平潭竹屿湾潮流泥沙运动特征的数值模拟分析

Simulation Movement Features of Currents and Suspended Sediment Transport in Zhuyu Bay Pingtan in Southeast China

基于非结构网格FVCOM模型构建平潭竹屿湾潮流泥沙计算模型,开展竹屿湾附近海域潮汐潮流、悬浮泥沙输运模拟计算,分析其潮流泥沙的运动特征。模型计算结果显示,海坛海峡内潮波为前进波,潮流与潮位变化同步,但竹屿湾内的潮波为驻波;海坛海峡内大潮、小潮期间垂线平均悬浮泥沙浓度差别较小;现状条件下海床的年最大冲刷强度约为1.0 cm·a^-1。实测数据与模拟计算结果的对比研究表明,模型可以较好地模拟竹屿湾附近潮汐潮流和泥沙的运动特征;竹屿湾海床总体稳定,可能是周围工程建设和人工采砂导致竹屿湾海床局部发生冲淤。

An unstructured grid FVCOM-based hydrodynamic model was used to simulate the water level,currents and suspend-sediment transport patterns in Zhuyu Bay.The results show that the tidal wave in Haitan Strait maintains the properties of a progressive wave,which means that the tidal current and tide level change synchronously,but the tidal wave in Zhuyu Bay is in the form of a standing wave.The simulation illustrate that the depth-averaged suspended sediment concentration during spring tide and neap tide in Haitan Strait shows litter difference,with the annual maximum erosion intensity standing at about 1.0 cm/a.The comparison between measured data and modeled results shows that the model can simulate the movement characteristics of tidal current and sediment transport in Zhuyu Bay.The comparisons of bathymetry data show that the seabed of Zhuyu Bay is generally stable.Which may suggest that the surrounding engineering construction and sand mining have caused partial erosion and deposition of the seabed of Zhuyu Bay.