Numerical Investigations on the Transient Behavior of Sand Waves in Beibu Gulf Under Normal and Extreme Sea Conditions

作     者：ZANG Zhi-peng XIE Bo-tao CHENG Liang HE Fang ZOU Xing ZANG Zhi-peng;XIE Bo-tao;CHENG Liang;HE Fang;ZOU Xing

作者机构：State Key Laboratory of Hydraulic Engineering Simulation and SafetyTianjin UniversityTianjin 300072China Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake AdministrationTianjin UniversityTianjin 300350China CNOOC Research Institute Co.Ltd.Beijing 100028China School of Marine Science and EngineeringGuangzhou International CampusSouth China University of Technology Ocean CollegeZhejiang UniversityZhoushan 316021China 

出 版 物：《China Ocean Engineering》 (中国海洋工程（英文版）)

年 卷 期：2023年第37卷第2期

页      面：232-246页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 0707[理学-海洋科学] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 0706[理学-大气科学] 

基　　金：financially supported by the National Natural Science Foundation of China (Grant Nos. 51579232 and 51890913) the Open Funding of State Key Laboratory of Hydraulic Engineering Simulation and Safety (Grant No. HESS-1712)。 

主　　题：sand waves morphodynamic numerical model normal sea condition extreme sea conditions transient behaviors 

摘      要：In this study, a morphodynamic numerical model is established with the Regional Ocean Modeling System(ROMS)to investigate the transient behavior of sand waves under realistic sea conditions. The simulation of sand wave evolution comprises two steps: 1) a regional-scale model is configured first to simulate the ocean hydrodynamics, i.e., tides and tidal currents, and 2) the transient behavior of sand waves is simulated in a small computational domain under the time-variant currents extracted from the large model. The evolution of sand waves on the continental shelf in the Beibu Gulf is specifically investigated. The numerical results of the two-year evolution of sand waves under normal sea conditions compare well with the field survey data. The transient behavior of sand waves in individual months shows that the sand waves are more stable in April and October than that in other months, which can be selected as the windows for seabed operations. The effects of sediment properties, including settling velocity, critical shear stress and surface erosion rate, on sand wave evolution are also analyzed. Then, the typhoon-induced currents are further superimposed on the tidal currents as the extreme weather conditions. Sand waves with the average wavelength generally have more active behavior than smaller or larger sand waves. The characteristics of the evolution of sand waves in an individual typhoon process are quite different for different hydrodynamic combinations. For the storm conditions, i.e., the real combination and maximum combination cases, the sand waves experience a significant migration together with a damping in height due to the dominant suspended sediment transport. For the mild conditions, i.e., the pure tidal current and minimum combination cases, the sand waves migrate less, but the heights continue growing due to the dominant bedload transport.