海口湾人工填海前后冲淤演变数值模拟

为了解近年南海明珠项目、葫芦岛、秀英港扩建工程等人工填海工程对海口湾冲淤变化的影响,基于FVCOM海洋数值模型,对研究区人工填海前后潮流场、波浪场及冲淤变化进行了数值模拟。人工填海后,综合各条件下的冲淤情况,海口湾受潮流和波浪共同作用大部分区域处于淤积状态,年淤积量预测值为0.1～1.0 m;白沙角等局部区域处于侵蚀状态,年冲刷量预测值为0.1～0.3 m;受海口湾人工填海工程的影响,秀英港航道的水动力条件减弱,对通航条件改善有利,需加强航道的水深监测和定时的清淤工作;在南海明珠人工岛南侧波影区泥沙堆积会形成向海的舌状的突出体,其两侧海岸形成侵蚀后退带,需人工补沙等措施以保证岸线稳定。

Numerical Simulation of Scouring and Silting Evolution in the Haikou Bay Before and After Artificial Reclamations

In order to understand the impact of the artificial reclamations carried out in the South China Sea Bright Pearl Project, the Huludao Island extension and the Xiuying Port expansion in recent years on the changes of scouring and silting in the Haikou Bay, the changes in tidal current field, wave field and scouring and silting before and after the reclamations in the Haikou Bay are simulated numerically based on the finite-volume coastal ocean model (FVCOM). According to the comprehensive situation of scouring and silting under various conditions, most areas of the Haikou Bay are in a silting state after the reclamations in bay due to the actions of tidal currents and wind waves. The predicted annual amount of siltation is in the range of 0.1 m to 1.0 m. Some local areas such as the Baisha headland are in an erosion state, with the predicted annual scour volume being 0.1 m to 0.3 m. Due to the influence of the artificial reclamations, the hydrodynamic condition in the channel of the Xiuying Port is weakened. This is beneficial to the improvement of navigation conditions, but it is still needed to strengthen the monitoring of water depth and the dredging regularly in the channel. In the wave shadow area on the south side of the "South Sea Pearl" Island, the sediment accumulations may cause a tongue like protrusion forming toward the sea. At the two sides of the protrusion, an erosive and retreated belt may possibly form along the coast so that some measures such as artificial sand replenishment will be needed in order to ensure the stability of the shoreline.