Impact of tropical cyclones on the suspended sediment transport in the Bohai Sea since the 21st century

Abstract

Under the background of global climate warming, the impact of tropical cyclones (TCs) on mid-latitude semi-enclosed bays will be enhanced. A hydrodynamics-sediment model was used to study the impact of TCs on sediment transport in the Bohai Sea during the 21st century, further revealing the mechanism of TCs influence on sediment dynamic processes in semi-enclosed bays. During the 21st century, a total of 10 TCs have passed through the Bohai Sea, with the total suspended sediment flux (SSF) output from the Bohai Sea reaching 14.34 Mt. During TC events in the Bohai Sea, the Bohai Bay was the main erosion zone, and resuspended sediments were transported downwind to Laizhou Bay, which was contrary to the normal sediment transport track in the Bohai Sea during the summer. The increase in wave-induced shear stress and the disruption of vertical stratification were the primary causes of the increase in SSF. Additionally, numerical experiments indicate that the TC tracks passing zonally through the central Bohai Sea have the greatest impact. This study helps to deepen the understanding of sediment dynamic processes in bays during TCs, provides useful information for policies and coastal development, and thereby reduces the risks of TCs to coastal communities under future climate change scenarios.