east,while typhoons(Sarika)passing over the central part of Hainan is-land strengthened the residual current from east to west.During typhoons,1.2× 1010 m3 westward un-der typhoon Sarika,1.6×1010 m3 eastward under typhoon Kalmaegi and 5×1010 m3 eastward under ty-phoon Rammasun,the volume of water transport increased by 100％,167％and 760％respectively compared to tidal forcing.The different circulation structures generated by typhoons with different routes caused different directions of water transport in the Qiongzhou Strait.The material residence rate in the Qiongzhou Strait was 81.5％under typhoon Sarika,62.6％under typhoon Kalmaegi and 8.1％under typhoon Rammasun.