Residual Sediment Transport in the Fine-Grained Jiangsu Coast under Changing Climate: The Role of Wind-Driven Currents

Abstract

Residual sediment transport, which is influenced by many factors including tide, wind, and waves, controls coastal morphological changes on different time scales. For fine-grained coasts where the wave effects are limited, it is still unclear to what extent the wind-driven current can impact the residual sediment transport. Taking the fine-grained Jiangsu Coast as an example, this study aimed to identify the contribution of wind on residual sediment transport over different time scales using a newly developed model. On a seasonal scale, wind-induced sediment transport shows strong seasonal characteristics, where the residual transport is more significant in the winter and summer. Nevertheless, the tide plays a dominant role in both residual current and sediment transport and the annual sediment budget over the coast. On the scale of tidal cycles, the extreme winds overwhelm the tides, controlling the residual sediment transport. However, the net sediment transport caused by the northerly winds (representing cold waves) is comparable to that of the southerly winds (representing typhoons). Therefore, although extreme winds can drive massive sediment transport in a short period, their contribution to annual sediment transport is limited.