## 1 Introduction  
The coastline of China is twisty and turning, and foreign trade in coastal areas prospers. The economy develops rapidly but is also threatened by marine disasters [1], among which the storm surge brings the most severe losses [2, 3, 4]. The post-disaster reconstruction after the storm surge requires a large number of materials and personnel investment. Storm surges are generally caused by typhoons [5]. In summer, the southeast coast of China is easily attacked by tropical cyclones, causing massive casualties. As a typical coastal special economic zone in China, Shantou has experienced many typhoons landing [6]. The accompanying storm surges cause heavy financial losses and often cause thousands or even tens of thousands of casualties. The formation and development mechanism of storm surge was put forward in the early 20 th century. Firstly, the theoretical storm surge model was put forward, which was constantly supplemented and improved, and its mechanism was deeply discussed [7]. With the rapid development of geodetic techniques, the research on numerical models has been deepened. Since the 21 st century, many numerical models for storm surge models have existed. For example, the POM (Princeton Ocean Model) and the improved ECM (Estuary Coast and Ocean Model) of Princeton University in the United States are three-dimensional baroclinic models; the Delft-3D model of Delft Water Conservancy Research Institute in the Netherlands; HAMSOM (Hamburg Shelf Ocean Model) developed by the University of Hamburg, Germany; and the FVCOM (An Unstructured Grid Finite Volume Coastal OceanModel) of the Massachusetts Institute of Technology are all models used previously [8; 9; 10]. The storm surge model in this paper is based on the FVCOM model and is coupled with the typhoon data of a 10-year return period has been verified in the reference. In order to resist the storm surge, many scholars put forward coastal port facilities protection measures and disaster reduction measures [11; 12; 13]. Currently, there are mainly two kinds of protection against storm surges: one is to set up a bank, and the other is to build an ecological vegetation coast [14]. The former is a traditional protective measure that can weaken the waves caused by the storm surge. It has a positive effect in weakening the storm surge, but its influence range is limited, and it has little impact on the sea area far away from the shoreline [15; 16; 17]; the latter is that blueprint of green seawall recently put forward, and the previous study have shown that salt marsh vegetation can attenuate tidal current velocity, and a model that can be used to study the interaction mechanism between wetland vegetation and hydrodynamic forces during storm surge transit has been established [18]. In this paper, we consider the effectiveness of setting up the embankment to weaken the storm surge under the typhoon storm surge model with a 10-year return period. No matter whether the embankment is set up or the vegetation is covered, it belongs to human activities, which will destroy the original coastline in this area, leading to the reduction of the sea area and the tidal volume in the bay, thus affecting the sediment carrying capacity of the sea area, accelerating the sediment deposition rate in the bay [19], and changing the coastline shape again, forming the positive feedback of sediment deposition. Therefore, coastal cities are affected by human activities in bays, estuaries, and ports, and sediment deposition often occurs. It is necessary to analyze and evaluate the sediment in the port area to protect the topography and ecological environment of the basin. Tides usually control the deposition, so the sediment model needs to be coupled with the hydrodynamic model for overall analysis [20; 21; 22; 23]. Currently, the widely used sediment transport models include the MIKE model, MOHID model, ECOM, FVCOM, Delft3D model, etc. [24; 25; 26].