九龙江河口洪水期悬沙及冲於变化的数值模拟

Distribution of Suspended Sediment and Erosion Simulation of the Jiulong River Estuary During a Flood Process

利用ROMS（Regional ocean modeling system）建立了九龙江河口区三维水动力与泥沙输运数值计算模式.模式模拟了九龙江河口区在洪水期间的悬沙浓度变化过程,将模拟结果和实测资料进行比较,两者吻合较好.在此基础上,对河口区在洪水期间各潮时的悬沙浓度变化以及洪水造成的冲於情况进行分析.结果表明：洪水期九龙江河口区的泥沙浓度受潮汐和上游来沙的共同影响,表现出较强的规律性;低潮时,在鸡屿断面附近存在表层泥沙浓度大于底层泥沙浓度的过程,该过程持续1 h左右;一个洪水过程泥沙在九龙江口的淤积厚度可达2~3 cm.

A three-dimensional hydrodynamic model for Jiulong River Estuary was established with the use of ROMS（Regional ocean modeling system）.The model was employed to carry out numerical simulations of suspended sediment processes during a flood process.The comparison between the measured data and computed results seems fine.The results showed that the distribution of sediment had a regular variation in Jiulong River Estuary during the flood process,and there was a higher concentration of suspended sediment at the surface during the low slack tide,which continue for about 1 h.The deposition thickness reached 2 cm to 3 cm in some areas of the estuary after a flood process.