水利学报2025，Vol.56Issue(4)：477-487,11.DOI:10.13243/j.cnki.slxb.20240389
伶仃洋河口枯季径-潮-盐-悬沙动力特征对海床地形异变响应
Response of river-tide-salt-suspended sediment dynamics to seabed topographic abnormal-ity during dry season in the Lingdingyang Bay
摘要
Abstract
During the period of 1974-2016,due to the impacts of human activities like reclamation projects,channel dredging projects,and sand mining in the estuary,the shoreline and seabed topography of Lingdingyang Bay changed abnormally,and the characteristics of the distribution of river-tide-salt-suspended sediment changed accord-ingly.It is necessary to study the characteristics of river-tide-salt-suspended sediment dynamics after topographic anomalies and the response mechanism of such characteristics to seabed topographic anomalies.Therefore,this study analyzed the turbidity-salinity data of suspended sediment measured from stations in Lingdingyang Bay during the dry season of 2016,and established a three-dimensional mathematical model of runoff-tide-salt-suspended sediment dynamics based on EFDC software to study the changing mechanisms of salinity stratification and vertical distribution of suspended sediment in the mouth of the Lingdingyang Bay under the drive of anomalous changes of the shoreline and the topography.The results show that the increased convergence and seaward extension of the shoreline and the downcutting of the topography lead to a relative enhancement of the tidal dynamics of the Lingdingyang Bay.During flood tide,the water column salinity and suspended sediment concentration are mixed relatively uniformly in the verti-cal direction.During ebb tide,the water column salinity is stratified significantly,and the buoyancy item accounts for a larger proportion of the turbulent kinetic energy,which provides energy for the salinity stratification.The turbu-lent mixing is weakened,inhibiting the re-suspension of the bottom sediments and increasing the dispersion coeffi-cient(CV)from 0.51 to 1.02,which characterizes the degree of non-uniformity in the vertical distribution of the sus-pended sediment.During a tidal cycle,CV exhibits a lagged positive correlation with the overall Richardson number that characterizes stratification.The results of this study revealed the mutual feed-influence relationship between saline water and suspended sediment transport in the estuary of Lingdingyang Bay during the dry season,and provide a scientific basis for the management of water and sediment in the Lingdingyang Bay.关键词
伶仃洋/悬沙垂向分布/层化/河口潮动力Key words
Lingdingyang Bay/vertical suspended sediment distribution/stratification/estuarine tidal dynamics分类
水利科学引用本文复制引用
钟子悦,向波,余明辉,刘书宝..伶仃洋河口枯季径-潮-盐-悬沙动力特征对海床地形异变响应[J].水利学报,2025,56(4):477-487,11.基金项目
国家自然科学基金项目(12372385) （12372385）
